Quality evaluation of herbal teas

Abstract

The object of the research was herbal teas made from natural Lithuanian herbs and berries and characterized by different healing properties. Quality of teas was assessed using chemical and holistic research methods. The research was conducted at the Open Access Joint Research Centre of Agriculture and Forestry Laboratory Quality of Raw Materials and Laboratory of Environmental Research of VMU Agriculture Academy in the period of 2015– 2016. Collected herbs (Pharm Chamomile (Matricaria chamomilla), Field Mint (Mentha arvensis), St John‘s wort (Hypericum perforatum), Oregano (Origanum vulgare), Small-leaved linden (Tilia cordata), Caraway (Carum carvi), European Dewberry leaves (Rubus caesius), Blackberry leaves (Rubus nessensis)) were dried for 2-3 days, until the set 8-14% of moisture. The berries and fruit (Blueberry (Vaccinium myrtillus), Honeyberry (Lonicera caerulea), Cranberry (Oxycoccus palustris), Maule‘s quince (Chaenomeles japonica)) were freeze-dried. 6 tea blends were prepared from the dried herbs and beries according to their healing properties: ‘Calming’, ‘Healing’, ‘Against the cold’, ‘Immune boosting’, ‘Digestive’, ‘Against the flu’. Tea infusions were made from the tea blends: 5 g of tea blend was poured with 200 ml of 90 ° C water, covered with a lid for 15 and 30 min. After extraction time, tea infusions are separated and analysed. Chemical composition (dry matter content, soluble solids, vitamin C, titratable acidity) was analyzed using standard methods. pH and redox potential was measured by 781 pH/Ion Meter (Metrohm, Switzerland), electrochemical conductivity – by conductometer inoLab Cond 7310 (WTW, Germany). [...]