A Multilayered Edible Coating to Extend Produce Shelf Life

Abstract

In this study, a new edible coating material with enhanced mechanical and gas barrier properties was studied by coupling silk fibroin (SF) with poly(vinyl alcohol) (PVOH). SF and PVOH water suspensions were mixed at different ratios to form multilayered membranes that, after a phase separation, assembled on the surface of fresh-cut produce upon dip coating. The effects of the mixing ratio on transparency, mechanical properties, water vapor, and oxygen permeability of the films were investigated. Higher PVOH fractions corresponded to an increased ductility (increased elongation at break and decreased Young's modulus), which is essential for a food packaging material. A coating with SF:PVOH weight ratio 1:1 presented the minimum water vapor permeability and was selected to perform perishable food preservation studies. Weight loss and color changes of coated fresh-cut apples over 14 days of storage at 4 °C were significantly lower than those of uncoated controls. The addition of ascorbic acid to the coating material was also investigated to obtain an active food coating with oxygen scavenging properties. The obtained results demonstrated the ability of SF:PVOH blends to assemble into bilayered edible coatings that extend the shelf life of fresh-cut produce.

Natural Silk Spinning‐Inspired Meso‐Assembly‐Processing Engineering Strategy for Fabricating Soft Tissue‐Mimicking Biomaterials

“…As summarized in Figure 5g, similar to the hydrated BMAFs, the balance between the Young's modulus and toughness of the dehydrated O-BMAFs was superior to previously-reported RSSF materials and composites (Table S6, Supporting Information). [49,[51][52][53] More interestingly, when the mechanical properties of the BMAFs were compared with those of other biological and engineered materials [50,54] (Figure 5h,i), it was found that the mechanical performance of BMAFs matched well with that of a series of soft tissues (e.g., skin, muscles, and cartilages) and biological materials (e.g., keratin, collagen, and actin). For example, the O-BMAFs exhibited comparable extensibility and modulus to those of skin, muscles, and eye crystalline lenses.…”

Potential of engineered nanostructured biopolymer based coatings for perishable fruits with Coronavirus safety perspectives

“…In this work, ascorbic acid was also added to increase the oxygen scavenging properties of the developed coatings [ Fig. 5 ] [ 63 ]. The images of SEM and fluorescence microscopy indicated successful formation of binary structure with separate layers of two polymers.…”

Growing silk fibroin in advanced materials for food security

“…For example, silk fibroin is blended with poly(vinyl alcohol) (PVOH) at different ratios for use as food coating and packaging materials. 89 The choice of PVOH is based on its GRAS status, low water vapor and oxygen permeability, immiscibility with silk fibroin, good thermal and chemical stability, and high stretchability. Of all the SF:PVOH ratios studied, SF:PVOH 1:1 results to be the most promising material candidate for edible food coatings as demonstrated by efficacy tests on preservation of fresh-cut apples (Figs.…”