EFFECT OF FORTIFICATION WITH WHEY PROTEIN ON THE CHEMICAL, MICROBIAL AND ORGANOLEPTICAL PROPERTIES OF LABNEH

Abstract

The aim of this study was to investigate the effects of incorporation of acid whey proteins (AWP) locally produced in Egypt on the chemical, microbial and organoleptical properties of Labneh made from goat's milk using ABT-5 culture. Five concentrations of AWP (5, 10, 15, 20 and 25%) were added to Labneh paste and well mixed. Labneh was stored for 21 days at 5°C and samples were taken and analysed at 7 days intervals. The addition of AWP increased values of titratable acidity, redox potential, ash, salt, total protein, water soluble nitrogen, non-protein-nitrogen, total phenol contents and total volatile fatty acids. On contrary, pH, total solids, fat and carbohydrate contents slightly decreased. Labneh contained AWP had higher numbers of L. acidophilus, S. thermophilus and B. bifidum. Scores of sensory evaluation of Labneh contained 5, 10 and 15% AWP were similar to those of control whereas sensory ratings and acceptability of Labneh decreased significantly when increasing AWP to 20 and 25%. Addition of AWP reduced production cost of Labneh. Thus, numerous nutritional and economic benefits can be gained by fortifying Labneh with 5, 10 and 15% AWP.