Bionanocomposite Films Prepared from Corn Starch With and Without Nanopackaged Jamaica (Hibiscus sabdariffa) Flower Extract

Abstract

Active and pH-sensitive nano-fillers were prepared from natural and modified montmorillonite (Mnt) and nanopackaged with anthocyanins extracted from the Jamaica (Hibiscus sabdariffa) flower. These were then used to reinforce corn (Zea mays) starchbased films plasticized with glycerol, and processed by extrusion and thermo-molding. Seven film systems were investigated for their potential as Bactive and intelligent^(A&I) bionanocomposite films with improved properties. The thermal and mechanical properties of the bionanocomposite films obtained were enhanced largely due to the added modified clay nano-fillers, and the nanopackaging of the anthocyanins between the nano-clay layers. Unfortunately, however, the bionanocomposite films failed as A&I materials, despite the supposed effect of the nano-clays as protective nano-encapsulating materials for the active and pHsensitive compound (anthocyanins). The results obtained suggest that the exfoliation of the nano-fillers as a consequence of the shear forces inside the extruder led to the exposure of the anthocyanins during extrusion. Because of this, we consider the largescale development of A&I biodegradable films incorporating natural pigments very unlikely being processed by extrusion/ thermo-molding, since there are several significant processes involved in the techniques currently available in the food and polymer industries that leave the active and pH-sensitive compounds unprotected.

Thermoplastic Starch–Based Composite Reinforced by Conductive Filler Networks: Physical Properties and Electrical Conductivity Changes during Cyclic Deformation

“…Stress increases continuously with rising strain until fracture, which is typically referred to as plastic deformation. This behavior is similar to that indicated in the literature for starch-based films [36,37]. The addition of higher amounts of CB results in a progressive enhancement in maximum tensile strength along with a substantial decrease in elongation at break, indicating filler-matrix interactions.…”

Development of active and intelligent films based on cassava starch and Chinese bayberry (Myrica rubra Sieb. et Zucc.) anthocyanins

“…Thicknesses of starch-BBE lms Film thickness is an important parameter that directly affects the mechanical strength, WVP and light transmittance of the lm. 47 As presented in Table 3, the thickness of starch and starch-BBE lms varied from 0.076 to 0.089 mm. A signicant enhancement in lm thickness was observed when BBE content exceeded 1 wt%, which was because the high contents of the extract created heterogeneous lm network that made the lms became thicker.…”

Characterization of biodegradable/non-compostable films made from cellulose acetate/corn starch blends processed under reactive extrusion conditions

“…All the film systems were developed using a 56:190 (g/g) ratio (glycerol:starch). A similar glycerol:starch ratio was used by Toro-Márquez, Merino, and Gutiérrez (2018). To evaluate the effects of adding C and Cat to the starch matrix they were added separately to give two film systems: 19 g (10% w/w with respect to starch content) of C or 7 mL (3.68% v/w with respect to starch matrix) of Cat.…”