Pomegranate is a subtropical and chilling sensitive fruit. In this study, the effects of malic acid (50 and 100 mM) and oxalic acid (5 and 10 mM) on quality properties of pomegranate during cold storage (2 ℃) were investigated. The lowest weight loss was observed in fruit treated with 50 mM malic acid. Malic acid had positive effects on color parameters (L*, a*, and b*) of pomegranate at low temperature. Organic acid treatments reduced chilling injury, malondialdehyde, and hydrogen peroxide and increased catalase activity. The lowest activity of polyphenol oxidase and peroxidase was observed in 5 mM oxalic acid-treated fruit. On the other hand, fruit treated with 50 mM malic acid showed the maximum ascorbic acid and citric acid content. The most antioxidant activity was found in fruit treated with 5 mM oxalic acid and 50 mM malic acid. Also, all treatments except 10 mM oxalic acid and 100 mM malic acid resulted in higher titratable acidity than control fruit. Overall, 50 mM malic acid and 5 mM oxalic acid were the most effective for preserving the quality of pomegranate fruit at low temperature.

中文翻译：

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有机酸处理对冷藏石榴果实品质及生物活性成分的保持

石榴是一种亚热带和寒冷敏感的水果。本研究考察了苹果酸（50和100 mM）和草酸（5和10 mM）对冷藏（2 ℃）石榴品质特性的影响。在用 50 mM 苹果酸处理的水果中观察到最低的重量损失。苹果酸对低温下石榴的颜色参数（L*、a* 和 b*）有积极影响。有机酸处理减少了冷害、丙二醛和过氧化氢并增加了过氧化氢酶活性。在 5 mM 草酸处理的果实中观察到多酚氧化酶和过氧化物酶的最低活性。另一方面，用 50 mM 苹果酸处理的水果显示出最大的抗坏血酸和柠檬酸含量。在用 5 mM 草酸和 50 mM 苹果酸处理的水果中发现了最大的抗氧化活性。还，除 10 mM 草酸和 100 mM 苹果酸外，所有处理的可滴定酸度均高于对照水果。总体而言，50 mM 苹果酸和 5 mM 草酸在低温下对保持石榴果实的品质最有效。