Effect of sodium bicarbonate on gel properties and protein conformation of phosphorus-free chicken meat batters

Effect of partial substitution of complex phosphates with sodium bicarbonate on aggregation, conformation and gel properties of beef-pork-chicken complex myofibrillar proteins

BACKGROUND

Complex phosphates (CP) can improve the physicochemical properties and gelation properties of myofibrillar fibrous protein (MP) in mixed meat products, but an excessive intake of phosphates over a long period of time is harmful to health. The present study investigated the effects of partial or complete substitution of CP with sodium bicarbonate (SB) on the physicochemical properties and gel properties of beef-pork-chicken mixed myofibrillar protein (BPC-MP), aiming to evaluate the feasibility of this method in reducing the amount of phosphate in mixed meat products.

RESULTS

Under the optimal substitution conditions, the turbidity of BPC-MP was reduced by 37.8%, the net negative potential was increased by 28.9% and the modulus of elasticity (G') was increased. The tertiary structure indexes of protein (including fluorescence intensity, surface hydrophobicity and active thiol content) were significantly changed, whereas the α-helix and β-turn angle contents in the secondary structure of protein were significantly increased. In addition, the water retention ability and strength of gel were also improved, which were increased by 20.7% and 42.6%, respectively. The results of scanning electron microscopy showed that the SB substitution group had a more compact and ordered microstructure.

CONCLUSION

The results showed that partial substitution of CP with SB reduced the amount of phosphate added to BPC-MP and had a positive effect on the physicochemical and gel properties of BPC-MP. © 2024 Society of Chemical Industry.

Using ultrasonic-assisted sodium bicarbonate treatment to improve the gel and rheological properties of reduced-salt pork myofibrillar protein

To study the impact of ultrasonic duration (0, 30, and 60 min) and sodium bicarbonate concentration (0% and 0.2%) on the gel properties of reduced-salt pork myofibrillar protein, the changes in cooking yield, colour, water retention, texture properties, and dynamic rheology were investigated. The findings revealed that added sodium bicarbonate significantly increased (P < 0.05) cooking yield, hardness, springiness, and strength of myofibrillar protein while reducing centrifugal loss. Furthermore, the incorporation of sodium bicarbonate led to a significant decrease in L⁎, a⁎, b⁎, and white values of cooked myofibrillar protein; these effects were further amplified with increasing ultrasonic duration (P < 0.05). Additionally, storage modulus (G') significantly increased for myofibrillar protein treated with ultrasonic-assisted sodium bicarbonate treatment resulting in a more compact gel structure post-cooking. In summary, the results demonstrated that ultrasonic-assisted sodium bicarbonate treatment could enhance the tightness of reduced-salt myofibrillar protein gel structure while improving the water retention and texture properties.

Influence of seaweed dietary fibre as a potential alternative to phosphates on the quality profiles and flavour attributes of frankfurters

This study primarily aimed to investigate the influence of seaweed dietary fibre (SDF), as a potential alternative to phosphates, on the quality profiles and flavour attributes of frankfurters. The results revealed that SDF addition can significantly improve the cooking yield and texture characteristics of phosphate-free frankfurters (P < 0.05), and 1.00% SDF proved to be the optimal concentration for replacing phosphates in frankfurters. Moreover, electronic nose and electronic tongue analyses demonstrated that SDF incorporation potentially influences the aroma and taste of phosphate-free frankfurters. Furthermore, volatile compound analysis revealed that SDF addition potentially compensates for the decrease in volatile flavour compound content caused by phosphate deficiency. Generally, our results indicate that SDF can be successfully applied as a potential alternative to phosphates and subsequently improve the quality profiles and flavour attributes of phosphate-free frankfurters. Moreover, they provide valuable theoretical guidance for the processing of phosphate-free emulsified meat products.

