Study On Preparation Of Total Saponins And Peptides From Momordica Charantia By Enzymolysis And The Peptides Stability Protection

Momordica charantia is a kind of natural plant with good medicine and food,and its hypoglycemic function is remarkable.Saponins and polypeptides in Momordica charantia were prepared by biological enzyme technique,which is of great significance for the development and utilization of balsam pear resources.However,due to the poor stability of peptides,it is easy to be destroyed by gastric acid and digestive enzymes and lose its activity.Its application in the field of food has been greatly limited.In this work,the experimental material is fresh Momordica charantia.The instant soluble powder of Momordica charantia was prepared by enzyme method with Momordica charantia pulp as experimental material.The preparation process was optimized with the content of total saponins as the index,and its hypoglycemic activity in vitro was studied.Using Momordica charantia seed as experimental material,polypeptide of Momordica charantia was prepared by enzymatic hydrolysis.(DH)and a-glucosidase inhibition rate were used as indexes to optimize the preparation process.The polypeptide of Momordica charantia was isolated and purified by ultrafiltration system and gel chromatography.The purified active polypolypeptide is embedded by using chitosan hydrochloride(CHC)and sodium carboxymethyl cellulose(CMC)as wall materials,and the response surface was optimized by the embedding rate.The properties of CHC/CMC polypeptide complexes were characterized by IR,X-ray diffraction,DSC,Scanning electron microscopy(SEM)and in vitro release.And finally,taking the Momordica charantia.instant powder and the CHC/CMC polypolypeptide of Momordica charantia compound as the main raw material,adding auxiliary materials,and preparing a Momordica charantia.Solid beverage by using the swinging granulation method.The main contents of the study are as follows:1.Study on the preparation of instant powder of Momordica charantia by enzyme method.The main factors affecting the preparation of instant powder of Momordica charantia.were studied,including the addition of Pectinase,pH value,enzymolysis time and enzymolysis temperature.On the basis of single factor,the total saponins content of Momordica charantia.was used as the response value to optimize the process parameters by response surface method.The results showed that the content of total saponins in the instant soluble powder of Momordica charantia.was 12.28 mg·g-1 when the amount of enzyme was 0.06%,pH 4.0,enzymatic hydrolysis time 83 min and enzymatic hydrolysis temperature 53?.2.Study on the characteristics of Momordica charantia instant soluble powder.The volatile components of Momordica charantia.instant soluble powder was analyzed by GC-MS.A total of 27 flavor substances were detected,among which the relative percentage of alcohols and aldehydes accounted for 26.44%and 35.65%,respectively.The flavor substances of the instant powder of Momordica charantia mainly come from alcohols and aldehydes.The detection results of free amino acids showed that the content of free amino acids in the instant soluble powder of Momordica charantia prepared by enzyme method was equal to that of the original powder of Momordica charantia.The results of in vitro antioxidant experiments showed that the instant powder prepared by enzymatic preparation of Momordica charantia showed good antioxidant performance compared with ascorbic acid.The results of hypoglycemic experiment in vitro showed that compared with acarbose,the enzymatic preparation of Momordica charantia instant soluble powder had a strong inhibitory effect on a-amylase and a-glucosidase.3.Study on preparation and ultrafiltration of Momordica charantia polypeptide.The main factors influencing the preparation of polypolypeptide of Momordica charantia,including papain addition,substrate concentration and enzymolysis time were studied.On the basis of single factor,the degree of hydrolysis(DH)and the inhibition rate of?-glucosidase were used as the indexes of orthogonal optimization.The results showed that the optimum conditions for the preparation of polypolypeptide from Momordica charantia by enzyme method were as follows:enzyme addition 8000 u/g,enzymatic hydrolysis time 4 h,substrate concentration 10%.At this time,the degree of hydrolysis of Momordica charantia seed protein was 12.98%,and the inhibition rate of ?-glucosidase was 42.35%.The results showed that the enzyme products with molecular weight less than 3 kDa had the highest inhibitory activity on ?-glucosidase.The enzymatic hydrolysates with molecular weight less than 3 kDa were further separated and purified by ion gel chromatography.The results showed that the purified small molecular polypolypeptide of Momordica charantia showed a strong inhibitory effect on a-glucosidase,and the smaller the molecular weight,the stronger the inhibitory activity,4.Study on preparation and parameters of polypeptide from Momordica charantia complex loaded with CHC/CMC.Chitosan hydrochloride(CHC)and carboxymethyl cellulose sodium(CMC)were used to embed the purified polypeptide.The main factors affecting the preparation of the composites,including the concentration of CHC,the concentration of CMC and the embedding time,were investigated.On the basis of the single factor,the preparation process was optimized by response surface method with the embedding rate as the response value.The results showed that when the concentration of CHC was 5.35 mg/mL,the concentration of CHC was 1.60mg/mL and the embedding time was 33 min,the entrapment rate was 69.98%.5.Study on the properties of CHC/CMC Momordica charantia polypeptide complex.The results of Fourier transform infrared spectroscopy(FTIR)show that CHC/CMC Momordica charantia polypeptide complexes was formed mainly by ion cross-linking and some non-covalent bond interactions.X-ray diffraction results show that the CHC/CMC Momordica charantia polypeptide complex had no crystalline structure.After the formation of the complex,the peak position of the complex was shifted by ion cross-linking.The results of scanning electron microscopy(SEM)showed that the CHC/CMC Momordica charantia polypeptide complex formed a new phase compared with that of CHC/CMC.The results of DSC showed that the CHC/CMC Momordica charantia polypeptide complex showed good thermal stability.In vitro release studies have shown that the CHC/CMC Momordica charantia polypeptide complex showed a good slow release of the polypeptide in simulated gastrointestinal juice environment.The results of short-term storage test showed that the bioactivity of CHC/CMC Momordica charantia polypeptide complex was effectively protected compared with that of small molecular polypolypeptide.6.Study on a solid drink of Momordica charantia.Momordica charantia solid beverage was prepared from the instant powder of Momordica charantia and the CHC/CMC Momordica charantia polypeptide complex.The results of sensory test showed that the solid drinks have a unique flavor of Momordica charantia.