Cashew, in addition to the well known nut, also bears a false fruit or cashew apple which is usually discarded when the nuts are processed because of its bitter and unpleasant taste. It was suggested to Pueblo a Pueblo (a small non-profit NGO in Honduras) that the fruit might form the basis of a by-product which could provide additional income and create work, particularly for the women in the community. Ideas discussed included jams, wines, vinegars and semi-crystallized, dried fruit. At about the same time, by good luck, Dr Rodney Cooke of the Tropical Products Institute was investigating cashew fruit utilization in Costa Rica, where there was a tradition of drying the fruit with sugar.
The astringent, bitter flavor cat the final product however, made it unacceptable to many people. In 1982, Dr Cooke found a way of countering the bitterness by adding caustic soda and sugar before drying the fruit and this information was transmitted to Pueblo a Pueblo. Trials were carried out which proved encouraging.
Cashew Fruit Caramel
The process is simple and involves immersing the fruit in 1% sodium hydroxide (caustic soda) for three minutes, before thoroughly rinsing it in clean water. This treatment affects the waxy surface layer which produces the fruit’s bitter taste. (Recent communications with the producers in Honduras have revealed that the caustic soda treatment has been discontinued and the final product is still popular with the consumers.)
The fruit is then pressed between two boards to a thickness of approximately 1.5 cm. This removes much of the moisture as a juice and also makes small holes in the skin which allows quicker penetration of the sugar syrup used in later stages of the process. The squashed fruit is then simmered in a strong hot sugar syrup (75lb sugar per 1000 pieces of fruit with enough water to cover) for two hours. (The syrup can only be used a limited number of times and is financially a key raw material. Any alternative use of the syrups, for example in the production of wine, vinegar or sweets, could markedly improve the overall profitability of the enterprise.)
Finally, the fruit is removed from the syrup with tongs, placed on mesh trays and dried in small Brace-type solar driers (8ft x 4ft). After two to three days drying, the fruit is removed with tongs to avoid handling, and packaged in heat sealed cellophane bags of average net weight 4oz.
Solar drying improves on open-air drying by protecting the products from rain, insects, other animals and dust which may contain fecal material. Faster drying reduces the likelihood of mold growth, and higher drying temperatures mean that more complete drying is possible which may allow much longer storage times.
The more valuable the crop to be dried, the higher the financial risks involved if the producer has to accept spoilage rates from open-air drying, and the more often the solar drier would be used.
Initially, the solar driers were not well liked by the women at Pueblo a Pueblo; the polythene darkened with the sunlight and was easily damaged. Intermediate Technology assisted by providing a sample of an ultra violet sunlight resistant film (ICI Melinex) which proved most acceptable, being strong and long-lasting.
The NGO purchased 100m of this film which lasted six years. A solar roof inclination of 9° was used, later increased to 15° to improve efficiency.
In 1986, 40 women were involved in the production of cashew fruit caramel. Each team of 10 women could produce 800 dry fruits per day. The women were earning 2 US$ per day, which was more than the average man’s earnings. The market in the USA was paying $2 per pound and was buying 5,000 lb each year.
By 1990, the size of the group had increased to between 60 and 70, and 40 solar driers were in use. Sales to the USA had reached 9,000 lb per year and Pueblo a Pueblo expect to increase the size of the project for the 1991 season to meet growing demand. A total of five more women’s groups with 50 members is planned.
It is clear that this is an example of a viable, sustainable income-generating project. It is also one of the very few examples of the successful commercial application of small solar driers.
source: www.practicalaction.org, photo from salvaide.ca