Effect of high voltage cold atmospheric plasma processing on the quality and shelf-life of Pacific white shrimp treated with Chamuang leaf extract

Abstract

High voltage cold atmospheric plasma (HV-CAP) using dielectric barrier discharge was implemented on Pacific white shrimp (PWS) pre-soaked with 0.5 or 1% Chamuang leaf extract (CLE). PWS were firstly packed under different gas ratios of Ar, O2 or air and then subjected to HV-CAP for 10 min. Lower melanosis scores were found in the samples treated with 1% CLE and HV-CAP in the presence of Ar and air (80:20) than the control and other samples throughout the storage of 15 days at 4 °C (P < 0.05). Chemical quality changes in CP-Ar/Air-1 CLE sample were not significantly found at day 15. Those were evidenced by lower changes in pH (6.90), lower carbonyl content (2.41 μmol/mg protein), total volatile base (TVB) content (17.81 mgN/100 g meat), peroxide value (4.21 mg cumene hydroxide/kg meat) and thiobarbituric acid reactive substances (TBARS) (2.35 mgMDA/kg meat) at the end of storage, compared to those of the control and other samples treated with 0.5% CLE and HV-CAP under different gas compositions at day 15 of storage (P < 0.05). Mesophilic bacteria, Pseudomonas, H2S-producing bacteria, Enterobacteriaceae, lactic acid bacteria and psychrophilic bacterial counts were less or equal to 5 log CFU/g meat in CP-Ar/Air-1 CLE sample, which were lower than the control and other treated samples at the end of the storage (4 °C) (P < 0.05). CP-Ar/Air-1 CLE sample also exhibited higher likeness scores for all the tested attributes, mostly associated with the reduced protein and lipid oxidation at the end of storage. After treatment, oxidation of polyunsaturated fatty acids (EPA and DHA) was lowered by 14.9% and 12.4% in CP-Ar/Air-1 CLE sample, compared to that found in the control (P < 0.05). Protein oxidation of HV-CAP treated sample was prevented by 1% CLE, irrespective of gas composition. Therefore, HV-CAP especially under the mixture of Ar and air along with high level of CLE, exhibited high efficacy in prolonging shelf-life of refrigerated (4 °C) Pacific white shrimp up to 15 days.