Study On Preparation Of Barley Extracts And Protein Complexes From Malt Roots And Their Composition Analysis

Malt extract is used for deep processing of barley malt,a viscous extracted from barley extract made from malt,with special aromatic products.Malt extract contains large amounts of polysaccharides.It also contains trace elements which are beneficial to human body.They can promote the body's normal metabolism.Therefore,malt extract is widely used in food industry,the market prospect is very broad.In addition,malt root is a by-product of malt beer,the annual output is very large.Malt roots are usually used as feed,and the economic utilization rate is low.Therefore,the aim of this study was to explore the method of extracting malt extract as much as possible,as well as the extract of malt root protein complex.This method provided technical support for the comprehensive utilization of domestic barley and malt root and the added value of barley.In the thesis,the preparation process of malt extract and malt root protein complex was researched by using barley malt and malt roots as raw materials.The contents of the product and the changes of the physical and chemical properties in the process of malt starch liquefaction were studied.Through single factor and orthogonal experiment,the best technology of preparing barley extract was optimized.The extraction time 180 min,solid-liquid ratio 1:20(g/mL),extraction temperature 80? were the optimal extraction conditions.Under the three parallel experiments,the average solubility was 61.63%,the relative standard deviation(RSD)was 1.31%(n=3).The extract contained 4.90%protein,total sugar accounted for 82.86%,0.21%of the 0.38%polyphenols,flavonoids and other mineral elements.The preparation of protein complexes of malt roots procession was optimized.The optimal extraction conditions were determined as follows:extraction temperature 40?,time 80 min,pH 9.0,and the ratio of solvent to raw material 30:1(mL/g).Under this optimized conditions,the yield of ASC was(23.67 ± 0.45)%.The extracts of barley malt roots were analyzed for proximate chemical composition according to the national standards.The experimental resulted indicated that this extracts contained 29.59%protein,40.35%total sugar,1.00%polyphenols,0.96%flavonoids and many mineral elements.The experiment investigated the changes of barley starch liquefaction process of physicochemical properties.The results showed that the content of protein increased from 0.40%to 7.27%,freeze-thaw stability decreased,during the liquefaction process(0?120 min).TG analysis results were similar,the band centered around 330?.The morphology of barley malt starch granules was from complete to broken.The X-ray diffraction analysis was obtained that barley starch was a typical A-type in the whole liquefaction process.In this study we described the properties of barley starch in the process of enzymatic hydrolysis.The results showed that the the reaction time 15 h,solid-liquid ratio 1:4?1:5(g/mL),enzymatic hydrolysis pH value 5.5 were optimal conditions.Under this condition,the adsorption ability of pigment was best.The process conditions for the optimal extraction of malt extract and malt root protein complex were basically stable,and the reproducibility was good.We provided an extraction of malt extract and malt root protein complex process was for efficient utilization of malt.Barley malt starch hydrolysis can be applied to porous starch preparation and development.