The comparison of pepsin and trypsin action on goat, cow, mare and human caseins.

The research compares how pepsin and trypsin enzymes break down casein proteins in goat, cow, mare, and human milk. It found that human and goat’s casein were hydrolysed most effectively, which could be linked to the prevalence of beta casein.

Introduction and Methodology

• The study focuses on the extent of proteolysis, the breakdown of proteins into smaller polypeptides or amino acids, in micellar caseins found in human, goat, mare, and cow’s milk. Milk from two breeds of cows – Black&White and Red Polish – was used for comparison. Pepsin and trypsin enzymes were used to induce the proteolysis process in an in vitro setup.

Results and Findings

• Human and goat’s casein had the highest levels of hydrolysis, at 100% and 96% respectively. This shows that these two types of casein are more efficiently broken down by pepsin and trypsin.
• The mare’s casein was hydrolysed to a degree of 92% while that of the Black&White cow’s casein was at 90%. The Red Polish cow’s casein showed the least level of hydrolysis at 76%. This suggests that the casein found in these milks is less efficiently hydrolysed by pepsin and trypsin enzymes when compared to human and goat’s casein.

Interpretation and Insights

• The differences in hydrolysis can potentially be linked to the structure of micelle and, more specifically, the prevalence of beta casein in the human and goat’s casein. The micelle structure in different milk and casein types can potentially influence how responsive they are to enzymatic actions.
• Interestingly, a significant difference was observed between the two breeds of cows, namely Black&White and Red Polish. This suggests that geometry of micellar aggregates may vary across different cow breeds, leading to different efficiencies in casein hydrolysis.