Bioactive peptides and lactic fermentations

Abstract

Milk proteins contain regions within their primary structures that encrypt for many latent biological activities. The beneficial health effects associated with some fermented dairy products may, in part, be attributed to the release of bioactive peptide sequences during the fermentation process. Peptides displaying opioid, mineral binding, cytomodulatory and hypotensive activities, for example, have been identified in cheese and yogurt. Much effort has to date concentrated on the release of angiotensin‐converting enzyme (ACE) inhibitory peptides due to their potential to act as hypotensive agents. Peptide fractions obtained by hydrophobic interaction chromatography of different cheese varieties (Blue, Camembert, Edam, Emmental, Gouda and Havarti) were reported to give systolic blood pressure (SBP) decreases in spontaneously hypertensive rats (SHR) ranging from 7.1 to 29.3 mm mercury (Hg). Skim milks fermented with various strains of Lactobacillus helveticus, and in one case also with Saccharomyces cerevisiae, have been reported to display SBP decreases in mildly hypertensive human volunteers ranging from 4.6 to 14.1 mmHg. These human hypotensive effects have, in part, been attributed to the release of potent casein‐derived tripeptide inhibitors of ACE during fermentation. In general, the likelihood of any bioactive peptide released during fermentation mediating a physiological response is dependent on the ability of that peptide to reach an appropriate target site. Therefore, peptides may need to be resistant to further degradation by gastrointestinal and serum proteinases/peptidases following oral ingestion in order to display a functional food effect.

In vitro immuno-modulatory ability of tryptic caseinate hydrolysate affected by prior caseinate glycation using the Maillard reaction or transglutaminase

“…A glycated lysozyme (LZM) via the Maillard reaction has also been assessed for its immune activities using these immune cells and cytokines (Ha et al, 2013). In general, immune functions of the body can be improved by the so-called immuno-modulatory peptides via modulating lymphocyte proliferation, NK cell activity, antibody synthesis, and cytokine secretion (FitzGerald & Murray, 2006). This fact implies that the effect of prior protein glycation on immuno-modulatory abilities of the resultant protein hydrolysates is an important issue, and should be given a detailed investigation.…”

Proteolytic and ACE-inhibitory activities of probiotic yogurt containing non-viable bacteria as affected by different levels of fat, inulin and starter culture

“…Some of the resulting peptides are used by the bacteria and the most are accumulated in the medium (Leclerc et al 2002). Bioactive peptides have been identified and characterized in many dairy products such as cheese, yogurt, and fermented sour milks (Seppo et al 2003;Fitzgerald and Murray 2006;Pihlanto-Leppala 2001). Among these, yogurt and its peptides have been more widely studied for their effects in reducing blood pressure (Ramchandran and Shah 2011).…”

Cholesterol Metabolism and Its Regulation by Functional Foods

“…Its activity is similar to a hormone or drug that modulates a physiological role through its interaction with a specific receptor triggering a physiological response 47 . Typically, the bioactive peptides are hydrophobic and absorbed between 70 and 80% faster compared to free amino acids 48 .…”