Comparison and Evaluation of Functional Properties, Amino Acid Profiles and Chemical Index of Hydrolyzed Proteins Produced from Different Sources of Waste (Fish, Chicken and Shrimp) by Enzymatic Method

One of the things that determines the type and limit of efficiency of hydrolyzed proteins in the food industry (humans and livestock, poultry and aquatic animals) is the degree of desirability of functional properties and the type and composition of amino acids. The aim of the present study was to produce hydrolyzed protein from three sources including fish (FPH), poultry (PPH) and shrimp (SPH) waste in the first stage and to compare the functional properties, amino acid profiles and chemical index of these three types of proteins in the second stage. The results showed that among these three types of proteins, the highest solubility (94.26±1.18%), emulsion stability index (115.42±2.24 min), foaming capacity (182.61±3.15) and foam stability (134.75±1.46%) and water holding capacity (4.87±0.2 ml/g) were significantly related to SPH (p<0.05). In addition, no significant difference was recorded between SPH and FPH in terms of emulsifying activity index and oil absorption capacity (p>0.05). It was further found that the emulsion stability index in PPH and FPH are almost the same (p>0.05). The ratio of essential amino acids to total amino acids in SPH, PPH and FPH are 0.54, 0.55 and 0.52, respectively, and the ratio of flavorful amino acids to total amino acids in these proteins is 0.35, 0.34 and 0.41 was reported. Comparing the amino acids of these proteins with the needs of carp, it was found that the amino acids methionine and phenylalanine are limiter in all three proteins (chemical index<1). From among the three proteins produced, only SPH was fully able to meet human needs, and the chemical index of all its amino acids for humans was reported to be higher than one.