Zhao Chenxu, Niu Junpeng, Wang Wei, Wang Yebo, Cheng Linlin, Meng Yonghong, Guo Yurong, Song Shujie
College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710119, China.
Engineering Research Center of High-Valued Utilization of Fruit Resources in Western China, Ministry of Education, Xi'an 710119, China.
Foods. 2025 Jun 30;14(13):2322. doi: 10.3390/foods14132322.
Kiwifruit has attracted much attention in fruit and vegetable processing due to its high nutritional and economic value. However, there is a lack of systematic research on the effects of long-term frozen storage on the pulp quality of kiwifruit. Using kiwifruit pulp stored at -20 °C for 0, 3, 6, 9, and 12 months as the research materials, the dynamic changes in the phenotype, color, antioxidant activity, and flavor compounds were comprehensively evaluated. The results showed that frozen storage caused a significant decline in the quality of the fruit pulp. Specifically, the contents of chlorophyll and carotenoids decreased and the color deteriorated (color difference increased); the turbidity and centrifugal sedimentation rates increased, and pH and viscosity changed in different stages. Additionally, antioxidant compounds, such as vitamin C and total phenols, were significantly reduced with the extension of storage duration, and the 2,2-diphenyl-1-picrylhydrazyl (DPPH)/2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging ability was decreased. The content of volatile aroma compounds diminished, leading to a notable shift in the flavor profile. Correlation analysis revealed that changes in volatile substances were significantly correlated with physical, chemical, and antioxidant indicators ( < 0.05). These correlations can serve as a key basis for assessing quality deterioration. This study systematically elucidated, for the first time, the mechanism of quality deterioration in kiwifruit pulp during frozen storage, thereby providing theoretical support for enterprises to optimize pulp grading strategies and the timing of by-product development. Hence, it is recommended that the duration of freezing should be limited to less than 9 months for kiwifruit pulp. Moreover, it is essential to consider varietal differences and new pretreatment technologies to further enhance the industrial utilization and economic value of frozen pulp.
猕猴桃因其高营养价值和经济价值在果蔬加工中备受关注。然而，对于长期冷冻贮藏对猕猴桃果肉品质的影响缺乏系统研究。以在-20℃下贮藏0、3、6、9和12个月的猕猴桃果肉为研究材料，综合评价了其表型、颜色、抗氧化活性和风味化合物的动态变化。结果表明，冷冻贮藏导致果肉品质显著下降。具体而言，叶绿素和类胡萝卜素含量降低，颜色变差（色差增大）；浊度和离心沉降率增加，pH值和粘度在不同阶段发生变化。此外，随着贮藏时间的延长，维生素C和总酚等抗氧化化合物显著减少，2,2-二苯基-1-苦基肼（DPPH）/2,2-联氮-双-（3-乙基苯并噻唑啉-6-磺酸）（ABTS）自由基清除能力降低。挥发性香气化合物含量减少，导致风味特征发生显著变化。相关性分析表明，挥发性物质的变化与物理、化学和抗氧化指标显著相关（<0.05）。这些相关性可作为评估品质劣化的关键依据。本研究首次系统阐明了猕猴桃果肉冷冻贮藏期间品质劣化的机制，从而为企业优化果肉分级策略和副产品开发时机提供了理论支持。因此，建议猕猴桃果肉的冷冻时间应限制在9个月以内。此外，必须考虑品种差异和新的预处理技术，以进一步提高冷冻果肉的工业利用率和经济价值。
