| Abstract: | Protein modification via covalent bonds by using microbial transglutaminase (TGase) has generated many processing functionality improvements in specific food ingredients. In this study, TGase was added into different cake portions (foam and yolk batter) at levels of 0, 0.5, and 1.0% (w/w, total protein weight basis). The treatment of 0.5% TGase in the yolk batter portion significantly (P ≤ 0.05) increased its emulsion activity. The addition of 1.0% TGase in the yolk batter portion significantly increased both foam stability and emulsion activity of cake batter, whereas the addition in the foam portion only increased the emulsion activity of cake batter significantly (P ≤ 0.05). As the addition of TGase, in foam or in the yolk batter portion, rose from 0 to 1.0%, the specific volume of chiffon cake increased. Cakes with 1.0% TGase in the foam portion had the maximum specific volume, 7.078 mL/g, and the softest texture. SDS‐PAGE was used to analyze the modifications of TGase to the protein fractions from different cake portions. The effect of TGase on protein fractions from the yolk batter portion was more evident than that on protein fractions from the foam portion. However, there was no significant difference between the protein fractions of cake batters with the same level of TGase in the foam and yolk portions, which suggested that the main substrates of TGase were yolk protein and wheat protein, instead of egg white protein. |
