Development of a technology for obtaining encapsulated forms of biologically valuable plant extracts from beet leaves (Beta Vulgaris cv)

Abstract

This paper is aimed at developing a technology for obtaining encapsulated forms of biologically active substances exhibiting antioxidant properties from secondary agricultural materials. A technology for ultrasoundassisted extraction of antioxidants followed by their encapsulation was developed. We studied the structural and functional interactions between the structural units of biopolymer capsules using the methods of Fourier transform infrared spectroscopy. The spectrum of alginate capsules containing extract shows a number of differences as compared to those of capsules without extract, which indicates successful inclusion of biologically active plant substances (peak intensity varies within the range of 800–1600 cm-1 , 1240.30 cm-1 and 1512.26 cm-1 ). However, these changes do not suggest any significant chemical interactions between the biopolymers and the encapsulated substance. The results of the developed encapsulated antioxidants in terms of their size, moisture, encapsulation efficiency and yield, extract content, as well as other physico-chemical parameters were similar to each other and in good agreement with literature data. The experiments showed that all of the capsules began to swell to varying degrees in an artificial intestinal tract due to increased electrostatic repulsion forces. The obtained results on the change in mechanical properties of the developed capsules show the degradation of the capsules (with the values of capsule strength tending to zero) to occur with time and under the influence of alkaline conditions and monovalent ion salts. These facts confirm the feasibility of developing encapsulated antioxidant forms from secondary agricultural materials, which can help bridge the deficiency of bioactive substances in the human diet in the bioavailable form.