Processing of Horticultural Crops in the Tropics

Abstract

Horticultural crops such as fruits and vegetables are very important in human nutrition because when consumed in adequate amounts, they are an important source of vitamins, mineral nutrients and fibre. Processing of fruits and vegetables is very important in the tropics where most of the developing countries like Zimbabwe are located. The magnitude of postharvest losses of fresh fruits and vegetables is estimated to be 5 to 25% in developed countries and 20 to 50% in developing countries depending upon commodity (Kader, 1992). For Zimbabwe’s rural poor, smallholder horticultural production provides extra income when the produce is marketed locally or transported, packed, processed and marketed in distant places, including highly populated local urban areas and internationally. Employment creation, reduction of postharvest losses and enhancing of household food security are also some of the reasons why small holder farmers process their crops. Most fruits and vegetables are highly perishable commodities and if they are not processed they quickly deteriorate due to spoilage and microbial attack. In Zimbabwe, postharvest losses of fruits and vegetables were studied by Masanganise (1994), who estimated the losses to range between 35% and 45% for the small-scale producers. The extent of postharvest losses depends on several factors, such as (i) perishability of the commodity, (ii) environmental factors, (iii) interval between harvest and consumption and (iv) postharvest handling, storage and processing practices. The most widely practised method of fruit and vegetable processing in the smallholder areas is direct sun drying or boiling followed by sun drying especially for vegetables. The problem with this method is that drying conditions may not be clean and considerable quantities of nutrients are lost (Tembo, 1996). Fruits and vegetables can also be processed into high value products like juice, wine, puree, jam and jelly. Processing of fruits and vegetables grown by smallholder farmers has great potential in the tropics. A considerable amount of information already exists on small scale processing of horticultural crops (Richter et al., 1996), however, this would have to be complemented by medium to large scale processing plants located at