Development and discussion of low-salt foods

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

Abstract:

The effects of phosphate sucrose on the physicochemical properties, lipid distribution and protein structure of low-salt salted egg yolk (SEY) during pickling were studied. A low-salt system was constructed using sucrose-phosphate from the perspective of promoting permeation. The results showed that SEY-28d achieved the ideal salt content (1.07%), hardness (573.46 g) and elasticity (0.65 g). Mature SEY has excellent quality, orange-red color, loose texture and fine sand. This is because lipoproteins aggregate with each other through hydrophobic interactions to form a stable network structure. In addition, the high osmotic environment accelerates the penetration of salt. These also create good conditions for lipid overflow. The results of confocal laser scanning microscopy also verified this phenomenon. The experiment has important guiding significance for the new salt reduction pickling of traditional pickled foods, deep processing of SEY and industrial development in the field of poultry and eggs.

Conclusion:

The macroscopic characterization of sucrose-phosphate in low-salt SEY pickling was evaluated in terms of gelling and lipid distribution. Then, the structural changes of the protein were analyzed in order to achieve mechanism research. Sucrose-phosphate increased the osmotic pressure in the solution and shortened the production cycle (only 28 days). The high osmotic environment led to significant dehydration of salted eggs. That is, the water loss rate of SEY-28d reached 17.47%. In addition, phosphate improved the quality characteristics of SEY. Compared with the traditional pickling method, the SRY obtained by this method had a loose sandy texture (hardness of 573.46 g), high oil yield (64.55%), and low salt content (1.07%). During the pickling process, the secondary structure of the protein changed and transitioned to a stable state. This stable structure is maintained by hydrophobic interactions. The small molecules of lipoproteins aggregated with each other to form large aggregates, which in turn formed gels.

Dual enhancement of gel properties and salty taste of low-salt silver carp surimi gel by different yeast extracts

Abstract:

The dual enhancement of gel properties and salty taste of low-salt (1% NaCl) surimi gel by five yeast extracts (YE) was studied. The addition of YE not only significantly improved the gel strength, texture properties (hardness, cohesiveness and chewiness) and elasticity of low-salt surimi gel (P < 0.05), but also increased the gelation rate of surimi during the fish cake stage. After adding YE, the water holding capacity of surimi gel increased, but the fluidity of water decreased, and the microstructure of the composite gel was relatively dense and ordered. The results of electronic tongue analysis showed that the addition of YE increased the umami and salty taste, and reduced the characteristic values ​​of sourness and bitterness (P < 0.05). Sensory evaluation showed that YE improved the texture, saltiness, umami and olfactory scores of low-salt surimi gel (P < 0.05). The saltiness perception of low-salt surimi gel with YE1 and YE2 was similar to that of normal salt surimi gel (2% NaCl), which was consistent with the results of the electronic tongue experiment. Correlation analysis results showed that the enhancement of surimi gel properties may be related to the charged amino acids (Arg, Lys, His, Glu and Asp) in YE, while the umami substances (Glu, Asp, IMP and GMP) in YE can not only improve the umami taste of surimi, but also enhance the saltiness of low-salt surimi gel. In general, YE has the dual effects of significantly improving the gel properties of low-salt surimi gel and enhancing the saltiness, and has a salt reduction effect, among which YE2 has the best effect.

Conclusion:

The effects of five kinds of YE on the gel properties and saltiness of low-salt surimi gel were studied. On the one hand, the addition of YE can significantly improve the gel properties of low-salt surimi gel, showing higher gel strength and texture properties, including hardness, adhesion and chewiness, as well as the elasticity and gelling ability of YE/surimi composite gel. In addition, the addition of YE not only increases WHC, but also promotes the formation of a relatively dense and ordered network structure. Correlation analysis results show that the gel properties of surimi gel are positively correlated with the content of charged amino acids in YE. On the other hand, the addition of YE not only increases the umami taste, reduces the characteristic values ​​of bitterness and sourness, but also enhances the saltiness of low-salt surimi gel. Correlation analysis results show that umami substances enhance umami and synergistically enhance saltiness perception. YE has a dual enhancing effect on the gel properties and saltiness of low-salt surimi gel, among which YE2 has the best effect. This work reveals the enhancing effect of YE on the gel properties and saltiness of low-salt surimi gel, providing a reference for the production of low-salt surimi gel products without sacrificing saltiness.

Ultrasonic-assisted sodium bicarbonate treatment improves gel and rheological properties of low-salt pork myofibrillar protein

Abstract:

To investigate the effects of ultrasonic time (0, 30, and 60 min) and sodium bicarbonate concentration (0% and 0.2%) on the gel properties of low-salt pork myofibrillar protein, the changes in cooking rate, color, water retention, texture properties, and dynamic rheology were investigated. The results showed that the addition of sodium bicarbonate significantly improved the cooking rate, hardness, elasticity, and strength of myofibrillar protein (P < 0.05), while reducing the centrifugal loss. In addition, the incorporation of sodium bicarbonate led to a significant decrease in the L*, a*, b*, and white values ​​of cooked myofibrillar protein; these effects were further enhanced with the extension of ultrasonic time (P < 0.05). In addition, the storage modulus (G') of myofibrillar protein treated with ultrasound-assisted sodium bicarbonate increased significantly, resulting in a tighter gel structure after cooking. This indicates that ultrasound-assisted sodium bicarbonate treatment can enhance the compactness of the reduced-salt myofibrillar protein gel structure while improving water retention and textural properties.

Conclusion:

Ultrasound-assisted sodium bicarbonate treatment significantly affects the water retention, microstructure and rheological properties of pork myofibrillar protein. The addition of sodium bicarbonate to the myofibrillar protein gel matrix and prolonged ultrasound exposure significantly increased the cooking yield and gel strength. Moreover, prolonged ultrasound treatment duration caused significant changes in gel coloration, mainly characterized by decreased whiteness. Microscopic examination revealed that the optimal compactness was achieved within the formed gel after 60 min of ultrasound with 0.2% sodium bicarbonate addition. The application of ultrasound combined with sodium bicarbonate effectively promoted the dissolution of myofibrillar fibers, while increasing the denaturation temperature associated with the myosin tail with increasing ultrasound duration. It is noteworthy that after 60 min of ultrasound treatment, G´ reached its maximum value and the gel network structure was optimal.