Rheological and Textural Properties of Sodium Reduced Salt Soluble Myofibrillar Protein Gels Containing Sodium Tri-Polyphosphate

Structural properties and emulsification of myofibrillar proteins from hairtail (Trichiurus haumela) at different salt ions

The structural properties and emulsification of myofibrillar proteins (MPs) are susceptibly affected by salt ions. The effect of different salt ions on the structural properties and emulsification of MPs from hairtail (Trichiurus haumela) remains unclear. Hairtail MPs were analyzed under different ion treatments of Na+, K+, Ca2+ and Mg2+. MPs at K+ and Na+ treatment showed a similar trend on salt effect due to the unfolding of proteins under salt ions. However, the excessive electrostatic effect of divalent ions could enhance protein aggregation, especially at Ca2+ and Mg2+. The β-sheet of MPs at different salt ions interconverted with α-helix and random coil at ionic strengths from 0.1 mol/L to 1.0 mol/L. The surface hydrophobicity and active sulfhydryl content of MPs increased with the improvement of ionic strengths at 0-0.8 mol/L. Under Ca2+ and Mg2+ treatments, the turbidity of MPs was low compared to that under the treatment of Na+ and K+. Additionally, the emulsification of hairtail MPs treated with different ions was improved at an ionic strength of 0.6 mol/L. This study can contribute to using salts in constructing fish protein-based emulsions for manufacturing emulsified surimi products and promoting the development and utilization of hairtail proteins.

Ultrasound and salt reduction effect on physicochemical and rheological properties of meat emulsions

Power ultrasound and salt reduction effects on meat emulsions' physicochemical and rheological properties were determined. Therefore, meat emulsions with different NaCl concentrations (1, 1.5, 2, and 2.5%) were treated in an ultrasonic bath (40 kHz, 200 W, & 9.34 W/cm2 ) at different times (0, 15, and 45 min). Results showed that salt reduction and ultrasound time significantly (p < 0.05) affected the cooking loss, water holding capacity, water activity, pH, color, hardness, viscosity, storage modulus (G'), loss modulus (G″), and phase angle δ. Meat emulsions with low salt content (1 and 1.5% NaCl) showed significantly higher values of cooking loss than standard emulsions (2.5% NaCl), while ultrasound duration of 15 min reduced the cooking loss (12 to 27%). Hardness, color, pH, and water activity (aw) decreased with salt reduction. Ultrasounds increased the hardness, viscosity, G', and G'' values in reduced-salt meat. The experimental data of apparent viscosity were properly fitted to the mathematical model of Ostwald-de-Waele. Ultrasound increased consistency (k) and decreased flow behavior index (n) in emulsions with 1.5 to 2.5% NaCl. Ultrasound at 15 min induced gelation in emulsions with 1.5 and 2.0% NaCl (40 and 20% NaCl reduction). The formulation with 2.0% NaCl was found to be the maximum concentration that did not sacrifice meat emulsion quality. When combined with 15 min of ultrasound, this formulation yielded results comparable to the standard formulation. PRACTICAL APPLICATION: Results contribute to developing reduced-salt meat emulsions using power ultrasounds. Therefore, using ultrasounds allows for a 20% reduction in salt content while maintaining the quality of the meat emulsion.

Effect of sodium salt on meat products and reduction sodium strategies - A review

Sodium salt is one of the important additives in food processing. However, excessive intake of sodium salt may cause a series of cardiovascular diseases. Nowadays, sodium intake in most countries is higher than the World Health Organization recommends maximum consumption (5 g/d). 20% of the sodium intake in diets comes from meat products. Therefore, reducing the content of sodium salt in meat products and developing sodium salt-reduction meat products have attracted more and more attention for consumers. In this paper, the roles of sodium salt in meat product processing were reviewed. At the same time, sodium salt reduction strategies and existing problems were summarized and discussed. Multiple factors need to be considered to improve the salt-reduction meat product's quality. Relying on a single technology has a narrow application area, and it is difficult to achieve salt reduction. Therefore, a combination of multiple strategies could obtain a more ideal effect.

