“真空预冷+气调包装”提高桑叶菜在模拟电商物流条件下的贮藏品质

Improvement of the Storage Quality of Mulberry Leaf Vegetable by Vacuum Precooling Combined with Modified Atmosphere Packaging Under Simulated E-commerce Logistics Conditions

摘要:

为探索一种更有效的延长桑叶菜货架期的保鲜技术，本试验以单一气调包装为对照，研究不同真空预冷终温结合气调包装对桑叶菜在模拟电商物流贮藏条件下外观品质、失重率、顶空气体分压、呼吸强度和部分营养成分的影响。结果表明：真空预冷对桑叶菜品质具有双面性。较低的预冷终温（5 ℃）反而加速桑叶菜采后品质劣变、不利于贮藏保鲜；适宜的预冷终温（15 ℃）可显著延缓桑叶菜采后外观品质劣变、抑制呼吸作用，减少营养价值流失。15 ℃真空预冷结合气调包装技术可使桑叶菜在模拟电商物流条件下（非冷链）的保鲜期延长到不少于96 h；处理后桑叶菜的呼吸强度显著低于CK（597.20~308 mg CO2/(kg h) vs 464.66~298 mg CO2/(kg h)），袋内的气体氛围保持较佳水平（氧气：1.44~3.13 kPa、二氧化碳：7.30~7.56 kPa）；贮藏96 h后，与CK相比，真空预冷+气体包装处理桑叶菜的色差L*值高0.52°，a*值低0.41°，多酚和维生素C保留率分别高了7.89%和7.00%，这表明适宜的真空预冷结合气调包装技术可延缓桑叶菜采后品质下降。研究结果不仅为桑叶菜常温物流保鲜提供一种有效的技术解决方案，而且对丰富目前有关桑叶菜采后保鲜技术理论具有重要意义。

Abstract:

To explore a more effective preservation technology to prolong the shelf-life of mulberry leaf vegetables, the effects of vacuum precooling combined with modified atmosphere packaging (MAP) under different conditions on the appearance quality, weight loss rate,headspace gas partial pressure, respiration intensity and some nutrients of mulberry leaf vegetables were studied under simulated e-commerce logistics conditions, by comparing modified atmosphere packaging only (as the control). The results showed the two-sided effects of vacuum precooling on the quality of mulberry leaf vegetable. A lower precooling treatment (5 ℃) accelerated the deterioration of the quality of mulberry leaf vegetables thereby was not conducive to vegetable storage and preservation. Appropriate precooling treatment (15 ℃) could delay significantly the deterioration of appearance quality, inhibit respiration and reduce the loss of nutritional value. Vacuum precooling (15 ℃) combined with MAP could prolong the shelf life of mulberry leaf vegetables not less than 96 h under simulated e-commerce logistics conditions (non-cold chain). The respiration intensity of the mulberry leaf vegetables treated by vacuum precooling combined with MAP was remarkably lower than that of control (597.20~308 mg CO2/(kg h) vs 464.66~298 mg CO2/(kg h)), with the gas atmosphere in the package being maintained better (O2: 1.44~3.13 kPa, CO2: 7.30~7.56 kPa). After the 96-h storage, the mulberry leaf vegetables treated by vacuum precooling combined with MAP had a L* value higher than 0.52° and a* value lower than 0.41°, with the retention rates of polyphenol and vitamin C being increased by 7.89% and 7.00%, respectively. Accordingly, an appropriate vacuum precooling-MAP treatment could delay the decline of the postharvest quality of mulberry leaf vegetables. The research results not only provide an effective solution strategy for preserving mulberry leaf vegetables during logistics transportation at room temperature, but also are of great significance to enrich the existing technical theories for postharvest preserving mulberry leaf vegetables.