PHYSICOCHEMICAL AND ORGANOLEPTIC CHARACTERISTICS OF GREEK-TYPE YOGHURT DIFFERENTLY FORMULATED

Abstract

The demand for high protein and low carbohydrate (sugar) diet has resulted into development of Greek-type yoghurt, which is reported to have an improved nutrient profile, texture and an extended shelf-life. Therefore, this study evaluated the physicochemical and organoleptic properties of Greek-type yoghurt differently formulated. Greek-type yoghurt was prepared from 45 litters of fresh milk, divided into three batches to differently formulate: TN (fortified with gelatine), ST (traditionally strained) and TS (increased total solid). The organoleptic, physicochemical and microbial populations of Greek yoghurt produced commercially (A, B and C) and in the laboratory (TN, ST and TS) were evaluated using the standard procedure on day 0, 14 and 28 in a completely randomized design. Data were subjected to ANOVA at α = 0.05. The results show that there was no significant (P > 0.05) difference in the TBC of the three commercially available Greek-type yoghurts (A, B, C); product A contained high fungi (0.4 × 105) with no coliform recorded in the three products (A, B, C). Formulated samples revealed TN as a sample with highest number of microbes, while ST had the lowest. As the storage days progressed, microbial count increased; the highest microbial load was recorded on day 28. ST was significantly higher in CP, pH, WHC, fat, total solid and has the lowest value in lactose, syneresis and TTA, while TN was significantly (P < 0.05) higher in syneresis and TTA. No significant difference (P > 0.05) was observed in the CP of Greek-type yoghurt as the storage days increased; fat, total solid, pH and WHC declined with storage days, while TTA and syneresis increased with storage days. Significant changes in storage were observed during the early days (0 − 13) with no significant changes on latter days (14 − 28). The yoghurt was accepted and rated by the consumer in this sequence: TS>ST>TN.