Influence of Incorporation of Different Dried Dairy Ingredients and Inulin on the Physicochemical Properties of Non-fat Set Yoghurt

Abstract

This study was carried out to investigate the possibility of manufacturing non-fat set yogurt with acceptable quality from reconstituted skim milk powder (SMP) 10% T.S, enriched by adding one of the four dried dairy ingredients namely; skim milk powder, milk protein concentrate (MPC), whey protein concentrate (WPC) or sodium caseinate (NaCn) to achieve a concentrations of 1.5, 3.0, and 4.5%, respectively in the final mixes. A control sample was prepared without any additives. The other twelve mixes were fortified with % 1 (wt/wt) Inulin. Physiochemical properties of yoghurts were evaluated during cold storage for 14 d. The results showed that increasing the added ratios of different dried dairy ingredients and inulin led to the increase in total solids, protein, soluble nitrogen, acidity, and ash content, whereas the fat percentage did not affect. Enrichment of non-fat yoghurt with different dried dairy ingredients and inulin caused a decrease in the pH values. There was a negative correlation between syneresis and the added percentage of dried dairy ingredients and inulin. During storage, the total solids content, protein, soluble nitrogen, fat, ash, acidity and syneresis were increased in contrast with pH level. This study suggests that the using mixes of the different dried dairy ingredients in appropriate ratios along with inulin seems as a useful and interesting approach for manufacture of non-fat set yogurt.