Bioaccessibility and Cell Metabolic Activity Studies of Antioxidant Low Molecular Weight Peptides Obtained by Ultrafiltration of iα/i-Lactalbumin Enzymatic Hydrolysates

摘要

α-lactalbumin (α-LA) might increase its antioxidant potential after hydrolysis. In particular, low molecular weight (LMW) peptides showed greater antioxidant capacity. Different hydrolysis conditions with Alcalase enzyme were optimized with a composite central design and surface methodology. Sample obtained after 0.1% (w/w enzyme:substrate), 60 min hydrolysis, ultrafiltrated with membranes of 3 kDa (named 4 LMW), showed the greatest antioxidant values: 1.574 ± 0.060 and 1.636 ± 0.076 μmolTE/mg of protein for ABTS and ORAC-FL, respectively. Sample 4 LMW produced mild ACE inhibition capacity, 22% related to Captopril. 4 LMW was submitted to in vitro gastrointestinal conditions using α-amylase, pepsin, pancreatin and bile-extract;its antioxidant capacity was enhanced by the shorter peptides released, confirmed by SE-HPLC. Antioxidant capacity of digested 4 LMW sample (D 4 LMW) was 1.743 ± 0.086 and 2.542 ± 0.245 μmolTE/mg of protein for ABTS and ORAC-FL, respectively, showing improvement on bioaccessibility. Intestinal cells viability was higher for D 4 LMW.