UTILIZATION OF WASTE FEATHERS FROM POULTRY SLAUGHTER FOR PRODUCTION OF A PROTEIN-CONCENTRATE

A combined enzyme-alkaline technology for processing waste feathers from poultry slaughterhouses was elaborated. The enzyme, alkaline proteinase, is produced on a large scale and is used in the food industry. Full solubilisation of feathers was achieved after pretreatment with 0.3 M NaOH solution at 80-degrees-C, mechanical disintegration and enzyme hydrolysis at 55-60-degrees-C. After spray-drying the end-product was a heavy, greyish powder with a protein content of 795 g kg-1 and with a not unpleasant smell. The high protein content defines the product as a 'protein concentrate'. Amino acid content proved it of high biological value. The preparation method could lead to the possibility of application in a large-scale production.