Impact of static electric field on different freezing rates in quality preservation of scallops

Abstract

This study investigates the impact of static electric field (SEF) assisted freezing at different freezing rates on the quality of scallops (Mizuhopecten yessoensis). Samples were frozen in static air at −20 °C, −40 °C, and − 60 °C with applied SEF intensities of 0, 2.77 × 10⁵ V/m, 5.55 × 10⁵ V/m, and 8.33 × 10⁵ V/m. Key quality attributes, including nucleation temperature, phase transition time, textural properties, color changes, protein solubility, and microstructural integrity were evaluated. Results show that applying an electric field shortens the nucleation time. From an SEF of 0 to 8.33 × 10⁵ V/m, the degree of supercooling has decreased by 1.14 °C, 1.87 °C, and 2.03 °C at freezing temperatures of −20 °C, −40 °C, and − 60 °C, respectively. The application of SEF also demonstrated an improvement in post-thaw texture, particularly chewiness and resilience, while minimizing structural damage to muscle fibers. Microstructural analysis revealed that 8.33 × 10⁵ V/m SEF has reduced the ice crystal size by 29.01 %, 36.04 %, and 44.05 % at −20 °C, −40 °C, and − 60 °C, respectively, in comparison to the control group. Additionally, the color differences between the fresh and thawed samples were minimized under the highest electric field and fastest freezing rate condition at −60 °C. Interestingly, under slow freezing condition at −20 °C and 8.33 × 10⁵ V/m SEF, ice crystal size, color difference, and other quality indicators approached those achieved by rapid freezing at −60 °C without SEF. This study confirms that electric field-assisted freezing enhances the quality of scallops and provides valuable insights for potential improvement of food freezing processes.