DRYING OF MEAT MATERIALS (LEAN AND FAT) BY DEEP-FAT FRYING IN ANIMAL FAT

Deep-fat frying, mainly used for cooking purposes, can also be used fo r drying meat materials prior to pressing for fat extraction and meal production purposes. It is a key stage in the production process, enab ling the water content of the material to be reduced from 80% to 4% we t basis (wb). The present study assesses the changes occurring in core temperature and mass (water and fat) transfer during the deep-fat fry ing of meat materials: lean stewing beef, beef tripes, pork loin, chic ken feet and pork belly (initial water content 56 to 80% wb). In each case the material was cut into parallelepipeds (characteristic length 0.0035 to 0.005 m) and fried in animal fat at either 130 degrees C or 150 degrees C for a period of 4 to 90 min. The frying time to reach th e required residual water content of 8% wb for animal meal production (denoted t(8%)) ranged from 17 to 90 min according to frying temperatu re and material. Increasing the oil bath temperature from 130 to 150 d egrees C reduced frying time by a factor of at least 2.3. Core tempera ture variations followed the typical periods described by the theory o f boiling phenomena during high temperature drying.