Extraction of water-soluble polysaccharides (WSPS) from Chinese truffle and its application in frozen yogurt

WSPS from truffles are very valuable source which can be used in the areas of foods as natural functional ingredient. In this work, WSPS were extracted from Chinese truffle by RSM combined with single-factor screening, and applied into milk to make a frozen yogurt. Optimum conditions were: temperature 98.96-100 °C, time 4.94-5.37 h, particle size 155.91-164.77 mesh, water to truffle ratio 46.66-49.3:1 and pH value at 7.0. These optimum conditions yielded WSPS of 12.89-13.03%, which is well matched with the predictive yield. WSPS prepared contained 86.37% carbohydrates, 3.15% proteins, 7.54% moisture and 2.88% ash. WSPS consisted of glucose, mannose, galactose, and lyxopyranose. Based on the experiments of the addition, the presence of WSPS reduced significantly the syneresis, improved the viscosity and titratable acidity and contributed better flavour in the FYP yogurt in comparison to the FYC yogurt, which provided important insight in the potential commercialization of WSPS as a functional component of yogurt.