Allium sativum and fish collagen enhanced proteolysis pattern of milk protein during cheddar cheese ripening

Abstract

In the present study, the characteristics of Allium sativum (AS) cheddar cheese was compared to plain cheese in the presence or absence of fish collagen (FC), in relation to acidity and proteolysis of milk protein during 0, 14, 30, and 60 days of ripening. Cadmium-ninhydrin method was used to determine the concentrations of free amino acids (FAAs) in cheese. In addition, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS–PAGE) was used to study the casein hydrolysis and the type of proteolysis in all cheese types. Based on the present results, AS showed the ability to enhance the acid production of cheese (p < 0.05) than plain cheese (control) on day 30 onwards. No significant difference in the acid production (p > 0.05) between AS- and plain- (control) cheese in the presence of FC on day 14 onwards. AS- cheese showed the highest (p < 0.05) FAAs content (1.66 ± 0.04 mM Leucine equivalent) compared to control (1.43 ± 0.09 mmol/L Leucine equivalent) on day 60 of ripening. However, the presence of FC lowered (p < 0.05) FAAs content in AS- cheese (2.47 ± 0.04 mmol/L Leucine equivalent) compared to FC- cheese alone (3.12 ± 0.10 mmol/L Leucine equivalent). The presence of AS in cheese increased the degradation of αs- & β-caseins compared to control on 14 and 30 days of ripening. On the other hand, FC improved the degradation of milk proteins (αs- & β-caseins and α-lactalbumin) in AS- cheese after 1 month of ripening. In conclusion, AS in the presence and absence of FC enhanced the proteolytic effects of cheese during ripening. • The presence of AS enhanced the acid content in cheese. • AS increased (p < 0.05) free amino acids in cheeses on day 60 of ripening. • AS in cheese increased the degradation of caseins in milk in the last two weeks. • FC improved the degradation of milk proteins in AS-cheese after 1 month of ripening.