OBTAINING RED CABBAGE ANTHOCYANIN COLORED ENCAPSULATED FORMS BY THE METHOD OF FREEZE-DRYING

The method of reversed-phase HPLC with diode-array and mass-spectrometric detection was explored to determine the qualitative composition of red cabbage anthocyanins. Mono- and diacylated derivatives of cyanidin-3,5-diglycosides with a complex structure of the substituent in position were found, as well as non-esterified compounds. The acylation acids were paracoumaric, ferulic and sinapic. Quantitative analysis was performed according to a simplified spectrophotometric method: absorbance measurement at pH 4.5 was excluded. The measurement showed that the level of anthocyanins accumulation is as high as 0.100 g of anthocyanins per 100 g of raw plant material (as cyanidin-3-glucoside chloride equivalent). Analysis of electronic spectra of the extract at different pH revealed the existence of some basic structures with absorbance maxima shifted bathochromically as compared to the spectrum of flavylium structure. The existence of one basic form at pH 4.5 forced us to exclude absorbance measurement at pH 4.5 during quantitative anthocyanin determination. Thus, the possibility of obtaining some differently colored encapsulated forms was proved. Because of relative instability of non-flavylium forms of anthocyanins the freeze drying technique was used to prepare six differently colored forms of 3% anthocyanins encapsulated in maltodextrin. The decrease of anthocyanins contents at drying did not exceed 30%, while no statistically proved loss of anthocyanins was found at storage in a refrigerator during more than six months