Stability of a Pancreatic Enzyme Cocktail During in Vitro Protein Digestibility Assays

Abstract

To maximize the efficiency of utilization of a pancreatic enzyme cocktail and estimate the contamination for in vitro protein digestibility assays, the specific activity losses of trypsin and chymotrypsin and the digestion of the enzyme proteins were studied. In the absence of protein substrate, increase of enzyme concentration augmented the half‐lives of trypsin and chymotrypsin and decreased the digestion of enzymatic proteins. In contrast, in the presence of substrate, increase of enzyme concentration decreased trypsin's half‐life. Increase of pH augmented the digestion of enzymatic proteins. The results indicated the optimum time for utilization of the enzymes depended on pH, enzyme concentration and presence of substrate. At the time when digestion of the proteins ceased, the average size of the hydrolysates was calculated between 3.1 and 5.4 amino acid residues, suggesting most proteins in the enzyme cocktail would be detected as digestible proteins.

Soy Protein Pressed Gels: Gelation Mechanism Affects the In Vitro Proteolysis and Bioaccessibility of Added Phenolic Acids

“…In addition, enzyme autolysis releases peptides and amino acids bearing alpha-amino groups, leading to inflation of OPA and amino acid bioaccessibility results. Qiao and co-workers studied the autolytic reaction of pepsin and pancreatic enzymes and they reported important findings [ 63 , 64 ]. We believe that the autolytic activity of the digestive enzymes is a very serious issue that needs to be researched further.…”

In Vitro Assessment of the Impact of Industrial Processes on the Gastrointestinal Digestion of Milk Protein Matrices Using the INFOGEST Protocol

“…Indeed, it has already been shown in previous studies [19,20] that autolysis of proteases present in pancreatin occurred and varied according to in vitro digestion conditions. This is especially true at high concentrations of pancreatin where the activity of certain proteases such as trypsin is lost more quickly than at lower concentrations in the presence of substrate [21]. This autolysis mechanism thus explains the increase in the proportion of peptides harboring apparent molecular weights comprised between 4 and 10 kDa (Figure 1) and the increase in band intensities for molecular weights inferior to 15 kDa (Figure 2) for quantities of pancreatin superior to 400 mg.…”

Advances in the study of activity additivity of supplemented proteases to improve digestion of feed protein byPenaeus vannamei

“…Qiao et al . () found full enzyme activity, when a proteinaceous substrate was present in enzyme mixtures and suggests substrate protection. With an in vitro study, Wang & Hsu () report that trypsin and chymotrypsin were significantly more resistant to acid and pepsin hydrolysis in the presence of casein or soybean protein as substrate, amounting to eight times more residual activity than without the substrate.…”

“…In vitro studies are essential to help predict ways that enzyme cocktails act under varied conditions: pH, concentration of enzymes and the presence of a protein substrate affects the activity of proteases (Qiao et al . ).…”