Effect of konjac glucomannan coating on antioxidant capacity and phenolic metabolism in fresh-cut lotus roots
Effect of konjac glucomannan coating on antioxidant capacity and phenolic metabolism in fresh-cut lotus roots
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DOI：
10.1111/jfpp.13759
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发表时间：
2018-09
影响因子：
2.5
通讯作者：
Dandan Zhou;Yangmin Huang;K. Tu
中科院分区：
文献类型：
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作者：
Dandan Zhou;Yangmin Huang;K. Tu
以魔芋葡甘露聚糖(KGM)为天然涂膜基质，在4℃条件下贮藏8d。20 mg/L KGM处理显著地保持了莲藕的色泽(L值)，抑制了呼吸强度，延缓了可溶性固形物含量的下降。在抗氧化能力试验中，KGM可通过提高过氧化氢酶和超氧化物歧化酶的活性来增强抗氧化能力，提高抗氧化能力。与抗氧化能力类似，处理组的总酚含量也表现出高于未处理组的值。魔芋葡甘聚糖还能抑制邻苯二酚的降解，增加肉桂酸的含量。与酚类代谢有关的是，20 mg/L的魔芋葡甘聚糖能提高过氧化物酶和苯丙氨酸解氨酶的活性，但抑制多酚氧化酶的活性。这些观察结果表明，魔芋葡甘聚糖可通过其酚类代谢和抗氧化能力来维持鲜切莲藕的品质。实践应用表明，魔芋葡甘聚糖可抑制组织褐变，保持鲜切莲藕的品质。本研究也有助于了解魔芋葡甘聚糖对鲜切莲藕组织褐变的影响规律。我们还从反应氧和酚类物质的途径探讨了魔芋葡甘聚糖包衣莲片抑制组织褐变的机理。魔芋葡甘聚糖具有无毒、保鲜效果好等特点，是一种很有潜力的保鲜鲜切果蔬保鲜保鲜的天然产品，是一种很好的商业保鲜产品。
Konjac glucomannan (KGM) was used as a natural coating matrix applied on fresh‐cut lotus roots at 4°C during 8 days storage. Treatment with 20 g/L KGM significantly maintained the color (L value), inhibited the respiration rate and delayed the decrease of the soluble solid content of lotus roots. For the antioxidant capacity test, KGM can enhance the antioxidant capacity by increasing activities of catalase and superoxide dismutase and increase the antioxidant capacity. Similar to the antioxidant capacity, the total phenolic contents in treated groups also exhibited higher value than untreated ones. Also, konjac glucomannan inhibited the degradation of catechol and increased cinnamic acid contents. In relation with phenolic metabolism, KGM at 20 g/L can improve the activities of peroxidase and phenylalanine ammonia lyase, but inhibit the activity of polyphenol oxidase. These observations indicted that KGM could maintain the quality of fresh‐cut lotus root by the phenolic metabolism and antioxidant capacity.Practical applicationsThis study suggested that konjac glucomannan inhibited tissue browning and maintain qualities of fresh‐cut lotus roots. This study is also helpful to understand the regulation of tissue browning in fresh‐cut lotus roots treated by konjac glucomannan. We have also explored the mechanism of the inhibition of tissue browning in lotus root slices coated with konjac glucomannan by the pathways of reactive oxygens and phenols. Concerned the nontoxic character and the high efficiency to preserve lotus root slices, konjac glucomannan can be a promising potential treatment to preserve qualities of fresh‐cut fruits and vegetables, and this natural product could be considered as good candidates to be commercial preservations.