Effect of carboxymethyl cellulose (CMC) on some physico-chemical and mechanical properties of unrinsed surimi gels

 LWT, 2023 (114653)

The objective of this study was to evaluate the effect of the carboxymethyl cellulose (CMC) on the physico-chemical and mechanical properties of unrinsed surimi gels during heat treatment. The results revealed that the addition of CMC could significantly (p < 0.05) improve the gel strength, texture properties of unrinsed surimi gels and imparted better color perception compared with the control group showing lower gel strength and poorer water-holding capacity. The addition of 0.5 and 1.5 g/100 g CMC also promoted the formation of a more uniform and compact gel network structure of the unrinsed surimi gels, locking more water in the gel network, significantly improved the water holding capacity of the gels and enhancing their viscoelastic properties (p < 0.05). In conclusion, an appropriate amount of CMC can be added to unrinsed surimi as a food additive, and 1.5 g/100 g was the optimal addition amount obtained in this study, which provides important information for improved the gel properties of unrinsed surimi.

Influence of pH on viscoelastic properties of heat-induced gels obtained with a β-Lactoglobulin fraction isolated from bovine milk whey hydrolysates

Food Chemistry, 219, 2017, 169–178

http://dx.doi.org/10.1016/j.foodchem.2016.09.137

A β-Lactoglobulin fraction (r-βLg) was isolated from whey hydrolysates produced with cardosins from Cynara cardunculus. The impact of the hydrolysis process on the r-βLg structure and the rheological properties of heat-induced gels obtained thereafter were studied at different pH values. Differences were observed between r-βLg and commercial β-Lg used as control. Higher values for the fluorescence emission intensity and red shifts of the emission wavelength of r-βLg suggested changes in its tertiary structure and more solvent-exposed tryptophan residues. Circular dichroism spectra also supported these evidences indicating that hydrolysis yielded an intermediate (non-native) β-Lg state.

The thermal history of r-βLg through the new adopted conformation improved the microstructure of the gels at acidic pH. So, a new microstructure with better rheological characteristics (higher conformational flexibility and lower rigidity) and greater water holding ability was founded for r-βLg gel. These results were reflected in the microstructural analysis by scanning electron microscopy.