Agroindustrial project analysi

Table A-1. Comparison of Selected Dryers(costs in U.S. dollars)Mode and scaleDryer of operation 1977 capital cost' 1977 operating costb CommentSun Batch operation for Negligible (for High labor requirement Loss of products from adverse changessmall- to large-scale racks, trays, and but free energy; no in weather during drying season canproduction of dried the like) maintenance problems be substantial; not suited to areas withfruits, fish, and othercool or humid climate (or both); morepiece-form foods destructive to provitamin A carotenes,vitamin C, and (possibly) riboflavinthan mechanical dehydration; addingsulfite to fruits and vegetables to pre-Na vent browning causes large losses ofthiamin but is beneficial to provitaminA and vitamin C retention; long dryingtime contributes to nutrient losses;products (such as dried fruits) havespecial accepted organoleptic characteristicsdifficult to reproduce in mechanicaldryingCabinet Batch operation for $13,000 for 3¾ High labor requirement Long drying time because of slow resmall-scaleproduction ton, $24,000 for for loading/unloading; moval of water (0.2 pounds hourly per(1-20 metric tons daily) 3 tons, $45,000 labor cost is 55-75 per- square foot) contributes to high lossesof such foods as dried for 6 tons daily cent of total operating of nutrients and lower organolepticvegetables, fruits, meat cost; relatively low main- quality; long drying time and relaproducts,egg whites; tenance cost (simple op- tively low drying temperature some-