By Baruch "Buki" Glasner, A.
A. Zaid and J. Emmens
Date Production is a world agricultural industry producing about 4,7 million tonnes of fruit in 1997 (FAO, 1998).The date fruit, which is produced largely in the hot arid regions of Southern Asia and North Africa, is marketed all over the world as a high value confectionery or fruit, and remains an extremely important subsistence crop in most of the desert regions.
In this chapter the main focus is on date harvesting, packinghouse management and marketing aspects for the purpose of selling the produce as whole dates. Other date palm products, mostly prepared from dates of lower quality than those sold as whole dates, are also described.
In their analysis of the essence of quality, all modern approaches focus on the client (the consumer), his perception of the product, and the behaviour of the product according to defi nite specifi cations. There is progressive improvement in the quality of the product in line with the rising expectations of clients. This process must be stable, repeatable and capable of producing identical qualities for any length of time.
People very often think of marketing as the activities which take place after the product leaves the production point. Marketing, however, involves more than just that and might be defi ned as the set of economic and behavioural activities that are involved in co-ordinating the various stages of economic activity from production to consumption (Purcell, 1979). It is important to note that the benefi ts of a year- long and outstanding job of production can be wiped out with a single bad marketing decision.
A farmer's job does not begin and end with producing something. The first agricultural marketing job is thus to determine accurately and in quantitative and qualitative terms just what consumer demands are in time, place and form, and what changes are taking place in those demands over time. The more time, effort and money a fi rm spends in carefully and completely planning the product which it wants to produce, the less time it is likely to need to spend in selling.
Large amounts of money are being spent to produce the fruit. One should thus put in as much effort as possible to capitalise on the investment through marketing. Marketing is expensive, but to be successful one needs to invest and to be creative. Fresh dates are not something new on the European market. Therefore, to be able to sell the date fruit, the packaging should be more attractive, and the contents should be of a higher quality than the competitors'. Low input gives low output.
Profitability is also an important measure, making additional investments possible for improvement and growth. The approach is one of delegation of authority to the people who are at the heart of the production process; who may work according to well defi ned procedures and at the same time use their common sense and act judiciously. Emphasis is placed on cooperation between suppliers and clients in order to make it possible to work with precision, to receive feedback detecting mishaps, and to develop new products.
Emphasis has traditionally been placed on the commodity involved, or the economic functions performed, or the institutions that are involved in performing the various functions. Focusing on these issues separately is important, but the marketing strategy should be to adopt a marketing approach where emphasis is placed on the total system. With this, the entire continuum, from producer to consumer, becomes the focal point.
While describing the process which the fruit undergoes in the packinghouse, from the moment of entry until the product is ready for marketing, emphasis is given to the various aspects of quality control, mandatory in high quality products.
There are specifi c harvesting and packing considerations for each date variety and the form in which they will be consumed.
Harvesting means physically detaching the fruit from the palm. Differences in the state of the fruit, from the point of view of harvesting, are great at the level of spikelets, bunches and palms. These differences are both visible, such as the fruit colour and the degree of ripeness; and invisible, such as the percentage of water and of sugar and the activity of various enzymes.
Whole dates are harvested and marketed at three stages of their development. The choice for harvesting at one or another stage depends on varietal characteristics, climatological conditions and market demand.
The three stages are as follows:
Khalal: Physiological mature, hard and crisp, moisture content: 50 - 85 %, bright yellow or red in colour, perishable;
Rutab: Partially browned, reduced moisture content (30 - 45 %), fibres softened, perishable;
Tamar: Colour from amber to dark brown, moisture content further reduced (below 25 % down to 10% and less), texture from soft pliable to fi rm to hard, protected from insects it can be kept without special precautions over longer periods.
In general, when dates reach the Khalal stage, they are regarded to be ready for trading as "fresh" fruit. Dates in Khalal stage are the first in the harvesting season and therefore have aready market. Only date varieties with a low amount of tannin at Khalal stage are suitable for consumption. The low amount of tannin results in low astringency. Furthermore, it is important that the fruit is sweet and not bitter. Date varieties suitable for marketing at Khalal stage are Barhee, Zaghlool, Hayany and Khalas. Of these varieties, only Barhee is sold in England, France and Australia, while the other two are mostly consumed locally.
Experience in most date producing countries showed that a well matured Rutab, handled with care, is one, if not the most, appreciated form in which the dates is consumed and which gives the grower the highest rate of return. However, Rutab has three serious setbacks: it is produced in comparatively short periods with the tendency of production peaks; it is highly perishable; and it is delicate, which makes handling and transport diffi cult and expensive.
Major commercial date varieties harvested at Rutab stage are Deglet Nour and Medjool. Deglet Nour is harvested yearly in tens of thousands of tons in Algeria, Israel, Tunisia and the USA. The production of Medjool is more limited (less than 5,000 tons per year) and mostly produced in Coachella Valley and Bard in California, USA, Morocco and Israel. Small amounts are produced in Mexico, Namibia and South Africa.
Fruit harvested at Tamar stage is non-perishable, i.e. micro-organisms cannot grow on it, moisture uptake and its consequences, and changes in colour and taste occur during storage. Most of the dates of Dayri, Halawy, Khadrawy, Thoori, Zahidi, Sayer and Aliig varieties are harvested after the fruit has undergone the process of ripening and drying on the palms.
Fruit at the Tamar stage is ideal for marketing as "dried" dates. This fruit is used for preservation and year-round consumption and also for the production of various types of products, e.g. cakes, sauces and components of granules or date honey.
The main outlets for dates at the Tamar stage are the following:
home consumption, local markets
wider regional distribution
collecting/bulk packing centres
small, medium, and large-scale packing plants for bulk shipments and retail packs.
The softening of the fruit is mainly infl uenced by polygalacturonase and cellulase enzymes. The activity of these enzymes depends on the slow drying of the fruit.
The invertase enzyme determines the speed and level of transition from disaccharid to two monosaccharids, fructose and glucose. These changes determine the speed of evaporation of water from the fruit. The level of fructose and glucose infl uences both the speed of drying and the activity of the polygalacturonase and cellulase, and also the relationship between the water activity Aw and the water content, and so the extent of shelf life. Water activity can be expressed by Equilibrium Moisture Content (EMC) expressed in percentages; the EMC expresses the sensitivity of the fruit to microbiological infestation. EMC below 65 % ensures resistance to microbiological factors such as moulds, yeast and bacteria that attack the fruit (Figure 87).
Although attempts are being made to harvest the fruit by shaking the trunk of the palm in order to avoid having to climb it, it is still necessary to reach the top of the palm to harvest the fruit. The palm grows up to one meter every year (depending on variety and the intensity of treatment). Harvesting the fruit entails the use of experienced workers, or investment in aluminium ladders, in attaching ladders to the palms permanently or in purchasing mechanical appliance to lift workers to the top of the palm (Figure 80).
Harvesting in the northern hemisphere takes place at the end of summer and in the fall, starting at the end of July (depending on the geographical area), with the harvesting of the Khalal varieties (especially Barhee), and ending in the middle of November. The harvesting of certain of the varieties continues after the rain starts (The end of summer rain in California,and the fall rain in North Africa and Israel). Rain can cause damage to the fruit and impair its quality due to rotting, fermentation and insect infestation. The fruit must therefore be protected against rain with the help of wax-covered paper or nylon sleeves. In the southern hemisphere harvesting takes place in February, March and April.
