莲藕贮藏期间褐变生理的比较研究

Comparative study on browning of lotus in storage

莲藕是我国出口创汇的重要蔬菜之一,而褐变是莲藕贮藏和加工过程中限制其品质的关键问题。研究莲藕贮藏期间不同温度条件下可溶性蛋白质、还原糖等褐变相关成分,以及多酚氧化酶活性、呼吸强度等生理生化指标,从各指标的变化规律出发,探讨两类指标与褐变的相互关系。研究结果表明:莲藕采后贮藏期间,褐变度和PPO活性均呈上升趋势,可溶性蛋白质含量呈先上升后下降的趋势,还原糖含量在不同温度下变化差异显著。与室温贮藏相比,冷藏条件下的莲藕褐变度和PPO活性较低,而可溶性蛋白质和还原糖含量较高。室温和冷藏贮藏下莲藕的呼吸强度高峰分别出现在采后的第4天和第15天。莲藕褐变度与PPO活性之间、还原糖含量与呼吸强度之间存在很大的相关性。

Lotus is one of the important vegetable to earn foreign exchange through exports, but browning is the key problem on limiting the quality of lotus during the storage and processing. Biophysical and biochemical indexes correlating with the browning under different temperature during storage had been studied. The results showed that the degree of browning and PPO activity were in a general trend of increasing. Solute proteincontent rised firstly and then decreased. Reducing sugar content showed significant differences between room temperature and lower temperature. When lotus were stored at a lower temperature, the degree of browning and PPO activity were low, but solute protein content and reducing sugar content were high. The time of respiratory peak appeared at the 4th day and the 15th day respectively, The PPO activity was positively correlated with the degree of browning, and reducing sugar content was positively correlated with the respiratory rate.