This work monitors flavonoid pigments (theaflavins and thearubigins), and chlorophyll in green teas from different growing regions (India, China, Russia, Vietnam). These pigments affect the quality of the finished tea infusion and their quantity is affected by the way of tea processing (fermentation). 15 samples of green loose teas were selected for the analysis. The content of these pigments was determined using UV-Vis spectrophotometry, the concentration of flavonoid pigments was measured at a wavelength of 665 nm (theaflavins) and 825 nm (thearubigins). Concentration of flavonoid pigments was determined using the standard conversion coefficients, which are 38.7 for TRs and 1.4 for TFs. Chlorophyll concentration was measured at 642.5 and 660 nm. Chlorophyll concentration was determined by the conversion using international standard conversion coefficients and calculation of linear regressions. The results were statistically processed and evaluated in the program of UNISTAT version 5.6. The total amount of chlorophyll ranged from 0.20 to 1.33 mg/L of tea. Concentrations of theaflavin ranged from 0.15 to 0.66 g/100 g of tea and TRs from 2.00 to 11.15 g/100 g of tea. The results showed that the amount of theaflavins, thearubigins and chlorophyll in green teas varied (P <0,05), especially in teas from lowlands in Vietnam and Krasnodar (Russia). Statistically demonstrable difference (P <0,05) in the content of pigments was also recorded in a group of Indian teas (from lowlands) and, from a group of Chinese teas, a statistical difference (P <0,05) was demonstrated in the content of pigments in the mountain teas. On the basis of the results it can be concluded that the quality of green tea is mainly influenced by the processing method depending on the processing area (the factory), than by their country of origin.

This study deals with the effects of selected additions of vegetable origin on the colour of whole grain breads. The colour was assessed using model samples which were made of mixtures containing various wholemeal flour types (wheat, spelt, and rye flour) and increasing amounts of additions in the form of buckwheat, oat, and barley flour. The additions were 10, 20, 30, 40 and 50 per cent. Colour measurement was performed instrumentally, using an image analysis method which was modified for the purposes of this study. It was found out that, regardless of the flour/addition ratio, both factors in the form of wheat, spelt, and rye wholemeal flour, and barley, oat and buckwheat flour additions and their interactions exhibited a significant influence on the colour of the bakery products (P < 0.05). As far as dependence of colour on the flour/addition ratio is concerned, significant differences (P < 0.05) were found for the following combinations: mixture of wheat flour with buckwheat, barley, and oat; mixture of spelt flour with buckwheat and oat; and mixture of rye flour with buckwheat and barley. The proposed general regression model which was created using the data obtained in the experiment, showed colour variability of more than 95 per cent.