Modeling of moisture sorption isotherms of poly(vinyl alcohol)/starch films

Abstract

Studies on the moisture sorption characteristics of poly(vinyl alcohol)/starch blends for water activity (a w ) values of 0.1-0.9 were performed at 27°C. The equilibrium moisture content at different a w values was used to fit different sorption isotherm models proposed in the literature. The ranges of a w applicable for the different sorption isotherms were reported. The model constants of the sorption equations were determined by linear fitting. The value of the coefficient of determination (0.98 Ϯ 0.01) confirmed the goodness of fit of the equations studied.

Mixture design applied to evaluating the effects of polyvinyl alcohol (PVOH) and alginate on the properties of starch‐based films

“…The addition of PVOH to starch films was studied by Raj et al , and similar to what was found in this study, they found that the addition of 10% starch decreased the monolayer value of PVOH films. According to these authors, hydrogen bonds can form between starch and PVOH, which decreases the availability of bonding sites for water adsorption.…”

Adsorción de Vapor de Agua de Bioplásticos Elaborados con Harina de dos Variedades de Yuca (Adsorción Manihot esculenta Crantz)

“…Similar comportamiento se ha presentado en diversos productos amiláceos cuyas curvas de adsorción son convexas al eje de las abscisas, como en papa (Kaymak y Gedik, 2004), galletas (McMinn et al, 2007, películas con almidón de yuca (Chen y Lai, 2008). Las isotermas de tipo III son características de productos ricos en componentes solubles, como los azúcares (Raj et al, 2003). En el caso de los bioplásticos estudiados se presenta una alta proporción de componentes solubles representados principalmente por el almidón contenido en la harina de yuca como componente mayoritario de las mezclas (Tabla 1), y la fracción de componentes solubles del fique como material reforzante en las diferentes formulaciones evaluadas.…”

Moisture Adsorption Isotherm Model for Edible Food Film Packaging – A Review

“…Other than that, it gives an acceptable description of the isotherms of vegetables and meats. In a study r study conducted by Raj, Eugene Raj [23] for polyvinyl alcohol -corn starch film, th model showed a good fit for water activity ranged between 0.1 and 0.6. is given by ( 9 odified Henderson that includes the temperature parameter was used to study th therm of chitosan films. The sorption data is suitable for water activity range betwee ith r 2 = 0.9729 [22].…”

“…A study of polyethylene oxide -blended starch films found that the Henderson model is suitable for water activity ranged from 0.33 to 0.86 [4]. Another study conducted by Raj, Eugene Raj [23] for polyvinyl alcohol -corn starch film, the Henderson model showed a good fit for water activity ranged between 0.1 and 0.6.…”