Studies On Techniques And Mechanism Of Inhibiting The Browning Of Fresh-cut Potatoes

Fresh-cut vegetables with the charicteristics of being100%edible, convenientlyconsumed, fresh, good quality has been widely accepted in developed countries. It is also thedevelopment trend of vegetable market supply in future in China. Some vegetables are easyto browning after cutting, resulting in greatly reduced commodity value. Browning not onlydirectly affect the sensory quality, but also cause loss of functional ingredients and the declinein nutritional quality. Fresh-cut potato is an important varieties of fresh-cut vegetables, butthe browning problem during processing and shelf life has not been solved. In this paper, theeffect of pre-cutting hot air and curing treatment to control the browning and its mechanismwere investigated. Results showed:1. Hot air treatment significantly prevented browning of fresh-cut potato slices duringstorage. During storage appearance color L value and overall sensory score of hot air treatedpotato were more stable. Potato did not appear browning after12days. Overall sensoryquality score and L values of control group decreased significantly. Browning occurred fromday3. They completely lose the value of the goods on day12.2. Hot air treatment inhibited browning associated with relatively decreasing electrolyteleakage, MDA content, respiration rate and the activity of phenolic enzymes of fresh-cutpotato.4CL activity and electrolyte leakage increased gradually; C4H activity and MDAincreased and then decreased during shelf life, but the data of treatment group weresignificantly lower than the control group. The present data suggests that hot air treatment canprotect the cell membrane stability and inhibit the key enzyme of phenylpropanoidmetabolism. Hot air treatment has the potential to improve the quality of fresh-cut potato andextend its shelf-life.3. The curing treatment can inhibiti browning of fresh-cut potato significantly. Curing treated slices still had good color till day12, moreover overall sensory quality was muchbetter than control. Overall sensory quality score and L values of control group decreasedsignificantly, completely losing the commodity value on day12.4. Application of curing also inhibited the gene expression of PAL and PPO of fresh-cutpotato, which was related to the browning in potato. The curing treatment inhibited mRNAlevels encoding key enzyme of phenylpropanoid metabolism, revealing its mechanism toinhibit browning from the perspective of the level of gene expression.