Application of yam bean syrup in drinking yogurt product

Abstract

The objectives of this research were to prepare the syrup from the extracted yam bean and apply this syrup for adjusting the sweetness in the orange flavor drinking yogurt. The study made a yam bean extract concentrated by 3 difference heating methods; steaming, boiling and boiled-evaporating. The results showed that a proper method was boiling yam bean, extracted at a temperature of 90°C for one hour. The syrup was light brown color and not very strong smell of yam bean, the total soluble solid was 20 °Brix and the non-reducing sugar content was 17.80 %. The drinking yogurt which was formulated using a ratio of set yogurt: orange juice (100%): yam bean syrup at 1:1:1 had the sensory properties (9-Point Hedonic Scale) higher than the ratio of 1:1:0.5 and 1:1:1.5 (p≤0.05). This drinking yogurt had a pH at 4.2, the total soluble solid was 15 °Brix, protein was 1.75 %, fat was 2.1% and non-reducing sugar content was 5.39 %. The microbiological properties passed quality standards (drinking yogurt) of Notification of the Ministry of Public Health No. 353 B.E 2556. The study of consumer acceptance on the drinking yoghurt with yam bean syrup showed that consumers had a preference for the product at like - most like level at 72 %, acceptance on the product at 97 % and would buy this product at 76 %.