Effect of microbial transglutaminase on functional and rheological properties of ice cream with different fat contents

This study study evaluated the effects of microbial transglutaminase (TG) (Streptoverticillium mobaraense) on the properties of ice cream with 4, 6 and 8 g/100 g fat. The TG was added at a concentration of 4 U g(-1) and the chemical characteristics, capacity to incorporate air (overrun), fat coalescence, melting behavior, rheological properties and texture were evaluated. The TG was effective in controlling the ice cream properties providing greater overrun, greater fat coalescence and melting resistance in relation to samples without TG. These modifications can be attributed to the formation of a more cohesive protein network which increased the stability of the ice cream. Regarding the rheological parameters, it was found that TG caused an increase in the flow behavior index and pseudoplastic properties of the samples. The firmness of the ice cream was decreased by the addition of TG and was inversely proportional to the fat content. Ice cream with fat contents of 4 and 6 g/100 g subjected to enzymatic treatment had similar characteristics to samples formulated with 8 g/100 g fat, demonstrating that TG can be used to partially replace fat in ice cream. (C) 2012 Elsevier Ltd. All rights reserved.