Preparation And Anti-inflammatory Activity Evaluation Of Ginger Peel Polysaccharide Zinc Complex

In the process of ginger processing,a large amount of ginger peel is produced,which is mostly used as feed or discarded as waste,resulting in resource waste and environmental pollution.Polysaccharide is an important functional component of ginger peel,which has biological activities of anti-oxidation,anti-tumor,hypoglycemic and anti-fatigue.Zinc is one of the important mineral elements in human body,and zinc deficiency is easy to cause many diseases such as low immunity and growth retardation.Polysaccharide zinc complex has higher utilization rate and biological activity than inorganic zinc.In this study,GP-Zn was prepared using GP,and then the structure characterization,digestion characteristics analysis and biological activity evaluation of GP-Zn were carried out.The main research contents and results are as follows:(1)To establish the best preparation technology of GP-Zn.Single factor and response surface test were used to optimize the weight ratio,reaction time and reaction p H,and the optimal preparation conditions of GP-Zn were as follows:Weight ratio 24:1,reaction time125 min,reaction p H 8,under these conditions,the chelation rate of GP-Zn was 98.53±0.31%,and zinc content was 21.17±0.25 mg/g.(2)The structure and properties of GP-Zn were characterized.GP and zinc are linked by a Zn-O bond,and the surface of GP-Zn was smooth and thin.The amorphous state has not changed;The thermal stability decreased slightly;Circular dichroism analysis showed that zinc attenuated the negative Cotton effect and changed the conformation of polysaccharides.The molecular weight of the polysaccharides increased from 150 k Da to 730 k Da when combined with zinc,and the monosaccharides consisted of arabinose,galactose,glucose and mannose with the molar ratio of 1.20:2.10:95.10:1.60.(3)In the process of simulated gastric juice digestion,the final dissolution rate of zinc ion of GP-Zn was 8.35%,which was 47.44%lower than that of zinc sulfate(55.79%);In the simulated digestion process of intestinal fluid,the final dissolution rate and end-dialysis rate of zinc ion of GP-Zn were 1.16%and 14.04%respectively,which were 1.03%and 13.48%higher than zinc sulfate.The results showed that the utilization rate of GP-Zn was higher than that of zinc sulfate in intestinal tract.(4)GP-Zn can significantly inhibit Cu SO₄-induced macrophage migration to the lateral line of zebrafish.At the concentration of 5?g/m L,the number of cell migration in GP-Zn group was reduced by 47.62%compared with that in GP group,the results showed that GP-Zn had better anti-inflammatory activity than GP.Real-time quantitative PCR was used to detect the expression of inflammation-related genes.It was found that GP and GP-Zn had anti-inflammatory activities by down-regulating the m RNA expression levels of IL-6,IL-8,IL-12,MAPK and JNK1.