Effects of different thawing methods on the physicochemical changes, water migration and protein characteristic of frozen pompano ( Trachinotus ovatus )

Abstract

The effects of five thawing methods (ultrasonic thawing [UT], radiofrequency thawing [RFT], water immersion thawing [WIT], microwave thawing [MT], and cold storage thawing [CST]) on physicochemical properties, water migration, and protein characteristic of whole frozen pompano (Trachinotus ovatus) were investigated and compared with fresh samples (FS). The physicochemical changes of thawed pompano were analyzed based on pH, total volatile basic nitrogen (TVB‐N), color difference. The protein aggregation, physicochemical properties and conformation of myofibrillar proteins (MPs) were evaluated by Sodium dodecyl sulfate polyacrylamide gel electrophoresis, differential scanning calorimetry, and Raman spectra, respectively. Water migration and MPs microstructure were measured by low‐field nuclear magnetic resonance (LF‐NMR) and scanning electron microscope (SEM), respectively. The results showed that different thawing methods could accelerate the protein denaturation and decrease of quality in pompano, especially MT treatment causing more seriously local overheating phenomena. Among the samples with different thawing treatments, the changes of pH, TVB‐N values, and color difference in RFT and UT were closed to that from FS. The MT had the shortest thawing time, but could produce the damage of structural muscle. RFT had desirable thermal stability and made the protein secondary structure more stable, the myofibril bundles were also straight and smooth by SEM observation. The content of bound water and free water had no significant changes by LF‐NMR. Therefore, compared with other thawing methods, RFT is a desirable thawing method for maintaining the quality of thawed pompano. Practical applications Before further processing of frozen pompano, the thawing process is an important part, which is highly associated with the quality of products. The damage of conformation and properties in aquatic protein caused by freeze‐thaw process is very obvious in food processing industry. Compared to microwave thawing, ultrasonic thawing, and traditional methods, the radiofrequency thawing (RFT) could reduce changes in structure and properties of protein, and have higher thawing efficiency. The temperature distribution on the pompano surface was uniform during the radiofrequency process with higher strong penetration and less local overheating. The RFT is a desirable thawing method to maintain the quality and extend the shelf life of frozen pompano for application in food industry.

Freeze-Thawing Treatment as a Simple Way to Tune the Gel Property and Digestibility of Minced Meat from Red Swamp Crayfish (Procambarus clarkiix)

“…The thawing times of CT for the RF and SF groups were 264 min and 451 min, respectively, while the thawing times of WT for those groups were 4.41 min and 8.17 min, respectively ( Figure 1 D), indicating that WT greatly shortened the thawing time of the frozen crayfish. Similar results were also found in the thawing process for the frozen bighead carp ( Aristichthys nobilis ) fillets [ 24 ], as well as the frozen pompano ( Trachinotus ovatus ) [ 25 ]. This might be explained by the fact that the water [0.604 W/(m•K)] has a higher thermal conductivity (i.e., heat transfer rate) than air [0.066 W/(m•K)] [ 19 , 21 ].…”

A comprehensive review of the principles, key factors, application, and assessment of thawing technologies for muscle foods

“…In addition, they found that under constant voltage conditions (10.5 kV), the rate of change of the TVB-N value was inversely proportional to the electrode distance. A similar conclusion was drawn from the other studies regarding electric field-based thawing (Gan et al, 2021;He et al, 2016;Hu et al, 2021;Jia, Sha, et al, 2019;Lan et al, 2021;Mousakhani-Ganjeh et al, 2016b;Qian et al, 2019). Indeed, in addition to HVEFT, other thawing techniques can also achieve lower TVB-N values.…”

“…Recently, pH, as an essential evaluation index, has frequently appeared in research on various thawing technologies. Lan et al (2021) compared the effects of five thawing methods (UT, 20 • C, 200 W, 33 min; RFT, 25 • C, 27.12 MHz, 22 min; MT, 500 W, 5.8 min; WIT, 16 • C, 40 min and cold storage thawing, CST, 4 • C, 20.6 h) on the physicochemical properties of whole frozen pompano (Trachinotus ovatus) and used pH as an important indicator to evaluate the freshness of the thawed samples. The results showed that pH values of samples treated by RFT and UT were closer to those of the fresh samples (FS) than those of samples treated with the other three methods, while the CST treatment, which had a longer time consumption, resulted in a more noticeable pH increase compared to the fresh samples (pH values of 6.56, 6.54, 6.67, 6.68, 6.55, and 6.80 for FS, UT, RFT, WIT, MT, and CST, respectively).…”

“…Subsequently, Lan et al. (2021) observed that AT (25°C) exhibited the highest cooking loss compared with WT (16°C, 40 min) and UT (20°C, 200 W, 33 min), while UT had the lowest cooking loss at a power level of 300 W, which was 27.6% lower than that of WT. The appearance of the former highest cooking loss might be because AT was used to treat chicken breast for a very long time, which damaged the structure of the muscle, resulting in poor water retention capacity, thus increasing cooking loss.…”

Effects of ultrasound-assisted thawing on lamb meat quality and oxidative stability during refrigerated storage using non-targeted metabolomics

“…The pH of lamb stored for 7 days in the UT group was higher than that in the FW group ( P < 0.05). This was due to the longer thawing time in the FW group, and the loss of minerals with the aqueous solution disrupted the ionic balance in the meat and resulted in a decrease in pH [26] . The pH increase due to storage time may be related to the formation of alkaline compounds in the meat [27] .…”