Effect of Nitric Oxide on Alcoholic Fermentation and Qualities of Chinese Winter Jujube During Storage

This article investigates the effects of nitric oxide （NO） on alcoholic fermentation and the qualities of Chinese Winter Jujube during storage, and explores the action mechanisms of browning and softening of fruits to provide theoretical proofs for using NO in the storage of Chinese Winter Jujube. Chinese Winter Jujube fruits were fumigated with different concentrations of NO gas （0, 10, 20, 30 μL L^-1） under anaerobic conditions and stored at 22±1℃ and 4± 1℃. The changes in appearance qualities, the contents of pyruvate, ethanol, acetaldehyde, and the activities of alcohol dehydrogenase （ADH） and lactate dehydrogenase （LDH） were investigated. The contents of pyruvate, ethanol, and acetaldehyde were significantly reduced, and the peak of pyruvate content was delayed by 20 μL L^-1 NO. The activities of ADH and LDH in 20 μL L^-1 NO treated fruits were also significantly inhibited. However, the alcoholic fermentation and softening of Chinese Winter Jujube fruits were promoted by 30 μL L^-1 NO during storage. The results indicated that 20 μL L^-1 NO could mitigate the injury of ethanol on Chinese Winter Jujube and effectively delay the browning and softening of fruits during storage.

一氧化氮处理对冬枣贮藏期间乙醇代谢及相关品质的影响

【目的】研究NO处理对冬枣贮藏期间乙醇代谢及相关品质的影响,探讨NO对冬枣褐变软化的作用机理,为NO应用于冬枣的贮藏保鲜提供理论依据。【方法】用0、10、20、30μl·L-1NO气体熏蒸4h白熟期冬枣,研究了冬枣室温[(22±1)℃]贮藏和冷藏[(4±1)℃]期间外观品质变化的相关参数,丙酮酸、乙醇、乙醛等含量以及乙醇脱氢酶(ADH)和乳酸脱氢酶(LDH)活性的变化。【结果】20μl·L-1NO处理明显地减少了果实中乙醇、乙醛和丙酮酸的含量,且延缓了丙酮酸含量高峰的出现;显著抑制了乙醇脱氢酶(ADH)和乳酸脱氢酶(LDH)活性。30μl·L-1NO处理促进了冬枣果实在室温或冷藏期间的酒化软化。【结论】20μl·L-1NO处理可以减少乙醇积累对冬枣的毒害,有效抑制了冬枣果实贮藏期间的褐变软化。

河北和山东冬枣果实品质评价及AFLP分子标记的研究

为探讨产区间冬枣的品质、遗传差异，将来源于河北和山东不同产地的冬枣按照完全随机区组设计栽种于河北、山东、北京的4个试验园，采取同样的栽培管理措施。通过对试验园冬枣果实的形态、品质等各项指标进行连年的分析测定和感官评价，并进行了DNA—AFLP分子标记研究。结果表明：河北、山东两省冬枣的单果质量、纵横径、果形指数、可食率、含水率、着色指数，果实Vc、总糖、可滴定酸和可溶性固形物含量等指标间没有明显差异，在同一试验园两省冬枣的感官评价差异也不明显；AFLP分析证明两省冬枣样品间遗传相似性很高（SM=0．9873～1．0000），被聚为一类，表明产自河北、山东的冬枣属于同一品种，造成冬枣果实品质差异的主要原因是立地条件和管理措施。冬枣品种内确实存在一定差异，这些差异属于单株变异，与产地来源无关。

超声波提取金丝小枣多糖的工艺研究

通过分析5种枣的化学成分，确定了金丝小枣为提取枣多糖的较佳原料。探讨了超声波提取枣多糖的优化工艺。通过响应面分析法考察超声波功率、提取时间、提取温度、料液比对枣多糖得率与纯度的影响，得出枣多糖最佳的提取工艺条件为：超声波功率86～96w，提取温度45～53℃．提取时间20min，料液比1：20（g：mL），枣多糖得率7．63％，纯度35．57％。与传统的水浴浸提法相比，该方法不仅缩短了提取时间，且提高了枣多糖得率与纯度。同时，用红外光谱技术分析两种方法所得枣多糖，可知其化学结构基本一致。