Study On The Technology Of Corn Germ Protein Beverage

Corn germ meal is nutritional,rich in a variety of proteins,amino acids,vitamins and unsaturated fatty acids,etc.It has a variety of health functions,and has various effects such as lowering blood sugar,relieving constipation,and lowering blood lipids.Microbial fermentation and enzymatic hydrolysis can improve the taste of corn germ meal,increase its nutritional value.This article used corn germ meal as raw material to develop two corn germ plant protein beverages,and researched its antioxidant activity,antibacterial and quality.The main contents are as follows:(1)The defatted corn germ was fermented by Bacillus subtilis,Aspergillus niger,dry yeast and mixed bacteria(Lactobacillus plantarum:Lactobacillus acidophilus=1:1).Through analysis,the mixed bacteria(Lactobacillus plantarum and Lactobacillus acidophilus)was the best fermentation strain.Papain,acid protease,alkaline protease and neutral protease were selected to hydrolyze defatted corn germ,and papain was determined as the best enzyme.Using defatted corn germ as raw material,the optimal development technology of corn germ protein drink was studied.On the basis of the single factor tests,the response surface test was used to study the influence of factors such as the material-to-liquid ratio,temperature,time and enzyme/bacteria addition amount on the content of peptides.The results showed that the optimal process for enzymatic hydrolysis of corn germ protein drink was as follows: material-liquid ratio was 1:14,enzymolysis time was 5.5 h,enzyme addition was 0.62%,enzymolysis temperature was 50?,and peptide content was 57.92 mg/m L,and increased of 46.4 mg/m L compared to before fermentation;the optimal process for fermenting corn germ protein drink was: the ratio of material to liquid was 1:14,the fermentation time was 36 h,the amount of bacteria added was 5%,and the fermentation temperature was 32?,and the peptide content was 49.82 mg/m L,which was 38.3 mg/m L higher than before fermentation.(2)The effects of gastrointestinal digestion on total flavonoids content,total phenol content and DPPH free radical scavenging rate of corn germ protein beverage were investigated by simulating in vitro digestion experiment.The results showed that the contents of total phenols and total flavonoids,DPPH and ABTS free radical scavenging rates of fermented/enzymolyzed corn germ protein beverage were significantly higher than those of untreated corn germ protein beverage.And the fermented corn germ protein drink had obvious bacteriostasis against Salmonella,Aspergillus flavus and Staphylococcus aureus.(3)On the basis of the single factor tests,the orthogonal experiment was used to study the influence of factors such as sucrose,xylitol and anhydrous citric acid on the taste of corn germ protein beverage.The results showed that the optimal taste of the enzymatic hydrolysis of corn germ protein beverage was 3.5% sucrose,7% xylitol,and 0.035% anhydrous citric acid;the optimal taste of fermented corn germ protein beverage was 3.5% sucrose and 6%xylitol and 0.02% anhydrous citric acid.It was determined that the best stabilizer of corn germ protein beverage was carrageenan,and the added amount was 0.06%.(4)After sterilization at 90? for 10 minutes,the protein,lipid,and soluble solid content of the fermented/enzymolyzed corn germ protein beverage meet the national standard of vegetable protein beverage.After fermentation/enzymolysis,the flavor substances of the corn germ protein beverage increased,resulting in a pleasant smell.