Role of low molecular additives in the myofibrillar protein gelation: underlying mechanisms and recent applications

Understanding mechanisms of myofibrillar protein gelation is important for development of gel-type muscle foods. The protein-protein interactions are largely responsible for the heat-induced gelation. Exogenous additives have been extensively applied to improve gelling properties of myofibrillar proteins. Research has been carried out to investigate effects of different additives on protein gelation, among which low molecular substances as one of the most abundant additives have been recently implicated in the modifications of intermolecular interactions. In this review, the processes of myosin dissociation under salt and the subsequent interaction via intermolecular forces are elaborated. The underlying mechanisms focusing on the role of low molecular additives in myofibrillar protein interactions during gelation particularly in relation to modifications of the intermolecular forces are comprehensively discussed, and six different additives i.e. metal ions, phosphates, amino acids, hydrolysates, phenols and edible oils are involved. The promoting effect of low molecular additives on protein interactions is highly attributed to the strengthened hydrophobic interactions providing explanations for improved gelation. Other intermolecular forces i.e. covalent bonds, ionic and hydrogen bonds could also be influenced depending on varieties of additives. This review can hopefully be used as a reference for the development of gel-type muscle foods in the future.

Role of Food Hydrocolloids as Antioxidants along with Modern Processing Techniques on the Surimi Protein Gel Textural Properties, Developments, Limitation and Future Perspectives

Texture is an important parameter in determining the quality characteristics and consumer acceptability of seafood and fish protein-based products. The addition of food-based additives as antioxidants (monosaccharides, oilgosaccharides, polysaccharides and protein hydrolysates) in surimi and other seafood products has become a promising trend at an industrial scale. Improvement in gelling, textural and structural attributes of surimi gel could be attained by inhibiting the oxidative changes, protein denaturation and aggregation with these additives along with new emerging processing techniques. Moreover, the intermolecular crosslinking of surimi gel can be improved with the addition of different food hydrocolloid-based antioxidants in combination with modern processing techniques. The high-pressure processing (HPP) technique with polysaccharides can develop surimi gel with better physicochemical, antioxidative, textural attributes and increase the gel matrix than conventional processing methods. The increase in protein oxidation, denaturation, decline in water holding capacity, gel strength and viscoelastic properties of surimi gel can be substantially improved by microwave (MW) processing. The MW, ultrasonication and ultraviolet (UV) treatments can significantly increase the textural properties (hardness, gumminess and cohesiveness) and improve the antioxidative properties of surimi gel produced by different additives. This study will review potential opportunities and primary areas of future exploration for high-quality surimi gel products. Moreover, it also focuses on the influence of different antioxidants as additives and some new production strategies, such as HPP, ultrasonication, UV and MW and ohmic processing. The effects of additives in combination with different modern processing technologies on surimi gel texture are also compared.

Effect of Salt Content Reduction on Food Processing Technology

Higher salt intake is associated with the risk of cardiovascular and kidney diseases, hypertension and gastric cancer. Salt intake reduction represents an effective way to improve people’s health, either by the right choice of food or by a reduction of added salt. Salt substitutes are often used and also herb homogenates are treated by high pressure technology. Salt reduction significantly influences the shelf life, texture, pH, taste, and aroma of cheese. The composition of emulsifying salts or starter cultures must be modified to enact changes in microbial diversity, protease activity and the ripening process. The texture becomes softer and aroma atypical. In bakery products, a salt reduction of only 20–30% is acceptable. Water absorption, dough development, length and intensity of kneading and stability of dough are changed. Gluten development and its viscoelastic properties are affected. The salt reduction promotes yeast growth and CO₂ production. Specific volume and crust colour intensity decreased, and the crumb porosity changed. In meat products, salt provides flavour, texture, and shelf life, and water activity increases. In this case, myofibrillar proteins’ solubility, water binding activity and colour intensity changes were found. The composition of curing nitrite salt mixtures and starter cultures must be modified.

