UTILIZATION OF POULTRIES FEATHERS IN FOOD AND FEED: 5-NUTRITIONAL VALUE AND PHYSICAL PROPERTIES OF BEEFBURGERS PREPARED WITH DIFFERENT LEVELS OF CHICKEN FEATHERS PROTEIN ISOLATE.

Chicken feathers protein isolate ( F.P.I.) prepared by KOH hydroly­sis and precipitation at isoelectric point by orthophosphoric acid was used to replace 0, 10, 15, 20 and 25% of beef in beefburgers after it was F.P.I. diluted with water at 1:2 ratio. Protein was somewhat in­creased in fried burgers with increasing of diluted F.P.I. level. Up to 20% F. P. I. no deficiency in essential amino acids (EAA) was observed in fried products , but at 25% F. P. I. level as indicated by amino acid (A.S.) , very slight deficiency (2%) was found for threonine. The decrease in cal­culated essential amino acid index (EAAI), biological value ( B.11.) and protein efficiency ratio (PER) was not noticed as the level of F.P.I. in­creased in fried burgers. Grams consumed to cover the protein daily re­quirments of adult man (GDR) decreased, while GDR values for methio­nine (showed the highest GDR value, for EAA) increased. When consuming 1509m of fried 25 F.P.I. burgers, the protein and methionine daily requirements of adult man will be covered at the levels of 76% and 70%, respectively, whic is quite high (more than one half the daily re­quirements in one meal). As the percent of F. P. I. increased, water hold­ing capacity (WHC) and cooking yield improved , while cooking loss de­creased. Tenderness as indicated from PWFC value (protein- water fat coefficient and plasticity) somewhat decreased. At 25% F. P. I. level, aroma,taste , colour and overall acceptability scores were markedly high (rated very good, 8-9 scores), but due to some decrease in texture (rated good, 7 scores) it is enough to replace 20% of beef with equal proportion of diluted F.P.I.