Mechanism of plasma-activated water on the regulation of storage quality of fresh-cut carrots and activation of its antioxidant defence system

Abstract

This study investigated the impact of plasma-activated water (PAW) on the storage quality of fresh-cut carrots (FCC). The findings revealed that PAW treatment, particularly the 3-min immersion method, led to a substantial enhancement in the quality of the stored carrots. Specifically, the PAW-3 min group decreased by 20.08 %, 55.34 %, and 52.66 % in L*, a*, and b* values respectively (comparing storage days 7 d to 0 d). Notably, the PAW-3 min group demonstrated the least decrease in brightness and exhibited superior yellow color retention compared to the other treatment groups. Concerning weight, a 4.86 % decrease was observed in the PW group from day 0 to day 7 of storage, while the PAW-5 min group exhibited a 2.06 % decrease, suggesting that prolonging the PAW treatment time enhances the retention of sample weight. With regard to hardness, the PAW-3 min group exhibited the least weight loss of 4.62 % among all the treatment groups. The H₂O₂, a reactive oxygen content, increased from 6.22 ± 0.26 μmol/g to 10.55 ± 0.13 μmol/g with the extension of PAW treatment time, achieving an enzyme inhibition of browning, thus controlling water evaporation and microbial activity. The study demonstrated that PAW ensured uniform water distribution, activated the antioxidant system, and promoted phenolic compound synthesis. It was determined that extended treatment times resulted in cellular damage, and that shorter PAW treatment times (1 to 3 min) were optimal. The findings of this study suggest that this non-chemical method is effective in extending the shelf-life of FCC.