[For further information on the Electronic Forum on Biotechnology in Food and Agriculture see Forum website.
Note, participants are assumed to be speaking on their own behalf, unless they state otherwise.]

-----Original Message-----
From: Biotech-Mod3
Sent: 14 July 2004 11:02
To: biotech-room3@mailserv.fao.org
Subject: 59: Molecular ecology, food safety and intellectual property rights

From Carmen Wacher, Food and Biotechnology Dept., Universidad Nacional Autonoma de Mexico (UNAM), Mexico City. I work on the microbiology of Mexican traditional fermented foods.

Mexican traditional fermented foods have not been studied as well as those of other countries (as those that have been participating in this conference, which I have found very interesting). Most of our foods are based on maize, which is our staple food, and in many cases they are important as everyday food. This is the case of pozol, an acid beverage prepared from fermented nixtamal (maize cooked in lime-water) dough, which our team has been studying.

After studying the microbiology of pozol with traditional techniques, our team (in collaboration with the Institut de Recherche pour le Developpement (IRD), France) has been using several molecular ecology methods, of which denaturing gradient gel electrophoresis (DGGE) has been especially useful. It has been possible to determine changes in the microbiota with time and at different depths of the pozol ball, as well as to find that Streptococcus is the predominant bacterium throughout fermentation and also the dominant amylolytic lactic acid bacterium. By analyzing a number of pozol samples with DGGE, we have also recently confirmed that this genus is dominant during fermentation.

Unusual strains have been isolated, as a Leuconostoc citreum with a cell-associated inulosucrase that had only been reported in Streptococcus mutans.

Regarding microbiological safety, a variety of Escherichia coli strains belonging to different diarrheagenic groups have been isolated, even at low pH values (3.7). These strains have been found to be acid resistant (as resistant or more than the O157:H7 serotype). It is then essential to improve hygienic conditions during its preparation and to make use of other antimicrobial compounds. To achieve this, it would be important to improve the process, as has been proposed in this conference.

Other groups have been studying a Bacillus strain isolated from pozol that produces antimicrobial compounds, and aflatoxins, of which AFB2 was found to be present in 5.4% of non-fermented doughs. [Aflatoxins are mycotoxins (i.e. toxic secondary metabolises produced by fungi) produced by the fungi Aspergillus flavus and Aspergillus parasiticus. Of the different types of aflatoxins, the major ones are aflatoxin B1 (AFB1) aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2)...Moderator].

The Mexican law establishes that authorization is required to use Mexican biological resources. This authorization can only be granted with the consent of the owner of the place where the biological resource will be extracted, and this owner should be informed on how the biological resource will be used. The owners have the right to an equitable share of the economical benefit that may result from the studies or use of the resource.

Authorization is also required for sampling for scientific purposes and in this case there must be a guarantee that research results will be publicly accessible.

The above is well established for wild flora and fauna, but not for resources as fermented foods, in which traditional knowledge is involved. The main problem has been to decide who should give the consent and receive the economical share. The authorization has been given by the community leaders of the region under study, but for the case of foods that are produced in large regions (as pozol), other communities might claim they are also the "owners" or "inventors".

It has been very difficult to get funds to study our fermented foods (practically impossible in the last 3 years). I find interesting the idea of Folarin Oguntoyinbo (Message 58, July 12), who proposes to form regional groups to study similar fermented foods.

Dr. Carmen Wacher
Departamento de Alimentos y Biotecnologia
Facultad de Quimica,
Universidad Nacional Autonoma de Mexico (UNAM),
04510 Mexico, D.F.,
Mexico
Tel and fax 52 55 5622-5315
wacher (at) servidor.unam.mx

[Pozol is a fermented maize dough formed into balls of various shapes and sizes ranging from 10-12 cm in length, 5-8 cm in width and 70-170 g in weight. Some unusually large pozol balls weigh 1 kg or more. It is consumed by the Indian and mestizo populations, mainly in the Southeastern states of Mexico, such as Chiapas, Tabasco, Campeche, Yucatan, and on a smaller scale in Veracruz, Oaxaca and Guatemala. More information can be found in pages 105-108 of Chapter 4, entitled "Cereal fermentations in Latin Amercian countries" by Rodolfo Quintero-Ramirez, Argelia Lorence-Quinones and Carmen Wacher-Rodarte, in FAO Agricultural Services Bulletin nr. 138, entitled "Fermented cereals: A global prespective" , at http://www.fao.org/docrep/x2184e/x2184e00.htm ...Moderator].

-----Original Message-----
From: Biotech-Mod3
Sent: 14 July 2004 11:39
To: biotech-room3@mailserv.fao.org
Subject: 60: Bitter flavor in fresh cheese

I am Muhi El-Dine Hilali from ICARDA.

I have a question regarding cheese. Why there is sometimes a bitter flavor in fresh cheese? Is it due to the rennet type or because of the psychrotrophic bacteria which were not killed by pasteurization! The bitterness appears also in cheese manufactured without starter, and normally the bitterness appears after around 4 days of manufacturing. [Psychrotrophic bacteria are capable of developing over a wide temperature range and they can grow at temperatures close to or below freezing. They are important for spoilage of refrigerated food products...Moderator].