Harvesting must be faultless and clean, since it signifi cantly affects the rest of the process (packing and marketing). Harvesting the fruit straight into containers suitable for transport to the packinghouse prevents the infection of the fruit by the soil and sand under the palm and ensures that the fruit arrives in good condition, and that it is not crushed.
2.2 Field sorting of fruit
In 1997 the world production of dates was 4.7 million tons (FAO, 1998). Much of this fruit is still grown and processed by traditional methods described in great detail by Dowson (1962). These methods involve mainly the drying and curing or ripening of the fruits (which have been laid out on cloths or mats) in the sun, pitting (destoning) by hand and storing in jars.
The harvested fruit is transferred into containers (large plastic bins) for transport to the packing station. Each container contains 200 - 450 kg fruit and is suitable for dry fruit. Large wooden, plastic or cardboard cases of various sizes are also used, focusing on the need to prevent damage to the fruit (especially to soft and sensitive fruit). Baskets and sacks (for very dry fruit), as well as trays are also used. It is desirable to separate damaged fruit which is not destined for the market, while still at the site. Dates that are rotten, sour, with remains of insects, crushed, shrivelled up, unfertilized, or unripe fruit which are not intended for artifi cial ripening should be removed from the plantation. These fruits should be destroyed or fed to animals, in order to maintain sanitation of the plantation.
2.3 Transporting to the packinghouse
When transporting the fruit we must also take into account its sensitivity, and the importance of every link in the chain in the treatment of the fruit. Dates harvested at the Khalal stage must be transported as soon as possible to receive appropriate treatment, whether it is Barhee, Khalas, Hayany or Zaghlool for local consumption or for export. The fruit must be transported in the early hours of the morning to avoid the heat; if the distance is great, refrigeration during transport is advisable. Deglet Nour, which is to be marketed on the branches must not beshaken during transportation in order to prevent the fruit from falling off the branches. Speedy transport will also prevent infection by pests which attack the fruit during the post- harvesting period.
2.4 Quality control on the use of chemicals
Many clients, especially from European markets, demand that the quality control processes used be documented by the growers; especially a report concerning treatment (spraying) against insects. Such a report includes a list of the materials permitted for use and approved by an offi cial agent, in addition to the timetable of the spraying with details of materials used, the date, concentration, number of days before harvesting and the level of residue of pesticides; the level permitted appears in the Codex Alimentarius published by FAO. This book gives the permitted level MRL (minimum residue limit) according to types of material and species of fruit, vegetables and other foodstuffs. Today, it is possible to reach a level of detection of such remains at PPB (part per billion), but the cost of the test is considerable.
Packing is a vital stage in both the traditional and modern methods of marketing. At this stage many varieties of varying quality, water level and rate of pest infestation can be preserved up to a year. The aims of packing are:
a) To make it possible to transport the fruit by various means: from baskets made of palm leafl ets, to the use of modern packing containers, and transport by air or by sea in containers. The sturdiness of the packing must be adapted to the methods of transport.
b) To protect the fruit when packed so that it will remain in good condition under various circumstances and for various periods of time. The packing materials should be chosen according to the quality of the fruit as required by international standards or consumer needs (e.g. it is forbidden to use PVC). Packing must preserve the moisture of the fruit, prevent further drying out of the fruit and any loss of moisture in moist fruit. It must withstand conditions during storage (there are materials which do not withstand a temperature of - 18o C). The packing must preserve the fruit for as long as necessary.
c) To use packing in order to promote marketing. Some of the data on the packages are relevant to the laws in the importing countries; some provide information for the client and some serve the promotion of sales, or as labelling (such as EAT ME for Deglet Nour or CALIFORNIA DATES, or KING SOLOMON for American and Israeli Medjool, respectively). In most importing countries, the law demands that data such as weight, country of origin, quality and date of expiry, appear on the package.
In various countries there are several kinds of contracts between growers and the packinghouse. Family packinghouses may be small or large, built in or near the plantation, and they are owned by the grower. In such a packinghouse there is continuity and coordination between the activities at the plantation and in the packinghouse. Workers at the plantation supply thefruit in accordance with the potential of the packinghouse and the relevant installations to receive it, for instance for fumigation, refrigeration and storage. The packinghouse also adapts itself to the constraints of harvesting, such as the speed of ripening of varieties harvested at the Khalal stage, adding another shift when necessary, increasing its workforce (temporarily), renting storage space and operating fumigation rooms continuously.
Cooperative packinghouses are set up to exploit the advantage of size; growers get organised according to a specific region or fruit variety (especially for the packing of Deglet Nour on branches). These packinghouses usually accept fruit according to one of the following methods:
a) By keeping the fruit from each grower separate during all stages. To do this, labels (with the grower's number) are put on the crates (or any other packaging) at entry, during fumigation and storage, and during sorting and packing. One can also separate the fruit from different growers by storing it in different labelled areas or packing it on different days.
b) By sampling the fruit at entry. After sampling the fruit is separated according to the management, production and marketing needs (not according to suppliers).
Private packinghouses usually buy the fruit as raw material directly from growers. This has the following advantages:
* The grower is paid immediately for the crop.
* The packinghouse can sometimes acquire the fruit at a competitive price.
* The packinghouse functions independently of the grower after the purchase.
* The grower usually receives a lower price, since all the risks are transferred to the packing-house.
* The packinghouse may not receive good quality fruit.
Sub-contracted packinghouses usually receive the fruit after it has already undergone several processes, especially fumigation and preliminary sorting. These packinghouses are not always in the area or country where the fruit is grown. Some of them specialise in small scale packaging, directly connected to the marketing networks; they defi ne the desirable quality to the supplier and check the fruit at entry according to the required criteria.
3.2 Processes used to improve or maintain fruit quality
In the packinghouse there are a number of processes, designed to improve or maintain fruit quality. These processes are: fumigation, washing, storage, refrigeration, hydration, dehydration and curing.
In order to store the fruit for a long period (several months to one year), it must be completely cleaned of any pests (eggs, pupas, larva or adults). This is done by fumigation, either in the fi eld under various kinds of plastic sheets, or at the packinghouse in special sealed rooms.
Fumigation must not be carried out when the fruit is fresh, harvested at the Khalal stage, (Barhee, Khalas, Zaghlool and Hayany) or when stored under deep refrigeration. The substance most frequently used for fumigation is methyl bromide (CH3 Br), which makes most of the insects come out before they are killed by the gas. The concentration of the gas is 30 ppm, i.e. 30 g methyl bromide in 1 m3 of air. The time recommended for fumigation is 12 - 24 hours. The temperature must be above 16o C. It is important for the air to swirl within the fumigation installation, in order for it to spread uniformly within the chamber.
Methyl bromide is a dangerous poison. This fumigation process must, therefore, be done according to the law and all the regulations concerning the equipment and the protection of the people involved.
After fumigation the chambers must be aired according to the producers' instructions. The level of fumigation described above kills insects, while keeping within the level of remains at the MRL, permitted according to the Codex Alimentarius (FAO). After fumigation the fruit must be stored under conditions that prevent re-infestation. It is therefore undesirable to store fumigated fruit together with unfumigated one.
