Physical properties of zein-alginate-glycerol edible films and their application in the preservation of chili peppers (Capsicum annuum L.)

Edible films elaborated from macromolecules, like carbohydrates, proteins, and lipids, must protect and maintain the integrity of foods during their handling, storage, and transportation. In this work, the effect of the concentration of zein (1–2% w/v), sodium alginate (1.5–2% w/v), and glycerol (2–4% w/v) on edible films physicochemical properties was evaluated. The Zein-Alginate-Glycerol interaction was evidenced by the FTIR analysis, the high permeability to water vapor and contact angles less than 90° of the polymer matrices formed. The film made with 2% zein, 1.5% sodium alginate and 4% glycerol preserved the quality of the chili pepper during 15 days of storage at 20 °C, the edible films allowed 3 more days of shelf life for weight loss and 10 more days for firmness. Edible films could be used in chili peppers that are destined for industrial processing, and before use, remove the film with a simple wash.