Aim of this work was to investigate the influence of pretreatment on drying rates of chili pepper (Capsicum annum\r\nL.) at various air temperatures and pretreatment methods. Chilies were pretreated mechanically, chemically as well as by a\r\ncombined form before drying. The changes of moisture content were determined experimentally at temperatures of 35, 50, 60,\r\n70, and 90?? for pretreated and untreated red chilies. The total drying time required for each case was evaluated based on the\r\nacceptable value of moisture content (dry basis) for safe storage of vegetables and fruits obtained from literature. In this work,\r\na moisture content of 0.10 (kg water /kg dry chili) was taken as the final moisture content to determine the final drying time.\r\nThe results of this experiment showed that much shorter drying times were achieved with the application of pretreatments.\r\nIncreasing the drying air temperature from 35 to 50?? shortened the final drying time by 140 h, which is 72% reduction of the\r\noriginal drying time. The shortest drying time at lower as well as higher temperatures was achieved by making a number of\r\nsmall holes on the skin of chilies (mechanical pretreatment method). In this case, at a temperature of 60?? the final drying\r\ntime was shortened by 48% compared to the untreated method which was at the same temperature and in the same drying\r\nconditions.
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