Additional substances and methods are also being used, for instance irradiation by gamma rays or exposure to ozone. For dates grown and marketed by the bio-organic method, can be used. fumigation by CO2
It should be noted that in 1992 methyl bromide was placed under the Montreal Protocol on substances that deplete the ozone layer, because of international concern about the continued increase in its production and its damaging effect on the ozone layer. Actions taken by countries party to the Montreal Protocol are:
* Limitations on an increase in the production of methyl bromide from 1995, and
* Consideration of longer-term options to completely phase out its use.
At the moment there are no restrictions on the import/export of methyl bromide treated products. Restrictions on the import/export of these products were postponed till the year 2003. The latest information can be obtained from the UNEP Secretariat to the Montreal Protocol.
Alternatives for methyl bromide:
* Phosphine is the principal alternative to methyl bromide for fumigation of durable commodities and is widely used in developing countries.
* Controlled atmospheres high in carbon dioxide are in regular use in South East Asia for disinfecting bag-stacked durable commodities.
* The applications of physical control methods such as fi ltering, heating or cooling regimes, active oxygen (ozone, hydrogen peroxide) and irradiation. However, some of these methods are very costly (CBI, 1997/1).
3.2.2 Storage and refrigeration
After packing, the fruit will be sent according to market orders, or stored as the fi nished product. During storage, the material in which the fruit is packed must also be taken into account, for example: cardboard is sensitive to humidity; various plastics are sensitive to low temperatures; wooden surfaces may be attacked by various pests.
In the storehouses the produce must be protected from recontamination by pests (insects and rodents). The surfaces and packages must be well made in order to withstand being loaded, shaken on the way and unloaded.
The aim of storage is to attain the state of DQ = 0 for a long period (Q = quality; D = variation), which means creating a situation in which the quality of the fruit does not change during storage.
Much of the fruit is marketed throughout the year (especially fruit at the Tamar stage), and sometimes even after a year has passed, because of the need to prepare the fruit for Christian festivals, or at times when the Muslim Feast of Holy Ramadan is close to harvest time.
According to traditional methods, the fruit is protected from external hazards and preserved by being dried to a level of moisture that will ensure that it is not sensitive to microbiological contamination even in ambient temperatures, or by being pressed into sealed baskets or jars.
The current market demands fruit with higher moisture content. Preservation is ensured by storage under low temperatures.The temperature at which the fruit is stored is adapted to the time lag until the next treatment or until marketing. The temperature must ensure the continued extermination of insects that have survived fumigation, and prevent loss of moisture, or in the case of dry fruit, increase the moisture. Refrigeration must not infl uence properties, such as texture, moisture and colour.
The temperature and the speed of refrigeration also affect physiological phenomena, such as sugar crystallisation. Sugar crystallisation is caused by the breaking of cell walls or the tearing of the skin, facilitating the movement of water inside the fruit or out of it. This is connected to the amount of moisture in the fruit.The risk increases when the amount of moisture rises above 20 % (also in low temperatures). This phenomenon does not exist in Deglet Nour. Today, the temperature commonly used for long-term preservation of dates of several varieties including Medjool is - 18o C (0o F). This temperature decreases possible water loss and also decreases the sugar crystallisation and skin separation phenomena.
However, research done in Tunisia showed that:
* storage under conditions of 26 % humidity or higher requires a temperature of 0ºC enabling a storage period of 6 - 8 months;
* the storage period can be more than 1 -year if humidity is less than 26 %;
* if humidity is less than 20 %, dates can be stored at 25ºC for up to 1- year; and
* high sugar content coupled to high humidity tends to aggravate the situation of fruit going bad.
Varieties sold at Khalal stage, such as Barhee and Zaghlool, are stored at a temperature of 1°C, which increases their shelf life from a few weeks up to 6 - 8 weeks.
Just like all agricultural products, dates are grown in the fi eld and exposed to various types of contamination of physical, chemical or/and microbiological nature.
Physical factors: Sand and soil - both as a result of sand storms in many regions where dates are grown, and soil sticking to fruit lying on the ground.
Chemical factors: These are especially remnants of pesticides, some of which can be removed by washing.
Microbiological factors: External cleaning of the fruit by washing removes some of the microbiological pollution, also excretions of birds, which may spoil the fruit (Figure 81).
Clean water must be used and care taken that all the fruit is washed. Other methods exist, such as damp towelling attached to sloping mechanical shakers (California - USA). The fruit from Barhee and Deglet Nour are also cleaned by air pressure specially adapted for the removal of dust and sand, before they are packed on branches. While the fruit is still hanging, it can be cleaned by water spray, accompanied by the use of fine swivelling brushes, but they must be dried before being packed.
When the fruit is packed immediately after washing, it is important to dry it in drying cubicles or by means of large fans.
3.2.4 Hydration, curing and dehydration
The aim of dehydration and hydration is to improve the quality of the fruit, to produce uniform fruit with regard to moisture, and to extend its durability during storage and marketing.These processes are carried out by artifi cial means in the packinghouse when hydration or dehydration are not carried out earlier, during the treatment of the fruit in the field. When treated in the packinghouse, the fruit is dehydrated or hydrated after it has been stored or washed, when the moisture can range from 10 % in very dry fruit to 30-45 % in fruit at the stage of curing (Rutab). Of course, the moisture of the fruit also depends on variety, the region and the weather at the time of harvesting.
Some varieties (for example Amri and Zahidi) have a dry and hard texture in regions where, during the ripening of the fruit (the transition from Khalal to Rutab and from Rutab to Tamar), the temperature is high and moisture is low. In this situation moisture must be increased by hydration. This is a process of fruit saturation with water or steam, while ensuring the appropriate temperature in order to create optimal conditions for enzymatic activity, which will cause the fruit to soften. This softening is often accompanied by a rise in moisture to a level that can endanger the fruit by exposing it to microbiological elements (when moisture reaches over 20 % and EMC over 65 %). The appropriate hydration process depends on how long the dates have been exposed to these conditions.
An activity similar to hydration, by integrating temperature and moisture, is carried out when some of the dates are unripe, Khalal, or when a stage has been "skipped". Unripe fruit enters the packinghouse for two reasons:
* In cold regions (for example Elche in Spain) where the fruit does not ripen under natural conditions, or rain may threaten the fruit.
* When harvested in the usual way (Khalal).
"Skipping a stage": This situation arises when the transition from Khalal to Tamar is very fast (in hot regions) and some of the fruit is not ripe while the fruit is already shrivelling and at the Tamar stage. Such dates (usually of the Medjool variety) have white shoulders or are naturally white - these are the parts of the fruit in a light unripe state against a light brown background of Tamar. Most of the Deglet Nour in California is harvested when it is very dry and hard, and only hydration treatments bring it to a moisture of 23 to 25 %, and make it suitable for marketing (to meet consumer demands).
Dehydration is undertaken when the moisture of the fruit is higher than planned (with respect to market needs). In order to preserve the fruit for any length of time (without refrigeration), it is important to decrease the moisture to below 20 % (depending on variety). At a moisture percentage of 15 % to 20 %, varieties such as Khadrawy, Halawy and Medjool can be preserved for a long time, unharmed by microbiological processes (such as fermentation, souring or the emergence of mould). If the moisture percentage is too low, the fruit will be hard to eat and inappropriate for some of the consumers (mainly on the European market). Decreasing the moisture also reduces the risk of sugar crystallisation.
