Antioxidant activity and degradation kinetics of astaxanthin extracted from Penaeus sinensis (Solenocera crassicornis) byproducts under pasteurization treatment

The lipid oxidation of soybean oil or peanut oil under accelerated oxidation was retarded after addition of non-saponification (N-Asta) or saponification astaxanthin (S-Asta) derived from Penaeus sinensis by-products, determined by lower malondialdehyde and peroxide value as compared with the oil controls. S-Asta or N-Asta degradation in soybean oil or peanut oil fit well to first order model. Further, the soybean oil or peanut oil containing S-Asta demonstrated lower lipid oxidation as compared to those with N-Asta addition. The thermal stability of S-Asta was further evaluated under 60–90 °C pasteurization. Significant decreases of scavenging hydroxyl radical and superoxide anion, and Asta isomers concentrations were found for S-Asta under 90 °C pasteurization; whereas the antioxidant activity of S-Asta was largely restored under 60–70 °C pasteurization. The degradation kinetics of all tans, 9-cis and 13-cis Asta, as well as Asta stereoisomers in S-Asta fit to zero order kinetics, and well described by the Arrhenius equation. The highest and lowest activation energy values of 164.83 ± 14.87 kJ/mol for all trans Asta and 17.63 ± 0.99 kJ/mol for 3S,3′R Asta suggested their highest and the lowest pasteurization stabilities. By comparison, 13-cis, 3S,3′S, and 3R,3′R showed similar thermal stabilities under pasteurization.