Influence of Oat β-Glucan on the Survival and Proteolytic Activity of Lactobacillus rhamnosus GG in Milk Fermentation: Optimization by Response Surface

Abstract

β-glucans come from cereals that have been located within compounds with prebiotic activity. They have presented several bioactivities that have determined their high functional value. The aim of this study was to identify the influence of oat β-glucan on the survival and proteolytic activity of Lactobacillus rhamnosus GG in a milk fermentation through an experimental design to optimize the process. For β-glucan extraction after dry milling of oats, two methods were applied: with and without enzymatic inactivation of the semolina. The highest extraction yield (45.25 g/L) was obtained with enzymatic inactivation. For the optimization of survival and proteolytic activity, a central design composed of axial points with two factors on three levels was used. Control factors were β-glucan and inoculum concentrations. According to response surface, the best survival growth rate of probiotic was observed with 4.38% of inoculum and 22.46 g/L of β-glucan, and the highest production of free amino groups was observed with 4.18% of inoculum and 22.71 g/L of β-glucan. Thus, β-glucan promotes the proteolytic activity of Lb. rhamnosus GG in milk fermentation.

Aguamiel Enhance Proteolytic Activity and Survival of Lactiplantibacillus pentosus ABHEAU-05 during Refrigerated Storage of a Fermented Milk

“…In our study, microorganisms were contained by not observing a significant difference in concentration during storage. According to the results and bibliographic reports [55], this effect is attributable to aguamiel [18,19].…”

“…This is caused by transport changes in the cell membrane that can sometimes suffer irreversible damage, changing the entire nutrient transport scheme [53,54]. However, the presence of prebiotics accounts for their importance in the containment of viable cells in dairy products [55]. On the other hand, the acidification of the medium is a determining factor in the decrease of viable cells due to the modifications in the expression of proteins necessary for the transport of nutrients.…”

β-Glucan as a Techno-Functional Ingredient in Dairy and Milk-Based Products—A Review

“…Rhamnosus GG, β-glucan content should be 22.46 g per 1 liter of milk [ 97 ]. Poorva Sharma et al [ 98 ] established that the number of bacterial cells of Lactobacillus acidophilus and Lactobacillus bulgaricus during fermentation of mixtures with whey protein concentrate (70%) and oat β-glucan significantly increases during the first 10 hours of the process. Similar are the conclusions regarding the significant influence of oat β-glucan on the vital activity of Lactobacillus plantarum B28 in the composition of a probiotic drink made from oats [ 99 ].…”

Relationship between Oat Consumption, Gut Microbiota Modulation, and Short-Chain Fatty Acid Synthesis: An Integrative Review

“…Oats can be considered a functional food with prebiotic potential due to their fiber, lipid, and phenolic compound content [ 2 ]. Specifically, the prebiotic potential of β-glucan has been evaluated in several studies [ 3 , 4 , 5 , 6 ]. Of note, β-glucan has been associated with hypoglycemic and cholesterol-lowering effects [ 7 ].…”