It is important to ensure moisture uniformity. Fruit at an undesirable level of moisture will be spoilt by microbiological processes. This phenomenon is found in "Juicy Medjool" and in Deglet Nour on branches, when packed with a high level of moisture. First, alcoholic fermentation takes place as a result of yeast activity, and later a process of souring, caused by the activity of various kinds of lactobacilli. The following factors infl uence appropriate dehydration: temperature, moisture, speed of airfl ow, uniformity of the above variables and length of dehydration time.
Dehydration is carried out in special chambers. These chambers control the entry and fl ow of hot air, to ensure the appropriate moisture level. All these conditions must preserve the quality of the fruit, especially with regard to skin separation. The temperature must not rise above 70oC in order to prevent "the burning of sugars" (caramelisation). High temperatures will also cause the fruit to darken. Different temperatures suit different date varieties: Halawy 55oC (and 20 % moisture during the process); Deglet Nour and Medjool 50oC.
Quality control during hydration and dehydration
The amount of water in the fruit exerts a great infl uence on its quality and shelf life. It is mandatory to have a constant follow-up on the product by various means of testing. This is to ensure that the client receives fruit of the quality he or she requires, both with regard to softness and to moisture, which must not be too high. The latter prevents harmful microbiological processes and the rise of sugars.
An important aspect of quality control is the documentation of the findings, making it possible to check the amount of moisture during the various processes and facilitate the traceability of the product, which is important for the detection of mishaps during the various stages of production.
In order to ensure that the results of sorting are appropriate to client requirements, it is important to provide sorters with precise, unambiguous defi nitions of the defects of the fruit they are to transfer to another category. The following defects can be identifi ed in date fruits:
1. Defects stemming from microbiological processes: fermentation (alcoholic) resulting from the activity of yeast; souring resulting from lactobacilli, acetobacteri or aspergilus niger, a fungus which creates a black promycelium which fi lls up the stone cavity. These types of defects cannot be tolerated, such fruit must not reach the customer, nor can it serve as raw material for products. These defects may be due to inappropriate conditions during storage (for example wet fruit without refrigeration) or may arise while the fruit is still in the fi eld.
2. Defects caused by pests, resulting from the activity of insects and various mites. The most common are the remains of various moths, sour bugs and mites. Some of these pests leave signs of nibbling inside the fruit; some spoil the look of the skin. Tolerance for these defects differs according to various standards, going up to 4 %; in all cases there must be no live insects inside the package. Defects caused by birds, mice, bats or other rodents (mainly signs of nibbling on the outside) are often found on fruit grown without being covered by a net or paper, or stored under inappropriate conditions. Such fruit must be removed. These pests may leave remains of feathers, excrement of mice or birds, which stick to the fruit and may cause microbiological contamination.
3. Mechanical defects, as a result of the fruit being crushed while wet after harvesting, or grazed or scraped during the period of growth, leaving scars on the fruit. Sometimes the fruit is so badly soiled by earth and by mud that washing does not clean it.
4. Physiological defects:
* Unpollinated fruit that reaches sorting in an unripe state (its colour depending on the variety);
* Shriveled and dry dates, usually dates which have been detached from the spikelet while still unripe;
* Defects caused by water stress (excess or shortage), which may lead to checking (in Barhee) or blacknose.
Some defects will appear more frequently in certain species. Workers must become familiar with them. This information can be provided by drawings of the defects, and there must be guidance during the sorting and control of its results (Figure 82).
Quality control during sorting
Control and sampling is done by laboratory workers. Control must ensure that the demands of the sorting instructions and defi nitions have been respected. Testing for internal defects is done by cutting the fruit with a knife and checking the internal cavity. Sampling is carried out according to procedures defi ning the frequency of sampling and the size of the sample. The results are written on a specifi c form, and the forms are kept for the follow-up according to the demands of clients.
The clients are the buyers whose quality system demands that the suppliers have authorization, either via an acknowledged certifying body, or according to client specifi cation, which includes documented traceability.
This is usually done together with sorting, on the same installation, thus avoiding the need to transfer to a different storage (at the intermediate stages) and additional pouring of fruit onto the conveyer belt. Many attempts have been made to make this process more effi cient by automatic grading, but, owing to the complexity of the processes and the diffi culty of imitating human senses, especially that of sight, no solution has yet been found for sorting and grading "without human hands".
The aim of grading is to produce packed fruit which is uniform in size, shape, colour, texture, moisture and skin separation. For each variety the standards are different. Client's requirements can also determine the criteria during grading:
Size sorting can be done in one or two stages.
Grade A: Perfect fruit
Grade B: Fruit with skin separation
Grade C: Fruit for pitting and for industrial use
Grade D: Rotten and damaged fruit
The second stage of sorting is to sort the grade A product to size (jumbo, large and medium). This is particularly important for varieties with large fruit such as Medjool or Amri. For Medjool in Israel, sizes have been defi ned according to the weight of the fruit (moisture content fi xed at 16 % - 19 %):
more than 23 g;
18 g to 23 g; and
15 - 18 g.
In other countries (for instance USA) other defi nitions of size are used. Varieties with a certain texture can be mechanically sorted for size using a sorting machine on the basis of rollers, the diverging roller sizer. This machine is suitable for sorting species such as Amri, Zahidi, Deglet Nour and Hayany.
A uniform shape, typical for each variety, is required. Abnormal or misshaped fruit is removed. Regarding colour, one variety may have different colours depending on the way it was grown, the time of harvesting and the region. Texture depends mainly on the moisture content, but also on normal ripening which activates enzymes softening the fruit. Moisture must be appropriate to client requirements, to the date of marketing and to the conditions of storage.
Reasons for skin separation, also called puffi ng phenomenon, are still not known. During certain years, especially when it is relatively hot, the rate of fruit puffi ng is higher. Such fruit has not gone bad, but it is unsightly, especially when skin separation is extensive. The fruit lacks uniformity and its appearance is impaired. This phenomenon also differs in extent according to the region where the fruit is grown. It is more serious in varieties such as Medjool, signifi cantly lowering the price for export fruit.
Quality considerations during selection
It is important to make use of the laboratory at this stage; some of the criteria are quantitative and can be assessed objectively (unlike tests by human senses), and the tests are carried out according to defi nite standards, set by the importing countries or the customers.
It is important to document the tests and include the dates when they took place, their results, their Lot number or ID and deviation from the standard, corrective action (if necessary) and the signature of the authorised person. This ensures that the results conform
to the standard required and that any deviations can be treated. The laboratory and the people responsible for quality must have the authority (granted by regulations) to stop the process when its products are inadequate.
Fresh dates are perishable and are highly susceptible to losses from damage and deterioration between harvest and the fi nal consumer. Within the range of measures which can be applied to prevent such mechanical and/or biologically induced losses, appropriate packaging plays a vital role in protecting produce from avoidable deterioration.
Packing the fruit in various ways is the last stage of its preparation for the consumer. Therefore, there is no contact with the fruit itself, and we depend on packaging to protect, contain and market the product. Various methods of packing, including the traditional ways, are already described in detail by Dowson (1962). In this section we shall only relate to modern methods used for fruit intended mainly for export. The methods of packing are of two kinds: in bulk and for retail sales.
