Effects on the quality in using freezing equipment (weak oscillating magnetic field) on hybrid giant tiger grouper (Epinephelus fuscoguttatus × Epinephelus lanceolatus) fillets

Abstract

In food processing, freezing is vital in food preservation, specifically in preserving food quality, nutrition contents, and shelf-life. This study investigated the effects of different freezing equipment [such as cells alive system freezer (CAS) equipped with a weakly oscillating magnetic field (OMF), liquid nitrogen freezers (LNF), Air blow freezer (AF), and home freezer (HF)] on the preservation of giant tiger grouper [hybridized with giant grouper (Epinephelus fuscoguttatus) and tiger grouper (Epinephelus lanceolatus)] fillets with insight iaanto the changes in quality indexes and physicochemical properties of the fillets during the freezing process. This study showed that the CAS group could reduce the time it took for the sample to pass through the maximum icing crystal formation zone during freezing. It was determined by low-field pulsed nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) that the water migration and the formation of numerous tiny, uniformly dispersed ice crystals in the CAS group, while also defined by the tissue sections, revealed less damage to the muscle tissue of the fillet. Moreover, it also provides the fillets with better freezing loss, thawing loss, water holding capacity (WHC), and several satisfactory quality indexes (such as total volatile basic nitrogen (TVBN), total plate count (TPC), color (L*, a* and b* values), hardness and elasticity, etc.) within 4 weeks. This study's findings were expected to contribute to developing more effective and efficient freezing strategies for hybrid giant tiger grouper fillet preservation, thus enabling the production of high-quality products that meet the demands of consumers.

Keywords

• Hybrid giant tiger grouper
• Weak oscillating magnetic field
• Freezing
• Ice crystals
• Water migration