Impact of cold plasma processing on quality parameters of packaged fermented vegetable (radish paocai) in comparison with pasteurization processing: Insight into safety and storage stability of products

Abstract

Radish paocai is a representative of fermented vegetables in China. The objective of the present study was to evaluate the potential of cold plasma (CP) treatment as decontamination technology for packaged paocai. By comparing with heat pasteurization, the effect of CP on microbial, physicochemical and organoleptic properties of paocai during storage was investigated. Results showed that CP efficiently eliminated yeasts, especially gas-producing yeast, while allowing retention of lactic acid bacteria. Compared with pasteurization at 70 °C for 30 min which eliminated 5.00 logCFU/g of microorganisms, more reducing sugar was consumed by CP-treated paocai, leading to the increase of total acid content by 72.34% and a lower pH at 3.98 after storage of 7 days. Additionally, nitrite content in CP group was 48.54% lower than that of control and was 22.22% higher than that of pasteurization group, with no significant effect on salt content and amino acid nitrogen. As for organoleptic property, firmness and b* value of CP treated samples was 12.53% higher and 26.26% lower than those of pasteurization group after storage, respectively, indicating that CP could alleviate the softening and browning of paocai. Therefore, compared with control, CP could improve the storage stability of packaged paocai, meanwhile achieving similar safety quality as pasteurization, highlighting its potential in preserving packaged fermented vegetables.