Effect of five saturated fatty acids on the properties of sweet‐potato‐starch‐based films

Abstract

To fully explore the influences of saturated fatty acids (SFAs) on the properties of sweet‐potato‐starch (SPS)‐based films, five SFAs were chosen to add to SPS. The SPS‐based films were prepared by casting. The microstructure, mechanical, optical, water vapor barrier, and thermal properties of the films were investigated. The 2.0% (w/w, on the basis of starch) SFA significantly changed the SPS pasting characteristics in the peak viscosity, breakdown, and other feature point viscosity values as determined by a Rapid Visco Analyser. The amylose molecular weights decreased as measured by high‐performance size exclusion chromatography. A thermal study with differential scanning calorimetry suggested that the addition of SFA increased the onset temperature and peak temperature. Scanning electronic microscope (SEM) images showed a continuous and uniform structure in the films with SFA. The SPS–SFA composite films showed lower light transmission and elongation at break than the control. Compared with the control films, the addition of SFA increased the tensile strength and decreased the water vapor permeability of the films. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41380.

Physicochemical and Mechanical Properties of Bambara Groundnut Starch Films Modified with Stearic Acid

“…The improvement in barrier property of starch‐based films following the addition of lipids to starch matrix has also been reported (Jiménez and others ; Schmidt and others ; Ortega‐Toro and others ; Liu and others ). These improvements in barrier properties may vary with starch source and lipid type.…”

“…However, starch‐based plastics are inferior to the petrol‐based types (Ortega‐Toro and others ). The use of starch in bio‐plastic packaging is limited due to its hydrophilic and poor mechanical property (Ortega‐Toro and others ; Liu and others ). Addition of plasticizers such as glycerol and sorbitol have been found to improve films flexibility (Jiménez and others ).…”

“…According to Jiménez and others (), the improved barrier property of starch films modified with lipids is due to the overall increase in films hydrophobicity. Further, stearic acid addition has been found to improve the thermal stability of starch films (Liu and others ). Potato starch film modified with stearic was reported to exhibit higher melting temperature (191 °C) compared to the control film, which showed approximately 183 °C (Liu and others ).…”

“…Further, stearic acid addition has been found to improve the thermal stability of starch films (Liu and others ). Potato starch film modified with stearic was reported to exhibit higher melting temperature (191 °C) compared to the control film, which showed approximately 183 °C (Liu and others ). The formation of inclusion complexes between lipids and amylose in starch is well known.…”

“…The modification of starch with lipid results in the formation of amylose inclusion complexes. These complexes may be explored in making films with improved barrier properties (Jiménez and others ; Liu and others ). Most reported studies on improving physicochemical properties of starch films with lipids have focused mainly on conventional starch sources like cereals and tubers.…”