PRODUCTION OF PROBIOTIC YOGHURT FORTIFIED WITH DATE SEEDS (phoenix dactylifera L.) POWDER AS PREBIOTIC AND NATURAL STABILIZER

Abstract

The present study aimed to evaluate the use of date seeds powder (DSP) as a natural prebiotic stabilizer in the manufacture of set yoghurt and their effect on some physicochemical, microbiological, rheological and sensory properties of this yoghurt during storage period at 4±1°C. Probiotic set yoghurt was produced using common yoghurt starter culture and probiotic starter culture ABT-2. Titratable acidity showed a slight decrease as a result of increasing the percentage of DSP level. It was found that the water holding capacity of yoghurt samples ranged from 62.17% to 79.43% during storage period. The addition of DSP to probiotic set yoghurt stimulated the growth of probiotic bacteria. The total viable counts of (S. thermophilus ST-20Y, L. acidophilus LA-5 and B. bifidum BB-12) decreased slightly during the refrigerated storage, but remained at sufficient levels (>6 log cfu/g) for up to 14 days. The coliform and mould & yeast counts were not detected in all samples. The use of DSP as a prebiotic and natural stabilizer at concentration of 0.5% in probiotic set yoghurt manufacture improved their sensory and rheological properties.