Chemical, Morphological, Thermal and Technological Properties of Acetylated White Inhambu Starch

Starch is the main predominant food reserve in plants. Its characteristics stand out from other carbohydrates providing it with several industrial applications. However, the starch is chemically modified in order to improve and extend these aspects. The objective of this study was the characterization of unconventional starch from the modification by acetylation of white inhambu starch (Dioscorea trifida L.), in order to verify its possible applicability. Chemical, physicochemical, thermal, morphological, structural and technological properties were characterized. Chemical modification with acetic anhydride resulted in a low degree of acetyl group substitution, with 0.076. Starch was found to have high apparent amylose content and purity due to low ash, protein and lipid values. Thermogravimetric analysis of the modified starch showed stability in the temperature range from 120 to 255 °C, granule morphology showed spherical and smooth surface shapes ranging in size from 8.08 to 19.23 μm. The introduction of the functional group was confirmed by infrared spectroscopy at 1246 cm−1 and 1717 cm−1. The acetylation treatment presented high solubility index and, swelling power in relation to temperature and transparency of the paste in relation to time. It is concluded from the modification of white inhambu starch that its various characteristics may be intended for different segments of the food industry.