Low-field NMR determination of water distribution in meat batters with NaCl and polyphosphate addition

Effect of myoglobin, hemin, and ferric iron on quality of chicken breast meat

OBJECTIVE

The objective was to evaluate the impact of different forms of iron including myoglobin, hemin, and ferric chloride on the quality of chicken breast meat.

METHODS

Chicken breast muscles were subjected to 1, 2, 3 mg/mL of FeCl3, myoglobin and hemin treatment respectively, and the production of reactive oxygen species (ROS) and malondialdehyde, meat color, tenderness, water holding capacity and morphology of meat was evaluated.

RESULTS

Hemin was found to produce more ROS and induce greater extent of lipid oxidation than myoglobin and ferric chloride. However, it showed that hemin could significantly increase the redness and decrease the lightness of the muscle. Hemin was also shown to be prominent in improving water holding capacity of meat, maintaining a relatively higher level of the immobilized water from low-field nuclear magnetic resonance measurements. Morphology observation by hematoxylin-eosin staining further confirmed the results that hemin preserved the integrity of the muscle.

CONCLUSION

The results indicated that hemin may have economic benefit for the industry based on its advantage in improving water holding capacity and quality of meat.

Nitroso-hemoglobin-ginger conjugates effects on bacterial growth and color stability in a minced beef model

This study aims to enhance the color and microbiological qualities of a raw beef using natural ingredients. Nitroso-hemoglobin (NO-Hb) integrated with vitamin C (VC), calcium lactate, and ginger complexation were used as natural inhibitors against the growth of aerobic and pathogenic bacteria, namely (Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Salmonella. NO-Hb inhibited E. coli, S. aureus, and Salmonella, and enhanced the color stability more than nitrite in the minced beef model. After the multiexponential analysis of relaxation decays, the water component (T2b) was analyzed using the low-field NMR. The results indicated that, at the 7th d of cold-storage the third component (T2) was detected. Significant correlations were observed between T21 and T22 relaxation times and water-holding capacity in minced beef, implying that the LF-NMR measurements could be an efficient method for the determination and prediction of beef freshness. NO-Hb- ginger mixture, as a novel ingredient, could be used instead of nitrite in terms of meat safety.

Effects of fat/oil type and ethylcellulose on the gel characteristic of pork batter

The effects of fat/oil type (pork fat; sunflower seed, peanut, corn and flaxseed oils) and ethylcellulose (EC) concentration (8%, 10% and 12%) on the gel characteristic of pork batter were investigated in this study. Replacing pork fat in meat batter with organogels prepared with EC and vegetable oils obtained cooked batters with higher hardness, gumminess and chewiness, furthermore, increasing EC level in the organogels increased hardness, while cohesiveness and springiness showed no significant changes. Emulsion stability of all organogels groups was improved compared to pork fat group and the type of vegetable oil affected the emulsion stability. A shorter relaxation time T₂ and a larger peak area P₂₂ were observed for batters formulated with oraganogels, which indicated higher percentage of immobilized water. The batters prepared with pork fat displayed larger fat globules, lower L* value than those prepared with organogels, but the redness (a* values) had no significant difference.

Effect of pH and mixing ratio on interpolymer complexation of scallop (Patinopecten yessoensis) male gonad hydrolysates and κ-carrageenan

The electrostatic complex coacervation between scallop Patinopecten. yessoensis male gonad hydrolysates (SMGHs) and κ-carrageenan (κ-C) were monitored by using turbidimetry at various pH (1-12) and biopolymer mixing ratio (9:1-1:9). The pH_c exhibited ratio-independent behavior, and pH_φ1, pH_max exhibited ratio-dependent behavior, respectively. The decreasing ratio enhanced the gel strength of SMGHs/κ-C at higher pH while inversely at lower pH, ascribing to more SMGHs aggregates and stronger neutralization between positively charged patches in SMGHs and κ-C at lower pH and higher ratio. Moreover, SMGHs/κ-C gel at acid condition exhibited lower relaxation times (T₂₁ and T₂₃). Furthermore, the rheological and relaxation time T₂ data were well associated with microscopy images which indicated that SMGHs/κ-C gel showed a well-distributed network structure at more acidic domains, supporting stronger gel rigidity and water-holding capacity.