Using Potassium Bicarbonate to Improve the Water-Holding Capacity, Gel and Rheology Characteristics of Reduced-Phosphate Silver Carp Batters

To study the use of partial or total potassium bicarbonate (PBC) to replace sodium tripolyphosphate (STPP) on reduced-phosphate silver carp batters, all the batters were composed of silver carp surimi, pork back fat, ice water, spices, sugar, and sodium chloride. Therein, the sample of T1 contained 4 g/kg STPP; T2 contained 1 g/kg PBC, 3 g/kg STPP; T3 contained 2 g/kg PBC, 2 g/kg STPP; T4 contained 3 g/kg PBC, 1 g/kg STPP; T5 contained 4 g/kg PBC, and they were all produced using a bowl chopper. The changes in pH, whiteness, water- and oil-holding capacity, gel and rheological properties, as well as protein conformation were investigated. The pH, cooking yield, water- and oil-holding capacity, texture properties, and the G' values at 90 °C of the reduced-phosphate silver carp batters with PBC significantly increased (p < 0.05) compared to the sample without PBC. Due to the increasing pH and enhanced ion strength, more β-sheet and β-turns structures were formed. Furthermore, by increasing PBC, the pH significantly increased (p < 0.05) and the cooked silver carp batters became darkened. Meanwhile, more CO₂ was generated, which destroyed the gel structure, leading the water- and oil-holding capacity, texture properties, and G' values at 90 °C to be increased and then decreased. Overall, using PBC partial as a substitute of STPP enables reduced-phosphate silver carp batter to have better gel characteristics and water-holding capacity by increasing its pH and changing its rheology characteristic and protein conformation.

Thermal gelation and digestion properties of hen egg white: Study on the effect of neutral and alkaline salts addition

In this study, the thermal gelation and digestion properties of hen egg white (hen EW) proteins with different salts were investigated. Results show that the addition of neutral salt - sodium chloride (NaCl) decreased the gel hardness/resilience, increased gel lightness, aggregated particle size and digestibility of hen EW proteins significantly. In contrast, alkaline salts - phosphate and carbonate addition increased the gel resilience and strain tolerance as well as reduced the aggregated particle size and gel lightness of hen EW proteins due to the increase of solution pH and negative charge. Correlation analysis shows that the digestibility of hen EW gels was affected by gel viscoelasticity, molecule forces and texture. In conclusion, thermal gelation properties of hen EW proteins could be modulated by salts with different pH/ionic strength, and thus affected the protein digestion and peptide released.

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.

Changes in Gel Characteristics, Rheological Properties, and Water Migration of PSE Meat Myofibrillar Proteins with Different Amounts of Sodium Bicarbonate

The changes in the gel and rheological properties and water-holding capacity of PSE meat myofibrillar proteins with different amounts of sodium bicarbonate (SC, 0−0.6/100 g) were studied. Compared to the PSE meat myofibrillar proteins with 0/100 g SC, the texture properties and cooking yield significantly increased (p < 0.05) with increasing SC; meanwhile, adding SC caused the gel color to darken. All samples had similar curves with three phases, and the storage modulus (G’) values significantly increased with the increasing SC. The thermal stability of the PSE meat myofibrillar proteins was enhanced, and the G’ value at 80 °C increased with the increasing SC. Because water was bound more tightly to the protein matrix, the initial relaxation times of T21 and T22 shortened, the peak ratio of P21 significantly increased (p < 0.05), and the P22 significantly decreased (p < 0.05), which implied that the mobility of the water was reduced. Overall, SC could improve the thermal stability of the PSE meat myofibrillar proteins and increase the water-holding capacity and textural properties of the cooked PSE meat myofibrillar protein gels.

Effect of sodium bicarbonate on techno-functional and rheological properties of pale, soft, and exudative (PSE) meat batters

In the study, changes in salt-soluble protein (SSP) content, gel properties, rheological characteristic, and microstructure attributes of pale, soft, and exudative (PSE) pork batters with different concentrations of added sodium bicarbonate (0-0.6%) were investigated. The pH, b⁎ value, SSP content, cooking yield, texture properties, emulsion stability, and G' values at 72 °C significantly increased with the increase in sodium bicarbonate, but the texture properties and G' values of the samples with 0.4% and 0.6% did not significantly different, while the a⁎ value significantly decreased. Moreover, a greater G' value at 72 °C was in agreement with a higher hardness value of meat batter. The microstructure of cooked PSE meat batters with 0% and 0.2% sodium bicarbonate had a dense structure, and samples with 0.4% and 0.6% had some large cavities. In conclusion, the use of sodium bicarbonate can enhance the water holding capacity, texture and rheological properties of PSE meat batters by increasing their pH, SSP content, and emulsifying stability.

