黄肉红心猕猴桃‘东红’果实在不同贮藏方式下的生理和品质变化研究

Research on changes in postharvest physiology and fruit quality of Actinidia chinensis ’Donghong’ under different storage methods

以中华猕猴桃( Actinidia chinensis Planch.)黄肉红心新品种‘东红’为材料,对其果实在常温和低温贮藏方式下的生理及品质变化进行了研究。结果表明,果实硬度在2种贮藏方式下均呈先快速下降后缓慢下降的趋势。可溶性固形物含量、总糖含量、固酸比和糖酸比等4个品质指标均表现为先快速上升后维持在较高水平(低温贮藏下)或继续小幅上升(常温贮藏下)的趋势。总酸含量整体上均呈现逐渐下降之势,至果实软熟时稳定在0. 9%的水平。维生素C含量却在常温贮藏下基本呈逐渐上升之势,而在低温贮藏下大致表现为先上升后轻微下降。果实失重率和腐烂率均随贮藏时间的延长而逐渐增加,在常温贮藏时上升较快,而在低温贮藏时上升非常缓慢。总体而言,‘东红’果实主要的生理和品质指标在常温贮藏2 ~ 3周后或低温贮藏9周后发生明显转变,果实进入可食用阶段;并且继续低温贮藏15周内还能较好地保持果实品质,耐贮性较好。

Changes in the postharvest physiology and fruit quality of ‘Donghong’, a novel red-fleshed kiwifruit cultivar of Actinidia chinensis Planch., under ambient and cold storage were investigated to provide theoretical and technical guidelines for fruit preservation and marketing.‘Donghong’ fruits from an orchard in Pujiang county, Sichuan Province, were collected and stored at ambient (20℃±1℃, relative humidity 70%-75%) and cold temperatures (1. 5℃± 0. 5℃, relative humidity 90%- 95%). The main physiological indices of the fruit, including fruit firmness, soluble solids content (SSC), total sugar (TS) content, titratable acidity (TA) content, SSC/TA and TS/TA ratios, vitamin C (Vc) content, weight loss rate, and rot rate, were measured once a week under ambient storage and every three weeks under cold storage. Results indicated that during both ambient and cold storage, fruit firmness dropped rapidly during the first three weeks and nine weeks of ambient and cold storage, respectively, then slowed down slightly until the end of storage. Four physiological indices, including SSC, TS content, and SSC/TA and TS/TA ratios, showed similar patterns during both ambient and cold storage, first increasing sharply and then maintaining a highly stable level during cold storage or continuing to rise slightly during ambient storage. TA showed a gradual decrease from 1. 12% to 0. 92% during ambient storage and from 1. 12% to 0. 94% during cold storage. Vc content gradually increased and reached a maximum of 134. 40 mg/100 g after five weeks of ambient storage, or generally increased at first, then declined slightly, and finally reached a maximum of 151. 13 mg/100 g after 18 weeks of cold storage. Both the weight loss and rot rates gradually increased with storage length under both temperatures, with a rapid increase under ambient storage and extremely slow increase under cold storage. Both indices reached a maximum level of 16. 09% and 20% after 33 weeks of cold storage, respectively. The main physiological indices of the ‘Donghong’ fruit exhibited obvious changes in trends after three weeks of ambient storage and nine weeks of cold storage, respectively, after which the fruits reached optimal edibility. Moreover, the ‘Donghong’ fruit largely maintained a high quality, with a very low rate of fruit rot and rarely lignified flesh during the first 24 weeks of cold storage, revealing outstanding storability.