In vitro study on digestion of peptides in Emmental cheese: Analytical evaluation and influence on angiotensin I converting enzyme inhibitory peptides

Abstract

A simple in vitro protocol simulating gastrointestinal digestion of proteins and peptides to investigate the effect of digestive enzymes on the biological activity of peptides present in dairy products was developed. This protocol consisted in a 30 min incubation with pepsin followed by a 4 h incubation with trypsin or pancreatin. It was applied to an Emmental cheese water-soluble extract (WSE) and to a casein solution (as a control). Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) allowed to monitor the digestion of proteins. Reversed-phase high-performance liquid chromatography (RP-HPLC) allowed to monitor the conversion of proteins and peptides into peptides and amino acids: it is proposed to use the mean retention time corresponding to the overall retention time distribution of molecules to assess the effect of digestive enzymes. The biological activity focused in this study was the angiotensin I converting enzyme (ACE) inhibitory activity. Digestion of Emmental WSE induced an increase of the ACE inhibition as compared to undigested WSE while a 10 kDa ultrafiltered WSE lost a part of its ACE inhibitory activity after digestion process. These results strongly suggest that digestive enzymes diminished the ACE inhibition by the peptides present in Emmental cheese WSE, while the digestion of peptides of high molecular weight would generate new ACE inhibitory peptides.

ACE-inhibitory activity and ACE-inhibiting peptides in different cheese varieties

“…Incubation with ACE leads to the formation of hippuric acid that can be measured at 228 nm in a spectrophotometer. Parrot et al [90] used a modified method for the investigation of ACE-inhibitory peptides in Emmental cheese. In this assay, ACE-inhibitory activity is measured in the presence of a watersoluble cheese extract, and inhibition of ACE is expressed as percentage of reduction in the ACE-inhibitory activity as compared to the blank sample.…”

“…According to Hernández-Ledesma et al [38], gastrointestinal digestion of fermented milks promotes the formation of active peptides. Parrot et al [90] investigated the ACE-inhibitory activity of watersoluble extracts of Emmental before and after incubation with gastric enzymes. After digestion by pepsin and trypsin or by pepsin and pancreatin, the IC 50 values decreased by 33 ± 13% and 32 ± 13%, respectively.…”

Scientific Background of Dairy Protein Digestibility: A Review

“…They concluded the use of in vitro enzyme procedures would only give an approximate estimate of digestibility in humans. Parrot et al, (2003) measured the in vitro digestibility of cheese (as water soluble extract and casein) using multiple enzymes to study the effect of digestive enzymes on the biological activity of peptides present in dairy products. Initially acidi!…”

Milk proteins-derived bioactive peptides in dairy products: molecular, biological and methodological aspects

“…Milk is a rich source of bioactive substances with benefi cial effects for humans [Expósito and Recio 2006, Korhonen and Pihlanto 2006, Mils et al 2011, Phelan et al 2009]. Milk protein derivatives are physiologically active peptides which are released in the digestive tract [Chabance et al 1998, Ferranti et al 2004, Meisel and Frister 1989, Parrot et al 2003, Svedberg et al 1985. β-casomorphins and casein phosphopeptides (CPP) are produced in vivo after the consumption of dairy products, including milk, fermented milk, cheese and yogurt [Chabance et al 1998, Hernández-Ledesma et al 2004, Kasai et al 1992, Meisel and Frister 1989, Parrot et al 2003, Svedberg et al 1985.…”

“…Milk protein derivatives are physiologically active peptides which are released in the digestive tract [Chabance et al 1998, Ferranti et al 2004, Meisel and Frister 1989, Parrot et al 2003, Svedberg et al 1985. β-casomorphins and casein phosphopeptides (CPP) are produced in vivo after the consumption of dairy products, including milk, fermented milk, cheese and yogurt [Chabance et al 1998, Hernández-Ledesma et al 2004, Kasai et al 1992, Meisel and Frister 1989, Parrot et al 2003, Svedberg et al 1985. Food proteins and peptides are hydrolysed at different stages: ingestion, digestion and absorption [Shimizu 2004, Vermeirssen et al 2004.…”