Meat texture, muscle histochemistry and protein composition of Eriocheir sinensis with different size traits

The main aim of the present work was to investigate the effect of the inherent differences in the raw muscle on the textural quality of the cooked meat from different sized Eriocheir sinensis. The content of entrapped water was 73.8-77.7 g/100 g in raw muscle. The density and diameter of muscle thick microfilaments ranged between 137 and 158/μm² and 20.9-27.0 nm. These results demonstrated that the raw muscle from the tender group had a smaller density of larger diameter thick microfilaments and more entrapped water than other samples, which could explain the high tenderness of the cooked meat (P < 0.05). The potential structural proteins that indicated tenderness include myosin regulatory light chain 2, ancient ubiquitous protein 1, tubulin α-2 chain, and β-catenin, was determined using liquid chromatography-tandem mass spectrometry. The inherent attributes of raw muscle could explain the textural differences of the cooked meat from Eriocheir sinensis.

Effect of bamboo shoot dietary fiber on gel properties, microstructure and water distribution of pork meat batters

OBJECTIVE

To develop healthier comminuted meat products to meet consumer demand, the gel properties, rheological properties, microstructure and water distribution of pork meat batters formulated with various amounts of bamboo shoot dietary fiber (BSDF) were investigated.

METHODS

Different levels of BSDF (0% to 4%) were added to pork batters, and the pH, color, water-holding capacity, texture and rheological properties of pork batters were determined. Then, pork batters were analyzed for their microstructure and water distribution using scanning electron microscopy (SEM) and low-field nuclear magnetic resonance (LF-NMR).

RESULTS

Compared with the control, BSDF addition into meat batters showed a significant reduction in L*-value and a significant increase in b*-value (p<0.05). BSDF addition of up to 4% reduced the pH value of pork batters by approximately 0.15 units; however, the cooking loss and expressible water loss decreased significantly (p<0.05) with the increased addition of BSDF. The hardness and gel strength were noticeably enhanced (p<0.05) as the content of BSDF increased. The rheological results showed that BSDF added into pork batters produced higher storage modulus (G') and loss modulus (G″) values. The SEM images suggested that the addition of BSDF could promote pork batters to form a more uniform and compact microstructure. The proportion of immobilized water increased significantly (p<0.05), while the population of free water was decreased (p<0.05), indicating that BSDF improved the water-holding capability of pork batters by decreasing the fraction of free water.

CONCLUSION

BSDF could improve the gel properties, rheological properties and water distribution of pork meat batters and decrease the proportion of free water, suggesting that BSDF has great potential as an effective binder in comminuted meat products.

Comparative analysis of quality and microbial safety of ohmic and water bath cooked pork batter during refrigerated storage

In this study, the microbial safety, lipid and protein oxidation, and water characteristics of ohmic (OH) and water bath (WB) cooked pork batter during storage at 4 °C were investigated. The results indicated that the cooking time was much shorter for samples cooked to 72 °C by OH cooking (2 min) than WB cooking (41 min), but OH and WB cooked samples had no significant difference in total viable colony (TVC) at day 28. No significant differences were observed in thiobarbituric acid reactive substances (TBARS) and total sulfhydryl content between OH and WB cooked samples (P > 0.05), but the OH cooked samples had higher carbonyl content (P < 0.05). Although there were no significant differences for water content and drip loss between OH and WB cooked samples, the relaxation time T ₂₂ of the OH cooked samples were longer than WB cooked ones (P < 0.05). On the whole, the qualities of the OH cooked samples were comparable to the WB cooked ones during the entire storage period, indicating that there was a great prospect for OH cooking to be applied in the meat product industry.

