Application of a pressure-transform tumbling assisted curing technique for improving the tenderness of restructured pork chops

Effects of sodium tripolyphosphate on the quality and digestion properties of PSE pork

This study aimed to examine the impact of sodium tripolyphosphate (STPP) on the quality and digestive characteristics of PSE pork. The results showed a notable decrease in cooking loss of PSE pork from 29.11% to 25.67% with increasing STPP concentration (P < 0.05). Additionally, the gastric digestibility of PSE pork decreased significantly from 52.01% to 45.81% (P < 0.05). The particle size of digesta decreased significantly after gastrointestinal digestion (P < 0.05). These changes were primarily due to the enhanced cross-linking of proteins through ionic interactions, hydrogen bonds and hydrophobic interactions, and resulted in the embedding of hydrophobic groups and endogenous fluorophores. Furthermore, denser network was formed. These findings give a new insight into considering the impact of STPP on meat nutrition when used to enhance texture and water holding capacity.

Recent insights into bonding technologies in restructured meat production: A review

Restructuring meat products is one way of improving material utilization and economic efficiency. In this process of combining meat pieces or granules to form larger pieces of meat, the additives and processing techniques employed in bonding the restructured meat play crucial roles in the formation of the structure and appearance of the meat while simultaneously reducing nutrient and water loss and enhancing flavor. This study reviews the adhesives commonly used in meat recombination technology, including transglutaminase, glucono-delta-lactone, fibrin, gelatin, and gel emulsifiers such as hydrophilic colloid, phosphate, starch, and cellulose. Additionally, processing technologies such as high-pressure, ultrasonic, vacuum-assisted, microwave, and three-dimensional printing are discussed, with emphasis on their principles, properties, functionalities, and safety. The study further summarizes the application and research progress of various bonding techniques in restructured meat. It analyzes the advantages, challenges, and development prospects of these techniques to provide support for further research in this field.

Effects of brining, ultrasound, and ultrasound-assisted brining on quality characteristics of snakehead (Channa argus) fillets

The change of quality characteristics in snakehead fillets were investigated during brining, ultrasound, and ultrasound-assisted brining processing. Results showed that ultrasound and brine had significantly impact on the tissue microstructure and the color parameter of fillets. Compared to 60-min marination in deionized water, the shear force was reduced by 17.67 g by ultrasound, compared to 80-min marination in deionized water, the shear force was reduced by 28.68 g by brine. Brine significantly increased the water-holding capacity of fish fillets. Ultrasound resulted in increased random coils, β-turn and hydrophobic interaction, while brine significantly promoted the formation of the α-helix structure. The increase of the thermal stability of the myosin head was due to the synergistic effect of ultrasound and brine, but the decrease of the thermal stability of actin only associated with brine. The study provides the reference for the application of ultrasound-assisted brining technology to aquatic industry.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01506-8.

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.

Modern Concepts of Restructured Meat Production and Market Opportunities

Restructured meat (RM) products are gaining importance as an essential component of the meat industry due to consumers' interest in health benefits. RM products imply the binding or holding of meat, meat by-products, and vegetable proteins together to form a meat product with meat's sensory and textural properties. RM products provide consumers with diversified preferences like the intake of low salt, low fat, antioxidants, and high dietary fiber in meat products. From the point of environmental sustainability, RM may aid in combining underutilized products and low-valued meat by adequately utilizing them instead of dumping them as waste material. RM processing technique might also help develop diversified and new hybrid meat products. It is crucial to have more knowledge on the quality issues, selection of binding agents, their optimum proportion, and finally, the ideal processing techniques. It is observed in this study that the most crucial feature of RM could be its healthy products with reduced fat content, which aligns with the preferences of health-conscious consumers who seek low-fat, low-salt, high-fiber options with minimal synthetic additives. This review briefly overviews RM and the factors affecting the quality and shelf life. Moreover, it discusses the recent studies on binding agents in processing RM products. Nonetheless, the recent advancements in processing and market scenarios have been summarized to better understand future research needs. The purpose of this review was to bring light to the ways of sustainable and economical food production.

