Utilization Of Asparagus Leftovers After Juicing And Development Of Solid Beverage

Asparagus is sweet and feeds mainly on young stalks.It is rich in different nutrients,and its high nutritional value promotes the increase of planting area,which then results in the waste of asparagus,such as cauline leaf stalks after harvesting,leftovers after juicing and so on.Asparagus leftovers is rich in dietary fiber and a certain amount of amino acids,mineral elements,flavonoids,rutin,saponins and polysaccharides and other functional substances,which have good effects on improving animal intestinal health,enhancing animal immunity and improving animal production performance.This topic takes asparagus leftovers after juicing offal as the raw material and solid beverage of asparagus was prepared by crushing,enzymatic hydrolysis,wall breaking,fermentation,vacuum freeze-drying and grinding,which is of great significance to the utilization of asparagus resources and human health.The research contents and results of this subject are as follows:1.The asparagus leftovers after juicing was crushed into 300 meshes by cell wall breaking technique,and then the effects of cellulase and hemicellulase on enzymatic hydrolysis were investigated.The content of water soluble total sugar and soluble solid was taken as the indexes.Firstly,the effects of enzyme species,enzyme complex ratio,enzyme addition amount,pH,temperature and enzymatic hydrolysis time on the degree of enzymatic hydrolysis were investigated by single factor.Then the optimum conditions for enzymatic hydrolysis of cellulase and hemicellulase were determined by orthogonal experiment.The optimum conditions for enzymatic hydrolysis of asparagus juicing offal by complex cellulase and complex hemicellulase were determined after compound experiment of compound cellulase and compound hemicellulose.The optimum conditions were: ratio of leftovers and water was 1:20,the amount of compound hemicellulase added was enzyme activity 580U/g substrate(ratio of glucanase and xylanase activity was 2:1),pH 5.0,temperature 60? and enzymatic hydrolysis time 150 min.On this condition,soluble total sugar content and soluble solids content in solution after enzymolysis was 0.75% and 3.2%,respectively.2.After enzymolysis by complex cellulase and complex hemicellulose,protease was added for enzymolysis.Single factor and orthogonal experiment was used to confirm the optimum conditions and they were: ratio of acid proteinase and papain was 1:2,the amount of enzyme added was enzyme activity 580U/g substrate,temperature 60?,pH 5.5 and enzymatic hydrolysis time 150 min.On this condition,content of water soluble protein in enzymatic hydrolysate was 0.41%.3.The reuse of asparagus leftovers was studied after cellulase and hemicellulose was fixed by chitosan cross-linking.The results were compared with those of free enzyme hydrolysis,and the content of soluble solid and water soluble sugar were used as indexes.Compared to free enzymes,the amount of enzyme was reduced,the stability was better,and it was easy to recycle and reuse after immobilized treatment.The protease was immobilized by sodium alginate-gelatin co-embedding method,and the enzymatic hydrolysis of free protease and immobilized enzyme with different reuse times were compared.The results showed that the stability of protease increased after immobilization and it could be used repeatedly.4.Enzymatic hydrolysate was inoculated with saccharomycetes for fermentation after concentration and sterilization.The optimum conditions for saccharomycetes fermentation were determined by single factor experiment and they were: 200 ppm wine yeast was inoculated and cultured in table concentrator(120r/min)at 30? for 20 h.Then lactobacillus was inoculated for fermentation after the cell wall of saccharomycetes was broken by ultra-high pressure homogenizer at 120 MPa.The optimum conditions of lactobacillus fermentation were determined by single factor experiment and they were: 100 ppm lactobacillus was inoculated and cultured at 34? for 16 h.Immobilized strain method was studied.We obtained the best Glue bead performance was 2.0% sodium alginate and 1.0% calcium chloride.5.The fermentation broth was dried by vacuum freeze drying and smashed to obtain solid beverage.The products have uniform particles,no inclusion,aroma of asparagus,no peculiar smell and refreshing acidity.The SOD activity of products was about 387U/g and escherichia coli was not detected.