Aqueous washing of mechanically deboned chicken meat: effect on chemical and functional characteristics

Abstract

Mechanically deboned chicken meat (MDCM) was prepared from backs and necks of freshly slaughtered birds. Samples were then subjected to aqueous washings at various pH conditions using water, 0.5% NaCl or NaHCO ₃. Approximately 73.9% of the total hemoprotein pigments and 52.1% of total lipids were removed by washing with a sodium bicarbonate solution which resulted also in the best colour improvement in the products. Extraction of these components with water and NaCl solution was less effective. The yield of proteins ranged from 58.1% after one washing with water to 41.7% after washing with water and then with a sodium bicarbonate solution. The amino acid content and protein efficiency ratio (PER) values of washed meats, calculated by an amino acid scoring methodology, were comparable to those of unwashed MDCM. -- The concentration of flavour precursors, namely free amino acids and inosine 5'-monophosphate was decreased by over 50% in the washed samples. Similarly, the content of nucleic acids and cholesterol in the corresponding washed samples was reduced by 60.5 and 42.3%, respectively. A slight increase in the content of polyunsaturated fatty acids of phospholipids and content of phospholipids was also noted in the washed MDCM. The cook yield of washed MDCM was enhanced, while a decrease in sulphydryl groups and a proportionate increase in disulphide bonds due to washing was noted. The oxidative stability of washed raw products was less than their unwashed counterpart, however, the cooked washed meats were more resistant to lipid oxidation than the unwashed sample during a 2-week storage at 4°C.