Development of a dehydrated and laminated probiotic product with B. infantis and L. acidophilus using goat sweet whey

摘要

Whey is a by-product remainder from cheese manufacture that causes serious environmental problems when it is incorrectly disposed of, although it has high potential to be transformed into a surplus good, such as probiotic products. The objective of this work was to develop a dehydrated and laminated probiotic product (DLP) using goat’s sweet whey (GSW) and two strains of probiotic bacteria (B. infantis and L. acidophilus). A process and a formulation were developed to achieve a product with a probiotic bacteria concentration of at least of 10~7CFU/g. The process to obtain the DLP consisted of five stages: (1) fermentation of GSW with B. infantis or L. acidophilus; (2) formulation of the fermented GSW with inulin, resistant starch (RS), and gelatin; (3) pouring out the formulation on a nonstick surface; (4) drying it in a convection oven; and (5) dehydrating it in a dessicator at 0% relative humidity (RH). The formulation was determined through a factorial experiment where nine judges evaluated three quality characteristics (film formation, homogeneity, and smoothness). The most critical operation in terms of bacterial stress was the drying in a convection oven; therefore, three drying temperatures (40, 55, and 70°C) were evaluated in function of bacteria survival through plate count. The DLP was successfully developed, reaching viable probiotic bacteria concentrations of 10~9CFU/g. The kinetic growth parameters obtained in the fermentation were similar to that reported in literature. The formulation obtained from the factorial design consisted of 175ml of fermented GSW with B. infantis or L. acidophilus, 25ml of a 6%p/v dispersion of RS, 50ml of a 15%p/v solution of inulin, and 50ml of a 10% p/v solution of gelatin. The drying conditions that allowed the highest concentration of probiotic bacteria were 55±2°C for 2.66±0.22h. B. infantis resisted more than L. acidophilus to the drying conditions described.