Research On Flavor Components And Hypolipidemic Efficacy Of Millet Bran Oil Compound Beverage

Millet bran oil is a vegetable oil extracted and refined from the millet bran,which is rich in unsaturated fatty acids,especially the content of linoleic acid.In addition,it contains biological active substances of oryzanol,vitamin E(VE),plant sterols,squalene etc.This thesis,studied the flavor components and hypolipidemic efficacy of the compound beverage of millet bran oil,laying the foundation for the practical application of millet bran oil.The results were as follows:1.The analysis of flavor components of millet bran oil and its compound beverage.The method of analysising flavor of millet bran oil and its compound beverage was established through the technique of headspace-solid phase microextraction-gas chromatography-mass spectrometry(HS-SPME-GC-MS).The optimum conditions were as follows: Rtx-Wax chromatographic column,65 μm PDMS/DVB extraction head,extraction temperature of 75 ℃,equilibrium time of 20 minutes,extraction time of 45 minutes,desorption time of 5 minutes.The results showed that the number of hydrocarbons was the largest and the content of hydrocarbons and aromatic compounds were relatively rich in the flavor components of millet bran oil and its compound beverage.They contented the same materials with 13 compontents,accounted total flavor components of millet bran oil and its compound beverage for 49.49%,38.56%,respectively.In addition,18 compontents of aroma substances in beverage were determined by sniffing detection technology: 2-pentyl furan,hexyl alcohol,2-nonanone,trans-2-aldehyde,2,4-heptadienal,benzaldehyde,2-(2-furan methyl)-5-methyl furan,caryophyllene,methyl nonyl ketone,elemene,1,2,3,4,4a,5,6,8a-eight hydrogen-4a,8-two methyl-2-(1-methyl vinyl)-naphthalene,2,4-decadienal,4-(2,6,6-three methyl-1-cyclohexene)-3-butene-1-ketone,aromadendrene,ethyl laurate,4,5-dehydrogenate isolongifolene,9,10-dehydrogenate isolongifolene,phenethyl alcohol.Aroma intensity value analysis showed that the aromas of millet bran oil compound beverage were mainly composed of oil incense,the fragrance of fruits and flowers,and the fragrance of bean and woody were complementary and synergistic.2.The contents determination of three hypolipidemic components in millet bran oil compound beverage.Firstly,the optimum conditions of demulsification and extraction oil from beverage were determined through single factor and orthogonal test: the freezing time was 10 h,the volume ratio of ethanol to beverage was 2:1,pH was 2.Oil recovery rate under the optimal level was 97.68%±0.15.The analysis of variance showed that the effect of the volume ratio of ethanol to beverage to demulsification was significant,effects of other factors were not significant.The contents of linoleic acid,VE,oryzanol of beverage were determinated through GC-MS,fluorescence spectrophotometry,UV spectrophotometry respectively.Their retention rates in the beverage were 98.85%、92.10% and 99.03% respectively,compared with the raw materials of millet bran oil.The contents of linoleic acid,VE and oryzanol in the beverage were 2431.11 mg/100 mL、1.61 mg/100 mL and 33.34 mg/100 mL,respectively.It showed that the contents of hypolipidemic components were richer in the beverage.3.Animal experimental research on hypolipidemic effect of millet bran oil compound beverage.The animal model of hyperlipidemia was constructed to induced rats with high fat diet,and different doses of millet bran oil compound beverage were lavaged to rats after,and their serum lipid levels were determinated.The results showed that among the three doses of the millet bran oil compound beverage,the hypolipidemic effect of high dose(1.5 mL / 100 g · d)was the best.Compared with the model group,cholesterol(TC)content was decreased significantly(p<0.01),the serum triglyceride(TG)content was decreased significantly(p<0.05)and the high density lipoprotein cholesterol(HDL-C)content was increased remarkably(p<0.05);In middle dose(0.75 mL/100 g · d)group,TC content was decreased significantly(p<0.05),but the changes of TG and HDL-C contents were not significant(p>0.05),having the effect of cholesterol lowering;In low dose(0.30 mL/100 g · d)group,the TG,TC and HDL-C were not significantly changed(p>0.05),having no the effect of hypolipidemic.Illustration that the millet bran oil compound beverage could reduce serum lipid levels in hyperlipidemia rats effectively in a certain dose range.4.Study on the stability of hypolipidemic components in compound beverage under the levels of different temperature and light.The changes of the content of three kinds of hypolipidemic components were studied in the beverage under different temperature and light conditions over time.During the storage period of 3 months,the contents of the three kinds of hypolipidemic components decreased with the extension of storage time,and the higher of the temperature and the stronger of the illumination,the greater the degree of decline in range of investigate factors.Survival rates of linoleic acid,VE,oryzanol in the beverage were the highest under the condition of 25 ℃ and avoiding light,which were 97.23%±0.12 、87.08%±0.53 、98.27%±0.16,respectively.In conclusion,millet bran oil compound beverage needed to be stored in dark place and at room temperature.