Biological Potential of Flaxseed Protein Hydrolysates Obtained by Different Proteases

Flaxseed meal, a byproduct of flaxseed oil extraction, was treated as low-value agrowaste for a long time despite its high protein content. Flaxseed meal has recently garnered increasing interest as a source of proteins and other bioactive compounds with positive impacts on human health. The aim of this study was to investigate the in vitro biological potential of flaxseed protein hydrolysates (FPH). Three FPHs were prepared using three hydrolytic enzymes: Alcalase, Neutrase and Protamex. The molecular weight profile of peptides contained in the hydrolysates was determined by size exclusion chromatography (SEC). The oxygen radical absorbance capacity (ORAC) assay was used to determine the peptide antioxidant capacity, while proliferative effects were studied in two cell lines: HeLa and HaCaT. The latter was also used to determine the protective effect of the FPH during induced oxidative stress. Alcalase showed the highest proteolytic activity, while the produced flaxseed protein hydrolysate (FPH-A) exhibited the strongest antioxidant potential. FPH-A had cytotoxic effects at 10 mg/mL in HeLa cells, but it stimulated HaCaT cell growth. Moreover, a mild protective effect of FPH-A was detected in HaCaT cells after induction of oxidative stress. Flaxseed protein hydrolysates obtained by Neutrase (FPH-N) and Protamex (FPH-P) have less pronounced or no potential at all, with respect to their antioxidative or antiproliferative activity. Therefore, to increase value-added utilization of flaxseed meal we suggest further research on hydrolysate obtained by Alcalase.