Study on the textural and volatile characteristics of emulsion filled protein gels as influenced by different fat substitutes.

Emulsion filled protein (EFP) gels were prepared through a cold-set gelation process using denatured protein, and the effects of fat substitutes on the texture and volatile release of EFP gels were investigated. Pre-heating determined the denature degree of protein structure, and higher heating intensity resulted in higher viscosity of the emulsions, and larger storage modulus (G') of the corresponding gels. Oil-reduced EFP gels (15% sunflower oil) were prepared with the addition of fat substitutes (medium chain triglyceride-MCT, maltodextrin, or guar gum), and they showed different properties from the full-oil counterpart (20% sunflower oil). The three tested fat substitutes were effective in enhancing G' and stiffness of the gels, while the magnitude was dependent on the content and types of fat substitutes. The increase in the content of MCT or maltodextrin (5-15%) could lead to earlier onset of gelation, but the presence of fat substitutes did not affect the water holding capacities of the gels. With strengthened gel structures by the fat substitutes, oil-reduced gels could have decreased air-gel partition coefficients of the volatiles, particularly the more lipophilic compounds. Among the three fat substitutes, MCT and maltodextrin were more capable to retain volatiles in the gels.