ABSTRACT
The physicochemical properties of pressurized hot-water extract (PHE) from abalone muscle and the antioxidant activities of its digestive products were investigated in this study. The PHE contained protein of 49.58% and carbohydrate of 41.95%. After ethanol graded precipitation, most of carbohydrate and protein in PHE were successively remained in 40% ethanol precipitate (EP40) and 80% ethanol precipitate (EP80), respectively. High proportions of Glu and Gly were found in the PHE, EP40 and EP80, but the proportion of Ala in ethanol soluble extract (ESE) reached up to 46.00%. Both PHE and EP40 were rich in glucose, while galactose and glucose were main monosaccharides in the EP80 and ESE. Based on the results of SDS-PAGE and HPLC, high molecular weight components from PHE were precipitated in the EP40, but oligopeptides and free amino acids were fractionated in EP80 and ESE. Among the PHE and the digestive products, the highest antioxidant ability was found to be EP80 hydrolysate, the IC50 values of which for scavenging activity on hydroxyl radical, DMPD radical and ABTS radical were 1.05 mg/mL, 1.40 mg/mL and 0.56 mg/mL, respectively. It is concluded that carbohydrate of abalone muscle was dissolved more easily into hot water than protein, and protein hydrolysate of PHE might play an important role in antioxidant activity of gastrointestinal digestion.
ABSTRACT
Speciation transformation of arsenic in the abalone viscera hydrolysate fraction (AVHF) was evaluated using in vitro and in vivo methods to determine its safety given that AVHF is rich in arsenic. The dimethylarsinic acid (DMA) proportion and some free amino acid contents increased, whereas arsenobetaine (AB) proportion decreased when AVHF was digested by pepsin. However, molecular weight distribution was unchanged, and no obvious changes were found in the intestinal medium. In the single-dose experiment, the AB concentration on the mouse plasma rapidly increased, which reached up to 12.53â¯ng/mL in 2â¯h after the administration of AVHF (10â¯g/kg body weight) and reduced to half of the maximum at 8â¯h after administration. Furthermore, alanine (Ala) content in the urine of mice increased at 8â¯h after AVHF administration, suggesting that Ala might be chelated with arsenic and could not be absorbed well. Long-term experiments showed that AB was not accumulated in mice tissue/organ. However, some AB could be converted into DMA, which was mainly accumulated in mice hair. The in vivo experiments also suggested that the AVHF is safe as health food.
