Influence of hydrophilic polysaccharides as fat substitutes on the digestibility of myofibrillar protein gels.

Among all fat substitutes, hydrophilic polysaccharides can simultaneously meet the requirements of processing, sensory, and functional properties, thus have been widely used in meat products. However, there are few reports on the impact of the addition of hydrophilic polysaccharides on the digestibility of myofibrillar protein gels. This study focused on four hydrophilic polysaccharides including octenyl succinic anhydride (OSA) modified starch, sodium alginate (SA), konjac gum (KG) and xanthan gum (XG). In the myofibrillar protein gel system, the effects of these four polysaccharides on the digestibility of myofibrillar protein gels at different fat substitution levels were investigated by measuring the release of free amino acids, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, confocal laser scanning microscopy images, peptidomics, rheological characteristics, and circular dichroism of gel samples after in vitro simulated gastrointestinal digestion. The results showed that the addition of hydrophilic polysaccharides led to a decrease in the release of free amino acids, and as the level of fat substitution increased, the production of peptides decreased. Compared with the control group, the addition of SA significantly inhibited the hydrolysis of peptide bonds, while samples with the other three polysaccharides also showed varying degrees of digestive inhibition.