Muhi El-Dine Hilali
International Center for Agricultural Research in the Dry Areas (ICARDA)
Natural Resource Management Program
Sheep Unit
Tel +963-21-2213433
Fax +963-21-2213490
P.O.Box 5466
Aleppo
Syria
m.hilali (at) cgiar.org

-----Original Message-----
From: Biotech-Mod3
Sent: 14 July 2004 11:43
To: biotech-room3@mailserv.fao.org
Subject: 61: Need for research, data collecting and information distribution

Just a few words to thank the FAO and the moderator for organising this much enlightening conference, and all the contributors for many new insights and valuable information in the first instance about traditional fermentation technology.

One outstanding conclusion is that there is a wealth of knowledge available not only to enhance the local quality of life but also to fertilise global research on fermented food.

The main danger is that the fast progressing globalisation may replace much of the traditional food by standardized "western style" commodities. There is for sure an urgent need for research, data collecting and information distribution. The creation of regional data bases and culture collections has been proposed.

For wide distribution also in an environment where internet connections are not always widely available, the printed book remains the most efficient tool. I am well aware of the tremendous, but also very rewarding, task an edited book on traditional aspects of food fermentation represents. Many of the contributors to this conference are however well placed and fully qualified to undertake such a task, and if some of them feel interested I would only be to happy to propose to Springer-Kluwer, the publishers of the Focus on Biotechnology book series, to make sure that such a volume gets the platform and distribution it deserves.

Prof Dr ir Marcel Hofman
President SCIBB
Chairman ORCOM ECB9
Series Editor Focus on Biotechnology
Fax 32 2 767 21 91 Tel 32 2 767 2399
Hondsbergen 2, BE-3080 Tervuren
Belgium
mailto: secretariat (at) ecb9.be

-----Original Message-----
From: Biotech-Mod3
Sent: 14 July 2004 14:16
To: biotech-room3@mailserv.fao.org
Subject: 62: Re: Need for research, data collecting and information distribution

This conference really encouraged and must have given the new direction to individuals pursuing their higher studies or just starting their careers or who have established themselves as well as the scientific community all over the world engaged in biotechnology: food fermentation. The idea put forward by Marcel Hofman (Message 61, July 14), for collecting and compiling the knowledge available not only to enhance the local quality of life but also to fulfill the hunger of scientific community in global research on fermented food. The creation of regional data bases and culture collections has been proposed, which is required at ground level needs to be accomplished. The information circulated/communicated on traditional fermented food during this conference is of immence siginificance to all of us. Thanks are due to FAO and the organizers of such a wonderful electronic conference.

Dr. Shashi Bhushan,
Division of Biotechnology,
Institute of Himalayan Bioresource Technology (CSIR),
Palampur(HP)-176061
India
shashidbhushan (at) yahoo.co.in

-----Original Message-----
From: Biotech-Mod3
Sent: 14 July 2004 14:28
To: biotech-room3@mailserv.fao.org
Subject: 63: Re: Bitter flavor in fresh cheese

In reply to Muhi El-Dine Hilali (Message 60, July 14):

Slight bitterness (like young chicory and taste panel reference as diluted caffeine solution) is often searched for in some fresh goat cheeses. Excess bitterness up to astringency (taste panel reference diluted alum solution) is an off flavour in cured cheeses as well as in fresh cheeses.

When a starter is used, starter composition controls the flavour development. Bitterness is often due to proteolysis, so any factor that increases proteolysis can provoke bitterness, mostly by enzymes released into the cheese when the bacteria present (starter or autochtonous) die off. The other way round, endopeptidases also released will reduce bitterness. Flavor development in fresh (and also in cured) cheese is a matter of balance. Many factors apart from the bacterial population can contribute. Bitterness development is, for instance, prevalent in low-fat cured say cheddar-type cheeses and has been traced back to both the lower fat and higher water content, increasing acid development but also influencing proteolysis. A remedy has been the use of a combined three strain starter. My advice would be that supplementing the rennet with a suitable starter to control the bacterial population can bring the flavor development under control.

Prof Dr ir Marcel Hofman
President SCIBB
Chairman ORCOM ECB9
Series Editor Focus on Biotechnology
Fax 32 2 767 21 91 Tel 32 2 767 2399
Hondsbergen 2, BE-3080 Tervuren
Belgium
mailto: secretariat (at) ecb9.be

-----Original Message-----
From: Biotech-Mod3
Sent: 14 July 2004 15:14
To: biotech-room3@mailserv.fao.org
Subject: 64: Biotechnology and starter cultures

I am Steven Gendel, and I work at the National Center for Food Safety and Technology (in Chicago, Illinois) as the Biotechnology Program Lead.

A number of the previous posts in this conference have mentioned the importance of starter cultures for various fermented food products. It seems to me that the production and distribution of starters is one area in which biotechnology can have a positive impact on traditional food processing and preparation.

