Search

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.

Anthocyanins composition of five purple leaves cultivars of Ocimum basilicum L. was investigated by reversed-phase HPLC with mass-spectrometric detection in the conditions of ions partial fragmentation as well as preparation of dried differently colored forms of anthocyanins encapsulated into maltodextrin matrix. Mass-spectra analysis revealed that according to anthocyanin set basil cultivars under investigation may be divided onto two groups with common feature being high level of acylation with (mainly) p-coumaric, ferulic and malonic acids of the same base – cyanidin-3-dihexoside-5-hexoside. The presence of acylation with substituted cinnamic acids permits to obtain solutions not only with red color (the property of the flavylium form) but also with blue shades coloration due to quinoid and negatively charged quinoid forms. All forms exept of flavylium are not stable in solution but stable enough to prepare dried encapsulated forms by lyophilization. And thou the loss of anthocyanins at drying is not negligible the final product is characterized with high stability at storage in refrigerator., Исследован антоциановый состав листьев пяти пурпурнолистных сортов базилика обыкновенного Ocimum basilicum L. методом обращенно-фазовой ВЭЖХ с масс-спектрометрическим детектированием в условиях частичной фрагментации соединений и получены сухие разноцветные инкапсулированные в матрицу мальтодекстрина формы антоцианов. Анализ масс-спектров позволил установить, что по набору антоцианов (т.е. по хроматографическому профилю) исследованные сорта базилика могут быть разделены на две группы, общее свойство которых – высокая степень ацилирования п-кумаровой, феруловой и малоновой кислотами одной и той же основы – цианидин-3-дигексозид-5-гексозида. Наличие ацилирования (одинарного и двойного) замещенными коричными кислотами позволяет получать растворы не только с красной (характерной для флавилиевой формы) окраской, но и с бордовой и синей, за которые отвечают нейтральная и отрицательно заряженная хиноидные формы. Все нефлавилиевые формы антоцианов неустойчивы в растворах, но существует возможность получения сухих инкапсулированных форм методом лиофильной сушки. При этом заметна потеря антоцианов, но конечный продукт характеризуются высокой стабильностью при хранении в бытовом холодильнике.