室温和低温贮藏沙田柚果实的有机酸含量变化

【目的】研究沙田柚果实贮藏过程中的有机酸代谢及变化规律,为采后沙田柚品质保持及贮藏方式选择提供参考依据。【方法】采用高效液相色谱仪测定室温和4℃低温贮藏1~75 d沙田柚果实的柠檬酸、苹果酸、草酸、酒石酸、琥珀酸、乌头酸和延胡索酸含量。【结果】沙田柚果实的有机酸中,以柠檬酸含量最高,苹果酸含量次之,草酸、酒石酸及琥珀酸含量较低,乌头酸和延胡索酸含量为微量。室温贮藏条件下,沙田柚果实的柠檬酸含量在贮藏前期略有下降,贮藏15 d开始上升,贮藏60 d后下降;琥珀酸、乌头酸和延胡索酸含量变化趋势与柠檬酸基本相同,但出现峰值时间不同;苹果酸含量变化趋势与柠檬酸相反;草酸含量在贮藏前期上升,后期下降;酒石酸含量在贮藏前期略有下降,然后上升,60 d后下降。低温贮藏条件下,沙田柚果实的有机酸含量变化趋势与室温贮藏基本一致,但柠檬酸、草酸和延胡索酸含量低于室温贮藏,苹果酸和琥珀酸含量高于室温贮藏。【结论】沙田柚果实贮藏过程中有机酸含量变化受贮藏温度影响较小,室温贮藏沙田柚果实的总有机酸含量能维持在较高水平波动,对果实品质无明显影响。

Variation of organic acids in Citrus maxima(Burm.) Merr. cv. Shatian Yu under room and low temperature storage

Objective]The present study was conducted to study metabolism and variation of organic acid in Citrus maxima (Burm.) Merr. cv. Shatian Yu during room and 4 ℃ temperature storage in a bid, in order to provide reference for maintaining fruit quality and storage methods selection during postharvest storage. Method]Seven organic acids in C. maxima(Burm.) Merr. cv. Shatian Yu, namely citric acid,malic acid,oxilic acid,tartaric acid,fumaric acid,succinic acid and aconitic acid, were determined via high performance liquid chromatography during 1-75 days of room and 4 ℃ tem-perature storage. Result]The results showed that among 7 organic acids, citric acid content accounted for the highest proportion and followed by malic acid, contents of oxilic acid,tartaric acid and succinic acid were lower, contents of a-conitic acid and fumaric acid were trace amount. Under condition of room temperature storage,citric acid contents at early storage stage decreased slightly,began to rise after 15 days and decreased after 60 days. Vriation trend of succinic acid, aconitic acid and fumaric acid were almost the same with citric acid,but peak times were different. Different from citric acid, variation of malic acid content went up at early storage stage and decreased at late storage stage. Tartaric acid con-tent decreased slightly at early storage stage, increased later, and dropped after 60 days of storage. Under low temperature storage condition, variation of organic acid contents in C. maxima(Burm.) Merr. cv. Shatian Yu was in accordance with that under room temperature storage condition, yet contents of citric acid,oxalic acid and fumaric acid were lower than those under room temperature storage condition, malic acid and succinic acid contents were higher than those under room tempera-ture storage condition. Conclusion]Temperature has relatively small effect on variation of organic acid contents in C. maxima (Burm.) Merr. cv. Shatian Yu during storage. Under room temperature storage condition, total organic acid contents main-tain at a relatively high level, and fruit quality goes through no obvious variation.