不同贮藏方式对赣南纽荷尔脐橙果实品质的影响

【目的】研究机械冷库（Mcs）、山区水冷贮藏库（Ecvs）和通风贮藏库（Vws）对赣南纽荷尔脐橙(Citrus sinensis Osbeck‘Newhall’)果实的贮藏效果，为优化柑橘贮藏条件及贮藏库的改良提供理论依据。【方法】将商业成熟度的纽荷尔脐橙果实分别放置于3种不同类型的生产贮藏库，持续跟踪贮藏库的环境参数变化；运用气相色谱仪、红外线CO2分析仪等设备，分析贮藏果实的生理和生化指标，并进行感官评价。【结果】在贮藏期内，3种贮藏库内部环境参数持续变化，Mcs内部温度和相对湿度分别维持在2.1—11.2℃和64.4%—99.0%之间。随着气温升高，Mcs内部与运输或货架期环境的温差逐渐加大，与Vws、Ecvs存在显著差异。Vws与Ecvs内部温度和相对湿度的皮尔森系数分别达到0.80以上，变化趋势一致，但是，比较两种贮藏库相同时刻的温度和相对湿度，Ecvs延缓库内部温度升高，维持库内相对湿度的能力优于Vws。同时，Mcs内部CO2和乙烯浓度显著高于其他贮藏库。果实可滴定酸和可溶性固形物含量随着贮藏期的延长逐渐下降，而且果实可滴定酸比可溶性固形物下降更剧烈。在105 d(days of storage，DOS)后，Ecvs贮藏果实的可滴定酸含量显著高于Vws和Mcs贮藏果实，而果实可溶性固形物含量在各贮藏方式之间无显著性差异。果实的柠檬酸和苹果酸浓度在135 DOS显著下降，3种贮藏方式之间，果实柠檬酸和苹果酸的浓度存在差异，在65 DOS后，Ecvs贮藏果实柠檬酸和苹果酸浓度高于Mcs、Vws贮藏果实。在135 DOS前，Mcs维持果实硬度、可溶性糖、Vc效果明显优于Ecvs和Vws；但是在160 DOS，Mcs贮藏果实的硬度、可溶性糖和Vc损耗加剧，其含量显著低于Ecvs贮藏的果实。此外，果实的乙醇、乙醛、甲醇的浓度在105 DOS显著升高，3种贮藏方式之间，Mcs贮藏果实在160 DOS的乙醇积累量(723.02 μg?L-1)显著高于Ecvs、Vws贮藏果实，果实风味品质降低。Ecvs、Vws贮藏果实感官满意度随贮藏期延长不断波动，而Mcs贮藏果实感官满意度先升高后逐渐下降，在160 DOS显著低于Vws和Ecvs贮藏的果实。【结论】贮藏库与运输、货架期环境的温差，贮藏库内气体成份，尤其是乙烯，显著影响果实有机酸、乙醇、乙醛和甲醇的含量，导致不同贮藏库的果实品质和感官满意度的差异。Mcs贮藏果实在135 DOS品质出现劣变，Ecvs贮藏果实寿命可延长至160 DOS，而Vws贮藏果实品质在65 DOS后显著下降，不适于长期贮藏脐橙。

Effects of Different Storage Methods on Fruit Quality of ‘Newhall’ Navel Orange (Citrus sinensis Osbeck‘Newhall’) in Southern Jiangxi Province

【Objective】The objective of this study is to optimize the storage conditions of citrus and provide a scientific foundation for storage warehouse improvement.【Method】Storage experiments were performed with commercially mature ‘Newhall’ navel orange fruits using three storage methods, including mechanical cold storage (Mcs), evaporative cooling ventilating storage in mountainous region (Ecvs) and ventilating warehouse storage (Vws). Environmental parameters of these storage conditions were termly detected. Meanwhile, the fruit physiological and biochemical indexes were measured with gas chromatography and infra-red CO2 analyzer. Moreover, fruit organoleptic properties were evaluated as well. 【Result】 The environment parameters under the three storage conditions changed constantly. The temperature and relative humidity in Mcs ranged from 2.1℃ to 11.2℃ and 64.4% to 99.0%, respectively. As the weather gets warm, the temperature variations of Mcs between storehouse and transport or shelf life condition were significantly different from those of Ecvs and Vws. Although the changing trends of storage parameters in Ecvs were similar to those in Vws, industry experiences revealed that the storage condition was more suitable to orange storage in Ecvs than in Vws. The concentrations of CO2 and ethylene in Mcs were significantly higher than those in Ecvs and Vws. The contents of titratable acid, soluble solid and concentration of organic acids in fruit juice decreased with the extension of storage phase. Among these storage methods, there were significant differences in the content of titratable acid and malic acid, but not in total soluble solid in fruit juice. The content of titratable acidity after 105 days of storage (DOS) remained much higher in Ecvs than that in Mcs and Vws, and similar result was observed from the changing tendency of organic acids after 65 DOS. Prior to 135 DOS, fruit firmness, content of soluble sugar and vitamin C were higher in Mcs than those in Ecvs and Vws. The content of ethanol, acetaldehyde, methanol increased sharply at 105 DOS. At 160 DOS, the ethanol content was also significantly higher in Mcs than that in Ecvs and Vws, which aggravated fruit quality derogation and accumulated abundant off-flavor components in Mcs. During the storage, the hedonic scale of fruits in Ecvs and Vws fluctuated occasionally, the peak was observed at 35 DOS, subsequently declined gradually, and reached the lowest level at 135 DOS. Among these storage conditions, the lowest hedonic scale was detected in Mcs at 160 DOS.【Conclusion】In storage warehouse, the contents of fruit organic acids, ethanol, methanol and acetaldehyde were mainly affected by gas components, especially ethylene, and temperatures differences between storehouse and transport or shelf life conditions. And these indexes are directly related to fruit quality and organoleptic properties among these storage warehouses. Fruit quality in Mcs deteriorated at 135 DOS, while fruit in Ecvs could maintain relatively high quality until 160 DOS. Moreover, Vws is more suitable for orange short-term storage, as fruit quality degenerated gradually after 65 DOS.