Long-Term Physical Stability of Plasticized Hemicellulose Films

Abstract

aOat spelt arabinoxylan (OsAX) and spruce galactoglucomannan (GGM) are hemicelluloses that can be extracted in large quantities from sidestreams of the agriculture and forest industries. They both form selfstanding films, making them potential future packaging materials. This systematic study focuses on the effect of long-term storage on the physical stability of hemicellulose-based films. OsAX and GGM films were plasticized with 40% (w/w of the polysaccharide) of glycerol, sorbitol, or their blends, and their stability was followed for four months. Ageing especially affected the glycerol-containing films, in which the tensile strength and Young's modulus increased and elongation at break decreased. Although the mechanical properties were altered, storage did not affect crystallinity of the films. Oxygen gas permeability (OP) and water vapor permeability (WVP) properties were monitored in OsAX films. Interestingly WVP decreased during storage; more than a 40% decrease was seen when plasticizer blends contained 50% or more glycerol. In contrast, there were no drastic changes in the OP during storage; all the OPs obtained were between 3.7 and 8.9 [cm 3 µm/ (m 2 d kPa)].

Moisture sorption isotherm and changes in physico‐mechanical properties of films produced from waste flour and their application on preservation quality of fresh strawberry

“…In the current study, the WVP, tensile strength, and elongation at break of all film specimens decreased after storage at 5, 25, and 45°C for 30 days. These changes could possibly be attributed to the instability of the plasticizers (glycerol and/or sorbitol) due to plasticizer migration from the film matrix to the surface and the surrounding environment during storage time (Heikkinen et al., ; Osés et al., ). Storage time decreased the WVP and the elongation at break of all films.…”

“…Storage time decreased the WVP and the elongation at break of all films. It is indicated that plasticization and free volume in the film network were decreased after glycerol migration out of the film matrix (Heikkinen et al., ; Mikkonen et al., ).…”

“…In the current study, the WVP, tensile strength, and elongation at break of all film specimens decreased after storage at 5, 25, and 45°C for 30 days. These changes could possibly be attributed to the instability of the plasticizers (glycerol and/or sorbitol) due to plasticizer migration from the film matrix to the surface and the surrounding environment during storage time (Heikkinen et al, 2014;Osés et al, T A B L E 1 Model constants, adjusted coefficient of determination (R 2 adj ), and root mean square error (RMSE) of the best estimator (modified Henderson model) for moisture sorption isotherm of films produced from waste flour, with 40% plasticizers (2:1, 3:1, and 4:1 w/w glycerol:sorbitol ratio) and 200 ppm potassium sorbate 2009). Storage time decreased the WVP and the elongation at break of all films.…”

Enzymatic‐assisted extraction and modification of lignocellulosic plant polysaccharides for packaging applications

“…In another study, the aging of GGM and AX films with 20–60% incorporated glycerol or sorbitol revealed interesting changes of the materials after 4 months. Elongation at break and water vapor permeability decreased and the strength and Young's modulus increased, while degree of crystallinity and oxygen barrier properties remained unaffected with time . These changes were suggested to be associated with the water content in the films.…”

Hemicellulose-Based Film: Potential Green Films for Food Packaging

“…Food preservation is usually a long-term process, so the long-term stability of packaging is also important. When Susanna and co-workers [ 73 ] studied the plasticized film made from oat spelt arabinoxylan and spruce galactoglucomannan, they found that although the mechanical properties of the film slightly deteriorated after four months of use, water vapor permeability decreased significantly and oxygen permeability value changed little. Therefore, the barrier property of modified hemicellulose film will remain at a high level in the long term use.…”