Influence of salt concentration on the salting kinetics of cod loin (Gadus morhua) during brine salting

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.

Sucrose-phosphate osmotic system improves the quality characteristics of reduced-salt salted egg yolk: Profiling from protein structure and lipid distribution perspective

This paper was dedicated to the study of the effect of sucrose-phosphate on aspects of physicochemical properties, lipid distribution and protein structure during the picklig of reduced-salt salted egg yolk (SEY). This work constructed a reduced-salt pickling system from a new perspective (promoting osmosis) by using a sucrose-phosphate-salt. Results showed that SEY-28d achieved a desirable salt content (1.07 %), hardness (573.46 g) and springiness (0.65 g). The matured SEY was in excellent quality with orange-red color and loose sandy texture. This was because the lipoprotein aggregated with each other through hydrophobic interaction to form a stable network structure. In addition, the hypertonic environment accelerated salt penetration. These also created good condition for lipid spillage. The results of confocal laser scanning microscope also verified this phenomenon. This work provides important guidance for new reduced-salt curing of traditional pickled foods, deep processing of SEY, and industry development in the field of poultry egg.

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.

Use of yellow mombin (Spondias mombin L.) in marination: Effect on quality properties of Boston butt pork during refrigerated storage

This research aimed to evaluate the effect of yellow mombin (Spondias mombin L.) juice as a marinade liquid on the quality properties of Boston butt pork during refrigerated storage. Yellow mombin juice was used as a marinade liquid at different concentrations: 0% (C0), 50% (C50), 75% (C75), and 100% (C100) in Boston butt pork samples which were analyzed for technological properties, proximate composition, and sensory characteristics on day 0 of storage. In addition, the pH, lipid oxidation, textural, and microbiological analyzes were carried out during refrigerated storage for 21 days. The results showed that the pH of the marinated samples was affected by yellow mombin juice (P < 0.05), with final values of 4.65 (C50), 4.56 (C75), and 4.39 (C100). Regarding the texture properties, C75 and C100 had the lowest values for hardness during storage. In addition, C100 had the lowest total aerobic mesophilic (5.69 log CFU g-1), total aerobic psychrophilic (7.10 log CFU g-1), and Enterobacteriaceae (5.30 log CFU g-1) counts at the end of storage. Regarding sensory properties, samples C50 and C75 were the best-rated marinated samples regarding overall acceptability and purchase intention. Therefore, the use of 75% yellow mombin juice (C75) as a marinade liquid could be a viable alternative for marinating Boston butt pork.

Monitoring physicochemical modifications in beef steaks during dry salting using contact and non-contact ultrasonic techniques

In conventional ultrasonic techniques, the necessary contact between the sensor and the product has constrained the implementation of ultrasound for quality control purposes in the meat industry. The use of novel air-coupled ultrasonic technologies provides multiple advantages linked to contactless inspection. Therefore, this study aims to compare the feasibility of contact (C; 1 MHz) and non-contact (NC; 0.3 MHz) ultrasonic techniques for monitoring the physicochemical modifications undergone by beef steaks during dry salting after different times (0, 1, 4, 8 and 24 hours). Experimental results showed that the ultrasonic velocity increased during salting, which was linked to the reduction in Time-of-Flight ratio (RTOF) and sample shrinkage (velocity C: R2 = 0.99; velocity NC: R2 = 0.93 and RTOF C: R2 = 0.98; RTOF NC: R2 = 0.95). In terms of the compositional changes provoked by salting, the velocity variation (△V) increased linearly (C: R2 = 0.97; NC: R2 = 0.95) with the salt content. As for textural parameters, hardness (C: R2 = 0.99; NC: R2 = 0.97) and relaxation capacity (C: R2 = 0.96; NC: R2 = 0.94) were well correlated with the △V through power equations. Experimental results reflected that the performance of the non-contact ultrasonic technique was similar to that of the contact technique as regards the monitoring of the physicochemical changes undergone by beef steaks during dry salting.

Insight into mechanism of quality changes in tilapia fillets during salting from physicochemical and microstructural perspectives

The effects and mechanisms of salting on quality properties of tilapia fillets were investigated in the present study. Salting under high NaCl concentrations (12 % and 15 %) resulted in low water content and decreased yields, due to the salting-out effects and low pH. Water in fillets increased in the later stage of salting in 3 % and 6 % NaCl solutions (p < 0.05). The released proteins accumulated with increasing time (p < 0.05). The TBARS value increased from 0.01 to 0.20 mg/kg after 10 h in 15 % NaCl solution (p < 0.05). The quality changes were mainly correlated to the shrinking or swelling of myofibers, extracellular spaces, and existential state of muscle proteins. In consideration of fish quality and increasing call for low sodium intake, it was recommended to prepare fillets below 9 % NaCl with short times. The finding provided instructions to obtain target quality properties from tilapia by controlling salting conditions.

