Development of Antioxidant and Antihypertensive Properties during Growth of Lactobacillus helveticus, Lactobacillus rhamnosus and Lactobacillus reuteri on Cow’s Milk: Fermentation and Peptidomics Study

Abstract

Bioactive peptides derived from milk proteins are an active research area. Exhibiting numerous positive physiological effects on digestive, cardiovascular, immune and nervous systems, these peptides thought to be one of the most promising ingredients for functional food. Generally, these peptides are inactive within the parent proteins and can be liberated during milk fermentation by the specific proteolytic systems of various Lactobacillus spp. Here we present the study of milk fermentation by Lactobacillus helveticus NK1, Lactobacillus rhamnosus F and Lactobacillus reuteri LR1 strains. It was demonstrated that the antioxidant activity of the milk fermented by these strains concomitantly increased with the strains’ proteolytic activity. For the angiotensin I-converting enzyme (ACE) inhibitory activity, the same tendency was not observed. Although the proteolytic activity of L. helveticus NK1 was two times higher than that of L. rhamnosus F, the milk fermented by these strains showed comparable ACE inhibition. The analysis of the peptide profiles of the fermented milk samples allowed us to hypothesize that some previously unreported peptides can be produced by L. rhamnosus F. In addition, it was demonstrated that these potential ACE-inhibiting peptides originated from the C-terminus of αS2-casein.

Comparative Peptidomics Analysis of Milk Fermented by Lactobacillus helveticus

“…All three L. helveticus strains were able to cleave over 70% of the β-casein (84% in ATCC15009, 75% in DQHXN-Q32M42, and 73% in DYNDL36-6). These findings are in agreement with the results of Begunova et al [ 26 ]. Notably, β-casein seemed to be more accessible to cleavage and subsequently more hydrolyzed than the αS1-casein, probably because this molecule is considered to be an intrinsically unstructured protein [ 27 ].…”

Milk Fermentation by Lacticaseibacillus rhamnosus GG and Streptococcus thermophilus SY-102: Proteolytic Profile and ACE-Inhibitory Activity

“…Various studies have reported the release of this type of compound during fermentation of milk with different lactic acid bacteria, including antihypertensive peptides released by L. rhamnosus GG [12][13][14][15]. Begunova et al [16] determined that the antihypertensive activity of the peptides released by a milk fermentation with a specie of L. rhamnosus, is greater than that compared to other types of lactobacilli, which release a higher concentration of antioxidant peptides. Likewise, it has been observed that the greater antihypertensive capacity is related with long fermentation time.…”

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

“…In relation, it has been shown that an inoculum concentration of 1 × 10 6 CFU/mL is enough to generate free amino groups concentrations close to 1 mg/L of fermented milk inoculated with L. rhamnosus [17,19,43]. Furthermore, other reports found that the higher production of free amino groups in the fermentation with L. casei is related to the higher inulin concentration assay (0.5% of inulin) [44].…”