Green Development of Biodegradable Films Based on Native Yam (Dioscoreaceae) Starch Mixtures

Abstract

Mixtures of starch comprising starches from different botanical origins and species can improve the mechanical properties of films and coatings. Here, the aim is to develop a sustainable process of starch modification to obtain enhanced starch films through mixing three Dioscoreaceae starches and to study the films resultant mechanical (tensile strength and elongation at break), thermal (glass transition and melting temperature), and physicochemical (moisture, solubility, thickness, color, transparency, light transmission, water vapor permeability, crystallinity, and surface uniformity) properties. The films obtained after the mixing process show low moisture content and high transparency, high solubility desirable for biodegradability, and significantly different thickness. An improved light barrier is achieved and water vapor permeability barrier properties are obtained. Using differential scanning calorimetry, it is observed that the glass transition temperature of the films decreased. The starch mixture improves the mechanical characteristics of the films by 200% for tensile strength and 232% for elongation at break. After mixing, the films show increased crystallinity and no crack or pinholes in their surface. These findings demonstrate that the yam‐starch mixtures form strong and flexible films suitable for various industrial products through a simple green process.

Comparative study on properties of starch films obtained from potato, corn and wheat using 1-ethyl-3-methylimidazolium acetate as plasticizer

“…The nonbiodegradable aspect of such polymers has provoked the presence of microplastics in the environment that may reach humans in common table salt [3] or in the trophic chain in general [4,5]. This situation and increased environmental concerns have encouraged the scientific community to develop polymers based on natural resources (starch, cellulose, lignin…) [6][7][8][9], since they are considered renewable, biodegradable and biocompatible [10]. Among all the biopolymers studied, starch is the most interesting, because it is readily obtained from different types of plants and hence is very abundant and has a competitive price compared with other commodity polymers [1,11].…”

“…Starch films were prepared by the casting technique following the procedure previously described by Medina-Jaramillo et al [33]. In summary, the film-forming solution was composed of potato, corn or wheat starch ( The water content and solubility in water of the films were determined using 1 x 1 cm 2 samples following previously described procedures with slight modifications [7,33]. The water content was measured by determining the weight loss of films, previously dried in an oven at 110 ºC for 5 hours.…”

“…describes the use of ionic liquid or glycerol as starch plasticizers, and attributes the transparency of films to the botanical origin and the level of gelatinization [7,29,38,43]. The greater transparency of potato starch films could be indicative of a bigger amorphous phase in the films and hence a greater plasticization [43] as it will become clearer below with the XRD results.…”

Study of the behavior of biodegradable starch/polyvinyl alcohol/rosin blends

“…The water content and solubility in water of the samples was determined in 1 x 1 cm 2 specimens following the procedures described by Hornung et al (2018) and Medina-Jaramillo et al (2017) with some modifications. Firstly, the water content was measured by determining the loss of weight of the sheets after drying in an oven for 5 h at 110 ºC.…”

“…Hornung et al (2018);Luchese et al (2017);Edhirej et al (2018);Phetwarotai et al (2018); Medina Jaramillo et al(2015);Lopez et al (2014)). The samples were cut into dumbbell-shaped specimens.…”