Study On The Control Of The Lignification And Browning Of Fresh-Cut Bamboo Shoot

Bamboo shoot (Phyllostachys.praecox f.prevelnalis), as with high contents of protein, dietary fiber, essential amino-acids and trace mineral elements, and low contents of sugar and fat, has been appreciated by consumers for thousands of years. Fresh-cut bamboo shoot has already been saled in many supermarkets in the form of clean vegetables, but the physiological change often results in browning and lignification. Therefore, it is very important to control the lignification process and the degree of browning for extending storage-life of bamboo shoot.Temperature is one of the important external factors that affect the quality of fresh-cut bamboo shoot. This paper investigated the physiological and biochemical changes in fresh-cut bamboo shoot during storage at20℃(room temperature),10℃(supermarket freezer temperature) or4℃(refrigerator temperature). Compared with20℃, the activities of polyphenol oxidase (PPO), peroxidase (POD), and phenylalanine ammonia lyase (PAL) were significantly suppressed, and the accumulation of lignin, crude fiber, total phenolic and flavonoids were retarded, and lower browning degree and higher water and soluble proteins contents were also presented during storage at4℃and10℃. Therefore, low-temperature (4℃and10℃) inhibited the lignin metabolic, reduced the degree of browning, which was beneficial to maintain the nutritional quality of fresh-cut bamboo shoot.4℃is the best storage temperature of fresh-cut bamboo shoot compared to10℃and20℃worst.Ascorbic acid belongs to food antioxidant and is used as nutritional supplements. AsA is able to adjust lignin metabolic through regulating the oxidative polymerization of lignin monomer. This paper studied the effects of different concentrations of ascorbic acid on lignification and browning of fresh-cut bamboo shoot. The results showed that AsA treatment supressed the activities of PPO, POD and PAL, retarded the accumulation of crude fiber, lignin, total phenols and flavonoids, alleviated the browning degree, and maintained a high contents of soluble protein, soluble sugar and reducing sugar. Therefore, AsA treatment inhibited the lignin metabolic and reduced the degree of browning, which was beneficial to keep the nutritional quality of fresh-cut bamboo shoot. Also,0.8%AsA treatment achieved the best result.The paper also studied the effect of AsA treatment on the control of the lignification and browning of fresh-cut bamboo shoot in modified atmosphere packaging (MAP). The results showed that AsA treatment combined with modified atmosphere packaging (MAP+AsA) impacted on fresh shoots of woody and browning, and0.8%AsA treatment supressed the activities of PPO, POD and PAL, retarded the accumulation of crude fiber, lignin, total phenols and flavonoids, alleviated the browning degree, and maitained a high content of soluble protein, soluble sugar and reducing sugar. Therefore,0.8%AsA treatment inhibited the lignin metabolic and reduced the degree of browning, which was beneficial to keep the nutritional quality of fresh-cut bamboo shoot.