Study On The Fruit Characteristics And Oil Extracting Techniques Of Carya Cathayensis

Different varieties of the Carya cathayensis economic traits were compared, The results showed that C. hunanensis has largest weight and fruit nuclear diameter, but low kernel rate; C. cathayensis Sarg is smaller, high kernel rate and high oil content ratio; C. illinoensis Koch has a larger fruit, weight and higher kernel rate.Seven kinds of fatty acids have been detected,in which main component is palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, linolenic acid and arachidonic acid. The rank of variance coefficient of fatty acid content deviate from different varieties of the Carya cathayensis, the content of oleic acid is the smallest.Composition of fatty acid and four kinds of quality index iodin value,saponification value,acid value and peroxide value of Carya Kernel Oil were studied.The results shows that C. hunanensis has a low acid value and saponification value but high content of vitamin E, and C. dabieshanensis has a high acid value and iodine value but low saponification value.The quality indexes of C. cathayensis Sarg between C. hunanensis and C. dabieshanensis.Orthogonal contrast about3factors4levels of the main factors which have influence on the extraction of the Carya Kernel Oil with supercritical fluid CO2were studied. The results obtained showed that the optimum conditions were as follows:extrating in a pressure30MPa at45℃for2.5h with2L/min of CO2flow. Orthogonal contrast about3factors4levels of the main factors which have influence on the extraction of the Carya Kernel Oil with soluble extraction were studied. The results obtained showed that the optimum conditions were as follows:extrating in a liquid ratio1:5at60℃for6h, the yield of the Carya Kernel Oil was64.16%.The study on aqueous enzymatic extraction shows the result that the optimum conditions were as follows:Liquid ratio1:5, reaction at50℃and4hours. The maximum of Extraction rate reach to35.77%in this condition. The different technological conditions extract's Carya Kernel Oil, The best is from supercritical fluid CO2extraction which tests in better quality index.The antioxidative effect of a different antioxidant on oil was studied, With the same addition, the antioxidant activity of the Phytic acid was higher than that of vitamin E, but lower than that of TBHQ.Oxidation induction time(OIT) is about the composition of fatty acid content.In the same storage condition, oil content ratio of the different varieties of the Carya cathayensis decreases with increase in storage time, and the rate of descent have relative to the oil content ratio. The higher the initial oil content ratio, the higher the decreases rate, and vice versa. In the different storage condition, oil content ratio of the same species varieties of the Carya cathayensis decreases with the temperature.The higher storage temperature, the larger the rate of descent of oil content ratio, and vice versa. During storing period the content of Saturated fatty acid of nuts under conventional storage usually has apparent decreased, and the total content of unaturated fatty acid also changes distinctly.The results showed that the rate of declined clear in the content of Unaturated fatty acid,declined little in the content of Saturated fatty acid, and the fatty acid content of Carya Kernel Oil has the same trend in storage period.