Application of simultaneous ultrasonic curing on pork (Longissimus dorsi): Mass transport of NaCl, physical characteristics, and microstructure

Application of ultrasound treatment in pork marination: Effects on moisture migration and microstructure

To better understanding the effects of ultrasonic marination on the porcine tissue, the moisture migration and microstructure were investigated in this study. Additionally, the acoustic field distribution was analysis using COMSOL Multiphysics. The low-filed NMR results demonstrated that ultrasonic curing induced a leftward shift in T21 and a rightward shift in T22, accompanied by a significant reduction in A22, thereby enhancing the water-holding capacity of pork. The SEM and TEM observation showed that the presence of larger interstitial gaps between muscle fibers facilitated the diffusion of NaCl. The simulation analysis revealed that the acoustic field at 26.8 kHz showed minimal standing wave effects and more pronounced cavitation, which was the main reason for the best curing effect at this frequency. The scale-up test showed the NaCl content in pork reached 1% after ultrasound curing, indicating the potential application of ultrasonic marination technology in domestic refrigerators.

Effect of the temperature and ultrasound on salt impregnation process of haddock

The influence of different brine temperatures (5, 15 and 25 °C) and ultrasound on the salt gain (SG) and water gain (WG) kinetics of haddock cubes during vacuum impregnation (VI) process was evaluated. Samples were taken from salt solution (4 g NaCl/ 100 g solution) after 0, 20, 40, 60, 100, 140 and 180 min of brining process for salt and moisture analysis. Ultrasound assisted VI and increasing temperature in the salt solution increased (P < 0.05) the salt content, and SG value in the haddock cubes. Furthermore, ultrasound assisted VI enhanced the water diffusion into the cubes and resulted in an increase in WG value. The ultrasound process increased the salt effective diffusion coefficient (Ds) and the highest Ds was found at 25 °C brine temperature. Azuara, Diffusive, Peleg, Weibull, Z and L models were tested to predicting SG and WG kinetics and Azuara was the best model during brining process of haddock cubes.

Tri-frequency simultaneous ultrasound pickling for the acceleration of the NaCl content and quality improvement of pork (longissimus dorsi)

BACKGROUND

The pickling process with NaCl is an essential step for pork preservation. This study aimed to investigate the effect of different ultrasonic intensities of tri-frequency simultaneous ultrasound (TSIU) pickling on the NaCl content and quality of pork (longissimus dorsi). After 30 min pickling, the NaCl content, moisture content, pickling yield, cooking loss, textural properties, color, pH, moisture migration and distribution as well as microstructure of pork were assessed.

RESULTS

Results showed that among all the ultrasonic treatment intensities (85-150 W L-1 ), the NaCl content of the sample pickled by an intensity of 101.3 W L-1 was higher than that of other intensities. TSIU 101.3 W L-1 showed 59.95% higher NaCl content than the control sample. In addition, the sample treated with TSIU of 101.3 W L-1 had higher pickling yield and moisture content, better textural properties of pork (including hardness and chewiness), and less cooking loss. The results of the low-field nuclear magnetic resonance showed that, compared with the control group, the relaxation time T21 of the ultrasound-assisted pickling samples increased, while the proportion of T22 (A22 ) reduction ranged from 175.0% to 379.9%. The microstructure designated that the ultrasonic treatment could facilitate changes in meat texture.

CONCLUSION

Ultrasound marination of different intensities promoted the diffusion of NaCl and affected the quality of pork tenderloins. The TSIU at 101.3 W L-1 could better accelerate NaCl transport and homogeneous distribution on meat, thereby improving the sample quality. © 2024 Society of Chemical Industry.

Effects of ultrasound-assisted cooking on the physicochemical properties and microstructure of pork meatballs

This research aims to investigate the effect of different ultrasonic powers cooking on the quality of pork meatballs. Pork meatballs treated with ultrasound-assisted cooking at 450 W had the most uniform and smooth structures displayed by scanning electron microscopy. Furthermore, with increasing ultrasonic powers, the water retention capacity of pork meatballs first increased and then decreased, compared with the non-ultrasound group, when the ultrasonic power was 450 W, the cooking yield of pork meatballs increased from 82.55% to 92.87%, and the centrifugal loss decreased from 25.35% to 11.52%. Additionally, ultrasound-assisted cooking had a positive effect on the moisture migration, tenderness, and sensory property of pork meatballs, and 450 W sample exhibited the highest overall acceptability score (P < 0.05). In conclusion, the physicochemical properties and microstructure of pork meatballs could be improved by appropriate ultrasonic power, and ultrasonic technology was considered as an effective processing method for improving the quality of meat products.