Study on the Diffusion and Optimization of Sucrose in Gaido Seak Based on Finite Element Analysis and Hyperspectral Imaging Technology

As a traditional Chinese dish cutting technology process, Gaidao artificially create cuts embedded in the food surface by cutting through it with knife, a process that currently plays an important role in the beef marinating process. And different Gaidao processes directly affect the beef marination flavour and marination efficiency. This study is the first to propose the use of Hyperspectral imaging technology (HSI) combined with finite element analysis to investigate the effect of Gaidao process on the quality of marinated beef. The study was carried out by collecting spectral information of beef marinated with different sucrose concentrations and combining various pre-processing methods and algorithms such as PLS, BiPLS, iPLS, and SiPLS to establish a quantitative model of sucrose concentration in beef, and finally optimizing parameters such as the length, position and number of Gaidao by Finite Element Analysis (FEA), which showed that when marinated with 1.0 mol/m³ sucrose solution, the concentration of sucrose in all tissues in the Gaidao steak reached 0.8 mol/m³ and above, which greatly improved the diffusion effect of the marinade. This work provides new ideas and methods to optimize the beef marinade Gaidao process, which has important practical value and research significance.

Evaluation of ultrasonic-assisted pickling with different frequencies on NaCl transport, impedance properties, and microstructure in pork

The effects of ultrasonic curing with various frequencies on sodium chloride (NaCl) mass transfer in pork muscle and its potential mechanisms were investigated. The results showed that ultrasound curing dramatically increased the NaCl content in pork compared to static curing, especially curing at 26.8 kHz. The binarized images of NaCl penetration in pork visually confirmed that ultrasound enhanced the efficiency of mass transfer. Energy dispersive spectroscopy showed that the distribution of NaCl in pork tissue cured by ultrasound was the densest compared to the static curing. According to impedance analysis and microstructure observation, the structure of cell membranes was damaged to different extents during ultrasound treatments. The potential mechanisms of low-frequency ultrasound accelerated curing are mainly attributed to the action of acoustic cavitation and the sponge effect. Overall, the low-frequency ultrasound is a promising revolutionary technology in the food industry that can speed up the curing process of meat.

Phosphate alternatives for meat processing and challenges for the industry: A critical review

Meat and meat products provide high levels of nutrition and many health benefits to consumers, yet a controversy exists regarding the use of non-meat additives, such as the inorganic phosphates that are commonly used in meat processing, and particularly their relationship to cardiovascular health and kidney complications. Inorganic phosphates are salts of phosphoric acid (e.g., sodium phosphate, potassium phosphate, or calcium phosphate), whereas organic phosphates are ester compounds (e.g., the phospholipids found in cell membranes). In this sense, the meat industry remains active in its efforts to improve formulations for processed meat products with the use of natural ingredients. Despite efforts to improve formulations, many processed meat products still contain inorganic phosphates, which are used for their technological contributions to meat chemistry including improvements in water-holding capacity and protein solubilization. This review provides a thorough evaluation of phosphate substitutes in meat formulations and other processing technologies that can help eliminate phosphates from the formulations of processed meat products. In general, several ingredients have been evaluated as replacements for inorganic phosphates with varying degrees of success such as plant-based ingredients (e.g., starches, fibers, or seeds), fungi ingredients (e.g., mushrooms and mushroom extracts), algae ingredients, animal-based ingredients (e.g., meat/seafood, dairy, or egg materials), and inorganic compounds (i.e., minerals). Although these ingredients have shown some favorable effects in certain meat products, none have exactly matched the many functions of inorganic phosphates, so the support of extrinsic technologies, such as tumbling, ultrasound, high-pressure processing (HPP), and pulsed electric field (PEF), may be necessary to achieve similar physiochemical properties as conventional products. The meat industry should continue to investigate ways to scientifically innovate the formulations of, and the technologies used in, processed meat products while also listening to (and acting upon) the feedback from consumers.

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

This study aimed to investigate the effect of ultrasound curing with various working modes and frequency combinations, including mono-, dual- and tri-frequency, on the content of NaCl and tenderness of pork loins (Longissimus dorsi). The physical qualities, myoglobin, moisture migration, distribution, and microstructure of pork were also evaluated. The results displayed that the NaCl content of samples cured by simultaneous ultrasound (100 W/L) working mode with a frequency combination of 20, 40, and 60 kHz was higher than that of other ultrasound working modes. The effect of ultrasonic brining was significantly better than the static curing when the saline solution was >35 mL. In addition, the samples cured by simultaneous ultrasound had better physical qualities, including more pickling absorptivity, less cooking loss, and lower hardness, tenderness, and chewiness value. The intensity of lightness was reduced, although redness and yellowness remained unaltered compared to static curing. The myoglobin content decreased drastically without changing the oxygenation level, and the relaxation time of T_2b and T₂₁ was delayed. The microstructure indicated that the ultrasonic treatment could promote changes in meat texture. Overall, the simultaneous ultrasound at various frequencies could efficiently accelerate NaCl penetration and improve pork quality.

