低温气调贮藏对‘突尼斯软籽’石榴果实品质的影响

Effect of cold controlled atmosphere storage on fruit quality of‘Tunisia’soft-seed pomegranate

【目的】利用气调贮藏保鲜的方法筛选石榴气调贮藏的最优气体组合,提高石榴果实的贮藏品质。【方法】以商熟期采收的‘突尼斯软籽’石榴果实为试材,设置3种气体组合CA1(5%O_(2)+2%CO_(2)),CA2(6%O_(2)+3%CO_(2))和CA3(7%O_(2)+4%CO_(2)),于(5±0.5)℃、(85±1)%相对湿度条件下贮藏30 d,自然空气为对照(CK),测定并对比15个果实品质指标和6个生理指标;通过主成分分析(PCA)确定气调组合影响石榴贮藏的主要品质指标,并结合综合评分筛选最优气体参数。【结果】与CK相比,3种气调贮藏可以有效降低花色苷与抗坏血酸含量的损失;保持较高的果皮色泽和亮度;抑制石榴果皮相对电导率的升高和丙二醛含量的累积,因而维持了较高的膜完整性,尤其是CA3处理的果实效果显著。PCA结果表明,前3个主成分的累积贡献率达到87.67%,为本研究提供了可靠的数据。第一主成分(PC1)达到43.69%的累积贡献率,果皮花色苷含量、呼吸速率(籽粒)、籽粒含水量是改善果实品质的主要指标;第二主成分(PC2)占25.29%的累积贡献率,其中L^(*)、呼吸速率(整果)和乙烯释放速率(整果)占比最高;第三主成分(PC3)占18.69%的累积贡献率,C^(*)、乙烯释放速率(籽粒)、可溶性总糖含量占比最高;因此,果皮花色苷含量、呼吸速率、籽粒含水量、L^(*)是评价气调贮藏下石榴果实品质的重要指标。结合PCA综合评价,CA3气体组合贮藏的‘突尼斯软籽’石榴果实品质综合得分最高。【结论】CA3(7%O_(2)+4%CO_(2))有效抑制花色苷的损失,减轻细胞损伤,提高保鲜效果,是‘突尼斯软籽’石榴低温气调贮藏较适宜的气体组合。

【Objective】The research aims to prolong storage life and maintain high fruit quality of pomegranate by screening the optimal gas combination using the method of cold controlled atmosphere storage.【Method】‘Tunisia’pomegranate fruits were harvested at the commercial maturity stage as materials,and stored for 30 days at(5±0.5)℃and(85±1)%of the relative humidity with four treatments:CA1(5%O_(2)+2%CO_(2)),CA2(6%O_(2)+3%CO_(2)),CA3(7%O_(2)+4%CO_(2)),and CK(the regular air).A total of 15 fruit quality indexes and 6 physiological indexes were investigated during storage.Principal component analysis(PCA)was used to evaluate the key indicators affecting fruit quality during cold controlled atmosphere storage,and further determine the optimum gas parameters combined with the overall scores.【Result】Compared with the CK,three treatments with different gas compositions effectively reduced the loss of anthocyanin and ascorbic acid content,maintained redder and lighter husk color,inhibited the increase of relative electrical conductivity and the accumulation of malondialdehyde content in husks,which kept high integrity of the cell membrane,especially in CA3 treatment.The PCA results showed that the cumulative contribution rate of first three principal components could reach 87.67%in the total variation,which provided reliable data for this study.PC1,accounting for 43.69%of total variance,was greatly contributed by anthocyanin content(husk),respiratory rate(arils)and aril moisture percentage.PC2,accounting for 25.29%of total variance,was more linked with L^(*),respiratory rate(fruit)and ethylene production rate(fruit).C^(*),ethylene production rate(arils)and total soluble sugar were more important in PC3(accounting for 18.69%of total variance).Collectively,anthocyanin content(husk),respiration rate,aril moisture percentage and L^(*)were the key indexes to evaluate pomegranate fruit quality during controlled atmosphere storage.Furthermore,‘Tunisia’pomegranate fruit quality in CA3 treatment gained the highest score based on comprehensive scores of PCA.【Conclusion】CA3(7%O_(2)+4%CO_(2))is the optimum gas compositions for‘Tunisia’pomegranate during cold storage due to effectively inhibiting the anthocyanin loss,alleviating cell damage,and improving storage life in pomegranate fruit.