METHOD FOR QUANTITATIVE DETERMINATION OF STARCH FRACTIONS OF AMYLOSE AND AMYLOPECTIN Russian patent published in 2025 - IPC G01N33/10 G01N23/83 

FIELD: measuring.

SUBSTANCE: invention relates to methods for assessing the quality of starch and analytical methods for quantitative determination of starch fractions in starch. Method for quantitative determination of starch fractions of amylose and amylopectin in starch involves sample preparation of starch samples as a result of cold pressing in a mould at press pressure of not less than 100 kg/cm² for 15-30 minutes to obtain solid, strong flat-cylindrical tablets with a smooth and defect-free surface. Further, quantitative determination of amylose and amylopectin starch fractions is carried out on the basis of X-ray structural analysis as follows. Diffraction curves are recorded on an X-ray diffractometer using copper CuK_α radiation filtered by nickel in absolutely identical conditions in step mode of discrete scanning. Radiographs are recorded in reflection mode. Based on the analysis of the obtained X-ray patterns, the degree of crystallinity is found, which indicates the amount of the amylopectin fraction responsible for the formation on the linear sections of the crystalline sections, by calculating it from the intensity ratio ((I_o-I_a)/I_o)⋅100 %. I_a is the X-ray diffraction intensity on the amorphous regions, I_o is the total X-ray diffraction intensity. Degree of amorphism, which indicates the amount of the amylose fraction, is determined as difference between 100% and the degree of crystallinity.

EFFECT: invention enables to develop an analytical accurate, high-efficiency and simple method for quantitative determination of amylose and amylopectin starch fractions.

1 cl, 9 dwg, 2 tbl, 13 ex