title: Silk Fibroin as Edible Coating for Perishable Food Preservation.
abstract: The regeneration of structural biopolymers into micelles or nanoparticles suspended in water has enabled the design of new materials with unique and compelling properties that can serve at the interface between the biotic and the abiotic worlds. In this study, we leveraged silk fibroin quintessential properties (i.e. polymorphism, conformability and hydrophobicity) to design a water-based protein suspension that self-assembles on the surface of food upon dip coating. The water-based post-processing control of the protein polymorphism enables the modulation of the diffusion of gases through the silk fibroin thin membranes (e.g. O2 and CO2 diffusion, water vapour permeability), which is a key parameter to manage food freshness. In particular, an increased beta-sheet content corresponds to a reduction in oxygen diffusion through silk fibroin thin films. By using the dip coating of strawberries and bananas as proof of principle, we have shown that the formation of micrometre-thin silk fibroin membranes around the fruits helps the management of postharvest physiology of the fruits. Thus, silk fibroin coatings enhance fruits' shelf life at room conditions by reducing cell respiration rate and water evaporation. The water-based processing and edible nature of silk fibroin makes this approach a promising alternative for food preservation with a naturally derived material.
authors.affiliation: Department of Biomedical Engineering Tufts University 4 Colby St., Medford, MA, 02155, USA.
authors.forename: B
authors.initials: B
authors.lastname: Marelli
authors.affiliation: Department of Biomedical Engineering Tufts University 4 Colby St., Medford, MA, 02155, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Brenckle
authors.affiliation: Department of Biomedical Engineering Tufts University 4 Colby St., Medford, MA, 02155, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Kaplan
authors.affiliation: Department of Biomedical Engineering Tufts University 4 Colby St., Medford, MA, 02155, USA.
authors.forename: F G
authors.initials: FG
authors.lastname: Omenetto
mesh_terms: D005349:Fibroins / Q000494:pharmacology*; D005519:Food Preservation / Q000379:methods*; D005520:Food Preservatives / Q000494:pharmacology*; D031985:Fragaria; D028521:Musa
chemical_list: D005520:Food Preservatives; D005349:Fibroins