Pacific white shrimps were subjected to the pulsed electric field (PEF) at varying specific energy densities (54–483 kJ/kg) and pulse numbers (200–600). The polyphenol oxidase (PPO) activity in cephalothorax was decreased as both parameters increased (p < .05). Shrimp treated with PEF at highest level (PEF‐T3) (483 kJ/kg, 600 pulses) had lower melanosis score than other samples, packaged in polystyrene trays and wrapped with shrink film, during 10 days of storage at 4°C (p < .05). Highest shear force values were noticed for the PEF‐T3‐treated sample at Day 10 (p < .05). Microstructural gaping between shrimp muscle fibers was higher in PEF‐T3. No protein degradation was observed for all samples, regardless of PEF treatments. Lower mesophilic and psychrophilic microbial counts in shrimp were obtained when PEF‐T3 was implemented. After 10 days, higher sensory scores of PEF‐T3‐treated samples were attained, compared to others (p < .05). Quality deterioration of shrimp was therefore retarded with PEF.
Practical applications
Pacific white shrimp is an economically imporatnt crustacean, which undergoes discoloration (melanosis) during the extended storage. Melanosis, in which the formation of a black spot occurs as triggered by polyphenol oxidase, is the major problem in the shrimp industry. It is of primary concern to delay melanosis associated with quality loss. Pulsed electric field (PEF) can significantly inactivate shrimp polyphenol oxidase and spoilage causing microorganisms. PEF is additive‐free and nonthermal technology that does not alter the organoleptic properties of shrimp. Industrially, PEF can serve as a promising and eco‐friendly technology for the prevention of quality loss in shrimp.