Physicochemical and microstructural mechanisms for quality changes in lightly salted tilapia (Oreochromis niloticus) fillets during frozen storage

BACKGROUND

Frozen tilapia fillet has become a leading aquatic product. High drip loss, dry and fibrous mouthfeel, and an unappealing appearance are its main problems. It was hypothesized that light salting could improve the quality, and that the preparation conditions would affect the storage stability of frozen tilapia fillets.

RESULTS

The quality changes of lightly salted tilapia fillets were evaluated during frozen storage, and the underlying mechanisms were studied from the physicochemicaland microstructural perspectives. Though the salt content was 1.5% in all samples,the amount of ice crystals in frozen tissues decreased with the descending water content and freezing point (P < 0.05). No intracellular voids were observed in the samples prepared under proper salting conditions, and the myofibers were plump and smooth after freezing-thawing, which contributed to the high water-holding capacity of lightly salted fillets. After 28 days,the water-binding capacity of the salted groups was 14.69%-18.62% higher than that of their unsalted counterparts (P < 0.05). The reduced protein solubility in the salted fillets was likely to have occurred because the solubilized and unfolded proteins interacted more easily during frozen storage. The oxidation degree of myofibrillar proteins was also affected by salting condition, and the fillets with less oxidized sulfhydryl groups maintained high springiness after 28 days of frozen storage.

CONCLUSION

The salting condition of 9% NaCl solution for 1 h was recommended for the preparation of lightly salted fillets from freshwater fish, taking into account quality, processing efficiency, and storage stability. The enhanced water-holding capacity and texture of lightly salted tilapia fillets were attributed to modified physicochemical and microstructural properties. These results could provide a scientific basis for the processing and storage of high-quality, frozen, lightly salted fillets from freshwater fish. © 2022 Society of Chemical Industry.

Effects of CaCl2 on salting kinetics, water migration, aggregation behavior and protein structure in rapidly salted separated egg yolks

Salted egg yolks are valued by consumers for their delicious taste good processing characteristics. To improve the quality of rapidly salted separated egg yolks, we compared changes in the salting kinetics, textural properties, water migration, protein aggregation and structure of salted egg yolks in the presence or absence of CaCl₂ for 24 h. CaCl₂ increased the mass transfer driving force and diffusion coefficient during the salting process; as a result, the salted egg yolks exhibited increased hardness and decreased springiness and cohesiveness. Through low field nuclear magnetic resonance (LF NMR), it was confirmed that CaCl₂ promoted the precipitation of lipids and the dehydration of egg yolk. Furthermore, CaCl₂ promoted the bulk aggregation of proteins. The analyses of protein structures showed that the contents of β-sheets and irregular curls in CaCl₂-salted egg yolk protein increased, while the contents of α-helices and β-turns decreased. CaCl₂ affected the microenvironment of tryptophan residues and embedded these residues, enhancing protein aggregation. Based on the comprehensive information obtained in this study, adding CaCl₂ to the salting solution improved the degree of protein polymerization in egg yolk; thus, this method might be used to improve the quality of egg yolks separated by salt.

Mass transfer enhancement of tuna brining with different NaCl concentrations assisted by ultrasound

The influence of different NaCl concentrations (2.5, 5, 7.5 and 10% (w/w)) on the mass transfer kinetics of tuna during brining process with and without ultrasound assistance was evaluated. Results showed that an increase in NaCl concentration and the application of ultrasound accelerated the salt diffusion in the tuna muscle, and the highest yield was obtained in 5% brine concentration. Moreover, the kinetics parameters were significantly affected by the NaCl concentration and ultrasound application during brining. The values of the mass transfer kinetics parameters (k₁, k₂) for total and water weight changes decreased as NaCl concentration increased with and without ultrasound assistance during brining. In contrast, the higher the NaCl concentration, the higher the value of the salting kinetics parameters for salt weight changes. The application of ultrasound enhanced the salt effective diffusion coefficient (De) from 402.8% to 653.21% during the brining process, and the highest De was also found at 5% brine concentration. The application of ultrasound can improve the uniformity of salt distribution, enhance water holding capacity, reduce hardness and chewiness, but have no significant effect on color of tuna muscle.

