Study On The Compound Fruit And Vegetable Beverage Preparation Of Leek And Its Flavor

Leek belong to the herbs,in China’s distribution is wide,is one of the popular vegetables,it contains rich nutrients,such as protein、dietary fiber、carbohydrates、minerals、vitamins and so on,it also has some medicinal value,such as those containing sulfur compounds,flavonoids can reduce blood fat and blood pressure、blood glucose、impotence and other physiological effects.But at present leek is mainly based on fresh,with leek characteristics of the deep processing of products is not almost existence,it seriously restricted the development of leek industry.At present compound fruit and vegetable juice has becomed the focus of the development of the beverage industry,the fruit and vegetable beverage with leek as raw material is not reported in China.Therefore,the development of leek compound fruit vegetable drink has certain market prospect.In this paper,the development of new fruit and vegetable beverage with leek and corn as the main raw material is aimed to provide a new development direction for the deep processing of leek.The main results are as follows:1、By national standard method of leek basic components such as protein,fat,moisture content,crude fiber were measured,Using 3,5-two nitro salicylic acid colorimetric method determination of reducing sugar content in leek、rutin colorimetric method to measure total content of flavonoids in the leek、high performance liquid phase method to measure vitamin C content in leek、solid phase microextraction combined with GC-MS measurement of volatile flavor components in leek.To determine the content of leek of main nutrients:protein 2.43g/100 g,fat 0.49g/100 g,water 92.3g/100 g,crude fiber 2.13g/100 g,reducing sugar 4.56g/100 g,total flavonoids 17.59mg/100 g,vitamin C40.36mg/100g;at the same time determineing the leek in 40 kinds of flavor substances,is composed of sulfur compounds,a small amount of aldehydes,ketones,esters,alcohols,alkanes,Among them,the sulfide compounds accounted for 76.497%,two sulfur ether compounds accounted for 71.701%,is mainly fragrant material for leek.2、Using the sensory evaluation and through the design of single factor and orthogonal experiments of four factors and three levels to determine best recipe of the leek compound fruit vegetable drink:leek 5%,corn8%,sugar 5%,citric acid 0.03%,salt1‰.By sensory evaluation and physical and chemical indicators,the research and development of leek compound fruit and vegetable beverage has good flavor and taste,rich in nutrition.3、Better effect of xanthan gum,carboxyl methyl cellulose sodium,carrageenan were screened through the single factor experiment from five kinds of stabilizer.Through three compound stabilizer,designing factors and three binary regression rotational combination experiment,to determine the optimum mixture ratio:xanthan gum0.18%,CMC-Na 0.1%,carrageenan 0.09%.At this time leek compound fruit vegetable drink centrifugal precipitation rate is the lowest for 0.401% and beverage is not stratified and stable.Under the condition of room temperature,the compound fruit and vegetable beverage was stored under the optimum stabilizer,and the rate of centrifugal precipitation remained unchanged at 60 days.Beverage is not stratified and stable.4、Determination of compound fruit and vegetable beverage of leek by solid phase micro extraction combined with gas chromatography-mass spectrometry,Ultimately determine the 41 kinds of volatile flavor compounds,the alcohols five accounted for 23.707%,sulfur-containing compounds 7 accounted for 17.869%,esters six accounted for 19.018%,aldehydes 10 accounted for 10.338%,alkenes three accounted for 12.149%,alkanes three accounted for 4.961%,ketones three accounted for 2.224% and other substances four accounted for 9.733%,speculated that volatile flavor compounds in leek compound fruit vegetable drink is mainly alcohols and sulfur compounds and esters.Their mutual coordination fusion together to form volatile flavor of leek compound fruit vegetable drink.