| In this paper, the foxtail mille（tSetaria italica）was used as raw material, the methods ofsolvent extraction、 microwave-assisted and ultrasound-assisted was used as extractiontechnology to extract the polyphenol compound from foxtail millet, its crude ethanolic extractusing macroporous resins were investigated, then researched on the antioxidant activity ofpolyphenol compound from foxtail millet and to applicate in food industry.1、In order to make sure the optimal condition of extracting polyphenol compound fromfoxtail millet by the extraction technology of solvent extraction, this paper researched on theextraction yield of polyphenols from foxtail millet by single factor experiments and responsesurface analysis; make sure the four significant factors （the concentration of ethanol,extraction temperature, extraction time and solid to liquid ratio） impact on extraction yield ofpolyphenols from foxtail millet. And established a mathematical model between the extractionyield of polyphenols from foxtail millet and the four factors. The results showed of theoptimal extraction condition as follows:70%ethanol as solvent, extraction temperature was40℃, extraction time was1h, ratio of material to solvent was1:13, in these conditions theextraction rate by the millet,and the yield of total polyphenol was73.202mg·100g-1under theoptimal conditions。The optimal extraction condition of the Microwave-assisted Extraction Technology ofbioactive polyphenol compound from foxtail millet was66%ethanol as solvent,Microwavetime was120s, Microwave power was414W, ratio of material to solvent was1:12, and theyield of total polyphenol was105.38mg·100g-1under the optimal conditions。The optimal extraction condition of the Ultrasound-assisted Extraction Technology was70%ethanol as solvent,ultra-sound assisted time is40min, ultra-sound temperature is40℃,ratio of material to solvent is1:14.The yield of total polyphenol was75.765mg·100g-1underthe optimal conditions。2、Four types of macroporous resin were selected to compare their performances inabsorbing and desorbing polyphenol compound from foxtail millet,the optimal absorbentmaterial for polyphenol compound from foxtail millet was decided and it,s dynamic absorbingbehavior was studied.The results showed that AB-8resin possesses higher absorption anddesorption capacity and the optimal technologcial conditions of adsorption velocity was 2mL·min-1,solution pH was aboat4,solution concentration was0.12mg·mL-1to0.14mg·mL-1and the eluting solvent was70%ethanol at1mL·min-1flow rate.3、Antioxidant properties of polyphenol compound from foxtail millet were evaluated onthe basis of measuring scavenging activity for DPPH radicals, ABTS radical cations,superoxide anion and reducing power capability. The result showed that the scavengingcapacity on DPPH, ABTS+and superoxide anion of the JC was73.09%(5mg·ml-1),99.31%(3mg·ml-1),93.57%(5mg·ml-1) respectively, the polyphenol compound of foxtail milletshown to be more effective antioxidants in vitro and presented a certain degree of reducingpower. Hower, there is some gap compared to synthetic antioxidants and Vc.The effect of the polyphenol compound from foxtail millet on the oxidative stability oflard oil were measured by the Schaal-oven method and Rancimat method, and compared tobutylated hydroxytoluene, butylated hydroxyanisole, and tertiary butylhydroquinone. Theresult showed that the polyphenol compound from foxtail millet can inhibit the oxidation oflard partially. Hower, there is some gap compared to synthetic antioxidants, such as BHT、BHA and TBHQ; The different species of foxtail millet was, the slight difference was theantioxidant activity.4、The papers initially identified the chemical composition of extract in foxtail millet waspolyphenols by UV and IR spectra, and pH, extraction solvent and extraction methods（microwave assisted extraction and ultrasonic assisted extraction） had no significant damageon structure of polyphenol.The foxtail millet-polyphenols was subjected to separation, purification and identifiedreversed-phase HPLC,UV and IR spectra, MS. The Molecular weight of300-500polyphenolswas obtain under the experimental conditions at the end. |
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