Study On Stability And Quality Of Sesame Paste

Sesame paste is a kind of food made from sesame after high-temperature roasting and grinding,in which the protein content is over 20%,so the human body is easy to digest and utilize.On the basis of sesame paste,places in central and northern China have created delicious dishes with their own characteristics.Wuhan's Regan Noodles,cold noodle and sesame paste hotpot all have their own features.Sesame paste has been produced in China for a long time,but it is only sold in small quantities.Shelf life of sesame paste is mainly caused by chemical reactions,and colloidal stability is the most important factor.At present,its stability is improved by adjusting its technological parameters and adding food additives.This topic aims to explore methods that can effectively improve the stability and quality of sesame paste.The effects of neutral protease,papain,trypsin and flavourzyme on the stability of sesame paste were studied,the enzymatic hydrolysis conditions were optimized,and the effects of different proteases on the flavor and volatile substances of sesame paste were explored.The main research conclusions are as follows:(1)Effects of different concentrations of neutral proteinase,papain,trypsin and flavourzyme(1%,3%,5%,7%)on the stability of sesame paste.The results showed that sesame paste hydrolyzed by neutral protease and papain had the best physical stability.The centrifugal oil extraction rate of sesame paste increased with the increase of enzyme addition amount,while trypsin and flavor protease had weak stability improvement ability.The centrifugal oil extraction rate reached the peak value after the enzyme addition amount reached 5% and remained basically unchanged.The results of viscosity and hardness measurement show that neutral protease has the best effect of reducing viscosity.With the increase of sesame paste enzyme dosage,the hardness rise,while the overall viscosity shows a downward trend.The change trend of hardness is opposite to the change trend of viscosity.The friction in the paste decreases and the good mixing degree of the paste increases.Enzymatic hydrolysis of papain,trypsin and flavourzyme has a positive effect on the chemical stability of sesame paste,and papain has the best effect,with the acid value of 0.253 mg KOH/g oil when the enzyme dosage is 7%,which is lower than the acid value of 0.329 mg KOH/g oil of sesame paste without enzyme treatment.Within 28 days of storage,the physical stability of sesame paste treated with protease is better than that of sesame paste not treated with enzyme.The physical stability effect of sesame paste hydrolyzed with neutral protease is the best.The centrifugal oil separation rate of each concentration decreases by about 5%,followed by papain and trypsin.Protease enzymolysis can improve the stability of sesame sauce,not only effectively slow down the rate of sesame sauce stratification,extend shelf life of paste,but also enhance the good mixing degree of the sauce body.(2)Papain and neutral protease were selected to hydrolyze sesame paste through single-factor enzymolysis experiments,and the main factors affecting stability were determined:the proportion of enzyme,the amount of enzyme added,the enzymolysis time,the enzymolysis temperature,and the specific range of each factor,the enzymolysis time and the enzymolysis temperature.L16(45)orthogonal test was designed.through the analysis of the comprehensive results of centrifugal oil extraction rate and acid value,the best technological parameters are:neutral protease to papain ratio is 3:2,10% of the total amount of enzyme added,enzymolysis time is 45 minutes,and the enzymolysis temperature was 45?.After enzymatic hydrolysis of sesame paste under the optimum conditions,the centrifugal oil separation rate of sesame paste was 38.75% lower than that of sesame paste without enzymatic treatment,and its physical stability was increased.Oil with acid value of 0.32 mg KOH/g is the same as the original sesame paste,and its chemical stability remains unchanged.The overall stability is improved.(3)The sesame paste with the best stability of single enzymatic hydrolysis and composite enzymatic hydrolysis was selected to determine its texture,sensory and volatile substances.The texture of sesame paste is related to the degree of protease hydrolysis.Neutral protease and papain can enhance the hardness of sesame paste and improve the fluidity of the paste.Protease can effectively hydrolyze sesame paste to produce small peptides,promote Maillard reaction and enhance the overall flavor of sesame paste;Enzymatic hydrolysis of sesame paste with flavor protease and compound protease can greatly increase the total amount of flavor substances in the paste.Flavor protease has the best effect,followed by compound protease.Olefins account for more than 50% of the total volatile components in sesame paste.Olefin compounds are mainly limonene and cresulene,which enhance the sweet smell of sesame paste and the fragrance of orange pepper.Enzymatic hydrolysis has no negative effect on olefin compounds.2-methylpyrazine and 2,5-dimethylpyrazine are the main reasons for sesame paste baking aroma.Flavor protease and compound protease can effectively increase the content of these two pyrazine substances,and the effect of compound enzyme is slightly inferior to that of flavor protease.Nonal has a pungent taste that is not very pleasant due to the smell of fat and wax,but it also brings some characteristic citrus aroma.Enzymatic hydrolysis promotes the production of nonanoic acid,making sesame paste more unique in flavor.Protease hydrolysis can not only enhance the taste of sesame paste,but also improve enhance the flavor of paste.