Edible films to improve quality and shelf life of fresh tortillas

Abstract

Edible films have emerged as packaging aids to replace synthetic polymers due to their biodegradable nature. The aim of this study was to develop starch-based edible films for application in packaging, to inhibit moisture transfer from the filling to the tortilla, while maintaining physicochemical and organoleptic quality characteristics, and improving shelf life. Twenty-four types of filmogenic solutions were produced by casting from corn, pea, and chestnut starch blended with agar, guar, and potassium alginate, using glycerol as a plasticizer. The films were selected due to its surface properties and water absorption capacity, which allowed selecting the films that best retained moisture. The hydration properties of the selected films allowed to verify that the corn and pea starch films show good resistance to water and microbial development. Microstructural properties showed that the pea starch films exhibit a homogeneous and smooth surface without porosity. Fourier Transform Infrared Micro-Spectroscopy allowed the characterization of the starch films at the molecular level. The mechanical properties of corn and pea starch films were evaluated in tensile strength (21.98–27.5 KPa), elongation at break (59.17–185.96%), and elastic modulus (42.35–17.09 MPa). The results suggest that pea films are more flexible than starch films due to differences in the amylose and amylopectin molecules and molecular masses of the different starches. The sensory analysis concluded that the pea starch film delayed moisture transfer from the filling to the tortilla, maintaining the texture, appearance, and organoleptic characteristics for 6 days, improving the consumption experience of these food products.