Modification of gelatin functionality for culinary applications by using transglutaminase

Porcine gelatin was subjected to the action of different amounts of commercial transglutaminase (TGase) and subsequently used to produce foams or gels. Foam stability at 20 °C and 80 °C, and thermal stability and instrumental texture of the gels were studied. Gelatin and TGase contents significantly increased the foam stability at both temperatures, but the effect of TGase was much more marked. Also both factors enhanced the thermal stability of gelatin gels, so that gels containing 3% of gelatin and 0.7% TGase were still gelled after 1 h at 80 °C, while any of the gelatin-based gels without TGase turned rapidly into liquid in less than 10 min at 80 °C. Hardness and chewiness of the gels were strongly enhanced by gelatin content, but very especially by TGase concentration. Gels tended to be less springy with increasing amounts of TGase. Modification of gelatin-based foams and gels with the addition of TGase appears as an interesting approach for culinary recipes in which gelatin should be heated. However, a careful optimization should be done to avoid a too rubbery texture.