Characterization of amylose and amylopectin fractions separated from potato, banana, corn, and cassava starches

• Published in: International journal of biological macromolecules 2019-07, Vol.132, p.32-42
• Main Authors: Lemos, Paulo Vitor França, Barbosa, Leandro Santos, Ramos, Ingrid Graça, Coelho, Rodrigo Estevam, Druzian, Janice Izabel
• Format: Article
• Language: English
• Subjects: Amylose-1-butanol; Crystallinity; Deconvolution; Glass transition; Polymodal distribution of molecular weight; Thermogravimetry
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2019.03.086

Analytical techniques such HPSEC, DSC, and TGA have been employed for amylose determination in starch samples, though spectrophotometry by iodine binding is most commonly used. The vast majority of these techniques require an analytical curve, using amylose and amylopectin standards with physicochemical properties similar to those found in the original starch. The current study aimed to obtain the amylose and amylopectin fractions from potato, banana, corn, and cassava starches, characterize them, and evaluate their behavior via thermogravimetric curves. Blue amylose iodine complex and HPSEC-DRI methods have obtained high purity amylose and amylopectin fractions. All molecular weights of the obtained amylose and amylopectin fractions were similar to those presented in other reports. Different results were obtained by deconvolution of the amylopectin polymodal distribution. All amyloses presented as semi-crystalline V-type polymorphs, while all amylopectin fractions were amorphous. The Tg of all Vamyloses presented were directly proportional to their respective crystalline index. TGA evaluations have shown that selective precipitation of amylose with 1-butanol strongly changes its thermal behavior. Therefore, the separation procedure used was an ineffective pathway for obtaining standards for thermal studies. [Display omitted] •High purity amylose-1-butanol and amylopectin fractions were obtained by selective precipitation.•The algorithms used for peak deconvolution influenced the amylopectin polymodal distributions studies.•Every amylose fraction separated presented as a V-type polymorph.•V-amylose-1-butanol inclusion complexes presented higher thermal stability than non-complexed amyloses.•Amylose-1-butanol samples were inappropriate to construct the analytical curve for amylose ratio determination by TG.