POTATO STARCH MODIFICATION WITH BENZOIC ACID CHLORINE HYDRIDE

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Starch is a natural polymer due to modification, acquires the necessary properties for the needs of the food, packaging and other industries. The following modification methods are known: physical, chemical and biological. Starches modified with chloride, phosphate, sulfate acids, acetic anhydride, acetic and succinic acids, potassium hydroxide, ammonium persulfate are industrially produced in many countries in the world. A numeric of works concerns the interaction of various starch types with fatty acid chlorides. In addition, native and modified starch are biodegradable and allows them to be used for the ecological materials. The potato starch modification with benzoic acid chloride was carried out and was confirmed by elemental analysis. There were changes in the vibration frequency bands of native starch in the uncharacteristic region in the IR spectra: the vibration frequency at 981.81 cm-1 increased and in the spectrum of the modified starch it lies at 1024.82 cm-1, the band with the vibration frequency of 923.07 cm-1 shifted to 866.66 cm-1, and the band with an oscillation frequency of 609.79 cm-1 shifted to 672.22 cm-1,which indicates a change in the uncharacteristic region of the native starch spectrum after acylation. A signal appeared at 7.3 ppm in the modified starch NMR spectrum, which is characteristic of the benzoin ring. However, it was impossible to determine the degree of starch glucopyranose acylation chains and determine the substituent position by NMR spectrum. There were changes in the appearance of starch, which was determined by microscopy: the characteristic potato starch grains shape, elongated oval grains were destroyed. The obtained modified product properties were studied using thermogravimetric analysis and it was established the modification changed the forms of moisture bonds with starch, the grains appearance, and the crystallinity degree decreased from 12 to 5%.