Development and characterization of edible films based on cassava starch-glycerol blends to incorporate nutraceuticals

Edible films are thin layers made of materials such as starch and proteins. Starch is a polysaccharide that could be interesting in the edible film technology. An important starch source is cassava, produced abundantly, inexpensive, and is able to form films. However, for the production of edible film with good flexibility, a plasticizer such as glycerol is usually utilized and it can affect film physical properties. In addition, the current research on edible films is focused on the addition of active compounds that improve the food packaging and/or bring health benefits to consumers. One of those active compounds are nutraceuticals, diet supplements necessary for metabolism and to prevent diseases. Iron is one of the minerals that people do not consume in enough amounts and its deficiency may cause anemia. Therefore, the objectives of this research were: (1) Formulate a solution of cassava starch-glycerol that can effectively carry nutraceuticals into the matrix; and (2) Investigate the impacts of iron gluconate on properties and functionalities of the films.;Results obtained from gloss values, morphology and rheology of starch concentrations, it was determined that 3% cassava starch produced homogeneous and transparent films. Also, the results obtained with the addition of glycerol exhibited increased the gelatinization temperature, gelatinization enthalpy, and drying time. The tensile strength decreased with the glycerol content and Elongation at break decreased between 0 to 20% glycerol. It appears that glycerol can exert an antiplasticizing effect because glycerol did not affect the extensibility of plasticized films when it is introduced at low levels. Data from moisture sorption isotherms found that the more appropriate models to fit the experimental data were GAB (R2=0.85) and BET (R 2=0.9). Also, was detected the retrogradation of films during drying and films with glycerol needs the double of time to start retrogradation than films with no glycerol. Based on these results, the best formulation with good properties is 3% cassava and 30% glycerol.;Lastly, the results obtained with the incorporation of iron gluconate (IG) showed that apparent viscosity of solutions increased as IG concentration increased. Color of films were affected by IG, especially b* values due to its yellowish appearance. The GAB and BET model determined that allowed to determine the water adsorption values at the monolayer level (m o), and all films with IG adsorbed less water than films with no IG. Also, the addition of IG increased tensile strength and elongation at break. From the release kinetics of IG, no definitive conclusion could be drawn concerning the dominating release mechanism. This study demonstrated the capability of cassava-glycerol blends to carry iron gluconate.