QUALITY ASSESSMENT OF YOGURT ENRICHED WITH OAT AND CHICKPEA POWDERS AS SOURCE OF DIETARY FIBERS

Abstract

The aim of this study was to evaluate the effect of addition of oat and chickpea powders on the rheological, physicochemical and sensory characteristics of yogurt. Yogurt was fortified with oat and chickpea powders at ratios of 1, 2 and 3% of each. Yogurt was stored at 5 ±2˚C and analyzed when fresh and after 5, 10 and 15 days of storage. Results showed that:Control yogurt had the lowest total solids (TS), fat, protein,ash and fibers contents compared with fortified yogurt treatments. The TS, fat ,protein, ash and fibers contents of yogurt containing oat and chickpea powders at different concentrations increased gradually by increasing the percentage added, Addition of oat and chickpea powders at different concentrations increased the pH in yogurt. Whereas, titratable acidity decreased with increased fortification ratio. Fortification of yogurt with oat and chickpea powders at different concentrations significantly decreased whey syneresis and increased viscosity compared with control yogurt and this increasing was proportional to the fortification ratio. Addition of oat and chickpea powders at different concentrations significantly increased phenolic contents and antioxidant activity of yogurt treatments and these increments were proportional to the fortification ratio. Yogurt treatments fortified with oat and chickpea powders at different concentrations had the lowest counts of total bacteria, yeast and moulds,Streptococcus salivarius subsp.thermophilus andLactobacillus delbruekii subsp. bulgaricuscounts. Total bacteria, yeast and moulds,Streptococcus salivarius subsp. thermophilus and Lactobacillus delbruekii subsp. bulgaricuscounts decreased with increasing the fortification ratio.Control yogurt had the lowest sensory evaluations values. Addition of oat and chickpea powders improved the organoleptic properties of fortified yogurt; the highest mean value was related to sample containing 3% oat powder.