A Chemometric Approach to Establish Underlying Connections between Lipid and Protein Oxidation and Instrumental Color and Texture Characteristics in Brazilian Dry-cured Loin

This study aimed to use chemometrics to evaluate the influence of lipid and protein oxidation on the color and texture characteristics of Brazilian dry-cured loin (Socol, BDL). Upon exploration using hierarchical cluster analysis (HCA), two clusters were formed, indicating that higher water activity (aw) was associated with higher lipid and protein oxidation. However, this fact was associated with softening and low color quality (a*, chroma, and cured color). In a more in-depth exploration, using principal component analysis (PCA) for each cluster separately, connections between protein and lipid oxidation were found in high aw, as demonstrated by their statistical association. In the same way, relationships between high hardness and carbonyl contents were obtained only in high aw. In addition, an overall relationship (p < 0.05) between nondestructive measurements, such as hardness, and destructive methods (malonaldehyde and carbonyl contents) demonstrate that nondestructive techniques can be promising for further studies in the method replacement field. In this study, reasonable explanations of the connections between oxidative damage and quality traits in Socol are provided.

Improvement of gel properties of mackerel mince by phlorotannin extracts from sporophyll of Undaria pinnatifidai and UVA induced cross-linking

The effects of phlorotannin extracts (PTE) (from sporophyll of Undaria pinnatifida) added at different concentration (0, 1.6, 8, and 40 mg/g protein) with and without ultraviolet A (UVA) irradiation treatment on gel properties of mackerel (Scomberomorus niphonius) mince (MM) were investigated. The results indicated that both the breaking force and water-holding capacity (WHC) of the MM gel increased with addition of PTE, and the highest breaking force and WHC were observed with 40 mg/g PTE under UVA irradiation. Low-field nuclear magnetic resonance revealed that free water significantly decreased in this PTE-MM gel as well. UVA irradiation treatment led to reduction of total sulfhydryls and free amines in the PTE-MM gel, indicating more cross-linking between proteins. Electrophoresis results indicated that myosin heavy chains were aggregated in the UVA-treated PTE-MM gel. The microstructure of the UVA-treated PTE-MM gel showed that protein formed more evenly distributed cross-linked structures and was more compact than the untreated control gel. As a conclusion, PTE addition with UVA irradiation is shown to improve gelling properties of mackerel mince.

Compensation of high-pressure processing for the solubility of sodium-reduced chicken breast myosin with three anion types of potassium salts

The effect of high-pressure processing (200 MPa, 10 min) on the solubility of chicken breast myosin with 25% molar substitution of Na+ by 3 anion types of potassium salts (KCl, K-lactate, and K-citrate) was investigated. The results showed that the lower hydrophobic group and reactive sulfhydryl group of nonpressurized myosin with the replacement of organic K-lactate or K-citrate possibly contributed to the aggregation of myosin molecules compared with the KCl group and thus decreased the solubility of both. In the presence of lactate or citrate, the high-pressure processing caused an increase in the surface hydrophobicity and reactive sulfhydryl group, indicating the unfolding of myosin molecule. Meanwhile, the increased hydration state and the decreased apparent viscosity suggested the disruption of protein-protein interactions and the strengthening of myosin-water interactions in pressurized myosin, ultimately resulting in increased solubility of the pressurized myosin with both organic potassium salts. The compensation of high-pressure processing is interesting for the efficient selection of the anion type in developing sodium-reduced industrial meat products.

Ultrasound and basic electrolyzed water: A green approach to reduce the technological defects caused by NaCl reduction in meat emulsions

Meat emulsions were prepared by replacing water with basic electrolyzed water (BEW) and reducing NaCl content by 0, 10, 20, 30, 40, and 50%. The emulsions were sonicated in an ultrasound bath (25 kHz, 175 W, normal mode) for 0, 10, and 20 min. The physicochemical (pH, redox potential, water activity, and color parameters) and technological (cooking yield, emulsion stability, and texture) characteristics were evaluated. The US operation time of 20 min improved the emulsion stability, cooking yield, and texture of the emulsions with 10% and 20% NaCl reduction. The BEW-treated emulsions exhibited good fat retention and moderate water retention capacity. The combination of US and BEW for 20 min provided good emulsion stability and cooking yield for the formulations with up to 30% NaCl reduction, which exhibited texture profile similar to the control (0% NaCl reduction). Therefore, it is possible to produce reduced-salt meat emulsions using the combination of US and BEW.

