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6. Processing ventures

Simple-technology processing: foods and handicrafts
Intermediate processing: medicines, vegetable oils, food colorants, tannins and gum naval stores
Complex processing: essential oils, waxes and other products
Steps in processing
Quality standards
New product development and research support
Summary
References
For further reading

This chapter gives an illustrative overview of the range of processes by which enterprises can convert nonwood forest resources into market items, proceeding from less complex technologies to more sophisticated, capital-intensive processes. Readers should explore references in "For further reading" for more possibilities.

Evaluating options for processing requires up-to-date information on the natural resource, markets, processing technologies, and trade practices and regulations. It also requires a review of access to the resource for harvesting different products and the relative socio-economic and environmental impacts of different harvesting combinations (Lintu, 1995). For example, neem (Azadirachta indica) can be managed for leaves and seeds to produce many marketable products from soap to big-insecticide; cultural preferences and the biological resource might dictate an optimal product combination.

Simple-technology processing: foods and handicrafts

Foods
Handicrafts

Food processing and handicraft production can employ local skills and require low capital investments.

Foods

Forest: fruits, nuts, tubers, palm heart, tender shoots, wildlife and insects provide many foods for which little or no processing is required for local sale. But with relatively simple techniques for drying, preserving, shelling, storing, etc., producers can increase the value of these items and reduce seasonal fluctuations in supply.

These processes also permit a rural enterprise to reach urban markets (see text box 6.1). In cities where consumer's environmental awareness allows niche markets to develop, an enterprise can increase its revenues by demonstrating the ecological soundness of its operation and meeting market preferences.

Handicrafts

The example of rattan handicrafts in Chapter 5 showed how local processing can improve producers' return from these products.

Silk-making from silkworms raised on leaves from mulberry (Mows alba) and other trees is a widespread cottage industry (Iqbal, op. cit.). Raw materials are tree-leaf fodder and the worms themselves (for mulberry silk, Bombyx mori). Silk production also opens a wide range of other products: mulberry produces edible fruits, a fine wood and branches useful for basketry. Other silkworms include eri (Philosamia ricini and P. cynthia) raised on castor leaves, and tassar silkworms (Antheraea spp.) raised on Terminalia sp., oak and other species. Silk and silk products make up a significant international trade, with China being the largest exporting country. Some Asian silk industries are seeking new sources of raw silk in developing countries, particularly in Africa (Iqbal, op. cit.).

Intermediate processing: medicines, vegetable oils, food colorants, tannins and gum naval stores

Medicinal plant products
Vegetable oils
Dyes and food colorants
Tannins
Turpentine and other naval stores

With somewhat more investment and skills, rural processing centres can produce medicines, vegetable oils, food colorants, dyes and tannins.

Medicinal plant products

More than 80 percent of the world's people depend on traditional medicinal plants for their health care. Furthermore, about 20 percent of the drugs in modern allopathic medicine are derived from plant sources. Most plants used in traditional medicinal systems are still collected from wild sources. In some cases, this industry has caused local extinction of species (De Silva and Atal, op. cit.; Zuhud, 1995). Where communities take steps to improve and control harvesting practices, however, medicinal plants can provide sustainable employment and improved community health.

Traditional medicines for ingestion are usually prepared using the simple methods of (De Silva and Atal, op. cit.):

• extraction in hot or cold water;
• crushing an item to express the juice;
• powdering dried material;
• formulating powders into pastes using water, oil or honey;
• fermenting.

In preparing dosage forms, it is important to control quality and document traditional healers' standards (see Chapter 4).

Plants with medicinal properties can also provide raw materials for downstream processing operations in the pharmaceutical industry. Rawolfia serpentina and Strychnos nuxvomica are examples. The resin of Virola species in the nutmeg family is used in Colombia, Ecuador and Surinam to treat fungal infections for which modern allopathic medicine has no real cures (Shultes, 1992). Research suggests that Virola may provide the basis of an international anti-fungal ointment.

Vegetable oils

Many forest trees produce seeds that contain fatty oils; these can be processed into vegetable oils for use in cooking, food industry and soap-making, and also as fuel. Producing fixed oils is a simple process and can be done locally, with locally made equipment. In the first stage, the oil is extracted from the seeds by dry expression or by boiling the crushed raw material in water.

Vegetable oils also provide inputs to the more complex detergent industry, which uses fatty alcohol derivatives of lauric oils, which currently come mainly from palm kernels - primarily coconut (Cocos nucifera) and African oil palm (Elaeis guineensis), with smaller amounts from wild stands of babassu palm (Orbignya sp.) (De Silva and Atal, op. cit.).

