Study on The Ability of Selected Plant - Derived Stabilizers for Manufacturing Set Yoghurt

Abstract

An experiment was conducted to find out the suitability of selected plant-derived stabilizers for manufacturing set yoghurt. Three plant-derived stabilizers such as GumArabic, Pectin and Agar- Agar were selected after the preliminary study of each stabilizer. Six different concentrations of stabilizers such as 0.025%, 0.05%, 0.075%, 0.1%, 0.125% and 0.15% were used to prepare set yoghurt during the preliminary study and among which three suitable concentrations were selected by means of expert tasting panel for the organoleptic characteristics such as appearance, colour, taste, mouth feel, texture and overall acceptability. These three selected concentrations of each stabilizer were subjected for further sensory evaluation to select the most appropriate concentration for the yoghurt preparation. Among the three different concentrations of each stabilizer, 0.05% of Agar-Agar, 0.1% of Pectin and 0.075% of GumArabic were selected as the best concentration for the preparation of set yoghurt. The selected concentration from each stabilizer was compared with a control treatment prepared using 0.1% Gelatin stabilizer. The results of sensory evaluation were analyzed using Friedman’s test in Minitab statistical package. Yoghurt prepared using 0.05% of Agar-Agar was rated as the most suitable stabilizer in relation to all organoleptic characteristics for the preparation of set yoghurt compared to others. The shelf life of set yoghurts were tested by measuring the pH of yoghurts prepared using above selected stabilizers including the control treatment at two days interval, which were stored at 14 ± 10C.Asignificant decrease in pH with subsequent increase in acidity was observed during the storage period. The results revealed that the Agar-Agar could be incorporated at a concentration of 0.05% to prepare set yoghurt with a substantial storage life of 16 days at 14±10C without deterioration of quality