Effects of Multiple Freeze-Thaw Cycles on Protein and Lipid Oxidation, Microstructure and Quality Characteristics of Rainbow Trout (Oncorhynchus mykiss)

Abstract

Multiple freeze-thaw cycles due to temperature fluctuations irreversibly damage the muscle tissue of fish, thereby reducing their edibility. The aim of this study was to determine the effects of the number of freeze-thaw (F–T) cycles on protein and lipid oxidation, microstructure, physical index, and nutritional quality of rainbow trout muscle. The results showed that F–T cycles accelerated protein carbonyl formation and thiobarbituric acid reactive substances (TBARS) generation (p < 0.05), as well as increased the loss of total sulfhydryl (SH) groups (p < 0.05). Moreover, transmission electron microscope (TEM) images illustrated that the microstructure of muscle fibers was loosed and disintegrated after the third F–T cycle, causing a reduction in water holding capacity (WHC). In addition, muscles lost the intrinsic color of fresh meat after the fifth cycle, with lightness L* and yellowness b* increasing, while redness a* declined (p < 0.05). The hardness, springiness, and chewiness of muscles decreased, and the shear force first increased and then decreased after the third cycle. Furthermore, the proximate components, essential amino acids (EAAs), and total amino acids (TAAs), decreased significantly after the third cycle (p < 0.05) due to the decrease of WHC as well as protein and lipid oxidation. The results indicated that the quality of rainbow trout muscle changed after the third cycle, deteriorated seriously after the fifth cycle, and was unacceptable after the seventh cycle. Therefore, it is necessary to reduce the temperature fluctuation to less than three times during freezing. The results provided a reference for the identification and classification of frozen aquatic products.

Coexisting with Ice Crystals: Cryogenic Preservation of Muscle Food─Mechanisms, Challenges, and Cutting-Edge Strategies

“…Considering the contraction of myofibrillar lattice spacing caused by ice growth during freezing and thawing, it impacts the optical density, resulting in increased light scattering and a dimmer meat color. This finding has been preliminarily validated in recent research. ,, Generally, meat color relies not only on the pigment contribution but also on the essential muscle structural attributes. Therefore, open-minded consideration is required for understanding color variations in meat during the freezing and thawing processing.…”

“…This finding has been preliminarily validated in recent research. 55,58,61 Generally, meat color relies not only on the pigment contribution but also on the essential muscle structural attributes. Therefore, open-minded consideration is required for understanding color variations in meat during the freezing and thawing processing.…”

Assessment of cooking methods and freezing on the nutritional value and health risks of heavy metals in four fish species consumed in Douala, Cameroon

“…MDA is an indicator of lipid peroxidation in tissues and oils. High levels of MDA are thought to play a role in oxidative stress and the pathogenicity of atherosclerosis [ 115 ] . TBARS varies significantly (P < 0.05) in raw Cyprinus carpio, Arius parkii, and Ethmalosa fimbriata oil compared to raw Polydactilus quadrifilis oil different species ( Table 7 ).…”

“…Aydin and Gokoglu [ 113 ] showed that during freezing at −20 °C and storage at −18 °C in Engraulis encrasicholus oil, TOTOX value increased compared to raw fish oil. The increase in these values during smoking and boiling could be due to the hydrolysis of the ester bonds releasing the fatty acids which oxidise to give primary and secondary oxidation products which alter the quality of the oil [ 115 ] . The increase in these indices of alteration during freezing could be due to the breaking of double bonds by endogenous enzymes [ 25 ] .…”

Physicochemical and Microbiological Changes Associated with Processing in Dry-Cured Tuna

“…Three grams of sample were weighed and homogenized (Ultraturrax ® , Stauten, Germany) with 10 mL of 7.5% TCA solution. Next, the mixture was homogenized at 5000 rpm for 10 min at 4 • C. The supernatant was used for MDA determination according to Du et al [22] MDA-TBA complex was determined at 530 nm using a microplate spectrophotometer (ThermoFisher Scientific Oy, Vantaa, Finland). The results were expressed as µmols MDA per kilogram of muscle.…”