In vitro angiotensin-converting enzyme and dipeptidyl peptidase-IV inhibitory, and antioxidant activity of blue mussel (Mytilus edulis) byssus collagen hydrolysates

Large quantities of mussel byssus are generated annually as a co-product of the mussel-processing industry. This fibrous material is a rich source of collagen, which when extracted has potential uses as an alternative source of collagen for food applications. However, due the complex structure of the material, the extraction of the collagenous components using food-friendly strategies has proved challenging to date. An enzyme-aided method, using a proline endoproteinase, was employed for the extraction of collagen from mussel byssus yielding 138.82 +/- 2.25 mg collagen/g dry weight. Hydrolysates of the collagen extract were generated using five food-grade enzyme preparations with Corolase (R) PP giving the highest extent of hydrolysis. Reversed-phase and gel permeation high-performance liquid chromatography of the extracted collagen and its enzymatic hydrolysates showed significant hydrolysis of collagen. The hydrolysates generated with Corolase (R) PP showed the highest in vitro bioactivities: angiotensin-converting enzyme (ACE) IC50 = 0.79 +/- 0.17 mg/ml, dipeptidyl peptidase-IV (DPP-IV) IC50 = 0.66 +/- 0.17 mg/ml and oxygen radical absorbance capacity (ORAC) activity = 311.23 +/- 13.41 mu mol trolox equivalents (TE)/g. The results presented herein indicate that in addition to acting as an alternative source of collagen for food applications, mussel byssus collagen-derived hydrolysates have potential applications as functional food ingredients for the management of metabolic diseases such as type II diabetes and hypertension.

Automated summary

Large quantities of mussel byssus, a fibrous material rich in collagen, are generated as a byproduct of the mussel-processing industry. Extracting collagen from this material using food-friendly strategies has been challenging due to its complex structure. In this study, an enzyme-aided method was employed to extract collagen from mussel byssus, resulting in a yield of 138.82 +/- 2.25 mg collagen/g dry weight. The enzymatic hydrolysates of the extracted collagen showed significant hydrolysis and exhibited high in vitro bioactivities. These findings suggest that mussel byssus collagen-derived hydrolysates have potential applications as functional food ingredients for the management of metabolic diseases.