Effect of sodium starch octenyl succinate-based Pickering emulsion on the physicochemical properties of hairtail myofibrillar protein gel subjected to multiple freeze-thaw cycles

A Pickering emulsion based on sodium starch octenyl succinate(SSOS)was prepared and its effects on the physicochemical properties of hairtail myofibrillar protein gels(MPGs)subjected to multiple freeze-thaw(F-T)cycles were investigated.The whiteness,water-holding capacity,storage modulus(G')and texture properties of the MPGs were significantly improved by adding 1%-2%Pickering emulsion(P<0.05).Meanwhile,Raman spectral analysis demonstrated that Pickering emulsion promoted the transformation of secondary structure,enhanced hydrogen bonds and hydrophobic interactions,and promoted the transition of disulfide bond conformation from g-g-g to g-g-t and t-g-t.At an emulsion concentration of 2%,theα-helix content decreased by 10.37%,while theβ-sheet content increased by 7.94%,compared to the control.After F-T cycles,the structure of the MPGs was destroyed,with an increase in hardness and a decrease in whiteness and water-holding capacity,however,the quality degradation of MPGs was reduced with 1%-2%Pickering emulsion.These findings demonstrated that SSOS-Pickering emulsions,as potential fat substitutes,can enhance the gel properties and the F-T stability of MPGs.

Influence of soy protein isolate on the gel properties of walnut protein isolate-κ-carrageenan treated with NaCl

The demand for plant protein is increasing significantly due to the shortage of protein resources.Walnut protein,the main by-product of preparing walnut oil,has limited application in the food industry due to its poor solubility.It was found that the soy protein isolate(SPI)concentration had significant effects on the gel properties of the walnut protein isolate(WNPI)-κ-Carrageenan(KC)composite system treated with 15 mmol/L NaCl.The results showed that the gel strength of the composite system increased first and then decreased with the increased concentration of SPI from 0 to 2.5%.The best rheological properties,texture properties,water holding capacity((92.03±1.05)%),swelling ratio((2.04±0.19)%),freeze-thaw stability and thermal stability(85.53°C)of the composite gel were found at an SPI concentration of 1%.In the meantime,the secondary structure of protein had the least α-helix content of 10.17% and the highest β-sheet content of 39.64%,the fluorescence intensity and free sulfhydryl content reached the highest value.1% SPI could also act as a filler for WNPI to enhance the intermolecular forces such as hydrophobic interaction between the two substances,thus forming a stable gel network structure.This study can provide technical support for improving the gel properties of walnut protein and producing new plant protein gel products.

Properties and Anti-Ultraviolet Activity of Gallic Acid-Chitosan-Gelatin Mixed Gel

Hydrogel has high water content and structural similarity with natural extracellular matrix.So it has been widely studied and applied in the field of biomedicine.In order to further develop multifunctional hydrogels,we prepared mixed gels with antiultraviolet properties.This study found that the addition of polysaccharides and polyphenols was beneficial to the rheological,me-chanical properties,and biological activity of the protein.Chitosan(CS)could significantly improve the viscoelasticity,hardness,gel strength,thermal stability and crystallinity of gelatin.Interestingly,the addition of gallic acid(GA)could not only provide significant cross-linking effect,improve gel properties and microstructure,but also improve the UV resistance of the mixed gel.

Effects of phosphorylated ovalbumin on the quality of pork myofibrillar protein gel:an insight into gelling and physicochemical properties

This study aimed to investigate the effects of phosphorylated-ovalbumin(P-OVA)at different concentrations(0.5%and 1.0%)on the gel properties of pork myofibrillar protein(MP).The results showed that the textural properties such as gel hardness,cohesiveness,springiness and chewiness were improved with P-OVA addition at 0.5%.The water holding capacity(up to 75.89%)and gel strength(up to 168.56 g·mm)of MP gel were markedly increased after P-OVA addition.The absolute value of zeta potential reached 13.85 mV and maximum hydrophobicity(15.2μg)resulted from the addition of 0.5%P-OVA.The storage modulus(G’)and loss modulus(G’’)of MP gel were significantly increased from 50°C,and the G’and G’’significantly increased after 1.0%P-OVA addition,evidencing that the cross-linking effect of MP protein gel was enhanced.In addition,the P-OVA addition improved the structure of MP gel protein by reducing theα-helix,while increasing theβ-sheet and the r-value(the ratio between two ultraviolet second-derivative peak-to-trough distances),which further promoted the uniform and compact gel network structure.This work demonstrated that P-OVA is a highly effective modifier that significantly improves the quality of MP gel.From a view of practice,0.5%P-OVA is the optimal addition amount.

Effects of different calcium salts on the physicochemical properties of sliver carp myosin

To investigate the effects of different calcium salts on the physicochemical properties of myosin,the intermolecular interactions,particle size,surface hydrophobicity,reactive sulfhydryl group content and rheological properties of sliver carp myosin with the addition of four different kinds of calcium salts (CaCl_(2),calcium citrate (CC),nano-hydroxyapatite (HAP),tricalcium phosphate (TCP)) during gel processing were measured.The results showed that the addition of CaCl_(2) promoted the unwinding of α-helix,the increase in hydrophobic interactions,the formation of disulfide bonds of myosin,and increased the viscoelasticity of myosin.While,the addition of calcium citrate (CC) enhanced the hydrophobic interaction between myosin molecules,and the viscoelasticity of CC-added myosin was second only to the CaCl_(2)-added myosin.On the contrary,the addition of HAP and TCP interfered with the hydrophobic interaction between myosin molecules,and greatly reduced the viscoelasticity of myosin.In summary,calcium with high calcium release rate can improve the physicochemical properties of myosin,HAP and TCP with a very low calcium release rate interfered with the formation of myosin gelation.And it could be concluded that the calcium ions played a leading role in the physicochemical properties of myosin,the more calcium ion that the calcium salt can release,the better physicochemical properties the myosin were.Our work may provide an insight into the phenomenon why different kinds of calcium salts differ from each other on affecting the physicochemical properties of myosin during gel processing.