Abstract
Background: Starch is an alternative material for the production of biodegradable plastics; however, native starches have drawbacks due to their hydrophilic nature. Chemical modifications such as acetylation and crosslinking are used to broaden the potential end-uses of starch. Dual modification of starches increases their functionality compared to that of starches with similar single modifications. In this study, a dual-modified potato starch (acetylated and crosslinked) was used to produce films by casting. Results: Changes in the arrangement of the amylopectin double helices of dual-modified starch were evident from X-ray diffraction patterns, pasting profiles and thermal properties. The degree of substitution for acetyl groups was low (0.058 ± 0.006) because crosslinking dominated acetylation. Modified starch film had higher elongation percentage (82.81%) than its native counterpart (57.4%), but lower tensile strength (3.51 MPa for native and 2.17 MPa for dual-modified) and lower crystallinity in fresh and stored films. The sorption isotherms indicated that the dual modification decreased the number of reactive sites for binding water, resulting in a reduction in the monolayer value and a decrease in the solubility and water vapor permeability. Conclusions: Dual modification of starch may be a feasible option for improving the properties of biodegradable starch films.
Original language | English |
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Pages (from-to) | 3134-3141 |
Number of pages | 8 |
Journal | Journal of the Science of Food and Agriculture |
Volume | 99 |
Issue number | 6 |
DOIs | |
State | Published - Apr 2019 |
Keywords
- acetylation
- crosslinking
- dual modification
- potato starch
- starch films