The dates are usually packed in cardboard boxes (sometimes in plastic bags for additional protection and preservation of moisture, before being placed in boxes). The usual weight is 5 kg or 15 lbs. (depending on the country where the fruit was produced or where it is to be marketed). The quality of the fruit may differ according to customer requirements. The fruit is sold on the open market and intended for customers wanting to buy fruit in large quantities. The fruit may be handed over to be repacked in the countries where it is to be marketed and where retail packing will be carried out according to the customer requirements.
The fruit may also be used for products in which dates are the main or secondary component, such as sauces, syrups, spreads and products used in baking.
Retail packing has been greatly developed in recent years, especially since the large networks have increased their share of the food market throughout the world. These packages have to be adapted to consumer demands at all levels, starting with the codes used by a certain network, to repackaging and to the surface on which they are to be placed, ending with the writing on the packages such as the nutritional composition, and the last date for sale or for use.
Retail packages can be divided into two categories:
a) Packing according to some arrangement, usually 'fi sh bone', the traditional way, which was developed in Marseilles in France and is called 'glove box' or 'boite à gants' in French. There are usually 26 - 30 dates in this box, placed in two layers, separated by cellophane, weighing 220 g - 250 g. A natural or plastic spikelet is placed in the top layer. Most of the dates in such boxes are sold at Christmas time under various names. The variety most commonly used is Deglet Nour, but other varieties can also be found. Packing is done manually and much time is invested in arranging the dates in the boxes. The fruit is usually covered with glucose (natural) to give it a shine appearance.
b) Packing by automatic weighing (without any inner arrangement): Much packing is done in this way, starting with the 'window' type, where a cellophane window showing the fruit is part of the package design, which is usually made of cardboard.
Dates are also packed into tubs made of transparent plastic, showing the fruit as part of the package design. The information for the client is usually on the lid. This type of packing can be of varying sizes, according to the client demands. Bags, usually made of PET polyethylene, are the cheapest and most economical way of packing.
Many attempts are being made to introduce mechanisation and automation in order to save on packing and weighing. In recent years computerised combinatorial scales have been developed, making it possible to pack exact quantities, combined with automatic packing machines for many types of packages.
Quality considerations during packing
Quality control of packed products is the last time the fruit is checked before reaching the customer. Documented checking of the packages entails:
* weight of the package;
* weight of the fruit;
* arrangement of the fruit (in glove boxes);
* uniformity of the fruit;
* damage to the fruit;
* defects; and
* moisture content.
The surrounding area is also checked:
* cleanliness of the conveyer belts;
* calibration of the scales (automatic or manual);
* writing on the packages;
* satisfactory working of the metal detector (installed on every retail packing line);
* repackaging installations and marking; and
* qualifi cation for international standards such as ISO and HACCP (details follow in para. 6.2).
Although modern management takes marketing into consideration at all stages of production, in actual practice the shipment of the fruit takes it away from the region of the supplier and places it at the disposal of the market. All shipments are carried out according to the planning and direction of both the local and the export markets. Ttypes of shipment (relating mainly to export) are:
* overland transport;
* shipment by sea;
* overland and sea shipment combined; and
* shipment by air.
It is advisable to choose the cheapest transport which will bring the fruit to the client with DQ = 0 and at the right time. (DQ = 0: The fruit must not be damaged during shipment. It must be protected physically and kept at the appropriate temperature). The cheapest alternative makes it possible to compete against other suppliers and saves on expenses.
The appropriate time for shipment sometimes forces us to use more expensive transport in order to satisfy client requirements. For example, at the beginning of the season, in order to get in before other suppliers, or sensitive fruit such as Barhee when being shipped over great distances.
Overland transport to markets where this is possible. The fruit must be transported in a way that will protect it from the environment and, if necessary, in refrigerated trucks.
Shipment by sea in containers, an effi cient and (relatively) cheap means of transport; the fruit is protected from the environment from the moment it leaves the producer to the moment it reaches the customer's door. The containers are refrigerated (if refrigerated containers are used) by cold air fl owing horizontally over the layers of fruit. This air is distributed uniformly throughout the container.
Overland and sea shipment combined refrigerated trucks go from the supplier to a port where it is loaded to a ship that will transport the product further to its destination. This method is more expensive than shipment in containers (in the Mediterranean area and in Europe), but it is usually faster.
Shipment by air is the most expensive, but it is sometimes inevitable when the fruit must be supplied at short intervals. Transport to and from the airport must also be taken into account.
Documentation All the shipments must be documented in detail to ensure speedy transfer to the client (especially during export); beside documents for the customs, payment and transport, it is important to add a phytosanitary certifi cate stating that the fruit is healthy. This document is issued in every country by the relevant authorities and certifi es that the fruit is not infected by pests or diseases and is appropriate to the standards of the importing country.
Quality considerations during shipment
Sometimes the fruit is stored for a long time before shipment (up to several months). Owing to marketing conditions and packing possibilities, it is necessary to sample each consignment, in order to make sure that the quality of the fruit has not changed. During loading it is important to ensure that the surfaces or packaging are not damaged. All the labels and markings must be checked according to the requirements of the law and of the customer in the importing country.
Temperature recorder: Since temperature is an important factor in the preservation of the quality of the fruit, especially for fresh dates at Khalal or Rutab stage, a temperature recorder must be placed in the container, the truck or on the surface. This is a small mechanically operated unit. After the details of the shipment have been entered and the unit has been turned on, it records (on a ribbon) the necessary information about temperature during the shipment. The customer will only sign the receipt for the shipment if the temperature corresponds to the demands which were defi ned for the carrier.
This variety is harvested and consumed at an unripe yellow stage (Khalal). The fruit is locally marketed on branches or exported on branches in cardboard boxes. This way of marketing and consumption requires harvesting of the bunches in a state of Khalal before it turns into Rutab, and without any green fruit. Barhee can be consumed in this state owing to the low amount of tannin, which becomes non-soluble, and as a result the fruit is yellow Khalal with low astringency. It is also important that the fruit be sweet (not bitter) with a brix above 29. The timing of the harvesting of Barhee is very important to ensure that the fruit reaches customers in an unripe state. Whole bunches are harvested at the appropriate stage of ripeness. The harvesting of the bunch is carried out with a secateur or special knife, the heavy bunches (approx. 20 kg) are carefully lowered to the ground and placed on a clean platform or hung on a special hanger (Figure 84) and directly transported to the packinghouse. The harvesting is implemented in 3 to 5 rounds and only bunches in the appropriate state are cut off each time.
This variety (like Deglet Nour on branches) requires the combining of sorting with packing. The high moisture content of the date fruit at Khalal stage makes it necessary to shorten the time spent in packing and to keep the fruit at the appropriate temperature.
The fruit is packed on branches in cardboard boxes weighing 5 kg (in Jordan, Israel, USA and Saudi Arabia) (Figure 85). Green or ripe dates (Rutab) must be removed from the branches and only smooth, clean, yellow dates are packed. Since the fruit is fresh, the temperature must be lowered immediately after packing. It is also important to keep the fruit aired in order to remove substances, such as achetaldhide ethylene and CO2.
Characteristics of the fruit
Unripe, yellow, clean, smooth, hard without scratches, the fruit attached to the branches; diameter 26 mm minimum.
Branches at least 10 cm long and at least 5 dates for every 10 cm.
No tolerance of live insects: the fruit is not fumigated.
Tolerance of green fruit: 1 % (of the number of dates).
Tolerance of cured fruit: 1 % (of the number of dates).