A comparative study of vacuum tumbling and immersion marination on quality, microstructure, and protein changes of Xueshan chicken

Marination is a common technology in meat processing with advantages of enhancing tenderness, water retention, and overall quality. This study was conducted to investigate the effect of vacuum tumbling and immersion marination on meat quality, microstructure, water mobility, protein changes, and denaturation of Xueshan chicken. Results showed that vacuum tumbling significantly increased the marinating rate of chicken, tenderness, meat texture, and water retention. Meanwhile, vacuum tumbling decreased total sulfhydryl content alongside an increased protein surface hydrophobicity and free sulfhydryl content, indicating that vacuum tumbling elevated the degree of protein denaturation. Further, the peak area corresponding to the relaxation time T22 after vacuum tumbling was significantly higher than that of immersion marination, suggesting that the stability of the immobilized water of chicken was reduced by vacuum tumbling. Compared to immersion marination, vacuum tumbling improved myofibril fragmentation index (MFI) presenting fewer myofibrillar protein bands in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) gel and more damaged muscular cells. Overall, vacuum tumbling could improve the marination absorptivity, protein degradation, and denaturation, resulting in changes in myofibril structure and meat quality of Xueshan chicken.

Impact of Tumbling Process on the Toughness and Structure of Raw Beef Meat Pieces

Tenderness is a major factor in consumer perception and acceptability of beef meat. Here we used a laboratory tumbling simulator to investigate the effectiveness of the tumbling process in reducing the toughness of raw beef cuts. Twelve Semitendinosus beef muscles from cows were tumbled according to four programs: T1 (2500 consecutive compression cycles (CC), for about 3 h), T2 (6000 CC, about 7.5 h), T3 (9500 CC, about 12 h), and T4 (13,000 CC, about 16 h). The effect of tumbling on the toughness of raw meat was assessed using compression tests (stresses measured at 20% and 80% of deformation ratios) and microscopic observations made at the periphery and centre of meat samples, and compared against non-tumbled controls. Longer tumbling times significantly reduced the stresses measured at 20% and 80% compression rates, which reflected the toughness of muscle fibres and connective tissue, respectively. At the microscopic level, longer tumbling times led to reduced extracellular spaces, increased degradation of muscle structure, and the emergence of amorphous zones. A 12-h tumbling protocol ultimately makes the best compromise between the process time demand and toughness reduction in beef Semitendinosus meat pieces.

The effect of shower time, electrolyte treatment, and electrical stimulation on meat quality of cattle longissimus thoracis muscle in cold weather

The effects of three treatments (two levels each), namely shower time (ST), electrolyte treatment (ET), and electrical stimulation (ES), on meat quality were investigated using 112 cattle which were randomly allocated to different combinations of each treatment level. ST2, compared with ST1, increased ultimate pH from 6.05 to 6.23 and blood adrenaline levels while deteriorating beef color. ST2 also improved the water-holding capacity (WHC), exhibiting more immobilized water and less free water. Finally, it promoted protein unfolding and the conversion of α-helix to random coil, thus producing tenderer beef. In contrast, results indicated that ET either decreased pH_u in ST1 groups or relieved pre-slaughter stress in ST2 groups. ES accelerated pH₁ drop with maximum efficiency in an ST1-ET combination, but it did not alter pH_u. In addition, ES decreased WHC with an enlarged relaxation time for bound water while causing beef tenderization through protein unfolding. ST1-ET(-ES/NES) maximized pH_u reduction and provided an alternative for dark-cutting prevention in cold weather.

Techniques for postmortem tenderisation in meat processing: effectiveness, application and possible mechanisms

Abstract

Developing efficient and promising tenderising techniques for postmortem meat is a heavily researched topic among meat scientists as consumers are willing to pay more for guaranteed tender meat. However, emerging tenderising techniques are not broadly used in the meat industry and, to some degree, are controversial due to lack of theoretical support. Thus, understanding the mechanisms involved in postmortem tenderisation is essential. This article first provides an overview of the relationship of ageing tenderisation and calpain system, as well as proteomics applied to identify protein biomarkers characterizing tenderness. In general, the ageing tenderisation is mediated by multiple biochemical activities, and it can exhibit better palatability and commercial benefit by combining other interventions. The calpain system plays a key role in ageing tenderisation functions by rupturing myofibrils and regulating proteolysis, glycolysis, apoptosis and metabolic modification. Additionally, tenderising techniques from different aspects including exogenous enzymes, chemistry, physics and the combined methods are discussed in depth. Particularly, innovation of home cooking could be recommended to prepare relatively tender meat due to its convenience and ease of operation by consumers. Furthermore, the combined interventions provide better performance in controlled tenderness. Finally, future trends in developing new tenderising techniques, and applied consideration in the meat processing industry are proposed in order to improve meat quality with higher economical value.

