The growth of six probiotic commercial strains of lactobacilli was assessed in reconstituted dried whey and buttermilk supplemented with yeast extract, meat peptone, soy peptone, tryptone or casein acid hydrolysate at 0.3%, 0.6% or 1%. The addition of 1% glucose was also tested. Growth and acidification kinetics were determined at 37°C using MRS broth and a commercial culture medium as references. The suitability of whey and buttermilk as cryoprotectants at –20°C and –70°C was also assessed. Whey and buttermilk with 0.3% yeast extract were chosen for the growth of probiotic lactobacilli, since no satisfactory growth was observed without an external nitrogen source, whereas glucose did not improve the growth of any of the strains assayed. In general, buttermilk performed as satisfactorily as the reference media. The effectiveness of these media as cryoprotectants was strain dependent: skimmed milk and whey were the most suitable ones, especially for long‐term storage at –20°C. However, at –70°C, no significant differences were observed between the culture media assessed. The use of whey or buttermilk as culture media for the production of probiotic lactic acid bacteria and for their cryopreservation implies a novel use of these low‐cost products, offering an alternative way of utilizing the by‐products of the dairy industry, helping to minimize their negative impact on the environment.
Aim: To ferment buttermilk, a low‐cost by‐product of the manufacture of butter, with a proteolytic strain of Lactobacillus helveticus, to enhance its value by the production of a functional peptide‐enriched powder.
Methods and Results: Buttermilk was fermented with Lact. helveticus 209, a strain chosen for its high proteolytic activity. To enhance the release of peptidic fractions, during fermentation pH was kept at 6 by using NaOH, Ca(CO)3 or Ca(OH)2. Cell‐free supernatant was recovered by centrifugation, supplemented or not with maltodextrin and spray‐dried. The profile of peptidic fractions released was studied by RP‐HPLC. The lactose, Na and Ca content was also determined. The powder obtained was administered to BALB/c mice for 5 or 7 consecutive days, resulting in the proliferation of IgA‐producing cells in the small intestine mucosa of the animals.
Conclusions: Buttermilk is a suitable substrate for the fermentation with Lact. helveticus 209 and the release of peptide fractions able to be spray‐dried and to modulate the gut mucosa in vivo.
Significance and Impact of the Study: A powder enriched with peptides released from buttermilk proteins, with potential applications as a functional food additive, was obtained by spray‐drying. A novel use of buttermilk as substrate for lactic fermentation is reported.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.