Flocculation behavior and gel properties of egg yolk/κ-carrageenan composite aqueous and emulsion systems: Effect of NaCl

In this study, the influence of NaCl on the flocculation behavior and gel properties of egg yolk/κ-carrageenan mixed dispersions or emulsions were studied. As a result of NaCl incorporation, there was a decrease in the mean droplet size, zeta potential, degree of flocculation and viscosity of the mixed dispersions/emulsions, and the onset point of gelation was also brought forward. Increasing the concentration of NaCl led to a significant increase in gel strength and decrease in gel cohesiveness. Results from low field nuclear magnetic resonance (LF-NMR) confirmed that the addition of NaCl could significantly reduce the hydration ability of gel molecules and increase the content of immobilized water of hydrogels as the gel strength increased, while the water holding capacity of emulsion gels was depressed with the incorporation of oil. These findings suggested the flocculation state and gel properties of egg yolk/κ-carrageenan mixed dispersions/emulsions can be tailored by adjusting NaCl for food formulations.

Influence of sodium pyrophosphate on the physicochemical and gelling properties of myofibrillar proteins under hydroxyl radical-induced oxidative stress

Sodium pyrophosphate (PP) addition changed the rheological behavior and improved the gelling properties of oxidative stressed myofibrillar proteins (MP).

Nitroso-hemoglobin Increased the Color Stability and Inhibited the Pathogenic Bacteria in a Minced Beef Model: A Combined Low-field NMR Study

This study mainly investigated the improvement effect of nitroso-hemoglobin (NO-Hb) and four lactic acid bacteria (LAB) (Streptococcus thermophiles, Lactobacillus bulgaricus, Lactobacillus casei, and Montessori enterococcus) on the color and microbiological qualities of raw beef. Three strains of Escherichia coli, Staphylococcus, Salmonella, and Pseudomonas were used as pathogenic bacteria. The results showed that both NO-Hb and LAB could enhance the color stability and scavenged the spoilage bacteria in a minced beef model. But the improvement effect of NO-Hb was more significant than LAB. This suggested that NO-Hb, as a novel ingredient, could be used as a promising substitute for nitrite in meat products to improve the color and safety of meat products. In addition, low field (LF)-NMR method has been established to be practicable to identify changes in the relaxation times of water and fat caused by different type of bacteria and the storage periods. The number of relaxation components in minced beef was affected by bacteria and increase of the storage period.

Effects of high-speed shear homogenization on the emulsifying and structural properties of myofibrillar protein under low-fat conditions

BACKGROUND

Emulsification is important for food quality and processing functionality. Most emulsification occurs under high-fat conditions that eventually cause health concerns. Protein emulsifiers also have drawbacks such as lower dispersity. This study considered the effects of different high-speed shear homogenization (HSH) speeds on the emulsifying and structural properties of myofibrillar proteins (MPs) under low-fat conditions.

RESULTS

High-speed shear homogenization significantly increased the emulsifying activity and emulsifying stability of MPs at lower speeds (8000 to 14 500 rpm). The primary structure of MP was not altered significantly by HSH, whereas its secondary, tertiary, and quaternary structures were changed. Particle size decreased first and then increased significantly, and reached a minimum when the HSH speed was 14 500 rpm. The absolute zeta potential values increased significantly and the dendritic fibrous structure of sample was destroyed when the speed exceeded 14 500 rpm. High-speed shear homogenization (14 500 rpm) decreased the particle size and unfolded the protein, which improved the emulsifying properties of MPs. Excessive HSH speeds (20 500 rpm or higher) caused an aggregation of MP molecules, which was not conducive to improving their emulsifying properties.

CONCLUSION

Optimal HSH speed was achieved at 14 500 rpm to modify MPs' emulsifying and structural properties under low-fatconditions. © 2019 Society of Chemical Industry.

