Seed Melon Polysaccharide Extraction And Its Structural Characterization And Its Effects On The Growth Of Probiotics

Polysaccharides are widely distributed in plants,microorganisms,animals and algae.Relevant research results have shown that natural plant polysaccharides have a variety of physiological active functions,including regulating human immunity,fighting allergies,lowering blood sugar and inhibiting inflammation.Compared with synthetic drugs,plant polysaccharides can not only play a better probiotic effect,but also have higher safety and can be used as an alternative to synthetic drugs.Therefore,the extraction of active polysaccharides from new plant materials,and the study and analysis of basic structure and biological activity are the focus of the research field at home and abroad.At present,the main purpose of the seed melon is to collect the seeds,but the utilization rate is low.The pulp and skin of the melon are often discarded in the farmland,resulting in the waste of resources and environmental pollution.In addition,some by-products produced during processing have not been properly utilized.It can be said that in the field of seed melon processing,how to improve the effective utilization of processing by-products and develop high value-added products is an urgent problem to be solved.In general,there are few reports on polysaccharide extraction,physiological activity analysis and structure study of melon at home and abroad.Against this background,the extraction of polysaccharides from melon was analyzed,and its structure was characterized to clarify its practical effects on the proliferation of intestinal probiotics invitro.Onthe basis of optimizing the extraction process of polysaccharides from melon,the crude polysaccharides were prepared according to the conditions,and then three polysaccharide components(SMP-1、SMP-2 and SMP-3)were separated from the crude polysaccharides.The spatial primary structure of polysaccharides SMP-1 was analyzed.In vitro proliferation of probiotics was investigated.Main research contents and results are as follows:(1)Analyze the extraction temperature,extraction time,liquid-solid ratio,ultrasonic power and other technological parameters of polysaccharide from seed melon and determine the influence of the above four factors on the extraction rate of polysaccharide from seed melon through single factor experiment.Selection of extraction temperature,liquid ratio,extraction time and ultrasonic power and so on several factors as independent variables,and the response value is polysaccharide extraction yield,with the combination of experiment and response surface analysis,realize the optimization of melon seed polysaccharide extraction technology in perfect,building forecasting model,to obtain the best extraction process procedures,namely:the extracting temperature for 42℃,extraction time is 2 h,and liquid ratio is 1:30 g/mL,ultrasonic power is 220 W.(2)Characterization and analysis of polysaccharide structure in melon.GC-MS analysis showed that SMP was a homogeneous polysaccharide component with an average molecular weight of 97403 Da.GC-MS analysis showed that SMP-1 was composed of arabinose and galactose monosaccharides.Infrared spectroscopy showed that SMP-1 had characteristic absorption peaks of polysaccharides,and its structural formula could be inferred by methylation analysis and nuclear magnetic resonance analysis.(3)In vitro proliferation effects of polysaccharide from seed melon on intestinal probiotics.After inoculation of several probiotics,in vitro anaerobic culture was carried out for 48 hours,and the corresponding pH in the medium was determined.Polysaccharides SMP-1,SMP-2 and SMP-3 can play a role in promoting the proliferation of bifidobacterium bifidum,bifidobacterium longum,bifidobacterium infantile and lactobacillus acidophilus.However,under the culture link,the pH of the medium was reduced,so it could be seen that polysaccharides could be effectively utilized by probiotics and form short-chain fatty acids.In addition,the culture was incubated in an anaerobic environment at 37℃ for 48 h,and samples were taken at 0 h,4 h,8 h,16 h,24 h,32 h,40 h and 48 h,respectively.The absorbance value of the culture medium at 600 nm was detected.By taking the culture time as the abscissa and the absorbance value as the ordinate,the growth rate curves of bifidobacterium and lactobacillus acidophilus culture medium with polysaccharide added can be drawn,and then the influence of polysaccharide on the growth rate of each strain can be evaluated.