Detached fruit in the box: 3 % (of the number of dates).
Storage temperature: 1 °C.
Transport temperature: 1 - 5 °C.
4.2. Deglet Nour
Deglet Nour is marketed and consumed in two main ways, infl uencing considerations at the time of harvesting:
a) Harvesting the fruit on branches: tens of thousands of tons are harvested in this way in Algeria, Tunisia and Israel, where it is consumed but also exported, mainly to France, Spain and Italy. When marketed in this state, the fruit must be soft and juicy, but with a potential shelf life of several weeks. The bunches are harvested when most of the fruit is in a state of Rutab, before they become Tamar, with a few Khalal. Fruit turning from yellow Khalal to Rutab will ripen between harvesting and consumption, during transport.
The bunches are lowered carefully and placed in containers or on some other device, and transported to the packinghouse. In most cases the bunches are wrapped up in a net to protect them from pests or birds, or in waxed paper or nylon sleeves for protection against rain. It is important not to shake the bunch in order to keep the fruit from falling.
Harvesting is carried out in 3 to 5 rounds and at intervals of 5 to 7 days, until all the bunches have been cut off the palms. Bunches which have a low percentage of fruit but which are suitable for marketing are shaken from the bunch and marketed in a different way.
b) Harvesting loose fruits to be sold unattached: harvesting is done palm by palm and the fruit must be at the Tamar stage. This method is used for all Deglet Nour in the USA and for Deg-let Nour in other countries when it is to be marketed over a period of time. Since this fruit is subjected to hydration treatment, it can remain on the palm until all the fruit is at the same stage of ripeness and dryness. When harvesting is carried out, it is important to protect the fruit from rain, which causes rotting and fermentation, and from various pests.
Treatment of Deglet Nour in the packinghouse
A large part of the Deglet Nour crop grown throughout the world (in Tunisia, Algeria and parts of Israel) is marketed and consumed as Deglet Nour on branches. This product calls for special treatment, different from that described so far. Frequently, and mainly for fear of rain, bunches of Deglet Nour are harvested before they are completely ripe (at the stage of transition from Khalal to Rutab and the beginning of Tamar). Much of the fruit which has not ripened, ripens after it is harvested (fruit which is at the unripe stage, from red to yellow). These bunches are placed in aired containers or hung in large sheds (in Tunisia) and are kept for a certain period. This makes it possible to pack a larger percentage of the fruit.
The fl ow chart presented in Figure 86 describes the stages in the treatment of Deglet Nour for export (North Africa).
Various sorting systems are built in a way that makes it possible to perform several operations along the way and sometimes even to reach the fi nal stage of packing.
Packing Deglet Nour on branches
At first, all the packing for Europe was done in a packinghouse in the region near Marseilles, but in recent years it is carried out in the countries where the dates are grown. A telescopic cardboard box is used (it has a bottom and a lid), and the weight is 5 kg. The packages are decorated with pictures showing bunches of Deglet Nour or date palms.
The fruit is packed from hanging frames in sheds or from containers brought in from the fi eld. The branches suitable for marketing are cut and packed in rows along the length of the cardboard box. The size of the box is usually 50 × 30 cm and it is adapted so it can be stacked on a standard pallet of 120 × 100 cm. Transparent cellophane is placed on top of the fruit and the lid is closed using pressure to avoid reinfestation or moisture loss.
The standards for this product were set mainly by the Tunisians and the Algerians and adopted by importers and other suppliers (as in Israel). The fruit must be soft and juicy, preferably of a light colour and with a transparent look. In good Deglet Nour the seed can be seen when the fruit is held against the light. The fruit is attached to the branch and must be clean; the moisture must not rise above 26 %. Each branch is more than 10 cm long and for every 10 cm there are at least 5 dates. There should be no more than 1 % of green fruit and no more than 1 % of unripe fruit (Khalal stage). Unsuitable dry, rotten and unripe fruit is removed from the branches. Live insects are not tolerated; the fruit is fumigated by methyl bromide on entering the packing installation. It must not be covered with dust or sand; it is best cleaned by air pressure. Detached fruit should not amount to more than 3 % in the box. There is no defi nite standard size, but the desirable weight per fruit is more than 8.50 g.
Deglet Nour on branches offers two alternative packages:
* Bunches: the fruit is packed in long cardboard boxes containing 2 bunches, with a total weight of 10 kg. The quality required is identical to that of fruit packed in 5 kg boxes.
* Bouquets: 3 to 5 branches are packed in a cellophane bag on a little cardboard tray; the branches are tied at their base. This pack weighs 200 to 400 g and packaging is labour intensive. The quality of the fruit is identical to that in the 5 kg boxes.
Quality considerations in packing Deglet Nour
Since the texture of this fruit is unique, the soft and juicy textures are to be taken into account. It is also very important to ensure that there is no sand or dust on the fruit, and that its weight when packed is correct. During packing, storage and shipment conditions must be appropriate because the fruit is sensitive and goes bad quickly (mainly by souring); it is best kept at a temperature of 0 - 4oC. Freezing will cause the fruit to darken.
Most of the Medjool (less than 5,000 tons per year) is produced in the Coachella Valley and Bard in California, and in Israel, and additional small amounts in Mexico and South Africa. When harvesting this variety, clients' wishes (large soft fruit with a moisture content of about 20 to 26 percent) are also taken into account. Medjool is a soft and delicate fruit with a thin skin, requiring careful treatment. Harming the skin may cause sugar crystallisation. In a hot climate (such as at Bard in California and in southern Israel) harvesting begins by picking the dates one by one at the beginning of the ripening process, at the transition stage from Khalal to Rutab. The fruit which has remained on the palm will become too hard to satisfy the needs of customers. In less hot areas, besides the wish for fruit with a soft texture, the need to protect the fruits must also be taken into account. When the drying process is slow, the fruit is sensitive to fermentation bugs - carpopilus. The Medjool fruit dries slowly because of the relationship between volume and outside surface.
The harvesting method is planned in such a way as to ensure that the fruit has the appropriate texture when it reaches the market. It must be soft, elastic, so it can be packed and preserved without changing shape. Its moisture should be 20 % to 26 % (when fresh), with Equilibrium Moisture Content (also called Aw-water activity) of not more than 65 %. In this respect, EMC is very important, owing to the relatively high water content. Harvesting will therefore take place while the fruit has a relatively high water content in order to prevent the fruit from losing water and becoming hard in texture.
The demand is for large fruit (over 20 g) where no skin separation or blooming is taking place, with a soft texture, and colour ranging from light to dark brown. by timely and accurate thinning, appropriate irrigation and fertilisation (see Chapters VI, VII and VIII). The colour of the fruit is (probably) due to certain soil and climate related factors, not under the grower's control.
To make harvesting easy to handle, the worker is brought within reach of the bunch on a platform. Each bunch is then shaken gently to remove only ripe fruit i.e. those in the Rutab stage and at the beginning of transition to Tamar. The fruit is placed on shallow trays in a single layer.
Every bunch is harvested according to its state of ripeness, but it is important (especially in a hot climate) to begin when the ripe fruit is still soft; checking the fruit every fi ve to seven days makes it possible to harvest in an optimal condition, and prevents the fruit from being attacked by moths and nitidulid beetles. In regions where it is less hot the rounds can be made less frequently, keeping in mind that the fruit must be harvested before it dries. In some areas harvesting can also be carried out by selecting bunches with fruit that have passed from the Khalal to the Rutab stage; in this case some of the fruit will be at the Tamar stage.