Involvement of DNA in Gel Formation of Scallop (Patinopecten yessoensis) Male Gonad Hydrolysates and Corresponding Hybrid Gel with κ-Carrageenan

Involvement of DNA in gelation and microstructural properties of scallop (Patinopecten yessoensis) male gonad hydrolysates (SMGHs) and corresponding hybrid gel with κ-carrageenan (SMGHs/κ-C) was studied using DNase pretreatment. Although DNase pretreatment significantly transformed SMGHs from weak gels to liquid, it made SMGHs have a superior synergistic effect on gel formation with κ-C by evidence of 2.7-fold G' and 1.1-fold melting temperature. However, the relaxation time (T₂₁ and T₂₃), functional groups, and flocculation behavior were comparable between SMGHs/κ-C and SMGHs/DNase/κ-C. Moreover, SMGHs/DNase/κ-C exhibited a denser network with more numerous patches and larger void spaces. These results suggest that DNA contributes to the gel formation of SMGHs whereas restricts more cationic peptides in SMGHs to bind sulfate groups in κ-C during gel formation.

Nondestructive Detection Method for Beef Water-Holding Capacity Using Modified Test Paper

Water-holding capacity (WHC) is a critical indicator of beef quality. Several conventional test methods have high cost or spend more time. In this study, a rapid detection method was developed to measure WHC by modified test paper. The test paper was modified by cobalt chloride for its color turned from blue to red after contacting with water. When the test paper was attached to the surface of meat sample, its color would change. The time of color changing was related to WHC. A prediction model was built. The prediction accuracy was 90 % and the detection time was less than 1 min. The results of scanning electron microscope (SEM) analysis showed that the three-dimensional network structures of the test paper were more compact and homogeneous. Accordingly, the modified test paper exhibits a more stable property and can be used for other meat products.

Effect of secondary heat-induced aggregation on pork meat batter protein conformation, hydration characteristics, textural quality and in vitro digestibility

SH has caused fierce aggregation and the conformation transition from α-helix to β-sheets, which resulted in the decrease of WHC, textural quality and in vitro digestibility.

The impact of hydrophilic emulsifiers on the physico-chemical properties, microstructure, water distribution and in vitro digestibility of proteins in fried snacks based on fish meat

Hydrophillic emulsifiers strengthened the starch–protein interaction which resulted in improved physio-chemical properties of friend snacks based on fish meat.

Effect of gellan gum on functional properties of low-fat chicken meat batters

The effects of substituting pork back-fat with addition of gellan gum and water on gel characteristics, rheological property, water mobility, and distribution of chicken meat batters were studied. The addition of gellan gum significantly affected the cooking yield, color, texture, and rheological property of chicken meat batters (p < .05). The cooking yield and textural properties were not significantly different (p > .05) when gellan gum was added with 0, 0.2, and 0.4%. When the level of gellan gum reached 0.6%, the cooked chicken meat batters had significantly lower L* value, cooking yield, hardness, springiness, cohesiveness, and chewiness values (p < .05). The initial storage modulus (G') of chicken batters was significantly decreased (p < .05) with increasing gellan gum. During the heating, an increase in denaturation temperature of the myosin head and tail were observed in chicken batters with added gellan gum. The G' of chicken batters with 0, 0.2, and 0.4% gellan gum were not significant difference (p > .05) at 80C, but the G' of chicken batters with 0.6% gellan gum was significantly decreased (p < .05). LF-NMR revealed that T₂₁ and T₂₂ were significantly increased (p < .05) with increasing the water and gellan gum content while P₂₁ and P₂₂ were not significantly different (p > .05) in the chicken batters with 0, 0.2, and 0.4% gellan gum. A significant decrease was observed (p < .05) in the chicken batter with 0.6% gellan gum. Overall, added 0.2 and 0.4% gellan gum to chicken meat batters could reduce pork back-fat. PRACTICAL APPLICATIONS: Emulsion-type meat products contain a high level of fat, saturated fatty acids, and cholesterol, which have a potential negative effect on consumers health. However, animal fat plays an important role in the textural properties and water-holding capacity of meat products. One of great challenges in meat processing is how to find a fat substitute to produce low-fat meat products which have overall acceptable quality. This study showed that the addition of gellan gum influenced the textural properties of chicken batters and changed the dynamic rheological behavior. The addition of 0.2 and 0.4% gellan gum kept a stable cooking yield and textural properties of cooked chicken batters and also reduced the pork back-fat. LF-NMR could reflect the cooking yield and gel properties of the chicken batters. Gellan gum may be used to replace pork back-fat to produce low-fat chicken meat batters having overall acceptability in meat industry for meeting consumer demand.

