After the interdiction of using animal flours, important amounts of slaughterhouse by-products increased the waste quantity from meat processing technology, concomitant with a steady demand in pet foods. The aim of this work is to prove that some by-products from meat processing, considered right now as wastes, can became a valuable source of proteins, usable for functional or nutritional ingredients. Two types of by products have been used: pork lungs and poultry hearts. Based on their proteomic maps, the extraction pH has been determined. The extraction yield, as a function of temperature, time, solid:liquid ratio, solution ionic strength and pH, has been studied. For concentrating the protein solutions, membrane processes such as ultrafiltration and microfiltration have been used. The functional properties of the concentrates, gelation, foaming and emulsioning capacity have been compared to those of some commercial products. The results showed that proteic concentrates derived from pork lungs or poultry hearts are good foaming agents.
