WPC-80 hydrolysates as a promising functional ingredient for diabetes control via DPP-IV inhibition

Nowadays, type 2 diabetes has become a pathology with a high incidence worldwide, causing 4.2 million deaths, especially in middle-income countries. As the dairy industry grows yearly, an alternative way to mitigate whey contamination is to produce whey protein concentrates or whey hydrolysates, which are an adequate source of bioactive compounds and contain better-digestible proteins. Thus, this work tested the in vitro anti-diabetic capacity, achieved via DPP-IV enzyme inhibition, of WPC-80 hydrolysates obtained with alcalase and flavourzyme. WPC-80 powder was dispersed at 10% (w/v) in sterile phosphate buffer (0.01 M, pH=7.5). Then, the dispersion was heated at 90°C for 10 min. Enzymatic hydrolysis was performed by enzyme addition at a 100:2.5 mass ratio (soluble protein: enzyme), and the reaction proceeded for 6 h at 60°C and 130 rpm. Hydrolysis was stopped by boiling water treatment for 10 min, and samples were centrifugated at 10,000 rpm and 4°C for 10 min. Supernatants were used for hydrolysis degree determination and for the DPP-IV inhibition test using spectrophotometric methods. Free amino group concentration was slightly superior with alcalase, rising from 1198.04±24.21 to 2283.26±96.07 mg/L from 0 to 6 h, while in flavourzyme hydrolysis, it was 735.00±0.00 at 0 h and 1585.44±110.68 mg/L at 6 h. According to statistical analysis, both systems showed the same anti-diabetic capacity at the beginning of the hydrolysis, which was 22.03±1.92% for alcalase and 27.75±1.85% for flavourzyme. At the end of hydrolysis, alcalase exhibited slightly better DPP-IV inhibition, at 52.14±0.78%, compared to flavourzyme, at 43.26±1.42%. In conclusion, both WPC-80 hydrolysates showed a high potential to be incorporated into novel functional food formulations. However, sensory testing of those formulations must be performed to evaluate consumer acceptance.