Ultrasound-Assisted Enzymatic Protein Hydrolysis in Food Processing: Mechanism and Parameters

Ultrasound has been widely used as a green and efficient non-thermal processing technique to assist with enzymatic hydrolysis. Compared with traditional enzymatic hydrolysis, ultrasonic-pretreatment-assisted enzymatic hydrolysis can significantly improve the efficiency of enzymatic hydrolysis and enhance the biological activity of substrates. At present, this technology is mainly used for the extraction of bioactive substances and the degradation of biological macromolecules. This review is focused on the mechanism of enzymatic hydrolysis assisted by ultrasonic pretreatment, including the effects of ultrasonic pretreatment on the enzyme structure, substrate structure, enzymatic hydrolysis kinetics, and thermodynamics and the effects of the ultrasonic conditions on the enzymatic hydrolysis results. The development status of ultrasonic devices and the application of ultrasonic-assisted enzymatic hydrolysis in the food industry are briefly described in this study. In the future, more attention should be paid to research on ultrasound-assisted enzymatic hydrolysis devices to promote the expansion of production and improve production efficiency.

Underlying formation mechanisms of ultrasound-assisted brined porcine meat: The role of physicochemical modification, myofiber fragmentation and histological organization

Ultrasound treatment has been a good hurdle technique for meat curing processing, where both physical and chemical consequences can be involved towards final quality of obtained products. However, the specific correlation between ultrasound parameters and muscle fiber fragmentation and myofibrillar microstructural changes during curing deserve further evaluation. In present study, we comparatively studied the effect of ultrasound-assisted brining (UAB) and static brining (SB) on the muscle proteolysis events and microstructural/morphological variation of porcine meat as well as the physicochemical indices and histological characteristics. The results showed that UAB (20 kHz, 315 W for 1 h) could markedly enhance the muscle proteolysis with higher free-/peptide-bound alpha-amino-nitrogen (α-NH2-N) content (P < 0.05) than SB treatment and greatly improved the fragmentation of muscle fiber tissues of cured meat. Meanwhile, UAB processing favored more opening structures of myofibrillar proteins with more hydrophobic groups being exposed. The quantitative histological analysis revealed that, compared with SB treatment, UAB could significantly increase the gap between muscle fibers and the swelling of the perimysium (P < 0.01), proving an efficient curing process with better textural and water holding properties.

Ultrasound-enhanced interfacial adsorption and inactivation of soy trypsin inhibitors

In this study, liquid-liquid interfacial protein adsorption was proposed as a means of inactivating soy trypsin inhibitors (TIs, including Kunitz (KTI) and Bowman-Birk inhibitor (BBI)). Hexane-water was first selected as a model system to compare three emulsification methods (hand shaking, rotor-stator and ultrasound mixing). Ultrasound could generate the smallest and least polydisperse emulsion droplets, resulting in highest interfacial adsorption amount of KTI and BBI as well as the highest inactivation percentage of TIs (p < 0.05). Therefore, ultrasound was selected to further explore the effect of the non-aqueous phase on interfacial adsorption and inactivation kinetics of TIs in a food emulsion system containing vegetable oil (VTO). The adsorption amounts of KTI and BBI in the VTO-aqueous emulsion increased by ∼ 25 % compared to the hexane-aqueous emulsion. In addition, the adsorption amounts of KTI and BBI were rapidly increased as a function of sonication time, especially for the hexane-aqueous emulsion system. This result suggests that such inactivation of TIs could be implemented in continuous systems for large-scale processing. Finally, the pathways of interface-induced inactivation of BBI and KTI were investigated based on separate experiments on individual BBI and KTI systems. The results showed that the interface adsorption caused the changes in the secondary and tertiary structure of KTI that led to its activitation. However, BBI was quite stable at the liquid-liquid interface without significant conformational change. Overall, ultrasound-assisted interfacial adsorption can be considered a rapid and highly efficient method to inactivate KTI.

Proteomics in bovine semitendinosus muscle to assess emerging strategies based on papain injection and ultrasounds on meat tenderization process

The impact of papain and/or ultrasound treatments on tenderization of semitendinosus muscle through a proteomic approach was studied. Sixteen bovine muscles were submitted to the following treatments: aging at 3 °C (Control), papain injection (PI), ultrasound (US), PI followed by US (PIUS) and US followed by PI (USPI). pH, myofibrillar fragmentation indices (MFI), soluble collagen, texture profile and changes of myofibrillar proteins were investigated after 2, 24, 48 and 96 h of storage. The highest MFI and soluble collagen content were found in PI, PIUS and USPI samples while control samples showed the lowest values. PI samples showed the lowest WBSF and hardness values until 48 h of storage while at 96 h meat from USPI treatment showed WBSF value comparable to PI treatment. The lowest values of cohesiveness, gumminess and chewiness were found in PI samples during all storage times. Proteomic analysis revealed a different quantity and expression of proteins among tenderization treatments. US treatment did not exhibit a significant ability to degrade muscle proteins, while, all treatments containing papain, showed a greater ability to hydrolyse and degrade myofibrillar proteins. PI promoted intense proteolysis leading to an early tenderization process; on the contrary, in PIUS and USPI treatments the sequence of treatments was relevant on meat tenderization. Particularly, USPI treatment, after 96 h, reached the same improvement in tenderness of enzymatic treatment but with slower hydrolysing rate; this could be determinant to preserve textural structure.