Suitability of buttermilk for fermentation with Lactobacillus helveticus and production of a functional peptide-enriched powder by spray-drying

Abstract

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.

Postbiotics produced at laboratory and industrial level as potential functional food ingredients with the capacity to protect mice against Salmonella infection

“…), however, certain characteristics of probiotics in general (sensitivity to lactic acidity or osmotic pressure, need of low storage temperature) have confined them mainly to dairy products (yoghurt, cheese), limiting the development of other kinds of food products (Burns et al . ; Peteán et al . ).…”

Influence of technological variables on the functionality of the cell‐free fraction of fermented buttermilk

“…In previous work (Burns et al . ), it was observed that pH control of the fermentation using NaOH dramatically increased the content of sodium in the final product. The product under study will be used, once optimised, for the development of new functional foods.…”

“…In a previous work, it was observed that pH controlled buttermilk fermentation led to an increase in the salt content (as Na and Ca lactate) of the fermentation medium (Burns et al . ), which led to an increase of the osmotic pressure. Lactic acid bacteria display acid resistance mechanisms to survive the by‐products of their own metabolism (i.e.…”

“…In previous works (Burns et al . , ), it was demonstrated that buttermilk is an adequate substrate for the production of biomass of probiotic lactobacilli and for its fermentation with proteolytic strains of lactic acid starter lactobacilli in order to release bioactive components able to enhance the gut mucosal barrier mediated by IgA. These activities are part of a major project aiming at developing a low‐cost technologically simple functional powder carrying the beneficial metabolites left in fermented milk by the proteolytic action of specific strains of lactobacilli and at the same time able to be added to those foods where probiotic bacteria cannot be incorporated for reasons of poor viability.…”

“…In a previous work (Burns et al . ), we showed that buttermilk was a suitable substrate for fermentation with a proteolytic strain of Lactobacillus helveticus and the release of peptide fractions able to be spray‐dried and to modulate the gut mucosa in vivo . The final goal of these series of works is to obtain, by spray‐drying, the bioactive compounds released by an autochthonous strain of Lactobacillus in buttermilk, to confer functionality to foods not always able to carry viable probiotic bacteria, such as cereal bars, cookies or too‐acidic drinks.…”