As far as I can tell, much small scale or local production of fermented products depends on the action of whatever organisms happen to be present in the environment, perhaps aided by back inoculation from a previous batch. A well thought out starter culture program could provide several improvements over this. First, production of the starter (or starters) could be carried out at a central facility with access to the technology to ensure purity and consistency. For example, molecular fingerprinting could be used to ensure that only the desired strains are present. Second, the use of defined starters should improve product consistency - at least it will reduce one of the major sources of variability. Third, well designed starters could reduce the possibility of pathogen growth in the product.

The biggest technical hurdle to be overcome is preservation and distribution of the starter. Probably the best way to do this is in a dry ("shelf stable") form in a single use packet. This is one area where technology and research should be valuable - the development of technology for producing such dry material while maintaining viability and rapid regrowth.

It is also possible to envision a system in which genetically modified organisms could be introduced for improved performance and safety. There are several schemes that can be used to prevent growth of any modified organisms in the environment.

Given the variety in local tastes and inputs, such a starter culture program would probably need to be a distributed system - that is; there would need to be a number of different culture producers in different geographic areas.

Finally, genetic technology should also be able to contribute to simply characterizing the organisms present in the fermentations as they are currently used, and perhaps to developing tests that could be used to indicate whether undesired organisms are present.

Steven Gendel,
National Center for Food Safety and Technology
Chicago,
Illinois
United States
Steven.Gendel (at) CFSAN.FDA.GOV

-----Original Message-----
From: Biotech-Mod3
Sent: 14 July 2004 15:55
To: biotech-room3@mailserv.fao.org
Subject: 65: Re: Bitter flavor in fresh cheese

It might be useful to add more information on the taste panel, mentioned in my previous message 63 (July 14):

Even in an age where instrumental analysis becomes more and more performant, sensorial analysis is still unbeaten when studying flavours. Similar tastes may be generated by very different compounds or combinations thereof. Bitterness and astringency often give rise to discussions. When speaking about cheese, the position of customers is very relative and related to, for instance, accompanying drinks. In a beer drinking country, more bitterness may be tolerated than in a wine drinking country. And speaking about wine, different wines may influence the judgment appreciably: a Sancerre wine that is a perfect companion for a fresh goat cheese would make a tinge of bitterness very objectionable. That is why professional taste panels judge food, wine, beer, but also cheese or butter "on their own", rinsing the mouth between samples. Water rinse or chewing a piece of bread are common means to get rid of "aftertaste" effects.

Some tastes may create discussion even between experts. Simple solutions may be used as reference standards. In my previous message, I cited from memory caffeine and alum, looked up afterwards:
bitter : 0.8 g/L caffeine solution
astringent : 1 g/L alum (aluminium sulfate) solution

Prof Dr ir Marcel Hofman
President SCIBB
Chairman ORCOM ECB9
Series Editor Focus on Biotechnology
Fax 32 2 767 21 91 Tel 32 2 767 2399
Hondsbergen 2, BE-3080 Tervuren
Belgium
mailto: secretariat (at) ecb9.be

-----Original Message-----
From: Biotech-Mod3
Sent: 14 July 2004 16:45
To: biotech-room3@mailserv.fao.org
Subject: 66: Areas for national, regional and international co-operation

I am Ashok Seth. I work as a consultant in agriculture and rural development.

As someone not directly involved with food processing and biotechnology, I have learned a lot from postings of all the contributors. I am particularly taken by suggestions put forward by Marcel Hofman (Message 61, July 14) to collate and document available traditional and modern information. Such a move on a regional basis could of considerable value to all concerned. I was equally taken by the contribution of Steven Gendel (Message 64, July 14) who emphasised the importance of starter materials and pointed to a need for further research to produce these in forms that can be easily preserved and distributed. In my view, another possible area for regional co-operation. The important contributions in increasing agricultural production through germplasm improvement by both the public and the private sectors is a good parallel here.

One area that has not received attention is the possible backward linkages with researchers in the production phase of raw materials (e.g. cereals, cassava, etc.) to see how plant breeders (with or without tools of biotechnology) could contribute to the quality (ease and reliability of fermentation, nutritive value) of food products. There is clearly a need for multidisciplinary teams to work on priority targets that provide opportunities for value addition, improved nutrition, higher income and greater food security to both the rural and urban communities with limited free cash for 'pre-packaged' food products...

While we have successfully identified areas for national, regional and international co-operation, possibly involving both the public and the private institutions, there is room for further debate on 'enabling actions' that would make such co-operation a reality. Here, I feel there is an important role for institutions like FAO, World Bank and bilateral donors. They could either individually or collectively allocate resources through ongoing projects or new initiatives to bring together multidisciplinary teams who are able to identify and work on high priority research initiatives with monitorable outcomes to help poor communities.

Ashok Seth
ARD Consultants Ltd.
Alton
Hampshire,
UK
AKSth1 (at) aol.com