Optimization of Low Fat Probiotic Yogurt Production Using Combined Design

Heart disease - cardiovascular، cancer and obesity are the main causes of death and there are direct relationship between the consumption of high-fat foods and the incidence of these diseases. Therefore the demand for low-fat food products and probiotics has been dramatically increased. In this study، the effect of different levels of three hydrocolloids (inulin، chitosan and xanthan) at three levels (1، 2 and 3%) on survival of Lactobacillus acidophilus، physicochemical and sensory properties of yogurt during 15 days of storage was explored using a combined design. Increased levels of inulin and chitosan positively affected La-5 count، apparent viscosity، acidity and sensory scores during storage. Using graphical method of optimizing (overlaid contour plots)، optimum ratios were: inulin 93. 4%، xanthan 0. 6% and chitosan 6%.