The Medjool fruit falls off easily at the Rutab stage and the bunch is therefore wrapped up in a shade net (in Israel) or a cloth bag (in Bard, USA). The cover is open at the bottom and the ripe fruit is picked carefully from underneath through the openings, and placed on trays. This type of harvesting is very labour-intensive and costly; however at present the high price fetched by this fruit justifi es the process.
Field sorting Medjool
In order to preserve the softness of the fruit after harvesting, as described in the previous section, several rules must be respected: the fruit must be soft in texture but with a moisture content that will make it possible to pack and store it for a long time.
In order to preserve the softness of the fruit (together with the other criteria) it is necessary to obey certain rules while the fruit is being treated on site:
* Only fruit which has reached the Rutab stage but not yet the Tamar stage should be harvested.
* Fruit harvested at different levels of moisture content should be separated.
* Each section should be dried uniformly to 20 - 26 % of moisture content or according to EMC to the level of 65 - 70 %. (Figure 87)
* The dried fruit should be kept under conditions which will prevent further water loss (sealing and appropriate temperature).
Drying takes place on trays in one layer; spread out in the sun or on platforms or in drying ovens, depending on the climatic conditions at the time of harvesting and on technological solutions (Figure 88).
4.4. Harvesting other varieties
Beside Barhee, Deglet Nour and Medjool, the other varieties are harvested when all the dates in the bunch or even on the whole palm have less than 20 % water content (of the weight of the fruit). Dates containing more water must be dried (artifi cially or by the sun) to a level of 16 % to 19 %, to make it possible to preserve them without refrigeration. In this state the fruit has its customary appearance (according to each specifi c variety), with its characteristic wrinkles and colour, ranging from dark brown to light yellow.
There are many methods of harvesting, depending on different date growing countries, specifi c regions and local traditions. Some of the fruit is harvested when it is very hard and dr-y - stone dates. These varieties can be harvested at a great height and dropped right down to the ground.
Other varieties require gentler treatment, and the common method used is to cut the fruitstalk and to lower it on a rope with a hook or to use mechanised platforms which take the worker up to the bunch. For these varieties harvesting is also the first stage in the treatment process, so that the fruit reaches consumers in the state required.
Here we shall only mention products and by-products made from the fruit itself. Other parts of the palm, such as the trunk, the leaves and the male pollen, are also used in various ways, but will not be discussed in this chapter.
The raw material used for the products usually consists of dates of a lower quality, with a low percentage of sugar, but on no account rotten, sour or fermented dates. Good quality dates may also be used when there is a surplus of fruit on the market.
Most of the dates are sold without seeds, 80 % of Deglet Nour are sold in the USA in this way for consumer convenience. The seeds are removed by hand or by machine, the methods range from seed removal while ensuring the dates remain whole and their texture is not harmed, to the complete grinding of the product. When seed removal is done by machine, some seeds may remain, and a warning must be included on the packed product.
Pitted pressed dates: This is a very useful basic product both in producing and in importing countries (European countries, the USA and South Africa). The dates are pitted by hand or by machine, pressed into a mould and vacuum packed. Packing in this way and with the right amount of moisture (less than 20 %) preserves the stability of the product over time without refrigeration. If these rules are not adhered to, the product may be harmed by microbiological processes or through sugar crystallisation. This product is used mainly as a fi lling for cakes and biscuits, especially during the Muslim Feast of Holy Ramadan (Figure 83).
Date paste: In order to preserve the stability of the products over time and prevent their going bad, specifi c rules must be followed during the date paste production stage. Brix must not be less than 65o and the acidity must not rise above pH 4.5. In this case the paste can remain in its natural state (without the need for preservatives). If the above conditions do not exist, the product must be pasteurised or sterilised. These pastes can be used as fi llings for cakes (with the addition of various fl avours, as required). The great advantage of these pastes is that their melting temperature is higher than that used in baking, so that the fi lling does not run out of the cake during baking.
Date syrup (sometimes called dibs or rub): Five production stages are involved: pretreatment, extraction of juice, clarifi cation, concentration and fi ltration. The rules with regard to brix and sourness must be strictly kept. The syrup is used to sweeten various foods.
Date products resulting from intensive processing: Sauces for steak or chutney: The dates serve as a source of sugar and to form the body of the sauce.
Other types of products are extruded date pieces or diced dates. The dates are pressed through holes of 5 - 12 mm; the product is covered with dextrose or oat fl our in order to prevent the little pieces from sticking to each other.
Alcohol: Alcoholic drinks can be produced by the fermentation of the dates.
6.1 Packinghouse management
Modern management focuses on marketing and quality control. The manager is responsible for:
* Contact with marketing and production management according to the requirements of the market;
* The labour force (permanent and temporary), for its training and guidance in fulfi lling the necessary tasks, and for the well-being of the workers;
* The appointment of a team of assistants, and of the managers of the various departments;
* The purchase of raw materials and the administration of the stocks;
* For the whole issue of quality, working for constant improvement (standards, control, follow up);
* Development: long term perspectives of new ways of expanding the plant, its upgrading and the development of new products;
* Storage and shipment on the appropriate scale and according to demand;
* Ensuring funding of ongoing operations and of development, obtaining payments from clients and paying suppliers (especially suppliers of fruit, according to contract type);
* The execution of all safety instructions according to the law, in order to protect the workers;
* Care for the quality of the environment and the investment of the necessary funds (treatment of poisonous gases and of sewage etc.);
* Contact with the relevant Governmental institutions, the Ministry of Agriculture for phyto- sanitary permits and extension services, and other Ministries on the issues of quality and health;
* Ensuring the profi tability of the packinghouse by good management.
6.2 Quality standards
When dates are produced for export, certifi cation has to take place by an internationally recognized certifying body. Most importantly, it needs to be recognised by the buyer.
Quality standards for dates have been set by different bodies. Earlier in this chapter the Codex Alimentarius was mentioned. The Codex Alimentarius sets permitted levels of residues of pesticides (MRL = minimum residue limit) according to types of material and species of fruits, vegetables and other foodstuffs. The Codex Alimentarius is published by FAO and WHO and has been ratifi ed by most of the 146 member countries.
Furthermore, UN/ECE norms have been set for whole dates. Sorting criteria as well as criteria concerning moisture content are set in these norms, which are accepted in most EC countries, although the exact levels might differ per country.
Quality standards are set per country and per variety. Individual countries set their own standards with regard to quality. This can be seen as an agreement between the buyer and the producer with regard to what the product should look like.
Health regulations are designed to ensure that the produce is safe for human consumption.
Quality systems are complementary to the above technical requirements and those of the customer. They do not replace them.Two quality systems are ISO 9000 and HACCP- Hazardous Analytical Critical Control Point.
"ISO 9000".This is a quality system, a model for quality, assurance in design, development, production, installation and servicing, designed by the International Institute for Standardization (ISO). The ISO 9000 international standards were accepted as European standards in December 1987. On the one hand, these norms refl ect worldwide agreement in the fi eld of quality assurance, and on the other hand, they are binding for the European Union and the countries of European Free Trade Association.
Key concepts in the framework of the ISO 9000-9004 norms are: Quality management, Quality care, Quality system, Quality control, and Quality assurance.
