The Study On The Pupa Oil Ectracted And Analyzed From Pupa Of Dendrolimus Superans And Oxidation Stability (Lepidoptera:Lasiocampidae)

In this paper, Dendrolimus superans(Butler) of the forestry pests was for the research object. The pupa of D. superans was useed to extract the useful fatty acids to humans. With petroleum ether for extracting agent,the extraction of pupa with ultrasonic oscillations or Soxhlet’s extractor was compared on the basis of the yields of extracts. Orthogonal experimentwas conducted to investigate3influential factors:amount of extractant, extraction temperature and extraction time. In order to definite the composition and content of fatty acids in pupa, and explore the optimal combination of extraction solvent and extraction method, pupa oil was extracted by4kinds of extraction methods (ultrasonic oscillations extraction, soxhlet extraction and solvent extraction methods of hot soak and cold soak) in three kinds of extraction solvents (hexane, petroleum ether and ether) in this study. Capillary chromatography-mass spectrometry (GC-MS) was used to analyze the composition and relative content of fatty acids.Factors influencing pupo oil oxidation and antioxidation stability of different antioxidants and TP polyphenol for pupa oil were investigated by Schaal oven method. With the Peroxide Value(POV) as the index, the speed card and spectrophotometry determined the POV values. This paper for successful completion will lay a foundation of D. superans from resources angle. The main results were as follows.1、The optimal conditions for the extraction with Soxhlet’s extractor were A3B1C3, which were12times of amount of extravtant,90℃and2h, while those of ultrasonic oscillations were A3B3C3, which were12times of amount of extravtant,40℃and30minutes. The extracting effect of ultrasonic oscillations for30min was equal to that of Soxhlet s extraction for6h but the extracting rate was10.7times that of Soxhlet’s extraction.So the ultrasonic oscillations extraction takes shorter time, less energy and less energy consumption.2、The extraction rate using hot soak was the highest (25.60%) in hexane among the four extraction methods. Ten kinds of fatty acids were tested with each method except ultrasonic oscillations extraction (9kinds were tested). The extraction rate using soxhlet extraction was the highest (29.31%) in petroleum ether among four extraction methods. Amount of10kinds of fatty acids extracted was equal using four extraction methods. The extraction rate using cold soak was the highest (29.11%) in ether among four extraction methods. Number of different kinds of fatty acids extracted was in the following order from high to low:cold soak (13)> soxhlet extraction (12)> hot soak (11)> ultrasound oscillations extraction (9). Unsaturated fatty acids accounted for more than63%of total fatty acids, and their contents were not markedly influenced by the extraction solvent and different extraction methods. So it was proposed that the optimal extraction solvent and method for fatty acids in pupa of D. superans were petroleum ether and soxhlet extraction.3、Spectrophotometry determined10times on the same sample.The average of the determination results was2.576.Standard deviation was0.00267and the relative standard deviation was0.1%. The speed cardboard determined10times on the same sample.The average of the determination results was2.60.Standard deviation was0.06667and the relative standard deviation was2.56%. Thus,we can saw that the method of spectrophotometry’s precision was better than the speed cardboard.Light, metal ions can accelerate oxidation of pupa oil.But the light affecting the oxidation of pupa oil was greater than metal ions. The speed of the POV values of40℃rose gently when60℃and80℃rose severely. Therefore, in storage and processing the oil pupa, we should reduce temperature, avoid light, avoid contacting with metal ions.Compared with the blank, Vitamin E, BHA or BHT antioxidants effection were closely.The best effect was of TP than these three antioxidants. With the synergistic agent of citric acid,the influence of Vitamin E was not obvious.The influence of BHA and BHT was obvious.TP’s influence was the best. So in the condition of TP and citric acid coexistence, the antioxidant effect was2times to no citric acid.