Comparison of Effects from Ultrasound Thawing, Vacuum Thawing and Microwave Thawing on the Quality Properties and Oxidation of Porcine Longissimus Lumborum

Electrostatically-enhanced two-stage low-temperature tempering: Effects on the quality of frozen tan mutton

The two-stage low-temperature tempering (TLT) and TLT assisted by electrostatic fields (TLT-1500/2000/2500/3000) were developed to investigate their effects on the quality of frozen Tan mutton. The results demonstrated that both TLT and TLT-1500/2000/2500/3000 significantly (P < 0.05) enhanced the tempering rate compared to refrigerator tempering (4 °C, RT). The analysis of tempering, cooking, and centrifugal losses, along with the evaluation of electrical conductivity, pH, and TVB-N, showed that the water retention capacity and freshness of Tan mutton treated with TLT-2500 were closest to those of fresh Tan mutton. Scanning electron microscopy analysis demonstrated that TLT-2500 best maintained the tissue integrity of Tan mutton, while low-field nuclear magnetic resonance analysis revealed it contained the highest immobile water and least free water. Furthermore, Tan mutton treated with TLT-2000 and TLT-2500 exhibited minimal lipid oxidation and color change. In contrast, the most significant changes in all indicators were observed after RT.

Ultrasound-assisted improvement of thawing quality of Tibetan pork by inhibiting oxidation

The challenge of meat quality degradation due to transportation difficulties in high-altitude plateaus underscores the importance of an efficient thawing process for Tibetan pork to ensure its quality. This study compared four thawing methods ultrasound thawing (UT), refrigerator thawing (RT), hydrostatic thawing (HT), and microwave thawing (MT) to assess their impact on the quality of Tibetan pork, focusing on thawing loss, tenderness, color variation, and alterations in protein secondary structure and moisture content. Additionally, the study examined the impact of thawing on the metabolites of Tibetan pork using metabolomics techniques. The results indicated that UT yielded the highest quality samples. UT significantly accelerated the thawing rate and had minimal impact on tenderness compared to traditional thawing methods. Moreover, protein and lipid oxidation levels were reduced by UT treatment. Furthermore, it enhanced the binding capacity of protein and water molecules, reduced drip loss, and maintained meat color stability. What's more, amino acid metabolites such as l-glutamic acid, l-proline, oxidized glutathione, and 1-methylhistidine played a significant role in thawing oxidation in Tibetan pork, exhibiting a positive correlation with protein oxidation. UT resulted in a notable decrease in the levels of hypoxanthine and 2-aminomethylpyrimidine, contributing to the reduction of bitterness in the thawed meat and consequently enhancing the freshness of Tibetan pork. This study offers novel insights into understanding the biological changes occurring during the thawing process, while also furnishing a theoretical framework and technical assistance to improve the quality of Tibetan pork and propel advancements in food processing technology.

Effect of whey protein hydrolysate on the structural and functional stability of surimi myofibrillar protein gels during freeze-thaw cycles

This study investigates the effects of varying concentrations of whey protein hydrolysate (WPH) (5 %, 10 %, 15 %) on surimi myofibrillar protein gels subjected to freeze-thaw (FT) cycles. With an increase in the number of FT cycles, there was a decrease in both ionic and hydrogen bonding, resulting in reduced chewiness and elasticity. At the same time, hydrophobic interactions were strengthened, leading to disruptions in protein secondary structures. In contrast, the addition of WPH significantly improved and stabilized the gels' intermolecular interactions and textural properties, particularly at the 15 % concentration, which demonstrated superior effects compared to both the untreated control and the positive control treated with 0.02 % butylated hydroxyanisole (BHA) (P < 0.05). Furthermore, 15 % WPH effectively preserved the gel's secondary structure and water-holding capacity, significantly outperforming the 0.02 % BHA positive control group (P < 0.05). These findings highlight the potential of WPH to enhance intermolecular interactions and preserve the structural integrity of myofibrillar protein gels during FT cycles, indicating its promising application in food science.

Novel thawing method of ultrasound-assisted slightly basic electrolyzed water improves the processing quality of frozen shrimp compared with traditional thawing approaches

Thawing is the primary step in handling frozen aquatic products, which directly determines their end-product quality. This study firstly constructed a novel thawing method of ultrasound-assisted slightly basic electrolyzed water (UST), and its influences on the physicochemical and histological properties of shrimp, as well as the structural of myofibrillar proteins (MPs) in shrimp were evaluated. Results indicated that the UST treatment greatly reduced 48.9 % thawing time of frozen shrimp compared to traditional thawing approaches. Meanwhile, the UST effectively decreased the generation of malondialdehyde (MDA), total volatile basic nitrogen (TVB-N), and carbonyl compounds in the thawed shrimps. In addition, it significantly preserved the elasticity and integrity of muscle fiber. Notably, the UST reduced the damage of thawing to the spatial structures of MPs, thereby greatly keeping the stability of protein. All these favorable changes maintained the water holding capacity (WHC) and quality of shrimp. Therefore, the UST is a promising non-thermal thawing technology for aquatic products.

