Inhibitory Effect Of Plant Polyphenols On Lipid And Protein Oxidation Of Pork Patties And Related Interaction Mechanisms With Proteins

Lipid and protein oxidation is the main factor that resulting the deterioration in meat and meat products during storage.It is one of the effective methods to add the plant polyphenols into meat and meat products,which have special anti-oxidation against deterioration.In the recent researches,as safe and effective natural antioxidants,the plant polyphenols were increasely added in meat and meat products.However,action mechanism of antioxidation is not clear for polyphenols to lipid and protein and the influence of plant polyphenols on meat quality is not deeply investigated.Therefore,the pork as the research object,four representative polyphenols was selected to study during chilled storage,as catechin,quercetin,rutin and gallic acid.Inhibition of lipid and protein oxidation and impact on the quality of the pork meat were researched.Based on this,effect of protein and polyphenols on protein structure and functional properties are researched profoundly.It is a theoretical basis for plant polyphenols to apply to meat production.The main conclusions are as follows:1.During chilled storage,different concentrations of quercetin which added into minced pork could inhibit lipid and protein oxidation significantly.Quercetin has some inhibitory effect on the formation of TBARS,thiol loss,protein carbonyl and surface hydrophobicity.It could reduce the loss of ?-helix and ?-fold structure of protein.The color,cooking loss,hardness and elasticity of meat were improved by quercetin,especially the lower concentration.2.Following with the storage time,catechin could inhibit lipid and protein oxidation of minced pork.The results indicated that catechin had a better inhibitory effect on the formation of TBARS,thiol loss,protein carbonyl compounds and surface hydrophobicity.Protein secondary structure as ?-helix and ?-sheet structure were maintained well by catechin.But cooking loss of meat was increased in the story time.During initial storage catechin reduced the hardness and elasticity of minced pork,especially high concentrations.Therefore,selecting catechins as an antioxidant,it must take into account the effect of confrontation and double impact meat quality for the appropriate applications dose.3.Rutin has some inhibitory effect on the formation of TEARS,thiol loss and surface hydrophobicity.But rutin has no inhibitory effect on protein carbonyl,especially the higher concentration increased the protein carbonyl content.The color,cooking loss,hardness and elasticity of meat were improved by rutin.Therefore,appropriate amount of rutin had a better effect on inhibition of lipid and protein oxidation and improved the quality properties of minced pork.4.During chilled storage,gallic acid had some inhibitory effect on the formation of TEARS,thiol loss and surface hydrophobicity.The color of meat were improved by gallic acid.But gallic acid increased cooking loss of minced pork in storage and reduce hardness and elasticity of minced pork at initial storage.5.Polyphenols,as catechin,quercetin,rutin and gallic acid,which interacted with pork myofibrillar protein,structural and functional properties of the protein were studied in this paper.With concentration increased,catechin and rutin reduced thiol group of protein,gallic acid protected protein thiol content from losing.Catechins could promote an increase in fluorescence intensity of the protein,while the other three polyphenols were reduced.Interaction force of protein and polyphenol was indicated that the hydrogen bonds of four polyphenols and protein were increased.Catechins and gallic acid could promote the dissolution of protein,in contrast quercetin and rutin had an inhibitory effect.Following with concentration,catechins and gallic acid had a significant downward trend on protein gel strength and water retention.Except the maximum concentration,quercetin and rutin had an effect on enhancement of protein gel strength and water retention.Therefore protein structure and function were attributed to the kinds of plant polyphenol and its structure,related to concentration closely.