| Processing of crawfish invariably generates lots of solid waste,the crawfish head is the main by-product in crawfish processing. It contains chitin, protein,fat, and so on. The utilization of processing discards can not only protect environment, but can also save resources and bring in value.This paper studied the extraction,refining and antioxidation stability of crawfish oil from crawfish head. The extraction and refining conditions were optimized, the optimum antioxidant condition were conducted.The physicochemical properties of crawfish oil were determined,and the fatty acid compositions were inspected too.The optimum extraction conditions for crawfish oil yield were determined as follows. The mixture ratio of hexane and ethyl acetate was 46:54, the ratio of waste to mixture solvent 1:7(w:v), 60℃of extracting temperature for 50min.Under these conditions,the extraction rate was 16.62%.The optimum refining conditions of crawfish oil were also discussed, and the quantity of phosphorous acid on degumming was 0.2%, concentration of alkali lye on deacidification 17%,ultra-alkali capacity on deacidification 0.3%, quantity of activated carbon on decolorization 8%.The last recovery efficiency of crawfish oil was 63.6%. The physicochemical properties of refining crawfish, oil were that:Moisture and volatile matter 0.11%,acid value 1.37mgKOH/g, iodine value 87.5g/100g,saponification value 183mgKOH/g,peroxide value 1.32mmol/kg, unsaponifiable 2.14%, impurities 0.04%.The fatty acid analyse showed that the unsaturated fatty acids was comparatively high.Some trans-fatty acids and odd-carbon fatty acids also were given too.The study on the antioxidation stability of crawfish oil showed that crude crawfish oil was more stable than refining crawfish oil,and avoiding light helpful. Comparing with BHT, the effect of tea polyphenols was more suitable for preservation of crawfish oil. Preservation time was more than 20 days with 0.02% of TP at 60℃. |
