Study On Stability And Anti-lipid Oxidantion Of Phenolic Compounds From Endocarp Of Carya Cathayensis

The research object of this subject is the discarded endocarp of Carya cathayensis.The effects of temperature,pH,light,V_C,H₂O₂ and antiseptic on the stability of polyphenols,flavonoids and proanthocyanidins in the ethanol reflux extract of ECC were investigated.A preliminary assessment of the effect of ECC alcohol extract as a natural food antioxidant added to edible oils and fats.In order to inhibit lipid peroxide value and acid value of the ascending velocity and prolong shelf life to improve the quality of the oil grease.This study provides a theoretical basis for the development of new and natural antioxidants from the ECC.The results showed that:（1）Light is the most influential factor of these environmental factors on the stability and antioxidant activity of phenolic compounds in the extracts of ECC.Under the condition of light,the degradation rate of phenols was faster than that of light avoidance group.The phenolic compounds from extract have certain heat resistance and thermal stability,but should not be exposed to high temperature above 50 degrees.Strong acid and strong alkali can obviously destroy phenolic compounds in extracts,and alkaline destruction is stronger than acid.The suitable storage conditions are 0²5℃,neutral or weak acid and light avoidance environment.The correlation test showed that the antioxidant capacity of extracts had the most significant correlation with the content of proanthocyanidins,and the correlation was not high with the content of flavonoids.（2）The effects of several exogenous additives on phenolic compounds of extracts were also very different.The low concentration of V_C can effectively improve the stability of several phenolic compounds in the extracts from ECC,so that the antioxidant activity can be preserved for a long time,but the high concentration of V_C will cause damage.to the chemical structure of the phenol.The destructive effect of H₂O₂ on these components is obvious.The greater the dose,the faster the degradation rate.Preservatives commonly used in the market such as sodium benzoate and potassium sorbate can effectively improve the stability of procyanidins in the extract and slow down its degradation rate,but the preservative has obvious damage to other phenolic compounds.（3）The extracts from pecan inner shell were able to reduce peroxide value and acid value rise velocity of peanut oil and rapeseed oil.At room temperature,they have a effective enhancement on the extension of the shelf life of the edible oil.The shelf life of peanut oil and rapeseed oil added with 0.01%,0.02%,0.05%and 0.1%of pecan inner shell extract was 452,474,495,520 d and 430,446,468,495 d,which is longer than the life of the blank oil sample shelf without the addition of the extract.In addition,the antioxidant abilities of chemical synthesis antioxidants like BHT and TBHQ are stronger than those of the same dose of extracts.