Effect of formulation on physicochemical properties and water status of nutritionally enhanced tortillas

BACKGROUND: Various nutritionally enhanced tortillas were developed by incorporating ingredients with nutritional functionality (carrot, soy, wholemeal kamut and their combination (CSK)) in a standard wheat tortilla formulation. The effect of these ingredients on the physicochemical properties and water status of the products was evaluated. RESULTS: Partial substitution of carrot juice for water in the tortilla formulation significantly reduced the macroscopic (water activity and moisture content) and thermal (‘frozen’ water (FW) content) properties and marginally reduced the 1H molecular mobility (faster 1H free induction decay (FID)) compared with the standard. Wholemeal kamut increased the FW content via a possible water redistribution among ingredients. Whole soy flour induced higher 1H molecular mobility (T2B relaxation rate, % 1H T2B population and single T1), probably because a loose soy protein—water interaction and/or margarine. The water status of the CSK tortilla reflected the contribution of each ingredient in the respective prototype: fast 1H FID (carrot), high FW content (kamut), high 1H molecular mobility and low moisture content and water activity (soy). CONCLUSIONS: The changes in formulation used in this study to produce tortillas with enhanced nutritional value affected the water status of the products in a very interesting manner: the different ingredients altered the water status at different levels.