Influence of average molecular weight on antioxidant and functional properties of cartilage collagen hydrolysates from Sphyrna lewini, Dasyatis akjei and Raja porosa

In order to research the relationships between average molecular weight (AMW) and physicochemical, antioxidant and functional properties of collagen hydrolysates, thirty-nine hydrolysates (0.64 ≤ AMW ≤ 257.19 kDa) from the cartilage collagens of three commercially important marine fishes Sphyrna lewini, Dasyatis akjei and Raja porosa were prepared through the processes of extraction, hydrolysis and separation. The physicochemical properties of hydrolysates were investigated by SDS-PAGE, high-performance size exclusion chromatography, scanning electron microscope (SEM) and FT-IR. The results showed that, the antioxidant capacities (DPPH/hydroxyl radicals scavenging activities and reducing power) of hydrolysates were negatively correlated with the logarithm of their AMW. Meanwhile, the reduction of AMW considerably improved the solubility of collagen hydrolysates. However, the same reduction had enormously negative effects on the emulsifying and foaming capacity of hydrolysates, presenting that foaming capacity, foam stability, emulsifying activity index, and emulsion stability index were positively correlated with the logarithm of AMW.

► Influence of AMW on collagen hydrolysate properties was researched. ► Hydrolysate's antioxidant activity was negatively correlated with its AMW logarithm. ► Reduction of AMW considerably improved the solubility of collagen hydrolysates. ► Reduction of AMW had negative effects on emulsifying and foaming capacities. ► The desirable hydrolysates could be achieved on the basis of AMW.