Phosphate Elimination in Emulsified Meat Products: Impact of Protein-Based Ingredients on Quality Characteristics

The addition of phosphates to meat products improves the emulsifying and gelling properties of meat proteins, in turn enhancing overall product quality. The current market trend towards additive-free products and the health issues related to phosphate challenge the industry to develop phosphate-free meat products. The aim of this study was to evaluate the potential of seven protein-based ingredients (pea, blood plasma, gelatin, soy, whey, egg, and potato) to remediate quality losses of emulsified meat products (cooked sausages) upon phosphate elimination. First, the intrinsic gelling and emulsifying characteristics of the proteins were assessed. Next, the proteins were added to phosphate-free sausages, of which quality characteristics during production (viscoelastic behavior and emulsion stability) and of the final products (texture, cooking loss, and pH) were screened. Blood plasma and soy were superior in phosphate-free cooked sausages, as no significant differences in hardness, cooking yield, or stability were found compared to phosphate-containing sausages. Egg and pea also improved the previously mentioned quality characteristics of phosphate-free sausages, although to a lesser extent. These insights could not entirely be explained based on the intrinsic gelling and emulsifying capacity of the respective proteins. This indicated the importance of a well-defined standardized meat matrix to determine the potential of alternative proteins in meat products.

Effects of high pressure and thermal combinations on gel properties and water distribution of pork batters

The effects of high pressure (100-500 MPa) and heated (80 °C, 25 min) combinations on gel properties, rheological characteristic and water distribution of pork batters were investigated. Compared to the only-heat, the cooking yield, a* value, hardness, cohesiveness, and chewiness of cooked pork batters treated less than 300 MPa were significantly increased (P < 0.05), meanwhile, the b* value was significantly decreased (P < 0.05). Opposite, the color and cooking yield were not significant different (P > 0.05) when over 300 MPa, except the L* value. At 300 MPa, the cooking yield, hardness, chewiness, and G' value at 80 °C of pork batter were the highest. The initial relaxation time of T₂₁ was decreased significantly (P < 0.05), and the peak ration of P₂₁ was increased significantly (P < 0.05) when treated at 200 and 300 MPa, that indicated the water was bound tightly and the ratio of immobilized water was increased. Overall, 300 MPa treatment and thermal combinations could improve the gel properties of pork batters.

Effect of pork quality and salt replacer KCl on technological and sensorial characteristics of restructured cooked hams

The aim of this study was to evaluate the effects of replacing sodium chloride (NaCl) by 40% of potassium chloride (KCl), combined to the use of different proportions (0, 50, and 100%) of pale, soft, and exudative meat, on the technological and sensorial characteristics of restructured cooked hams. NaCl replacement and pale, soft, and exudative proportion did not change ( P > 0.05) the products’ chemical composition, water losses, pH, and color. The ham texture profile was not affected by pale, soft, and exudative meat, but the chewiness reduced ( P < 0.05) with NaCl replacement. Pale, soft, and exudative meat reduced ( P < 0.05) the ham sliceability from 94 to 88%, regardless of the proportion used. NaCl replacement did not affect the perceived saltiness and the products’ acceptability, but pale, soft, and exudative products were more accepted, and consumers noticed a higher salty taste. It was concluded that reducing the sodium content by partially replacing NaCl with KCl is feasible even in restructured cooked hams made with high proportions of pale, soft, and exudative meat.

Interactions between beef salt-soluble proteins and elephant foot yam (Amorphophallus campanulatus) flour in heat-induced gel matrix development

The objective of this study was to observe the interactions between salt-soluble proteins extracted from beef and elephant foot yam (Amorphophallus campanulatus) flour in heat-induced gel matrix development. The effect of salt concentration; 0.5%, 1.0%, 1.5%, and 2.0% in weight/weight basis (w/w), during protein extraction on pH, salt-soluble protein concentration and myofibril fractions of beef extract was determined firstly, and no significant effect was found. The beef salt-soluble proteins extracted using salt solution at different concentrations were then added with elephant foot yam flour at 5%, 10%, and 15% w/w, gelatinized at 90°C for 20 min, and cooled down at 4°C for 12 h. The interactions between beef salt-soluble proteins and elephant foot yam flour resulted in an improved gel strength (p < 0.01) and the addition level of elephant foot yam flour affected the pH, instrumental color, moisture, crude protein, and ash content significantly. The addition of elephant foot yam flour also reduced the size of the pores in the gel matrix as shown by scanning electron microscope (SEM) photographs. These suggest that elephant foot yam flour well interacts with beef salt-soluble proteins to form gel matrix.