Effect of using a high voltage electrostatic field on microbial communities, degradation of adenosine triphosphate, and water loss when thawing lightly-salted, frozen common carp (Cyprinus carpio)

As a novel technology, high voltage electrostatic field (HVEF) technology has been demonstrated to be a viable alternative to high-temperature treatments in food processing due to its ability to lower energy consumption, reduce thawing time, and maintain the post-thawing quality of several foods. We investigated the effect of HVEF thawing on microbial communities, degradation of adenosine triphosphate (ATP), and water loss of lightly-salted, frozen common carp (Cyprinus carpio) cubes stored at 4 °C compared to air-thawed or thawing by running tap water. Thawing time was shortened significantly under HVEF and running tap water compared to the control of thawing by air. Moreover, −12 kV HVEF treatment also reduced moisture loss, lowered the total viable counts, Pseudomonas, and lactic acid bacteria significantly after thawing, and lowered counts of Aeromonas, Pseudomonas, and halophilic bacteria by 0.5-1 log CFU/g in thawed fish cubes after 8 days refrigeration storage. Additionally, the activity of adenosine monophosphate deaminase (AMPD) was enhanced, but the activity of acid phosphatase (ACP) was decreased under −12 kV HVEF treatment. This resulted in delaying the degradation of inosine monophosphate (IMP) to hypoxanthine (Hx). These results suggested that HVEF treatment could be useful in the thawing and storage of frozen, lightly-salted fish.