Development and Characterization of an Edible Zein/Shellac Composite Film Loaded with Curcumin

Abstract

The development of functional edible films is promising for the food industry, and improving the water barrier of edible films has been a research challenge in recent years. In this study, curcumin (Cur) was added to zein (Z) and shellac (S) to prepare an edible composite film with a strong water barrier and antioxidant properties. The addition of curcumin significantly reduced the water vapor permeability (WVP), water solubility (WS), and elongation at break (EB), and it clearly improved the tensile strength (TS), water contact angle (WCA), and optical properties of the composite film. The ZS–Cur films were characterized by SEM, FT-IR, XRD, DSC, and TGA; the results indicated that hydrogen bonds were formed among the curcumin, zein, and shellac, which changed the microstructure and improved the thermal stability of the film. A test of curcumin release behavior showed controlled release of curcumin from the film matrix. ZS–Cur films displayed remarkable pH responsiveness, strong antioxidant properties, and inhibitory effects on E. coli. Therefore, the insoluble active food packaging prepared in this study provides a new strategy for the development of functional edible films and also provides a possibility for the application of edible films to extend the shelf life of fresh food.

Physico-Chemical Characteristics of pH-Driven Active Film Loading with Curcumin Based on the Egg White Protein and Sodium Alginate Matrices

“…On the contrary, all the films showed significant broad diffraction peaks centered at 2θ = 20 • , indicating that the films are predominantly amorphous in nature. Notably, even in the curcumin-containing films, the sharp diffraction peaks of the curcumin crystals were almost undetectable, suggesting the successful encapsulation of curcumin in the film matrix using the pH-driven method [61]. Furthermore, with the blending of Alg, the diffraction peaks of curcumin crystals disappeared completely, and the intensity of the peaks decreased at 2θ = 20 • .…”

Edible Packaging: A Technological Update for the Sustainable Future of the Food Industry

“…Zein is a prolamin protein present in corn that is insoluble in water but soluble in 60-90% ethanol solutions and also in alkaline solutions with pH greater than 11 [77,78]. It has thermoplastic behavior and hydrophobic, antioxidant, and antibacterial properties [79].…”

Curcumin Electrochemistry—Antioxidant Activity Assessment, Voltammetric Behavior and Quantitative Determination, Applications as Electrode Modifier

“…Photoactivated CU encapsulated in β-CD was used for the antibacterial treatment of berries, increasing their shelf life without changing their organoleptic properties [26], while recent studies emphasized that CU-NPs, even at low concentrations, improved soybean growth and could be employed as fertilizer [27]. CU loaded into a zein/shellac-based composite food packaging film conferred antioxidant properties, inhibited E. coli, and the color change with pH variation enabled the monitoring of the food freshness [28]. There are many such applications of CU in the development of bioactive thin-layer composite polymeric food packaging films, and they were recently reviewed by Roy et al [7].…”