Development, characterization, and stability of a functional beverage from whey

Abstract

Functional foods have become an important part of human diet, due to the contribution of these foods for health improving; being those products added with probiotics an example of functional foods. Whey is a by-product of cheese production considered as a waste, despite its protein content and nutritive value, whereas inulin has been recently used in food industry by adding it to foods in combination with certain probiotics, it is found naturally in the agave as part of dietary fiber. Then the objective of this research was to obtain a functional whey drink added with inulin and probiotic microorganisms. Therefore, different formulations of this beverage were obtained varying the content of inulin (0, 2, 4, 6 and 8% w/w) and the type of microorganism (Lactobacillus casei, L. plantarum and L. reuteri). Some properties and viability of microorganisms in the different systems were evaluated during 30 days of refrigerated storage, in which the physicochemical properties, flow parameters, and microbial stability were determined. Results showed that pH and acidity varied among different systems; pH values of whey beverages ranged between 4.75 and 6.18, decreasing with increasing of inulin content; in which there was a significant difference for initial pH. Acidity values ranged from 1.743 to 1.987 g/L, and also exhibiting significant difference. Soluble solids and moisture of beverages were stable through the storage period in contrast to acidity, color, pH, and flow properties. Whey beverages behaved as non-Newtonian fluids of pseudoplastic nature, better fitted by the Power Law equation, in which consistency increased with inulin content. All systems had the minimal level of BAL (lactic acid bacteria), and their growth was related to inulin content.