Certification mostly takes place by checking and supervision, carried out by an independent, impartial and expert certification institution. In most countries, it is possible to obtain detailed information about ISO 9000 and certifying bodies fromN ational Standardization Institutes. Information can also be obtained from ISO, P.O. Box 56, CH-1211 Geneva, Switzerland. (CBI, 1997/2: European regulations manual).
In the usual type of production plants such as packinghouses for dates, the relevant standard is 9002. The standard defi nes the requirements of the quality system. They are mainly intended to prevent lack of coordination at all stages of quality control, from the reception of the fruit from the field (in some cases even before) until it reaches the client and consumer (and deals with complaints, if necessary). Keeping to this standard assures the customer that the quality system of the supplier ensures that the product fulfi lls the stated quality requirements (as defi ned by the client or by the standard).
ISO 9002: 1987 Quality system requirements
1. Management responsibility
10. Inspection, measuring and test equipment
2. Quality system
11. Inspection and test status
3. Contract review
12. Control of non-conforming product
4. Document control
13. Corrective action
14. Handling, storage, packaging and delivery
6. Purchaser supplied product
15. Quality records
7. Product identification and traceability
16. Internal quality audits
8. Process control
9. Inspection and testing
18. Statistical techniques
Qualifying for "ISO 9000" has the advantage of providing a common language between supplier and client in matters of quality, ensuring that the product has been officially recognised as such.
Issues of quality will always be the responsibility of top management and will be passed down the hierarchy.
HACCP- Hazard Analysis Critical Control Point
The Hazard Analysis Critical Control Point (HACCP) is a European standard for the food industry. The EU Directive on Hygiene of Foodstuffs (93/43/EC) stipulates that "foodstuff companies shall identify each aspect of their activities which has a bearing on the safety of foodstuffs and ensure that suitable safety procedures are established, applied, maintained and revised on the basis of an HACCP system" (CBI, 1996). It is a method of analyzing risk factors related to food, the risks for the consumer using the fruit. The food is analyzed linearly throughout the process, and broadly for chemical, physical and microbiological risks. The method makes it possible to detect critical points of risk and fi nd ways of preventing it. The critical points in date processing are:
Chemical risk - in dates the source of risk is from the residue of substances used in pest control in the fi eld. This is a critical point when receiving the fruit at the plant. The solution lies in guidance and supervision in the fi eld, in the use of permitted substances only and in their correct concentration, and by sampling the fruit for testing for such residue.
Another, less signifi cant, chemical risk in the packinghouse is the use of detergents. This risk is prevented by the use of cleaning materials permitted in the food industry and separate locked storage.
Physical risk - various foreign bodies:
metals: the critical point is after final packing; using a metal detector; calibration and ongoing testing must be a regular procedure.
Glass: the following code must be followed:
a) no glass may enter the plant (no glasses, jars etc.)
b) light bulbs must be protected
c) the windows must be made of unbreakable material
d) specifi c procedures in case of broken glass
Microbiological risk - mainly infection, for example, by coliforms and salmonela. Prevention techniques are however available and can be summarised as follow:
1. Rules regarding personal hygiene; workers wash their hands with soap on entering the plant and on leaving the toilet.
2. Washing the fruit with water qualifying as drinking water.
3. Preventing fl ies, mice and birds from entering the area of the plant.
4. The sorting system must be cleaned according to regulations.
5. Ongoing checks of various parts of the plant in order to detect possible pollutants, ensuring that the fruit is clean.
6.3 Packinghouse requirements
In order to enter the supermarket level in Europe, it is necessary to maintain a minimum standard regarding cultural techniques, harvesting, post-harvest handling, packing, health and hygiene, and quality control systems.
* Must be a separate, defined area which is used only for packing. Storage of cartons must not be carried out in the packinghouse.
* The fabric of the building must be in good condition. Windows when open, must be screened to prevent insect ingress.
* Light level must be adequate for selection and grading.
* There should be adequate facilities for the collection and disposal of waste material at frequent intervals to discourage fl y infestation and the development of latent fungal infection.
* Risk of contamination from local industries should be minimised.
* The packinghouse layout should be designed in such a way as to keep the raw material and the fi nished product separate, and to encourage the smooth fl ow of the product through the selection and packing system.
* The packinghouse and equipment should be cleaned during the day on a "clean as you go" basis.
* Work surfaces should be non-porous and easy to clean. Materials such as stainless steel and formica are ideal.
* Containers used during production such as harvesting crates should be easy to clean polythene or other durable plastic. They should be cleaned regularly and stored in areas free from risk of contamination.
* Packing material must be stored in a clean dry area free from risk of contamination.
* All equipment used for quality control such as scales, temperature probes, refractometers, etc. must be regularly checked for accuracy.
The storage of packing material is very important and care should be taken that no insects can enter the material and be exported. Fly/insect catchers should be installed in the packinghouse and a no smoking policy should be implemented in the area where dates are packed.
* It is important that all staff are aware of their responsibilities for the health and
* Staff suffering from gastric disorders causing sickness must not be allowed to work until completely recovered and cleared of the disorder.
* All cuts, sores and other skin problems must be covered by a blue industrial dressing.
* Hand washing and toilet facilities should be adequate to meet staff requirements. Toilets must be maintained in a clean hygienic condition.
* Wearing of cosmetic jewellery should be discouraged and should be kept to an absolute minimum at all times.
* Protective clothing that adequately covers day-to-day clothes must be worn in the packinghouse at all times.
* Smoking, chewing tobacco and spitting is strictly forbidden in the packinghouse.
* Rest areas, away from production should be provided for food and drink consumption.
* The storage of chemicals, fuel and oil should be in a secure area away from the packinghouse.
The following information should be printed on all packaging material for exports:
* net weight;
* country of origin;
* grown and packed by (address);
* product and variety; and
* category (class 1 or grade 1).
The aim of setting these packinghouse requirements is to maintain uniformity in products, quality, production standards and liabilities of all packing stations supplying to an umbrella marketing organisation.
The conditions and requirements actually implemented in Israel are:
1. Certification - approved by the authorities as a food packer, e.g. Ministry of Health, FDA or equivalent body.
2. Knowledge of the sorting, selection, grading and packing of dates.
3. Approved fumigation facilities for use of methyl bromide.
4. Approved and licensed operator of methyl bromide fumigation facilities.
5. On site quality control and data recording throughout the whole process.
6. Weighing and measuring standards and set-up of equipment maintained.
7. Long term cold storage rooms to accommodate a range of varieties before and after selection and packaging.
8. Administration and office facilities to meet internal and marketing organisation needs.
9. Equipment and ramp to load sea containers/trucks.
10. Documentation of produce in/out that meets marketing organisation needs.
11. Packing station product quality guarantee to the consumer.
Figure 80. Date harvesting by mechanical ladder (Israel)
Figure 81. Washing of dates
Figure 82. Sorting of Medjool
Figure 83. Pitted pressed dates
Figure 84. Transport of Barhee bunches from the fi eld to the packinghouse
Figure 85. Packing of Barhee bunches in the 5 kg boxes
Figure 86. Classifi cation and treatment of Deglet Nour for export (North Africa).
(Source: Barreveld, 1993)
Figure 88. Sun drying of too soft Medjool fruits
Figure 87. The relationship between moisture % and water activity