Effect of Electrostatic Field Synergetic Modified Atmosphere Packaging Treatment on the Quality of Two Varieties of Litchi during Cold Storage

This study aimed to investigate the effects of electrostatic field (EF) combined with modified atmosphere packaging (MAP) on the preservation of litchi, focusing on two varieties: Jinggang Hongnuo and Ba Yuehong. This research utilized a separate electrostatic field treatment (LTS+EF) and a low temperature treatment (LTS) as control to evaluate quality changes during storage. The results showed that compared with LTS (browning index of 2.5 prevails), LTS+EF extended the storage period of Jinggang Hongnuo and Ba Yuehong from 10 days to 15 days and 10 days to 25 days, respectively. Furthermore, the combination of LTS+EF+MAP further prolonged the storage period to 30 days for Jinggang Hongnuo and 40 days for Ba Yuehong. Notably, on the 20th day of storage for Jinggang Hongnuo and the 25th day for Ba Yuehong, the effects were significant. The LTS+EF+MAP and LTS+EF treatments reduced the weight loss rate of 71.8% and 6.4% (Jinggang Hongnuo), 88.6% and 27.9% (Ba Yuehong) respectively, compared to LTS. The color differences were decreased by 35.3% and 10.4% (Jinggang Hongnuo), 58.1% and 27.6% (Ba Yuehong) respectively, and browning index decreased by 71.5% and 17.0% (Jinggang Hongnuo), 74.6% and 34.0% (Ba Yuehong) respectively. The soluble sugar retention rates increased by 8.0% and 2.4% (Jinggang Hongnuo), 14.0% and 1.4% (Ba Yuehong) respectively. VC retention increased by 31.1% and 5.6% (Jinggang Hongnuo), 84.6% and 54.5% (Ba Yuehong). These findings collectively suggested that LTS+EF+MAP provided the most effective method for both litchi varieties. The EF treatment demonstrated a superior protective effect on the moisture retention and color of the Ba Yuehong litchi pericarp. The preservation benefits of EF were primarily evident during the initial 15 days. When further combined with MAP treatment, the preservation effect extends to the first 20 days (maintaining the browning index at approximately 1.0). Moreover, the preservation effect of MAP treatment on VC was surpassed that of MAP and LTS treatments. Notably, Ba Yuehong exhibited greater storage resilience compared to Jinggang Hongnuo, and LTS+EF+MAP had better preserving effect on Ba Yuehong.