A novel, sensitive and non-destructive method for quantitative determination of lipid in live Eriocheir sinensis using low-field 1H Nuclear magnetic resonance

In this study, lipid content of live Eriocheir sinensis has been quickly and accurately determined by low-field 1H Nuclear magnetic resonance (LF-1H NMR). The experimental parameters of LF-1H NMR have been optimized and the validity of the established standard method has been confirmed with traditional Soxhlet extraction method. Results show that the lipid signal intensity is strongly correlated with its content and exhibits a good linear correlation (Y = 0.0376 + 4.899X, R 2 = 0.9999), thus demonstrating favorable accuracy and sensitivity for the quantitative determination of lipid content. In conclusion, the lipid content of live E. Sinensis can be directly obtained based on an established method, indicating a great application potential in food and other fields.

Effect of chopping time and heating on 1 H nuclear magnetic resonance and rheological behavior of meat batter matrix

The effect of chopping time and heating on physicochemical properties of meat batters was investigated by low-field nuclear magnetic resonance and rheology technology. Cooking loss and L* increased while texture profile analysis index decreased between chopping 5 and 6 min. The relaxation time T₂₁ (bound water) and its peak area ratio decreased, while the ratio of T₂₂ peak area (immobilized water) in raw meat batters gradually increased with the extension of chopping time. However, T₂₂ was opposite after being heated and a new component T₂₃ (free water) appeared (T_2i is the spin - spin relaxation time for the ith component.). The initial damping factor (Tan δ) gradually decreased and there were significant difference between 4 and 5 min of chopping time. There were significantly positive correlations between the ratio of peak area of T₂₂ and chopping time, the storage modulus (G'), cooking loss, and L*, respectively. Continued chopping time could improve the peak area proportion of T₂₂ in raw meat batters. Further, the higher the peak area proportion of T₂₂ in raw meat batters, the cooking loss of heated meat gel was higher. Also, the stronger the mobility of immobilized water in meat batter, the higher the L* of the fresh meat batters. Thus, it is revealed that the physicochemical properties of meat batter are significantly influenced by chopping time which further affects the water holding capacity and the texture of emulsification gel.

Effects of pulsed ultrasound on rheological and structural properties of chicken myofibrillar protein

The effects of pulsed ultrasound (PUS) (power: 240w) with varying time (0, 3, 6, 9, 12 and 15min) on rheological and structural properties of chicken myofibrillar protein (CMP) were examined. PUS treatment significantly caused a decrease in the viscosity coefficients (k) but an increase in the flow index (n) value of CMP solutions within short time (0-6min), while had no significant effect for longer time (9-15min). Besides, at 6min, the solubility and microstructure of CMP samples were optimum. The primary structure of CMP was not altered by PUS treatment. However, Raman spectroscopy revealed a decrease in the α-helix and β-sheets proportion and an increase in the β-turn of CMP following PUS treatment. Random coil reached a maximum at 6min. The changes in tertiary and quaternary structure of CMP by PUS treatment also occurred. As PUS time extended, S₀-ANS for CMP increased measured by ANS fluorescence probe method. However, the normalized intensity of 760cm^-1 increased from 0min to 6min, and then decreased to 15min by Raman test. Moreover, the reactive sulphur (SH) contents and disulfide bonds (S-S) of samples increased while the total SH contents decreased within 0-6min. At 9min and above, the contents of reactive SH groups were almost equal to the contents of total SH groups. Differential scanning calorimetry (DSC) of CMP showed that peak temperature (T_d2) for myosin and peak temperature (T_d3) for actin were both reduced in the first 6min, while T_d3 was not observed from 9min following PUS treatment. Therefore, 6min was the optimum PUS time to obtain better CMP rheological and structural properties.