Study On The Inhibition Technology And Mechanism Of Seabuckthorn Extract On Browning Of Fresh-cut Potatoes

Fresh-cut potatoes are popular with consumers due to their convenience,hygiene,and ready-to-eat features.However,with the influence of mechanical damage,fresh-cut potatoes are easy to water loss,browning,and microbial contamination,which greatly reduce the value of the commodity.Among them,browning is the most important factor affecting the quality and value of fresh-cut potatoes,and it is particularly important to study the technique of browning control.The water extracts of sea buckthorn are natural,safe and rich in antioxidants such as flavonoids and phenols,which have strong biological activity.However,there are not researches on the browning inhibition of fresh-cut potatoes.The experiment first identified the components of sea buckthorn,then the treatment technique of seabuckthorn extracts on the browning inhibition of fresh-cut potatoes was investigated,and the mechanism of browning inhibition was finally explored on the physiological and protein levels.The results are as follows:（1）The components of seabuckthorn extract were identified by liquid chromatography-mass spectrometry technology（LC-MS）,and it was found the gallic acid,ephedrine,peony,quercetin,isorhamnetin and other phenols were the main constituents of water and alcohol extracts of seabuckthorn.The contents of total phenolics and flavonoids were 2.85 mg/g and 9.60 mg/g,respectively.Seabuckthorn extracts have strong antioxidant activities,and the scavenging activities of DPPH and ABTS free radicals was 43.96%（after400 times dilution）and 39.86%（after 40 times dilution）,respectively.（2）Compared with 18 medicinal and edible plants,the water extracts of seabuckthorn leaves and fruits showed better browning inhibition effect.It exhibited the best browning inhibition effect with the ass ratio of 1:40（seabuckthorn leaf/water）,which was significantly better than the control and 0.5%Vc.The treatment time had little effect on the browning inhibition effect of seabuckthorn extracts,and treatment for 3min showed a better inhibition effect.After further components ratio experiments,it was found the best browning inhibition effect was obtained with the addition ratio of ascorbic acid,gallic acid,ephedrine,erythropeony,and isorhamnetin in 80 mg/L,120 mg/L,10 mg/L,10 mg/L,50 mg/L,respectively.（3）The results of physiological indexs of potatoes showed the seabuckthorn leaf extracts significantly inhibited the activity of PPO and POD enzymes in fresh-cut potatoes,and the inhibition effect was better than 0.5%Vc.The PAL enzyme activity of fresh-cut potatoes increased after the treatment of seabuckthorn leaf extracts,which in turn caused the accumulation of total phenols and increased the content.In addition,the treatment of seabuckthorn leaf extracts increased the antioxidant activities of fresh-cut potatoes,and the scavenging activities of DPPH and ABTS free radicals of fresh-cut potatoes were higher than those of water control.（4）The results of enzymatic kinetics and molecular docking showed the seabuckthorn leave extracts competitively inhibited the activity of PPO enzyme,and the IC₅₀was 0.704 g/L.Gallic acid and ascorbic acid in seabuckthorn extracts bind to the active site of PPO enzyme with low binding energy values of-9.129 and-7.942 kcal/moL,and also interacted with PPO enzyme through hydrogen bond,van der Waals force and electrostatic attraction,thus inhibiting the activity of PPO enzyme.But isorhamnetin has little effect on PPO enzyme.