Study On The Enrichment And Bioactivity Of Phenolic Substances In Pea Sprouts

Polyphenols are plant secondary metabolites with antioxidant,anticancer and bacteriostatic effects.Since the body lacks the ability to synthesize polyphenols itself and can only obtain them through diet,the development of foods rich in polyphenols is significant.Pea can germinate under adverse conditions,regulate physiological and biochemical processes,modify the direction of substance metabolism,and enrich a large amount of phenolic substances.Glutamic acid(L-Glu)is a protein amino acid that plays a regulatory role in plant growth and development.In this study,the regulation of L-Glu on the enrichment of phenolic substances in pea sprouts under NaCl stress was discussed from the physiological metabolism,enzymology and cellular levels,and the signal transduction mechanism of L-Glu on the synthesis of polyphenol in pea sprouts under NaCl stress was revealed from the enzymology level.At the same time,biological activity experiments were carried out to reveal its antibacterial,antioxidant and anti-inflammatory effects and mechanism at the cellular level.The main research results are as follows:1.The effects of NaCl stress on physiological metabolism,phenolic synthesis and antioxidant capacity of pea sprouts were studied.The oxidative damage of pea sprouts was caused by NaCl stress.Therefore,the pea sprouts made stress response,increased the content of phenolic substances and the activity of antioxidant enzymes,and enhanced the antioxidant capacity.Among them,60 m M NaCl treatment showed the best enrichment effect of phenolic substances in pea sprouts,and the contents of nine flavonoids including rutin,vitexin,quercetin,naringin,kaempferol,dihydroquercetin,apigenin,dihydrokaempferol and quercetin,and seven phenolic acids including caffeic acid,benzoic acid,p-coumaric acid,eugenic acid,erucic acid,p-hydroxybenzoic acid and ferulic acid significantly increased.2.The effects of L-Glu on physiological metabolism of pea sprouts under NaCl stress were studied.L-Glu treatment had a concentration effect on alleviating NaCl stress,and 5 m M L-Glu had the best effect.On the 8th day of germination,the sprout length of pea under L-Glu treatment increased by 3.77% compared to NaCl stress,and the content of malondialdehyde decreased by 37.17%.The content trends of O2-· and H2O2 were consistent with that of malondialdehyde.L-Glu treatment increased the cross-sectional area of the stem and the diameter of endothelial cells,and effectively alleviated epithelial cell fold.On the 8th day of germination,the content of L-Glu in pea sprouts was increased by 3.97% compared with the control.3.The effects of L-Glu on phenolic synthesis and antioxidant capacity of pea sprouts under NaCl stress were studied.L-Glu treatment significantly increased PAL,C4 H and4CL activities,and induced PAL,C4 H and 4CL protein expressions.DNQX reduced PAL,C4 H and 4CL activity,which could be reversed by L-Glu.L-Glu treatment increased the contents of total phenolic,dihydrokathreol,rutin,vanillic acid,caffeic acid,eugenic acid and ferulic acid in pea sprouts.DNQX treatment inhibited the synthesis of these phenolic substances and the contents of polyphenolics,which was reversible after the addition of L-Glu.On the 8th day of pea germination under L-Glu treatment,ABTS and DPPH increased by 25.18% and 13.94%,respectively,compared to the control.DNQX decreased antioxidant capacity,which could be reversed by L-Glu.4.The physiological activities of phenolic extracts from pea sprouts treated with L-Glu at the cellular level were studied.Pea polyphenol extract has the strongest inhibitory activity against Pseudomonas fluorescens,with a MIC of 12.5 mg/m L.Pea polyphenols can destroy the permeability of cell membranes,leading to a significant decrease in intracellular protein,alkaline phosphatase,and ATP content.When analyzing the activity of macrophages induced by pea polyphenols and H2O2 using the CCK8 method Compared with the H2O2 injury group of 400 μmol/L,the 100 mg/m L pea polyphenols increased cell survival.Pea polyphenols can increase the activity levels of SOD,CAT,GSH,and T-AOC,reduce the content of MDA,and inhibit IL-6,IL-1β And TNF-α Secretion of proinflammatory factors.