Study On Processing Of Purple Rice Tea

Purple rice is a precious variety of rice,rich in nutrition,and has a certain health care function,which is considered to be a tonic.In this paper,purple rice is the raw material which is used to study the extraction of anthocyanin and anthocyanin in purple rice and evaluation of method.In addition,the antioxidant capacity in vitro was determined.This paper studies and optimizes the processing technology of purple rice,and selects the packaging materials and methods suitable for the tea of purple rice,and studies the volatile aroma components in the tea of purple rice.It provides the basis for the deep processing of purple rice and lays the foundation for the development of rice tea products.The conclusions are as follows:1.Extraction of anthocyanin and anthocyanin from purple rice and evaluation of method(1)By comparing the ultrasonic method with the extraction effect of the normal temperature immersion method,it shows that the ultrasonic method has the advantages of high extraction efficiency.On the basis of single factor experiment,the optimized extraction process of purple rice procyanidin was: 60 min raw material particle size of 60 mu,ultrasonic time,ultrasonic temperature 45 ?,ultrasonic power 500 w.Under this condition,the extraction amount of proanthocyanidin was 0.26g/100 g,and the theoretical extraction amount was 0.24g/100 g,which increased by 8.33%.Accordingly,some indexes in the standard of health food inspection and evaluation(2003 edition)are optimized and quantified.Purple anthocyanin was extracted by acid extraction.By comparing the extraction effect of the acid method with the ultrasonic method and the normal temperature extraction method,it is shown that the acid extraction method has the advantages of high extraction efficiency.(2)The spectrophotometric method is suitable for the determination of the content of cyanogen and anthocyanin.The method is simple,sensitive and reproducible.The relative standard deviation of the precision,stability,repeatability and standard recovery of the instrument was 0.78%,0.28%,0.66% and 1.38%,respectively.The average recovery rate was 96.32% and the recovery rate was higher.(3)With the same concentration of VC as the control,the scavenging ability of the purple anthocyanin to DPPH,ABTS+· were compared with the VC > purple anthocyanin in the same concentration condition.2.Study on the process of purple rice tea.(1)Studied the temperature and time of making purple rice tea,proline content,the addition ratio of galactose,the results show that 150 ? making 4 min,proline content was 3%,galactose adding amount was 4%,respectively,has good sensory score,anthocyanins are relatively well preserved.(2)Craft of purple rice tea making orthogonal optimization,the optimized conditions for,making the temperature 140 ?,making time is 3 min,proline content was 3%,galactose adding amount was 3%,the anthocyanin content is 0.54 g / 100 g,while meet the sensory quality,maximum limit retains the anthocyanins in rice.3.Effect of packaging on quality of purple rice tea.(1)In terms of the sensory scores of purple rice tea,the sensory scores decreased significantly with the increase of the number of days.Among the packaging materials,the high barrier and middle barrier of the purple rice tea sensory scores decreased more slowly.In terms of packaging,the sensory grading of the purple rice with vacuum and vacuum deoxygenation decreased more slowly.In combination with the photosensitivity of anthocyanin,the packing material is high barrier,and the packing method is suitable for vacuum or vacuum deoxygenation.(2)In terms of the anthocyanin content of purple rice tea,at the time of storage time is less than 80 days,the anthocyanin content of purple rice tea decline were more slowly,when the storage days is more than 80 days,anthocyanin content began to be markedly reduced.When stored for 120 days,anthocyanin drops to about 50%.Among the packaging materials,the purple rice tea with high barrier and high barrier packaging is better preserved in the late storage of anthocyanin.In terms of packaging,the vacuum and vacuum de-oxygenated packaging is slow,and the normal packaging is going down faster.Therefore,the conclusion of the comprehensive sensory quality was concluded with a high barrier material of 0.78 + 0.076mL/m2 · day,and a combination of vacuum or vacuum deoxygenation packaging of purple rice tea.4.Analysis of aroma components of purple rice tea.(1)Purple rice volatile characteristic odour material mainly for ten methyl siloxane five,dodecane,3-methyl tridecane,octacosane etc hydrocarbons,esters such as phthalic acid butyl ester and a small amount of alcohol,aldehyde,etc.With the increase of the frying time,the type and concentration of volatile matter gradually enriched.The volatile composition of purple rice tea is given priority to with hydrocarbons,aldehydes,such as methyl siloxane ring five,ten natural nonyl aldehyde,benzene,formaldehyde,with a certain proportion of phenol,ketones and esters,material,for example-methoxy-4-2 vinyl phenol.The main aroma components of purple rice tea after cooking are 3-ethyl-2,5-methyl pyrazine and 2,5-dimethylpyrazine and other heterocyclic compounds.(2)Compared with purple rice tea,add the proline and galactose of purple rice tea,the types of hydrocarbons decreased significantly,which generates more pyrazine heterocyclic compounds and phenols,aldehydes substances.Compared with adding galactose rice tea,add the proline of hydrocarbons,rice tea varieties and content is richer,but aldehyde,phenol and pyrazine and type of material content decreased,this is also the reason why there are differences between flavor.The synthesis shows that the hydrocarbon and ester substances are very important for the formation of purple rice flavor,and aldehydes,pyrazines,hydrocarbons and phenolic compounds are essential to the formation of purple rice tea.