WHY PRESERVE FOODS BY DRYING?
Nowadays many foods are dried not solely for food security, but for commercial reasons, and this change has far reaching implications. The most important is that in many cases the foods to be processed are not selected for being in balance with the local ecology and climate, but for their market potential. This means, for example, that fruits which grow well in a humid tropical area have to be dried under conditions in which traditional sun drying simply will not work. Therefore new technologies have to be developed to make the drying process more independent of local climates, in other words -artificial dryers are needed. Other considerations of commercial dehydration are profitability, buyers’ demands for quality, and packaging for a long shelf life. When drying foods commercially the most important consideration is the value added (per unit weight) by processing which must be sufficient to cover all the costs involved. These include: · losses of rejected material · labour · fuel · d