| Chinese giant salamander(Andrias davidianus) is a precious amphibious animal. In recent years, with the growth of the scale of Chinese giant salamander, its deep processing must be developed to stretching the industry chain. Tails adipose tissue, high in fat, is the main processing by-products of Chinese giant salamander, which oil can be extracted from. In this paper, the nutrients composition in muscle of Chinese Giant Salamander. Then the extraction method of oil from tails adipose tissue of Chinese giant salamander, the process conditions of refinement oil and natural antioxidants for protecting the stability of the Chinese giant salamander oil were studied. At last, the enrichment of UFA in oil from viscera of Chinese giant salamander was studied. It provide a theoretical basis for the development of fish oil products and its deep processing.The results showed that the rate of flesh was 63.48%, and proportion of water, crude protein, fatty and ash was 80.40%,17.21%,1.30% and 1.01% respectively. The content of 18 amino acids were detected and the amount content were 18.92%, Among which the essential amino acids and delicious amino-acid were 7.61% and 9.19% and the necessary amino acids index was 91.53. The percentage of essential amino acids to total amino acids and non-essential amino acid were 40. 22% and 67.29%. Fourteen fatty acids were detected, with 71.43% unsaturated fatty acid,11.22% DHA and EPA altogether and 0.98 ratio of n-3PUFA to n-6PUFA. 10 kinds minerals were detected,which were abundant. The quality of muscle of Zhangjiajie giant salamander was superior to other district Chinese giant salamander, abalone, sea cucumber and Chinese soft-shelled turtle.The results showed that the optimal process parameters of organic solvent method were as follow: extraction solvent petroleum ether(30-60), extraction temperature 55℃, extraction time 1.75 h, ratio of material to solvent 1:8, the extraction rate was 89.33%. The optimal process parameters of enzymolysis were as follow: enzyme dosage 0.3%, enzymolysis time 1.0 h, water-material ratio 1.0:1, p H value 7, enzymolysis temperature℃, the extraction rate was 98.53%. The physicochemical properties of oil by two methods reached the primary standard of crude fish oil in China standard(SC/T3502-2000). Each physicochemical index of oil extracted by enzymolysis method is better than that of organic solvent method. The oil extracted by enzymolysis and organic solvent method was detected 12 and 17 fatty acids, with 49.89% and 49.42% MUFA,29.62% and 29.35%PUFA respectively. Enzymolysis method was.the better oil extraction method from the tails adipose tissue of the Chinese giant salamander.The result showed that the optimal refinement conditions were as follow: degelatinization with 40% H3PO4 added 1% of the oil; disacidify with 200g/L Na OH for 0.07% of the oil; and deodorization for 20 min at 55 by revolving evaporation meter. ℃Under the above conditions, the refined oil was light yellow, clear, with light fish smell, reaching to the first grade of refined fish oil in China standard(SC/T3502-2000).The peroxide value was taken as index, the blank sample and adding TBHQ sample were taken as comparison, the antioxidative effects of tea polyphenols, rosmarinic acid, phytic acid and antioxidant of bamboo leaf(AOB) on oil from the tails adipose tissue of Chinese giant salamander were studied by Schaal oven-storage test. The results showed that the antioxidative effect strength order was: phytic acid > AOB > rosmarinic acid > tea polyphenols, when the amount of antioxidants added 0.02% to the oil. The optimum dosages of tea rosmarinic acid, AOB, phytic acid were 0.06%, 0.06% and 0.04% respectively. The optimum formula of compound antioxidants were as follows: 0.015% rosmarinic acid, 0.015% AOB, 0.007% phytic acid showed good synergistic effect on Chinese giant salamander oil.The optimum conditions of prepared mixed fatty acid with saponification were as follows: saponification solvent ratio 1:5, saponification temperature 65℃, saponification time 1.5 h. The mixed fatty acid value was 236.76 mg KOH/g under this conditions. The optimal condition of enrichment of UFA in fish oil by low temperature crystallization was: the solvent ratio 1:6, crystallization temperature ﹣ 45℃, crystallization time 5 h. Under this condition, the iodine value was 188.67 g I2/100 g, with 70.14% yield. The content of UFA and PUFA was improved from 78.57% to 90.26% and 16.16% to 40.42%, separately. |
