Preserving harvested foods

Post-harvest practices include: in temperate countries, grains can be well conserved when harvested and stocked in conditions which allow air circulation (in jute sacs, ventilated silos, etc.).

In tropical countries, humidity and high temperatures pose problems which can be overcome through: harvesting at complete maturity and during dry weather; storing without stripping off the bark; drying of grains under the sun before storing; mixing sand, china-clay, or wood ash to grains; adding little quantities of nut oil to niebe grains (very effective on weevil); addition of smoke or certain plants to repel insects; etc.

In ancient Europe and the Mediterranean basin, grains were stored in buried pits for several years: the anaerobic conditions of these pits prevented insect proliferation and the grains underwent an initial fermentation which protected it from insects and mouldiness, despite the high degree of humidity.

Traditional procedures allow conservation and enhancement of the nutritional value of cereals and leguminous, such as: fomenting rice (rice is bathed, steamed and dried) destroys insect eggs; transforming wheat in bourghoul (wheat is germinated, boiled, dried and crushed) enriches the cereal with vitamins and essential amino-acids (lysine) and pre-digest starch; fermenting certain leguminous (for example, soy in the Far East and nere in Africa) gives high nutritional quality products which can be conserved for years; fermented fish sauce (nuoc-nam) allows simple fish conservation and offers an alternative to fish drying, especially that the latter entails inevitable losses in tropical conditions.