| Millet(Setaria italic)is one of the major crops in northern China.Millet is a good source of nutrition and it has a suitable proportion of various nutrients.Millet protein accounted 9.7% of the dry weight which is higher than other cereals and rich in a variety of amino acids,besides the polypeptide which in millet hydrolyzate hydrolysised by Enzymatic has a strong antioxdant activity.The oil of millet bran is accounted for the dry weight of 8%-10% and the unsaturated fatty acid can reach more than 80% with the highest content of linoleic acid.Firstly,we used the defatted millet as raw material and acquired the extraction of millet protein by Alkaline method.Then prepared millet protein by microbial fermentation of millet peptides and evaluated the in vitro activity of antioxidant peptide.At the same time,taking millet bran as raw material to analyze its physicochemical properties and antioxidant activity in vitro and in vivo by using supercritical CO2 extraction of millet bran,then exploring the metabolism in vivo absorption.The main results are as follows:1.The extraction teachnology of millet protein by Alkaline method.Using the defatted millet as raw material to hydrolyze the starch of the dafatted millet powder by medium temperature alpha amylase firstly in order to eliminate effect of starching on the steps of protein extraction for a higher extraction rate.The NaOH solution was used as the the solvent and the extraction temperature was fixed with 40 ℃.The study uses the method of alkaline with response surface analysis.The optimum extraction technology conditions were obtained as fellows:material liquid ratio:8.5ml/g,3 hours extraction,NaOH solution concentraction 0.75M.Under this condition,the extraction rate of millet protein can reach 80.153%2.The process study of millet protein peptides preparation fermented by Bacillus subtilis.Using the millet protein as raw material,the best process conditions of using response surface methodology and determining the preparation of millet active peptides fermented by Bacillus subtilis are:inoculation volume 9%,fermentation temperature 33 ℃,initial pH 6.4 of fermentation medium, then the content of millet peptides reached 6.1mg/mL.Through the preparation and detection of the fermentation millet activity peptides in vitro scavenging free radical and the scavenging of free radicals(DPPH,hydroxyl free radical,superoxide anion)ability was positively correlated with concentration.It’s shown that prepared by fermentation of anti oxygenation.3.The extraction process of millet bran oil optimizaed by Supercritical CO2 and its analysis of physical and chemical properties.Taking millet bran as raw material,by using the supercritical CO2 extraction device to obtain millet bran oil. With the response surface analysis and determine the optimum conditions as fellows:extraction pressure 30MPa,extraction temperature48℃,extraction time 2.5h,under this condition,the extraction rate of millet bran oil can reach 7.962%.Compared to petroleum ether extraction technology,the supercritical CO2 extraction technology can reduce the oil acid value.peroxide number and also improve the color and quality of oils and fats.Then the physical and chemical properties of the oil and other properties were analyzed.The results showed that the millet bran oil in unsaturated fatty acids accounted for 83.76% of the total fatty acids.In particular,linoleic acid content was 58.85%.Sn-2 fatty acids were mostly saturated fatty acids (such as palm acid,stearic acid),which accounted for 80.13%.Composition analysis showed that millet bran oil unsaponifiable matter,which contains a variety of plant sterols(such as β-stigmasterol, beans stanol, campesterol etc.),squalene and vitamin E.The results of FT-IR showed that the main constiuent of millet bran oil was triglyceride.TG-DSC showed that the mass loss of millet bran oil mainly occorred in temperature300-500℃ and the total loss was happened at512.2℃4.Millet bran oil antioxidant activity in vivo and in vitro evaluation of biological functions.In vitro antioxidant tests,including:scavebging DPPH free radical ability,total reduction ability,superoxide anion free radical scavenging ability of the determination,the results showed that millet bran oli has stronger antioxidant ability in vitro.Under the same dose, the antioxidant capacity in vitro was superior to that of tea seed oil.Select the acute liver injury model in mice induced by alcohol antioxidant in vivo evaluation of millet bran oil. The liver injury of mice induced by acute alcoholic which were fed millet bran oil for 4 weeks.Then determining the blood serum,included ALT.AST,TG and liver T-SOD,MDA levels of the mice.The results showed that millet bran oil pretreatment of mice serum ALT,AST and the content of TG was significantly decreased,SOD content was significantly increased,MAD content decreased significantly.Combined with biopsy of mice tissue morphology observation,indicating that the millet bran oil can reduce the degree of acute alcoholic liver injury and play a certain role in protecting liver.5.Evaluation of millet bran oil absorption in vivo metabolism. Detect the body weight,liver index and serum TQLDL-C,NEFA and other indexes after 2 weeks’ continuous perfusion of rats to find there is no significant effect on the physiological function of rats by the millet bran oil,but increased the level of HDL-C.In that millet bran oil can play a positive role to improve blood lipids in rats.Collecting and testing the fat content in the feces of rats to find it decreasing significantly,in that,millet bran oil may be more easily absorbed and digested in rats.We think it probably due to the millet bran oil contains a lot of unsaturated fatty acids and Sn-2 triglycerides are mostly saturated fatty acids. |
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