Effects of glycerol and sorbitol on optical, mechanical, and gas barrier properties of potato peel‐based films

Abstract

Potato peel is a by-product of potato-based food production and seen as a zero-or negative-value waste of which millions of tons are produced every year. Previous studies showed that potato peel is a potential material for film development when plasticized with 10% to 50% glycerol (w/w potato peel). To further investigate potato peel as a film-forming material, potato peel-based films containing the plasticizer sorbitol were prepared and investigated on their physicochemical properties in addition to films containing glycerol. Due to sufficient producibility and handling of casted films in preliminary trials, potato peel-based films containing 50%, 60%, or 70% glycerol (w/w potato peel) and films containing 90%, 100%, or 110% sorbitol (w/w potato peel) were prepared in this study. Generally, with increasing plasticizer concentration, water vapor and oxygen permeability of the films increased. Films containing glycerol showed higher water vapor and oxygen permeabilities than films containing sorbitol. Young's modulus, tensile strength, and elongation at break decreased with increasing sorbitol concentration, whereas no significant effect of plasticizer content on elongation at break was shown in films containing glycerol. Due to crystallization of films containing sorbitol as a plasticizer, potato peel-based films containing 50% glycerol (w/w) were identified as the most promising films, characterized by a water vapor transmission rate of 268 g 100 μm m −2 d −1 and an oxygen permeability of 4 cm 3 100 μm m −2 d −1 bar −1. Therefore, potato peel-based cast films in this study showed comparable tensile properties with those of potato starch-based films, comparable water vapor barrier with those of whey protein-based films, and comparable oxygen barrier with those of polyamide films.

Effect of glycerol and sorbitol on the mechanical and barrier properties of films based on pea protein isolate produced by high‐moisture extrusion processing

“…[6][7][8][9] The functionality of protein-based films depends on the molecular structures, which leads to different mechanical and barrier properties. [10,11] This study aims at investigating the potential of a pea protein isolate-based material to form films with interesting properties by a protein extrusion process. [12] There are several studies that have successfully investigated the properties of pea protein-based materials, but with different processing techniques and different applications.…”

Development of Flexible and Thin Films from Underutilized Indian Finger Millet (Eleusine coracana) Starch

“…Miller et al. [ 21 ] found that the film thickness of potato starch film increased with the addition of glycerol and sorbitol. Similarly, in the case of the film derived with cassava starch, it is found that film thickness increased when different types of plasticizers: fructose, tri‐ethylene glycol, and urea, were incorporated.…”

Biobased Food Packaging Materials: Sustainable Alternative to Conventional Petrochemical Packaging Materials: A Review

“…To overcome the brittleness of alginate films, some studies combine more than one plasticizer, such as glycerol, palmitic acid, β-cyclodextrin and glycerol monostearate used in film formulations (Fan et al, 2009). Miller et al, (2021) investigated the effect of glycerol and sorbitol plasticizers on potato-based film and discovered that as plasticizer concentration increased, so did the film's water vapor and oxygen permeability. A glycerol-containing film had higher water vapor and oxygen permeabilities than a sorbitol-containing film (Miller et al, 2021).…”

“…Miller et al, (2021) investigated the effect of glycerol and sorbitol plasticizers on potato-based film and discovered that as plasticizer concentration increased, so did the film's water vapor and oxygen permeability. A glycerol-containing film had higher water vapor and oxygen permeabilities than a sorbitol-containing film (Miller et al, 2021).…”