伤处理抑制鲜切马铃薯褐变的技术及机理研究

The Technique and Mechanism of Injury Induction to Inhibit Fresh-cut Potato Browning

为解决鲜切马铃薯易褐变的问题,寻找行之有效的褐变抑制方法,笔者研究伤处理对鲜切马铃薯褐变的抑制效果及机理。采用切伤和刮伤2种方式处理马铃薯块茎,然后分别置于5、20℃下放置12、18、36 h,探究不同伤处理方式及条件对鲜切马铃薯褐变的抑制效果。结果表明,采用刮伤并于20℃放置18 h处理对鲜切马铃薯褐变的抑制效果最佳;处理组鲜切马铃薯货架期比对照延长了4天。与对照相比,伤处理降低了贮藏期间鲜切马铃薯多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)活性及总酚含量,提高了超氧化物歧化酶(SOD)和过氧化物酶(POD)的活性及DPPH自由基清除能力,降低了丙二醛(MDA)的含量。研究结果表明伤处理通过显著降低酚类物质的积累、酶促氧化以及提高鲜切马铃薯的抗氧化能力降低膜透性来抑制鲜切马铃薯的褐变,为抑制鲜切马铃薯褐变提供了一种简便易行、安全有效的新方法。

To solve the browning problem of fresh-cut potatoes usually occurred during shelf-life storage and to develop a new technique with stable effect and simple operation on inhibiting browning, injury induction treatment was applied to prevent the browning of fresh-cut potato. Injury induction treatment was conducted by cutting off surface tissues at both ends of each potato with cutting or scraping and the condition were 5 or20℃ for 12, 18 or 36 h. Scrape injury induction treatment effectively inhibited the browning of fresh-cut potatoes and the best treatment condition was 20℃ for 18 h, which prolonged the shelf life of fresh-cut potatoes for 4 d. Compared with control, injury induction treatment significantly inhibited the activity of PPO,PAL and the content of total phenolics and MDA, increased the activity of SOD, POD and DPPH inhibition rate. The results showed that the injury induction treatment enhanced the antioxidant activity and reduced membrane permeability and lowered the accumulation and enzymatic oxidation of phenolics browning which inhibited the browning of fresh-cut potatoes. The treatment provides a new method to restrain the browning of fresh-cut potatoes during processing and storage.