精准温度处理对鲜切莲藕褐变、生理和品质的影响

为了明确精准温度处理对防褐变剂处理后鲜切莲藕褐变、生理和品质的调控作用，采用防褐变剂（质量分数1.0%无水柠檬酸+0.1%抗坏血酸钙+0.2% L-天门冬氨酸）处理鲜切莲藕，在相温（?0.5±0.1）℃、冰温（?0.5±0.3）℃和冷藏（4±1）℃的条件下贮藏，研究不同精准温度对鲜切莲藕表观色泽、褐变底物与相关酶活性、生理指标和营养品质的影响。结果表明，贮藏6 d时，精准温度（相温、冰温）处理可以延缓L*的降低、a*和褐变度的增加，抑制总酚的下降和褐变相关酶多酚氧化酶和过氧化物酶活性，其中相温贮藏维持鲜切莲藕原有色泽最佳。在贮藏过程中，精准温度（相温、冰温）处理能够抑制鲜切莲藕呼吸强度、乙烯生成速率、相对电导率和丙二醛含量上升，同时延缓鲜切莲藕还原糖的升高和V_C含量的下降。通过SPSS综合评分显示，相温组综合得分最高，主成分分析显示，相温组与多酚氧化酶、相对电导率、褐变度、丙二醛、a*的相关性较低。因此，相温贮藏更好地延缓鲜切莲藕贮藏期间褐变的发生并维持其品质。

Effects of Precise Temperature Treatment on the Browning,Physiological and Quality of Fresh Cut Lotus Root

In order to determine the effect of phase temperature storage on the quality of fresh cut lotus root after anti browning agents treatment. Fresh cut lotus roots were treated with anti browning agent (mass fraction of 1.0% anhydrous citric acid+0.1% calcium ascorbate+0.2% L-aspartic acid) and stored at phase temperature (?0.5±0.1) ℃, ice temperature (?0.5±0.3) ℃ and cold storage (4±1) ℃. The effects of different precise temperature on apparent color, browning substrate and related enzyme activities, physiological indices and nutrient quality of fresh cut lotus root were studied. The results showed that precise temperature (phase temperature and ice temperature) could delay the decrease of L*, the increase of a* and browning degree, inhibit the decrease of total phenol and the activities of polyphenol oxidase and peroxidase when stored for 6 d, and the phase temperature storage was the best to maintain the original color of fresh-cut lotus root. In the storage process, the precise temperature (phase temperature and ice temperature) treatment could inhibit the increase of respiratory intensity, ethylene production rate, relative conductivity and malondialdehyde content, while delaying the increase of reducing sugar and the decrease of V_C content in fresh cut lotus root. The comprehensive score of SPSS showed that the comprehensive score of phase temperature group was the highest. Principal component analysis showed that the correlation between phase temperature treatment group and polyphenol oxidase, relative conductivity, browning rate, malondialdehyde and a* was lower. Therefore, phase temperature storage could delay the browning and maintain the quality of fresh cut lotus root.