Effects of decapitation in combination with pulsed electric field and chitooligosaccharide pretreatment on freshness and physicochemical properties of muscle in Harpiosquillid mantis shrimp (Harpiosquilla raphidea) during storage

Freshness and physicochemical properties of myofibrillar protein (MP) from decapitated Harpiosquillid mantis shrimp (HMS) treated with pulsed electric field (PEF), followed by soaking in 2% chitooligosaccharide (D-P-COS) and whole HMS (U-W) during storage in iced water of 3 days were investigated. Lower rate of increase in K-value, freshness index, in D-P-COS was observed in comparison with U-W. For physicochemical properties of MP, MP from U-W had gradual decrease in ATPase activity throughout the storage of 3 days, whereas no drastic alteration was attained in MP from D-P-COS. Surface hydrophobicity and carbonyl contents of MP from both samples upsurged up to 3 days, nevertheless the increases were more pronounced in D-P-COS. The secondary conformation changes were affected by decapitation, treatment and storage time. Decapitation and treatments maintained freshness, however, slightly enhanced physicochemical changes of MP from HMS.