Effect of a moderate electric field on the salting of Atlantic Salmon (Salmo salar): An experimental study and phenomenological understanding

Salting is one of the oldest methods of preserving food. The main limitation of salting is its extended processing time due to slow salt diffusion. A moderate electric field (MEF) can improve the mass transfer rate through electroporation. Regularly, mass transfer processes are modeled with Fick's second law. However, due to the anisotropic nature of food microstructures, it might be more appropriate to use an anomalous model. The main objective of this study was to search for a phenomenological explanation for salt and water diffusion in the salmon brining process coupled with MEF. Salmon fillets were cut into finite cylinders (0.025 × 0.025 m) and brined in two salt concentrations (6 and 24% w/w NaCl) at 6 °C for 20 h. MEFs were applied in the range of 0 to 2 V/cm. The salt and water contents of the salmon were measured during the process. Fick's second law and anomalous model based on fractional calculus were used to describe the diffusion phenomena. The results showed that an MEF tended to reduce the brining processing time and increase the salt content of salmon. This effect is predominantly due to an increase in the equilibrium salt concentration in the salmon tissue. Mathematical analysis shows that the anomalous diffusion model is more suitable for representing the brining process, exhibiting superdiffusion behavior (α > 1). An MEF accelerates the salt mass transfer into salmon tissue even at lower temperatures, significantly reducing the processing time. In addition, the diffusion process can be characterized with an anomalous model.

Modeling the NaCl diffusion in beef during brining process

An in-depth understanding of mass transfer during brining process is important for improving the quality and characteristics of meat products. In this study, a fitted equation of time and NaCl concentrations in the aqueous phase of beef was established to calculate the NaCl diffusion coefficient for simulation. A three-dimensional simulating model of mass transfer was developed to evaluate the NaCl diffusion in beef during brining process. And the validity of this simulating model was verified by comparing the NaCl concentrations evaluated by the numerical simulation simulated with the experimental measurements. The results indicated that the power function time variant equation can predict NaCl concentrations (R² = 0.995) and accurately calculate the NaCl diffusion coefficient (8.46 × 10^-10 m² /s). The simulating model visually showed the NaCl diffusion in beef during brining process. Therefore, this research provided a new method for predicting the NaCl diffusion in realistic meat processing. PRACTICAL APPLICATION: This research gives a new method for predicting the NaCl diffusion in meat product. The method accurately evaluated NaCl concentrations in beef at different brining time and clearly showed NaCl diffusion in beef during brining process, which could be helpful in reducing the cost and the complexity of detecting NaCl concentrations in meat during brining process.

Effects of sodium alginate-based coating pretreatment on drying characteristics and quality of heat pump dried scallop adductors

BACKGROUND

Drying efficiency and quality maintenance are the major concerns of both manufactures and consumers. Heat pump drying (HPD) is suitable for heat sensitive foodstuffs due to its ability to independently control the drying operation parameters. However, lower drying rate and energy efficiency in the later period of HPD are the bottlenecks that restrain its application. A novel approach using hydrocolloids as pretreatment coatings prior to drying was designed to solve these problems. The effects of sodium alginate (SA) coating, drying temperatures and air velocities on the drying characteristics and quality attributes of scallop adductors were evaluated.

RESULTS

Drying took place in the falling rate period. Drying time decreased with increasing temperature, air velocity and SA coating. The Two Term model and the Wang and Singh model gained the best fit for thin-layer drying of scallop adductors and SA film, respectively. Effective moisture diffusivity increased with temperature, velocity and SA coating and were in the range 7.352-14.620 × 10^-11 , 9.890-17.100 × 10^-11 and 2.348-4.604 × 10^-10  m²  s^-1 for uncoated scallop adductors, SA coated scallop adductors and SA films, respectively. The activation energies for SA films, coated and uncoated scallop adductors were 17.07, 20.78 and 26.17 kJ mol^-1 , respectively. Dried scallop adductors with SA coating pretreatment exhibited a significant lower value of shrinkage rate and hardness, and higher value of toughness than uncoated ones at 30 °C and 2.0 m s^-1 (P < 0.05).

CONCLUSION

Hydrocolloid coating is a promising pretreatment in improving HPD efficiency and enhancing quality attributes of dried scallop adductors. © 2019 Society of Chemical Industry.

Mass transfer dynamics during brining of rabbit meat

As a traditional processing method, brining is a preliminary, critical and even essential process for many traditional rabbit meat products in China. The aim of this work was to investigate mass transfer of rabbit meat brined in different salt concentration. Rabbit meat (Longissimus dorsi) was brined for 24 h in 5 brine solutions (5, 10, 15, 20 and 25% NaCl [w/w]). Results indicated that mass transfer and kinetics parameters were significantly affected by the brine concentration during brining. When brine concentration increased, the total and water weight changes decreased, whereas the sodium chloride weight changes increased. Higher brine concentrations resulted in a higher degree of protein denaturation and consequently gave lower process yields. Samples treated with higher brine concentrations obtained lower brining kinetic parameter values for total weight changes and water weight changes, whereas they acquired higher values for sodium chloride weight changes.