Abstract
The effects of Codonopsis pilosula (CP) and/or fish collagen (FC) on post-acidification, proteolysis of milk proteins, angiotensin-I converting enzyme (ACE) inhibitory activity, and sensory evaluation were investigated in yogurt during 0, 7, & 21 days of storage at 4 degrees C. Two groups of yogurt samples were prepared: group 1 included plain yogurt (control) and CP-yogurt; group 2 included plain yogurt + FC (control) and CP-yogurt + FC. CP- yogurt showed a significant increase in total titratable acidity (TTA) on day 7 of storage. The presence of FC in yogurt significantly improved (p < 0.05) the content of free amino acids (FAA) compared to the absence. O-phthaldialdehyde (OPA) peptide concentration increased (p < 0.05) to the highest amount for CP-yogurt +/- FC on day 7 of storage. In addition, more degradation was observed in bovine serum albumin (BSA), alpha-, beta-, & kappa-caseins, beta-lactoglobulin, and alpha-lactalbumin of CP- yogurt + FC than its control on day 7 of storage. CP- yogurt with/without FC showed higher (p < 0.05) inhibitory ACE activity than their respective controls on day 7 of storage. The addition of fish collagen in CP- yogurt seemed to have good scoring in sensory evaluation. In conclusion, the presence of C. pilosula and fish collagen in the yogurt can bring about promising health benefits such as anti-ACE activity.