Development of yogurt fortified with four varieties of common bean (Phaseolus vulgaris) whey by using response surface methodology: a preliminary study.

In recent years, there has been a growing interest in developing novel foods with improved health and nutritional characteristics, particularly through the supplementation and development of dairy products with plant-based ingredients. In this study, the response surface methodology (RSM) was employed to optimize the ingredient formulation and processing parameters of common bean whey-fortified yogurt (CBWFY) production containing Lactobacillus bulgaricus, and common bean whey (CBW) with a high probiotic count, superior physicochemical and textural properties, and desirable sensory attributes. The experiments were planned using the "box-Behnken design" (BBD) with three independent variables: fermentation time (0-10 h), common bean ratio (25-100%), and the amount of starter culture (1-5%). To assess the physicochemical properties of the yogurt, such as pH, titratable acidity, viable cell count, and syneresis of the CBWFY, they were determined and optimized. In all the common bean whey samples, the optimum conditions were obtained by supplementing cow milk with 25% common bean whey (CBW), an inoculation ratio of 1-4%, and fermentation for 5.54 h. Fermentation time and CBW concentration significantly affected the viability of L. bulgaricus and the physicochemical attributes of yogurt. This study demonstrated that the addition of cow milk with 25% CBW from the white bean variety produced probiotic yogurt with the highest L. bulgaricus population (up to 8.55 log CFU/mL) compared to the other varieties and an enhancement in the yogurt's pH and acidity, while a decrease in yogurt syneresis occurred. In general, the results of the current study showed that adding up to 25% white common bean whey to probiotic yogurt can be an option for producing yogurt with potential functional and sensory quality. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-023-05876-z.