Study On Efficient Extraction And In Vitro Simulated Digestion Of Hawthorn Proanthocyanidins And Polysaccharides

Hawthorn anthocyanins and polysaccharides are the most important active ingredients in hawthorn fruit,which have antioxidant,regulating glucose and lipid metabolism,and moisturizing and defecating effects.At present,due to the combination of anthocyanins and polysaccharides in hawthorn,the extraction efficiency is low,which has become a technical bottleneck in this field.Therefore,it is urgent to study new extraction techniques to improve their yield.The low stability of anthocyanins during storage limits their application.In addition,due to the different macromolecular polymers of polysaccharides,they are difficult to depolymerize in the digestive tract,and there are few literature reports on the interaction between hawthorn polysaccharides and gut microbiota.Therefore,this study used hawthorn fruit as the raw material to study the efficient extraction technology of hawthorn anthocyanins(HPC)and hawthorn polysaccharides(HPS),and determined the optimal extraction process;Study the microencapsulation of hawthorn anthocyanins to improve their stability,and investigate the release of anthocyanins during in vitro simulated digestion processes;Studying the dynamic changes of HPS in in vitro digestion,especially the interaction effect between gut microbiota and HPS,provides a theoretical basis for the development of hawthorn anthocyanins and hawthorn polysaccharide functional foods.The main research content and results are as follows:1.Research on efficient extraction technology of hawthorn anthocyanins and hawthorn polysaccharides.HPC was extracted using ethanol reflux,ultrasonic assisted ionic liquid,and ultrasonic low eutectic solvent methods.By comparing the yield,an efficient extraction process was determined.The results showed that the ethanol reflux method achieved a yield of 3.80%of HPC under the conditions of a material liquid ratio of 1:25 and an 80℃ water bath for 2 hours;The ionic liquid is lmol/L[BMIM]Br,with a material liquid ratio of 1:30,cellulase dosage of 1.2%,ultrasound time of 41 minutes,ultrasound temperature of 49℃ and HPC yield of 6.23%;When the molar ratio of choline chloride to glucose is 1:1,the water content is 30%,the ultrasound time is 29 minutes,and the ultrasound temperature is 51℃ the HPC yield is 6.44%under these conditions.The filter residue was extracted using enzymatic hydrolysis assisted hot water extraction method,enzymatic hydrolysis assisted ionic liquid method,and low melting solvent method to determine the optimal HPS extraction process.The results showed that the HPS yield of the enzymatic hydrolysis assisted water extraction method was 4.89%under the conditions of a material liquid ratio of 1:10 and a 55℃ water bath for 5 hours;The ionic liquid is 0.7mol/L[BMIM]BF4,with a material liquid ratio of 1:25,a cellulase dosage of 1.4%,and an HPS yield of 5.91%;When the molar ratio of betaine to citric acid is 2:1,the water content is 29%,the water bath time is 49 minutes,and the water bath temperature is 87℃,the HPS yield is 21.99%.Therefore,the low eutectic solvent method for extracting HPC and HPS has achieved high yields,and this method has the advantages of simple operation,low cost,and short time.2.Study on microencapsulation and in vitro simulated digestion of hawthorn anthocyanins.Using Acacia senegal and gelatin as wall materials,HPC microcapsules were prepared by complex coacervation method.The measured embedding rate was 79.27%,the moisture content was 3.70%,and the solubility was 59.37%.The structure,surface morphology,thermal performance,and storage stability of microencapsulated particles were studied.It was found that microencapsulation did not change the original structure of HPC,and HPC microcapsules showed a multi-layer sheet structure.The enthalpy values of HPC and HPC microcapsules were 191.23 J/g and 226.90 J/g,respectively,indicating that HPC microcapsules had good thermal performance.Further research was conducted on the stability of microcapsules,and the results showed that the HPC retention rates of HPC microcapsules after treatment with light,pH,and temperature were 69.96%,79.08%,and 80.31%,respectively.On this basis,in vitro simulated gastrointestinal digestion experiments were conducted to study the release of procyanidins from microencapsulated HPC under the action of gastrointestinal digestive fluid.The results showed that the release of proanthocyanidins after simulated gastrointestinal digestion in vitro could reach 78.48%.3.Study on in vitro simulated digestion of hawthorn polysaccharides.In order to study the digestion of HPS extract in vitro,an in vitro model was established to simulate the continuous digestion of saliva,gastric juice and intestinal juice.The results showed that during the simulated gastric digestion process,the content of reducing sugars increased by 25.3%,but no free monosaccharides were detected throughout the simulated digestion process,indicating that HPS is indigestible.During the simulated gastrointestinal digestion process,the total carbohydrate residue decreases,which may be related to the utilization of gut microbiota.Meanwhile,due to the utilization of HPS,the content of short chain fatty acids increased by 308%.It is worth noting that HPS can significantly regulate the composition of human gut microbiota,especially increasing the abundance of Megasphaera,Acidaminococcus,and Mitsuokella,while decreasing the abundance of Escherichia shigella and Fusobacterium.HPS can reduce the abundance of harmful gut microbiota and regulate the proportion of beneficial gut bacteria.