Effects of acetic acid/acetic anhydride ratios on the properties of corn starch acetates

Autor:	Bi Jun Xie, John Shi, Cherif Ibrahima Khalil Diop, Hai Long Li
Rok vydání:	2011
Předmět:	chemistry.chemical_classification Absorption of water Starch food and beverages General Medicine Polysaccharide Analytical Chemistry chemistry.chemical_compound Acetic acid Crystallinity Acetic anhydride chemistry Reagent Hydroxyl value Organic chemistry Food Science Nuclear chemistry
Zdroj:	Food Chemistry. 126:1662-1669
ISSN:	0308-8146
Popis:	Corn starch was pre-treated with acetic acid and then acetylated by acetic anhydride under microwave irradiation. The effects of molar ratios of these two reagents on the acetylation of starch were investigated. Starch acetate with a high degree of substitution (DS, 2.93) was obtained at a molar ratio (acetic acid/acetic anhydride) of 1:1. However, the DS should tend to decrease with a change of this ratio. The FT-IR analysis indicated characteristic absorption peaks, with increasing DS materialised by an increase of the carbonyl CO group and a decrease of the hydroxyl O-H group, at about 1750cm(-1) and 3450cm(-1), respectively. The X-ray diffraction patterns of acetylated starch showed an amorphous structure. Degree of crystallinity, surface morphology, water solubility and water absorption index of corn starch were also affected by the changes in reagent ratios. The glass transition (Tg) and melting (Tm) temperatures of acetylated starches also decreased after acetylation.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::03001a8525b0d04089ae3a748410490e https://doi.org/10.1016/j.foodchem.2010.12.050 Zobrazit plný text záznamu Full Text from ScienceDirect