Graphical abstract

Effects of the structure and gel properties of myofibrillar protein on chicken breast quality treated with ultrasound-assisted potassium alginate

This paper aimed to evaluate the effects of the structure and gel properties of myofibrillar protein (MP) on 300-days-old chicken breast quality treated with ultrasound (300 W) and low addition (4 mg/mL) of potassium alginate (UPA). The results showed that UPA group exhibited lower liquid loss and optimized texture correlated with the formed water barrier and damaged myofibrils. UPA reduced the MP size and increased its solubility, and the decreased myosin thermostability and dissociated actomyosin reduced heating time for improved texture. UPA improved the gel strength, elastic modulus and ordered-arrangement of network. During gelation, the aggregation of myosin head was weakened and cross-linking of myosin tail and PA molecules was enhanced by hydrophobic interactions. UPA further inhibited the formation of disulfide bonds of myosin head and increased gel firmness. The lower myosin gelling temperature thus accelerated gel formation, and enhanced protein association with PA molecules facilitated the better gel performance.

Physicochemical and microstructural attributes of marinated chicken breast influenced by breathing ultrasonic tumbling

Currently, the conventional atmospheric pressure-based and vacuum-based tumbling processes have a limited improvement on the chicken characteristic attributes during the marination process. In view of this, through a breathing (pressure change) tumbling strategy, ultrasonication (40 kHz, 140 W) was applied to improve tenderness, taste, and microstructure of chicken by a redesigned tumbler. The results showed that the tumbling with the breathing action and ultrasonication significantly enhanced the marinating absorptivity, tenderness and taste, and accelerated the degradation of myosin light chain. Free peptides (from 1465.9 ± 34.6 to 4725.7 ± 43.2 μg/mL) and amino acids (from 1.503 ± 0.096 to 2.593 ± 0.109 mg/mL) rose evidently for the control and the breathing tumbling treatment assisted by ultrasound respectively. Raman analysis revealed that strength of disulfide bonds declined from 0.731 ± 0.006 to 0.607 ± 0.011 a.u. and the conversion from α-helix (decreased by 67.23%) into β-fold (increased by 1573%) conformation occurred. Low field NMR analysis indicated that the content of immobilized water increased from 77385 ± 14 to 137011 ± 106 au·ms by integral calculus. Scanning and transmission electron microscopies clearly showed a prospective rupture of myofibers, myofibrils, and lysosomes. Overall, as a potential alternative, the breathing ultrasonic tumbling means improved the marinating efficiency and characteristics of marinated chicken breast.

Combined effect of ultrasound and sodium bicarbonate marination on chicken breast tenderness and its molecular mechanism

The objective of this study was to explore the combined effect of ultrasound (20 kHz ultrasound probe (12 mm diameter), an output power of 350 W for 5 min (on-time and off-time pulse durations of 2 s and 3 s, respectively)) with low concentration (0.2 M) sodium bicarbonate solution (USB) on chicken breast tenderness and its preliminary molecular mechanism. Therefore, myofibril fragmentation index (MFI), filtering residues, cooking loss, shear force, histology of meat as well as SDS-PAGE, circular dichroism (CD), synchronous fluorescence spectroscopy, differential scanning calorimetrv (DSC) of actomyosin were investigated and compared with untreated (Control), deionized water (DW), ultrasound in deionized water (UDW), 0.2 M sodium bicarbonate solution (SB), respectively. The results showed that USB can effectively increase MFI, and reduce filtering residues, cooking loss and shear force by compared with UDW or SB. Furthermore, myofibril was presented with the largest interfibrillary spaces and the highest degree of actomyosin dissociation in USB group. The increase in α-helix content and decrease in fluorescence intensity of tyrosine and tryptophan implied that USB caused the conformation change in actomyosin. Additionally, actomyosin in USB group became more sensitive to temperature. Therefore, the treatment of ultrasound combined with low concentration of sodium bicarbonate accelerated actomyosin degeneration was considered as a promising and efficient technique in meat processing, especially for the fitness enthusiasts.