Effect of ultrasound-assisted sodium bicarbonate treatment on gel characteristics and water migration of reduced-salt pork batters

To study the potential usefulness of ultrasound (0, 30, and 60 min) and sodium bicarbonate (0 % and 0.2 %) combination on the reduced-salt pork batters, the changes in water holding capacity, gel properties, and microstructure were investigated. The pH, salt-soluble proteins solubility, cooking yield, and b* values of reduced-salt pork batters significantly increased (P < 0.05) with the increase in ultrasound time and the addition of sodium bicarbonate, leading to the hardness, springiness, cohesiveness, and chewiness significantly increased (P < 0.05). Furthermore, the use of ultrasound-assisted sodium bicarbonate treatment caused the reduced-salt pork batters to form a typical spongy structure with more evenly cavities. Due to the initial relaxation time of T₂₁ and T₂₂ were shorter, and the peak ratio of P₂₁ was increased and P₂₂ was decreased after ultrasound-assisted sodium bicarbonate treatment, implying that the mobility of water was reduced. Thus, the use of ultrasound-assisted sodium bicarbonate treatment enabled reduced-salt pork batters to have better gel characteristics and higher cooking yield.

Effect of sodium bicarbonate on textural properties and acceptability of gel from unwashed Asian sea bass mince

Asian sea bass mince gels having different adjusted moisture/water content (80 and 85%; w/w) were prepared with addition of sodium bicarbonate (SB) at various concentrations (0, 0.05 and 0.1%; w/w). Fish mince gels of 80% water content added with 0.05 and 0.1% SB (G80-0.05 and G80-0.1, respectively) had the highest increase (135-139%) in breaking force (BrF) than the respective control gel (G80) (P < 0.05). For gel with 85% water content, a lower increase (17-28%) in BrF was found with the addition of SB as compared to their corresponding control (G85). Whiteness of all samples was continuously decreased with increasing amount of SB, however the water holding capacity was increased drastically with augmenting levels of SB, regardless of the water content (P < 0.05). A loss in the elasticity of gel was attained with the addition of SB as indicated by decreasing storage modulus. A finer and more compact network was detected in a gel containing SB, irrespective of water content. Based on sensory scores, gel having 85% water content added with 0.05 and 0.1% SB had similar acceptability to the control gel (G80) containing 80% water content (commercial level). Therefore, SB at the appropriate level could improve the gelling properties with higher water holding ability of the mince gel with high acceptability.

Quantitative assessment of phosphate food additive in frozen and chilled chicken using spectrophotometric approach combined with graphitic digestion

A new method based on spectrophotometry combined with graphitic digestion was developed for quantitative assessment of phosphate in frozen and chilled chicken meat. Digestion reagents comprising HNO₃ (conc.) & H₂SO₄ (conc.) and HNO₃ (5 M) & H₂SO₄ (conc.) were found to have optimal composition, affording similar recovery values of 100% and 99%, respectively, with excellent linearity (R² > 0.999) and good limit of detection (LOD = 0.032 mg/L) and limit of quantification (LOQ = 0.10 mg/L), whereas other reagents offered lower recoveries (0-1.73%). Phosphate was found in concentrations of 3.38-5.90 g/kg and 3.96-26.94 g/kg in frozen and chilled chicken, respectively. Chilled chicken contained higher amounts of phosphate (>20 g/kg) than recommended by the European Commission (EC, 5 g/kg), either alone or in a mixture of processed meat products. This method is simple, cost-effective, and can be used as an alternative for analyzing phosphate in various samples comprising a similar matrix.

