精准温度控制对蓝莓的低温保鲜效果

为研究精准温度控制技术在蓝莓保鲜中的应用效果，该研究采用了对照组和3个精准温控组，分别是将蓝莓装入泡沫箱（control check，CK）、泡沫箱+蓄冷剂（冰温1）、精准温控箱（冰温2）和精准温控箱+蓄冷剂（相温）中，记录箱内温度，结合贮藏期间蓝莓的品质变化，通过主成分分析法对四组蓝莓进行综合评价，以得到最佳精准温度控制的处理方式。结果表明，冰温贮藏的箱内温度更低，相温贮藏箱内温度较CK波动更小，贮藏第60 d时，相温组蓝莓的好果率、软果率、风味指数及果霜覆盖指数分别为79.54%、17.87%、72.22%、76.00%，色泽变化低于2，L值达27.03，此外，精准温度控制贮藏的蓝莓硬度更高，可溶性固形物、可滴定酸、Vc、花青素等营养物质消耗速度更慢，其中CK组蓝莓贮藏期间Vc含量分别比精准温控组多下降了5.01、9.18、16.67 mg/100 g，经主成分分析后得到四组蓝莓的品质排序为相温组>冰温2组>冰温1组>CK组，且精准温度控制贮藏的蓝莓醛类、萜类、酯类等有利香气成分相对含量更高。因此，精准温度控制技术有利于蓝莓的冷藏保鲜，其中相温贮藏效果更好。

Effect of Precise Temperature Control on Low-temperature Preservation of Blueberries

In order to study the application potential of precision temperature control technology in the preservation of blueberries, blueberries were divided into a control group and three precision temperature control groups, which were put into a foam box (CK), a foam box + cool-storage agent (ice temperature 1), a precision temperature control box (ice temperature 2), and a precision temperature control box + cool-storage agent (phase temperature). The temperatures inside the boxes were recorded every day, and the quality changes of blueberries were measured during storage. Then the four groups of blueberries were comprehensively evaluated by the principal component analysis method, to obtain the most accurate temperature control processing method. The results showed that the inner temperature of the icestorage boxes was lower, and the inner temperature of the phase temperature storage boxes fluctuated to a lesser extent than that of the control. On the 60th day of storage, the good fruit rate, soft fruit rate, flavor index and fruit frost coverage index of blueberries of the phase temperature group were 79.54%, 17.87%, 72.22%, 76.00%, respectively, with their color changes less than 2, and their L values as 27.03. In addition, blueberries stored by the precision temperature control had higher hardness, and lower consumption rates for nutrients such as soluble solids, titratable acid, Vc and anthocyanins. Among which, the Vc content of blueberries of the CK group decreased by 5.01, 9.18 and 16.67 mg/100 g, respectively, compared with those of the ice temperature group 1, ice temperature group 2 and phase temperature group. After principal component analysis, the quality ranking of the four groups of blueberries was: phase temperature group> ice temperature group 2> ice temperature group 1> CK group. Moreover, the relative contents of the desirable aroma components (such as aldehydes, terpenoids and esters) of the blueberries stored by precision temperature control were higher. Therefore, precision temperature control technology is beneficial to the cold preservation of blueberries, with the effect of the phase temperature storage being better.