Cover Image
close this book FOOD CHAIN No. 1 - November 1990
View the document GREETINGS
View the document Cassava: processing a neglected root
View the document News Lines
View the document Making sweetmeats using soy
View the document Fish smoking: testing technologies
View the document A question OF FOOD
View the document Marketing snack foods in Asia
View the document BOOK LINES
View the document Small-scale equipment
View the document How to make Murukku
View the document Acknowledgments

A question OF FOOD

The following are a selection of the many technical enquiries about food that we receive at IT.

If you have any technical enquiries, please write to the Technical Enquiry Unit at IT. Enquiries of general interest will be published on this page in each issue of Food Chain.


Tomatoes grow all year but are very expensive (3 tomatoes for 50 db) for most of the year. In August and September they grow very quickly and the price falls (10 tomatoes for 50 db) at which point many remain unsold or untransported to market and are discarded. The Ministry is very interested in techniques to process the surplus for example tomato puree, sauce, soup powder, pickle etc. Because of the difficulty in transportation, small rural processing of the surplus may be possible. I would be interested in any specific ideas on tomato products but also in the wider aspects of setting up this type of business.

Mr A, Sao Tome and Principe

A number of products could be made locally. However, jams and sauces etc will require some form of packaging, preferably glass, and I would guess that given your geographical location, glass containers are likely to be unavailable or very expensive. Even if available from a market as second -hand containers they may still be prohibitively expensive. Tomato fruit leathers and/or dried and salted tomato balls may be your best alternative and reduce the packaging constraints.

I would suggest that the way to proceed is to ensure that you have a product acceptable to your local rural market, by doing some small-scale production runs and test marketing the products locally.


I am a volunteer who has recently become involved with a village where we are looking into the possibility of manufacturing soap on a small scale. We are trying to use local materials where possible, but we understand that one method calls for the use of tallow, which is unavailable on the Nevis. Is there any way we could produce tallow?

Ms C, Nevis, West Indies

Tallows are made from rendered animal fats, so unless you have a supply of animals for example pigs, sheep etc ora local slaughterhouse, you will either have to import tallow or dispense with it. Tallows are not essential for manufacturing soap, though their inclusion assists in producing a hard soap with good lathering properties. You could consider using coconut oil as a raw material, although this will produce rather a soft soap. However, you could use it in conjunction with tallow to offset import costs; this would produce an acceptable hard soap.


We are aware that unripe papaya produces a milk-like substance when cut which becomes a valuable commodity when it solidifies containing enzymes used in the manufacture of both medicines and beer.

We would like to know where one starts in actually producing papain (the enzyme).

Mr L, London

There is a book called 'A simple method of collecting and drying papaya (pawpaw) latex to produce crude papain.' available from the Natural Resources Institute, Chatham Maritime, Central Avenue, Chatham, Kent. ME4 4TB, England.

IT tried to set up a papain project but was unsuccessful. The trade in crude papain used to be quite extensive, but has decreased due to a better quality purified papain extract being produced in Sri Lanka and India; additionally the UK and European market has contracted due to EEC legislation restricting the use of enzymes in beer making.

There are additionally problems in collection and handling, particularly at a rural level. Exposure to crude papain causes a burnig sensation and medical treatment is necessary should it come into contact with eyes, mouth etc. Frequent exposure can lead to longer term allergic responses. To produce papain extract on a commercial scale would require around 100, 000 trees due to the small yields obtained per tree. This amount of trees in a non-estate situation would obviously be spread over a very large area, making collection difficult and costly. I would not be too optimistic about the prospects of succeeding with papain production.