Mineral and trace element composition after digestion and leaching into matcha ice tea infusions (Camellia sinensis L.)

Since matcha includes all leaf parts seems desirable to measure contents of elements before and after digestibility. This paper examines in vitro digestibility, mineral and trace element contents after digestion and their leaching ability during matcha ice tea processing. Digestibility values of matcha measured enzymatically reached 71.3 %. High contents of K, Mg, Mn, Ca, Fe and Zn were recorded by FAAS/ETAAS. Interestingly, element concentrations in non-digestible parts of matcha decreased in the following order: K > Mg > Mn > Fe >= Ca > Zn > Na > Se > Hg. Matcha ice teas were prepared using three different methods. Significant differences were found not only between the ice tea preparation methods, but also between the tea samples. Low values of leaching factors for Na, Fe and Se were identified (18, 21 and 37 %, respectively).