The Evolution of Sonochemistry: From the Beginnings to Novel Applications

Sonochemistry is the use of ultrasonic waves in an aqueous medium, to generate acoustic cavitation. In this context, sonochemistry emerged as a focal point over the past few decades, starting as a manageable process such as a cleaning technique. Now, it is found in a wide range of applications across various chemical, physical, and biological processes, creating opportunities for analysis between these processes. Sonochemistry is a powerful and eco-friendly technique often called "green chemistry" for less energy use, toxic reagents, and residues generation. It is increasing the number of applications achieved through the ultrasonic irradiation (USI) method. Sonochemistry has been established as a sustainable and cost-effective alternative compared to traditional industrial methods. It promotes scientific and social well-being, offering non-destructive advantages, including rapid processes, improved process efficiency, enhanced product quality, and, in some cases, the retention of key product characteristics. This versatile technology has significantly contributed to the food industry, materials technology, environmental remediation, and biological research. This review is created with enthusiasm and focus on shedding light on the manifold applications of sonochemistry. It delves into this technique's evolution and current applications in cleaning, environmental remediation, microfluidic, biological, and medical fields. The purpose is to show the physicochemical effects and characteristics of acoustic cavitation in different processes across various fields and to demonstrate the extending application reach of sonochemistry. Also to provide insights into the prospects of this versatile technique and demonstrating that sonochemistry is an adapting system able to generate more efficient products or processes.

Study on the thawing characteristics of beef in ultrasound combined with plasma-activated water

The effects of deionized water thawing (DT), plasma-activated water thawing (PT), ultrasound (150 W, 40 kHz) combined with deionized water thawing (UDT), and ultrasound combined with plasma-activated water thawing (UPT) on the thawing characteristics and the physicochemical properties of the beef were investigated. The results showed that the UPT group had a faster thawing rate (38 % higher compared to the PT group) and good bactericidal ability (75 % higher compared to the UDT group), and had no adverse effect on the color and pH value of the beef. Plasma-activated water (PAW) can maintain the stability of the beef fiber, improve the water holding capacity (WHC), inhibit lipid oxidation, and reduce the loss of soluble substances such as protein. Therefore, UPT thawing is a promising meat thawing technology, which provides practical guidance and methods for the wide application of UPT in the field of meat thawing.

Evaluating the effects of low-frequency alternating magnetic field thawing on oxidation, denaturation, and gelling properties of porcine myofibrillar proteins

The impact of low-frequency alternating magnetic field thawing (LF-MFT) on the physicochemical and gelling properties of porcine myofibrillar proteins (MP) was studied. Results showed that compared to atmosphere thawing (AT), LF-MFT helped in inhibiting the oxidation and denaturation of protein during thawing, thereby maintaining a superior MP gel (P < 0.05). In particular, LF-MFT-4 (LF-MFT at 4 mT) could decrease the oxidation of MP, which might be due to having a higher content of total sulfhydryl and less carbonyl of MP than other thawing treatments. The denaturation of MP was reduced since LF-MFT-4 led to less aggregation and degradation than AT. The gelling properties were also retained, and a compact and homogeneous network structure was formed after LF-MFT-4, resulting in excellent water retention. These findings suggested that LF-MFT-4 improved the gelling properties of MP by inhibiting its oxidation and denaturation, demonstrating a potential application of LF-MFT in meat thawing.

Physico-Chemical Properties and Storage Stability of an Emulsion as a Fat Replacer in Meat Analogs during the Freezing Storage

This study determined the effects of physicochemical and microbial properties of emulsion as a fat replacer in meat analogs during freezing storage. Meat analogs were prepared with different fat replacers: vegetable oil (O) for control, oil in water emulsion (E), and non-emulsified oil in water emulsion (EC) for emulsion control. After that, meat analogs were stored for 0.5, one, three, and six months at −18 °C and −60 °C. The results showed that the drip loss of all samples was not significantly different (p > 0.05). However, the liquid holding capacity of EC and E was significantly higher than that of O (p < 0.05). Additionally, the microstructures of meat analogs of E and EC were smaller with denser pore sizes than O. This explains the significantly lower hardness of E and EC compared to O (p < 0.05). Overall, E showed superior physiochemical and sensory quality. During the storage, the stability of chemical properties, such as volatile basic nitrogen and thiobarbituric acid reactive substances, showed no significant changes (p > 0.05). Moreover, the microbial studies (total viable counts and Escherichia coli count) suggested that meat analogs did not deteriorate during the preparation and storage. Thus, this study suggests that emulsion-type fat replacers influence meat analogs’ physicochemical and sensorial properties. However, these properties are not influenced by the storage temperature and duration.

Whey Protein Hydrolysates Improved the Oxidative Stability and Water-Holding Capacity of Pork Patties by Reducing Protein Aggregation during Repeated Freeze-Thaw Cycles

The effects of whey protein hydrolysates (WPH) on myofibrillar protein (MP) oxidative stability and the aggregation behavior and the water-holding capacity of pork patties during freeze-thaw (F-T) cycles were investigated. During F-T cycles, the total sulfhydryl content and zeta potential of MP decreased, while peroxide value, surface hydrophobicity, particle size, pressure loss and transverse relaxation times increase. The oxidative stability and the water-holding capacity of pork patties were enhanced by the addition of WPH in a dose-dependent manner, whereas the MP aggregation decreased. The addition of 15% WPH had the most obvious effects on the pork patties, which was similar to that of the 0.02% BHA. After nine F-T cycles, the POV, surface hydrophobicity, particle size and pressure loss of the pork patties with 15% WPH were reduced by 17.20%, 30.56%, 34.67% and 13.96%, respectively, while total sulfhydryl content and absolute value of zeta potential increased by 69.62% and 146.14%, respectively. The results showed that adding 15% WPH to pork patties can be an effective method to inhibit lipid and protein oxidation, reducing protein aggregation and improving the water-holding capacity of pork patties during F-T cycles.