Combined effects of pulsed electric field, Chamuang leaf extract and cold plasma on quality and shelf-life of Litopenaeus vannamei

Pulsed electric field (PEF) pre-treated Litopenaeus vannamei were immersed in Chamuang leaf extract (CLE) solutions (1 or 2%), followed by high voltage cold atmospheric plasma (HVCAP) in an argon/air (80:20) modified atmosphere for 10 min. Least melanosis scores were attained in the samples pre-treated with PEF (15 kV/cm, 800 pulses, 697 kJ/kg) and CLE (2%) prior to HVCAP compared to the untreated control, during 18 days at 4 degrees C (P < 0.05). The lowest microbial load and spoilage bacteria count (<= 5 log CFU/g meat) were attained in PEF treated sample with 2% CLE followed by HVCAP (P < 0.05). Prior PEF sample in presence of 2% CLE showed lower peroxide value, thiobarbituric acid reactive substances, pH, total volatile base and protein carbonyl content than others (P < 0.05). Higher likeness scores were noted for all the attributes of the sample with prior PEF and 2% CLE sujected to HVCAP. Oxidation of polyunsaturated fatty acids and proteins was alleviated by CLE treatment. Phenolic compounds in CLE along with active species generated from HVCAP effectively inhibited microbial growth of L. vannamei during refrigerated storage. Thus, shelf-life of L. vannamei could be extended to 18 days using the selected combined hurdle technologies, while the control (without treatment and kept in air) had the shorter shelf-life (9 days).

Automated summary

The combination of PEF pre-treatment with CLE immersion followed by HVCAP treatment resulted in reduced melanosis, microbial load, spoilage bacteria count, oxidation levels, and improved likeness scores in Litopenaeus vannamei samples during refrigerated storage. The presence of phenolic compounds in CLE along with active species generated from HVCAP effectively inhibited microbial growth, extending the shelf-life of the shrimp to 18 days, compared to the untreated control with a shelf-life of only 9 days.