Dyes and food colorants

As with many processed NWFPs, synthetic substitutes have restricted the use of natural dyes and colorants. Still, markets for certain natural food colorants have increased (De Silva and Atal, op. cit.). The annatto plant (Bixa orellana) produces a seed from which a reddish-orange food colorant, bixin, is derived. The international market for annatto has fluctuated widely in recent years but consumption in Japan, for example, has increased steadily (Iqbal, op. cit.). Native to tropical America, annatto is now also grown for export in Africa and Asia. It is important to know market quality standards: the international annatto market demands seeds with bixin contents of 2.7-3.5 percent, which disappointed many growers of varieties with lower bixin contents.

Tannins

Besides curing leather, tannins also go into dyes, inks, antioxidants, drugs and lubricants (including a viscous agent in oil drilling). Processing tannin extracts and powder from beans, nuts, fruits, galls, barks and stems is not complex, but it requires careful monitoring and control of conditions. Important tannin-producing tree species include: Terminalia chebula, Rhus sp., Cassia auriculata and Uncaria gambler in Asia; mangrove (Rhizophora mangle) in west Africa and Latin America; Schinopsis lorentzii and Caesalpinia spp. in Latin America and the Caribbean; and Acacia species worldwide.

Turpentine and other naval stores

Naval stores is the broad term covering pine oleoresins and their derivatives, such as turpentine. (The term comes from centuries when pine resin and pitch prevailed in ship building and repair.) Turpentine and rosin (a solid resin) are two constituent of pine oleoresins obtained by tapping of living pine trees. Producing gum naval stores requires plentiful labour (which comprises 50-80 percent of production costs); this particularly favours developing countries.

Carefully tapped trees can yield exudate for 15-20 years before being harvested for wood. In some developing countries, pine plantations and distillation facilities have been developed to produce gum rosin and turpentine. In one type of processing facility, pine resin is placed in a tank, where it is mixed with solvents and poured into decanters, after which it proceeds to an evaporator. The rosin is then packed in aluminum drums. The portion intended for turpentine is passed through a separator and on to a storage tank.

In most countries, these products are mostly for national markets, with about a third of all rosin going to international trade. If supply and stable prices can be ensured, natural rosin products appear safe from the threat of synthetic substitutes (Iqbal, op. cit.).

Complex processing: essential oils, waxes and other products

Essential oils
Waxes and other products

Essential oils, balsams, sweeteners, gums and waxes are all produced with more complex, capital-and technology-intensive processes.

Extraction processes for these products favour centralized, large-scale operations that use products from intermediate processing operations, as inputs. Because they remove operations further away from the household level and require full-time employment and specialized skills, such processing operations tend to disfavour women compared to the processes mentioned above.

Essential oils

Essential oils are volatile aromatic compounds located in many plant parts. They are used in many industries for adhesives, pharmaceuticals, cosmetics and toiletries, paints, paper and printing, insecticides, textile making, polishes, solvents, rubber and plastic products, and food and beverages (De Silva and Atal, op. cit.). The common method for extracting essential oils is steam distillation, although some, like citrus oils, are processed by cold expression. Steam distillation involves generating steam with a separate boiler and passing it through the plant material in order to carry off the volatile constituents.

Extraction with solvents or essential oils from flowers, or oleoresins from spices (for example, ginger, pepper and cardamon) requires an additional step of separation.

A plant's yield of essential oil depends on harvesting and post-harvest operations, including (De Silva and Atal, op. cit.):

• stage of harvesting (maturation, flowering stage);
• time of day when harvested;
• rate of drying;
• temperature of drying;
• moisture content after drying;
• storage conditions;
• storage time before processing.

The requirements are beyond the means of most rural enterprises, but in some developing countries the government operates processing centres to feed national industries (Table 6.1).

Table 6.1: Essential oils obtained from wild and cultivated forest species, in main producing countries

(Source: Iqbal, 1993)

For example, in Indonesia cayuput oil is extracted from the leaves of Melaleuca sp. (cayuput) for sale as a medicinal unguent, mainly within Indonesia. The State Forest Enterprise in Java (Perum Perhutani) manages 12 distillation centres for extracting the oil, and 9000 ha of Melaleuca plantations. In 1993, cayuput oil production was 279,800 kg, accounting for a considerable portion of the State Forest Enterprise's total income.

Farmers manage cayuput trees in agroforestry systems. Starting in the fourth year, the fanners coppice the trees, strip the leaves from branches and bag them for transport to a nearby facility. There the leaves are boiled and the leaf oil passes through separators. Waste leaves are used to fuel the boilers, and for organic matter. An eight-boiler cayuput distillation plant produces about 78000 litres of oil annually, from almost 9 thousand tons of cayuput leaf (FAO, 1995).

