Optimization of physical and optical properties of biodegradable edible films based on pea starch and guar gum

The influence of process variables (pea starch, guar gum and glycerol) on the viscosity (V), solubility (SOL), moisture content (MC), transparency (TR), Hunter parameters (L, a, and b), total color difference (ΔE), yellowness index (YI), and whiteness index (WI) of the pea starch based edible films was studied using three factors with three level Box–Behnken response surface design. The individual linear effect of pea starch, guar and glycerol was significant (p < 0.05) on all the responses. However, a value was only significantly (p < 0.05) affected by pea starch and guar gum in a positive and negative linear term, respectively. The effect of interaction of starch × glycerol was also significant (p < 0.05) on TR of edible films. Interaction between independent variables starch × guar gum had a significant impact on the b and YI values. The quadratic regression coefficient of pea starch showed a significant effect (p < 0.05) on V, MC, L, b, ΔE, YI, and WI; glycerol level on ΔE and WI; and guar gum on ΔE and SOL value. The results were analyzed by Pareto analysis of variance (ANOVA) and the second order polynomial models were developed from the experimental design with reliable and satisfactory fit with the corresponding experimental data and high coefficient of determination (R2) values (>0.93). Three-dimensional response surface plots were established to investigate the relationship between process variables and the responses. The optimized conditions with the goal of maximizing TR and minimizing SOL, YI and MC were 2.5 g pea starch, 25% glycerol and 0.3 g guar gum. Results revealed that pea starch/guar gum edible films with appropriate physical and optical characteristics can be effectively produced and successfully applied in the food packaging industry.

Development of the edible blend films with good mechanical and barrier properties from pea starch and guar gum

The individual and interactive impacts of guar gum and glycerol on the pea starch-based edible film characteristics were examined using three factors with three level Box–Behnken response surface design. The results showed that density and elongation at break were only significantly (p < 0.05) affected by pea starch and guar gum in a positive linear fashion. The quadratic regression coefficient of pea starch showed a significant effect (p < 0.05) on thickness, density, puncture force, water vapour permeability, and tensile strength. While tensile strength and Young modulus affected by the quadratic regression coefficient of glycerol and guar gum, respectively. The results were analysed using Pareto analysis of variance (ANOVA) and the developed predictive equations for each response variable presented reliable and satisfactory fit with high coefficient of determination (R2) values (≥ 0.96). The optimized conditions with the goal of maximizing mechanical properties and minimizing water vapour permeability were 2.5 g pea starch, 0.3 g guar gum and 25 % (w/w) glycerol based on the dry film matter in 100 ml of distilled water. Generally, changes in the concentrations of pea starch, guar gum and glycerol resulted in changes in the functional properties of film.

Conceptualising cosmopolitanism and entrepreneurship through the lens of the three-dimensional theory of power

Purpose – The paper aims to conceptualise cosmopolitanism drivers from the third-level power perspective by drawing on Lukes’ (1974; 2005) theory of power. In addition, the paper aims to investigate the relationship between entrepreneurs’ cosmopolitan dispositions and habitus, i.e. a pattern of an individual’s demeanour, as understood by Bourdieu. Design/methodology/approach – This conceptual paper makes use of Bourdieu’s framework (habitus) by extending it to the urban cosmopolitan environment and linking habitus to the three-dimensional theory of power and, importantly, to the power’s third dimension – preference-shaping. Findings – Once cosmopolitanism is embedded in the urban area’s values, this creates multiple endless rounds of mutual influence (by power holders onto entrepreneurs via political and business elites, and by entrepreneurs onto power holders via the same channels), with mutual benefit. Therefore, mutually beneficial influence that transpires in continuous support of a cosmopolitan city’s environment may be viewed as one of the factors that enhances cosmopolitan cities’ resilience to changes in macroeconomic conditions. Originality/value – The paper offers a theoretical model that enriches the understanding of the power-cosmopolitanism-entrepreneurship link, by emphasising the preference-shaping capacity of power, which leads to the embedment of cosmopolitanism in societal values. As a value shared by political and business elites, cosmopolitanism is also actively promoted by entrepreneurs through their disposition and habitus. This ensures not only their willing compliance with power and the environment, but also their enhancement of favourable business conditions. Entrepreneurs depart from mere acquiescence (to power and its explicit dominance), and instead practice their cosmopolitan influence by active preference-shaping.