Effect of temperature on chemical properties and antioxidant activities of abalone viscera subcritical water extract

The effect of temperature on the main components and antioxidant activities of abalone viscera subcritical water extract (AVSWE) was investigated. With the increase in temperature from 110 °C to 230 °C, the protein content in AVSWE increased from 57.4% to 68.5%, while the carbohydrate content decreased from 17.9% to 0.8%. The highest percentage of 1000–5000 Da peptide fraction and total essential amino acid content was found in the AVSWE extracted at 170 °C. The transformation rate of arsenobetaine into dimethylarsinic acid in AVSWE increased dramatically with the increase subcritical water temperature from 170 °C to 200 °C. The results of DPPH and hydroxyl radical scavenging activity, reducing power and lipid peroxidation inhibition effect showed that AVSWE with the highest antioxidant activities was extracted at 170 °C. However, the subcritical water temperature for AVSWE extraction should not exceed 140 °C according to arsenic speciation.