Waxes and other products

Natural waxes from forest sources are used in making candles, varnishes, pharmaceuticals and cosmetics. Some waxes are collected, melted and shaped into cakes. Others are obtained by solvent extraction. Natural waxes suffer from heavy competition with cheaper synthetic substitutes, but some of its specific properties help to maintain a demand. Processing of wax oils can be simple, but requires rigorous quality control.

Some plant residues can be used to produce market items. For example, in the Himalayan region of India pine needles under natural pine forests are collected, baled and processed as boards (De Silva and Atal, op. cit.).

Steps in processing

The steps involved in developing a processing operation are the following:

• Select non-wood product(s) for processing based on available resources, facilities and marketability.

• Start small-scale pilot production to test the feasibility of the process, product quality and market preferences. Gain a clear understanding of quality goals. For pilot-scale testing of medicinal and aromatic plants and spices, producers can use a transportable, small-scale plant, such as the polyvalent pilot plant designed by UNIDO (De Silva and Atal, op. cit.). This portable plant is intended as a tool for collaboration between researchers and producers (Figure 6.1). At this pilot stage, facility design should consider how to accommodate production of several products (for example, from plant parts produced in different seasons).

• Determine the cultivation, harvesting and/or post-harvest treatments best suited for the enterprise and to ensure sustainable supply (see Chapters 4 and 5).

• Make or purchase equipment and arrange for the space, utilities (water and energy) and human resources for production. Plan for storage and transport. This step often entails preliminary estimation of production volume and unit price, and arrangements to obtain credit for capital investments.

• arrange for training staff in processing methods and quality control. Establish measures for ensuring continual monitoring of these.

• start processing operations with technical assistance as needed. Continue to review estimates of production capacity, costs and product price.

Processing requirements can include steady supplies of water (for example, in steam distillation or cooling engines) and/or energy. Where running water is scarce, condensers can be air cooled instead. Where electricity is not available, alternatives may include fuelwood or other material; if so, the enterprise should promote fuelwood plantations early to supply its needs.

Quality standards

Processed products are frequently subject to national (and sometimes international) minimum standards for quality. Particularly for items intended for personal use or ingestion, such as soaps or medicines, these standards are important. They often cover processing operations and screening of raw materials (for example, to ensure good-quality genetic stock and post-harvest treatment that prevents contamination).

For products destined for international markets, the norms of the International Standards Organization (ISO) apply, usually the ISO 9000 series of specifications, which aim to ensure safety for workers, the environment and consumers. Compliance also has benefits for the processing enterprise: companies with ISO 9000 certification report that this has saved them money and yielded marketing benefits (De Silva and Atal, op. cit.).

Producers intending to sell to urban and national markets should consult government agencies and regulatory institutions concerning specifications, including limits on pollutants emitted by the processing facility.

The World Health Organization has prepared international guidelines for countries to evaluate quality, safety and effectiveness of long-term use of herbal medicines. The guidelines cover pharmaceutical assessment, crude plant material, plant preparations such as powders, extracts, tinctures and oils, descriptions of the finished product, testing of stability and safety in long-term use, toxicology, and assessment of efficacy. They also suggest criteria for product labelling and promotion (WHO, 1991).

New product development and research support

Research for identifying good processing options for non-wood resources can proceed in several ways. For aromatic and medicinal plant products, one way is the kind of collaboration mentioned earlier for trial distillation and chemical analysis. Other international agencies can similarly support research and collaborate with entrepreneur groups. Text box 5.1 illustrated examples of such support for studies on processing, export marketing, product quality and laboratory evaluation.

In South Asia, the Medicinal Plants Network established by the Canadian International Development Research Centre (IDRC) supports research and small-scale activities related to medicinal plants. The Network aims to document traditions in plant-based health care, protect and conserve medicinal plants (including cultivation), and share technology, standards, quality-control measures and studies on the impacts of medicinal plant trade (IDRC, 1994).

In many countries, consortiums of NGOs, universities and the private sector are evolving to bridge the information gap between forest-product research and producers. These consortiums can help evaluate new processing opportunities and disseminate valuable information on new technologies - those that rural enterprises can use and, equally important, those that may compete with them. Effective consortiums have grown up in Australia, the Philippines and Zimbabwe (see Chapter 9 and 10).

As regional centres of excellence emerge, they should further help to explore processing options for key species common to several countries, with reduced burdens to each country's scarce research resources (see Chapter 9)

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