Extraction And Application Of Bioactive Substances In Waste Burdock Skin

Burdock,as an important cash crop,is planted in a large area in Fengxian County,Xuzhou.While bringing economic benefits,a large number of burdock wastes such as burdock skin generated by processing are discarded,which not only causes the waste of biomass,but also intensifies the pressure on the local environment.In this study,burdock from Fengxian county of Xuzhou was used as the research object.The basal diet was supplemented with burdock skin,burdock skin polyphenols and crude polysaccharides,chlorogenic acid and rutin extracted from burdock skin,respectively,to carry out progressive feeding experiment of laying hens.The effects of the above additives on performance,egg quality and blood biochemical indexes of laying hens were determined.The optimal extraction method and extraction conditions of chlorogenic acid from burdock peel were determined by response surface,which provided reference for biomass utilization of burdock waste.The main research methods and results are as follows:1 Optimization of extraction technology of chlorogenic acid from burdock by response surface methodologyCombined with the results of single factor experiment and response surface experiment,the extraction process of chlorogenic acid from Burdock peel was optimized,and it was concluded that the extraction rate of chlorogenic acid was the highest when the concentration of ethanol was 46.84%,the extraction temperature was 47.94℃,and the extraction time was 0.68h,and the maximum estimated value was 0.147%.In 5 validation experiments,the average extraction rate was 0.146%,which differed little from the maximum estimated value of the model,indicating that the model was feasible.2 Experiment of feeding layer with burdock skinWith 1200 40-week-old Hy-line brown laying hens with the same performance and health status were used as the research subjects.Burdock root peel residues were added to the basic diet at the rate of 10 g.kg^-1、20 g.kg^-1、30 g.kg^-1、40 g.kg^-1、50 g.kg^-1,and the laying performance,egg quality and blood biochemical indexes were investigated.The results showed that the number of laying eggs,total weight of laying eggs and feed intake of laying hens were increased,and the egg quality was improved.Compared with the control group,the ratio of feed to egg and total waste eggs were decreased.The utilization rate of protein was improved,the activity of enzyme in serum was changed in different degrees,and the content of trace elements was increased.It was preliminarily concluded that there were active ingredients in burdock peel,which had positive effects on the growth,production and immunity of laying hens.3 The experiment of feeding laying hens with polyphenols and polysaccharides from burdock skinAccording to the test standard,feeding mode,management mode and investigation index of experiment 1,400 40-week-old hyline brown laying hens were selected and divided into seven groups for feeding experiment.Burdock crude polysaccharide and crude polyphenol were added into the basal diet at the ratio of 200 mg.kg^-1、400 mg.kg^-1、600 mg.kg^-1,respectively.The results showed that 200 mg.kg^-1polyphenol group significantly decreased the concentrations of total cholesterol（TC）and low density lipoprotein cholesterol（LDL-C）,and increased the concentrations of triglyceride（TG）.In 400 mg.kg^-1polysaccharide group,the increase and decrease of TC,TG,high density lipoprotein cholesterol（HDL-C）and LDL-C were limited,but both crude extracts could reduce the ratio of feed to egg.The results showed that polyphenols and polysaccharides in burdock peel were the main active substances to increase the weight and promote the growth of laying hens.4 Experiment on feeding layer hens with chlorogenic acid and rutin extracted from burdock skinAccording to the test standards,feeding methods,management methods and test indexes of experiment 2,intestinal microbes,yolk heavy metal concentration and yolk drug residue were detected,and 100 mg.kg^-1、200 mg.kg^-1、300 mg.kg^-1chlorogenic acid and rutin extract were added into the feed for feeding test.The results showed that both chlorogenic acid group and rutin group could improve the immunity and egg quality of laying hens,and the blood biochemical indexes were increased or decreased in different degrees.The effects of chlorogenic acid on the intestinal microflora of laying hens were more obvious.The new microecological balance created a new immune barrier,which improved immunity and reduced mortality.Heavy metal and drug residues are greatly reduced,lower than the industry and national standards.