Study On The Compounding Of Polyphenols And Natural Antioxidants From The Leaves Of Rhus Chinensis Mill And Its Application In The Oil Preservation

Rhus chinensis Mill is a small deciduous tree or shrub of Rhus chinensis family.It is widely distributed in China,especially the Chinese gall on the leaves of Rhus chinensis,which is used in production and life due to its high content of gallic tannin and potential health.In recent years,the applications and the extraction of natural products is becoming a hot spot research,studies have shown that Rhus chinensis leaf polyphenol with antioxidant effect,Rhus chinensis leaf is gallnut aphid in host plant poison sumac blade on the formation of the gall,so whether Rhus chinensis leaf polyphenol has the application value of the relevant,about Rhus chinensis leaf polyphenol composition analysis and application research becomes the research direction of this topic.In this study,the polyphenols in the leaves of Rhus chinensis were taken as the main research object.Different polyphenols in the leaves of Rhus chinensis were systematically extracted and analyzed to determine the composition and relative content of different polyphenols in the leaves of Rhus chinensis.Then,flax oil was used as the main raw material,different forms of polyphenols in the leaves of Rhus chinensis were used as the main addition amount,and tea polyphenols,rosemary extract and L-ascorbic acid palmitate were selected as synergistic agents,regular determination of fat peroxide value,anisidine value,conjugated diene value,such as physical and chemical indicators,with the induction period,total oxidation value and antioxidation coefficient as evaluation index of composite antioxidants composite antioxidant effect evaluation and selection;Finally,the response surface optimization test was carried out on the combination of the compound antioxidant of Rhus chinensis leaves to obtain the maximum response value,that is,the optimal addition amount of the compound antioxidant,and the verification test was carried out to apply it to the fresh-keeping of oil,in order to replace the artificial synthetic antioxidant.The main research results are as follows:1.The analysis results of the different forms of polyphenols in the leaves of Rhus chinensis.Using UHPLC-Q-Exactive HF/MS,30 kinds of polyphenols were identified,including 17 kinds of flavonoids,7 kinds of phenolicacids,2kinds of organic acids,1 kind of tannins and 3 kinds of other substances.UHPLC-Q-Exactive HF/MS was used to separate and identify the polyphenols of Rhus chinensis,combined with the information annotation and classification of the mass spectrometry database,and accurately qualitatively identified 30 polyphenols,including 17 flavonoids,7 kinds of phenolic acids,2 kinds of organic acids,1 kind of tannins,3 kinds of other substances.The highest relative content of total soluble polyphenols was myricin,which was 735.59 μg/m L.The highest relative content of quercitrin in esterification polyphenols was 178.85 μg/m L.The highest content of gallic acid in the bound polyphenols was 53.87 μg/m L,suggesting that flavonoids may play a relatively important role in the free polyphenols,while gallic acid may play a important role in the bound polyphenols.2.Comparison of the antioxidant capacity of different forms of polyphenols from the leaves of Rhus chinensis and the screening of compound antioxidantsThrough the oven method to accelerate oil oxidation,regular determination of oil related physical and chemical indexes,combined with the oil oxidation evaluation index,the following conclusions were drawn: the esterified polyphenols from the leaves of Rhus chinensis have a strong antioxidant capacity;The optimal supplemental amount was0.05%.The screening combination of the compound antioxidant of Rhus chinensis leaves was esterified polyphenols,tea polyphenols and L-ascorbate palmitate.3.Optimization of the combination of the polyphenols compound antioxidants of Rhus chinensisThrough single factor test and response surface optimization test,the optimal formulation of esterified polyphenols compound antioxidant was obtained as follows: 0.06% of esterified polyphenols,0.04% of tea polyphenols,and 0.01% of L-ascorbyl palmitate.The verification test is carried out under these conditions.The induction period of oil is 4.26 days,which is only 0.07 days away from the theoretical prediction value,indicating that this method and the prediction model can more accurately reflect the effect of the combination of esterified polyphenol compound antioxidants from the leaves of Rhus chinensis on the induction period of oil.Its antioxidant capacity is better than synthetic antioxidant BHT.