Influence of Bicarbonates and Salt on the Physicochemical and Sensory Properties of Meatloaf

The changing consumer attitude toward meat products warrants innovation. Recent years have seen a continuous rise in the consumer demand for ready-to-eat meat products that trigger innovations in the manufacture of restructured meat products. This study was designed to develop meatloaf with the intention of using the downgraded stream of trimmed meat and meat by-products, which are known to contain a higher quantity of connecting tissue that causes tenderness issues, moisture retention, mouthfeel, and perceived food quality. The physicochemical effects of sodium bicarbonate, potassium bicarbonate, and salt alone or in combination on physicochemical and sensory characteristics of cooked ground beef were investigated. The results obtained showed that cooked ground beef without salt had the lowest cooked yield. Instrumental textural and sensory analysis revealed that bicarbonate-treated meatloaf samples exhibited significantly better sensory and textural properties than the control ( $p\le 0.05$ ). Internal cooked color data revealed that meatloaf treated with sodium bicarbonate and potassium bicarbonate had a pinkish-red appearance with a significantly higher a ${}^{\ast }$ value ( $p\le 0.05$ ). The findings provide evidence that inclusion of bicarbonates had a significant tenderizing and juiciness effects with improved sensory attributes of the meatloaf. The evidence presented clearly shows the potential of bicarbonate and salt will exert synergistic effects and improve eating quality and textural and sensorial attributes of meatloaf and other meat products.

Recovery of emulsifying and gelling protein from waste chicken exudate by using a sustainable pH-shifting treatment

The inevitably generated chicken exudate was usually unconsciously discarded, leading to protein waste and environmental pollution. The study is performed to reveal the loss and constitute of different sourced exudate (purge exudate/defrozen exudate, PE/DE), investigate the efficiency of various pH-shifting strategies (Method I: NaOH-HCl, Method II: Ca(OH)₂-Critric acid, and Method III: Ca(OH)₂-Glucono δ-lactone) in recovering selected exudate, and evaluate the functionality of these recovered protein isolates. Accordingly, PE and DE shared greatly similar (P > 0.05) lipid and ash content. Despite sarcoplasmic protein, there are a small amount of functional myofibrillar protein in the exudate samples. During extraction, Method III had higher recovery yield (85.5%) than other two groups, but the isolates contained higher level of moisture. The protein isolates treated with Method II exhibited highest emulsion ability, while the Method III treated group obtained best gelation properties. Overall, pH-shifting could recover functional protein from chicken exudate for industrial application.

Future trends of processed meat products concerning perceived healthiness: A review

The 21st-century consumer is highly demanding when it comes to the health benefits of food and food products. In the pursuit of attracting these consumers and easing the rise in demand for high-quality meat products, the processed meat sector is intensely focused on developing reformulated, low-fat, healthy meat products. Meat and meat products are considered the primary sources of saturated fatty acids in the human diet. Therefore, these reformulation strategies aim to improve the fatty acid profile and reduce total fat and cholesterol, which can be achieved by replacing animal fat with plant-based oils; it could be performed as direct inclusion of these oils or pre-emulsified oils. However, emulsions offer a viable option for incorporating vegetable oils while avoiding the multiple issues of direct inclusion of these oils in meat products. Processed meat products are popular worldwide and showing a gradually increasing trend of consumption. Various types of plant-based oils have been studied as fat replacers in meat products. This review will focus on possible methods to reduce the saturated fatty acid content in meat products.

Effect of sodium bicarbonate and sodium chloride on aggregation and conformation of pork myofibrillar protein

To investigate the effect of sodium bicarbonate instead of sodium chloride, the changes in pH, turbidity, aggregation, and conformation of myofibrillar protein solution with various amounts of sodium chloride and sodium bicarbonate were studied. When the sodium bicarbonate was increased from 0% to 0.4%, accompanied by the sodium chloride being decreased from 2.0% to 0.8%, the pH increased about 1.20 unites; the absolute values of the Zeta potential, active sulfhydryl, and surface hydrophobicity increased significantly (p < 0.05); and the turbidity, particle size, and Ca²⁺-ATPase activity decreased significantly (p < 0.05). In addition, the Mg²⁺-ATPase activity was not significantly different (p > 0.05) when increasing sodium bicarbonate, implying that sodium bicarbonate did not affect the actin. Overall, the results indicated that an increase in sodium bicarbonate could improve solubility, expose more hydrophobic residues and sulfhydryl groups, and induce Ca²⁺-ATPase inactivation and protein unfolding, leading the myofibrillar protein to denaturation easily.