ACE and obesity disorder: In recent years, collagen oligopeptides attract more and more attention due to their various bioactive properties, such as angiotensin I converting enzyme (ACE) inhibitory activity, antioxidant activity, immunomodulatory and antimicrobial activities [6,7,8,9], and beneficial effects on human health, including improving skin health, muscle strength, and bone density [10,11,12], and reducing obesity, joint pain, and blood pressure [13,14,15].