Optimization of Process-Control, Size Reduction and Thermal Treatment of Animal By-Products

Abstract

Animal by-products (ABP) from slaughterhouses go through a process known as rendering to economically recover the protein sources. Common raw material treatment technologies include reduction of the size of raw material particles and thermal treatment with pressure or sub-pressure impact. Often the thermal treatment is a long-term process that lasts up to 120 minutes – and is the primary disadvantage of known solutions because hot processing influences the natural properties of proteins contained in the raw materials rendering them less valuable. To maximize the efficiency of heat treatment and fractionation operations on ABP it is necessary to optimally design the technological processes to fit within the specific requirements of the particular heat treatment application. The size reduction was performed in four stages in the present study and the fineness of material reached was 0.01…10 mm depending on the type of crushing. The treatment time which ensures the full penetration of heat into the meat-bone material was determined for fine grinded material 15…20 seconds, for small grinded material 0,5…2 minutes, for medium grinded material 5…10 minutes and for coarse grinded material up to one hour. The information gained from the study will enable more accurate determination of heating times corresponding to the processed material properties.