EJPAU, 2017, Volume 20, Issue 2

Nickel in excessive amounts deteriorates the nutritional status in plants, inter alia reduces the level of sulphur. Simultaneously, the common use of NPK fertilizers without sulphates (S-SO₄) together with the progressive process of reducing emissions of S compounds to the natural environment may lead to deficiency of this element involved in stress tolerance. The aim of the studies was to evaluate the changes in the macronutrient contents and accumulation in Sinapis alba L. cv. Rota grown for 2 weeks at different levels of S-SO₄ (S-2-standard dose, 6, 9 mM) and Ni (0, 0.0004, 0.04, 0.08 mM) in modified Hoagland’s nutrient solution. Intensive S-SO₄ nutrition of Ni-exposed mustard seems to improve to some extent the unfavourable macronutrient status. It substantially increased the root macronutrient content drop in the content of this macronutrient. The macronutrient status in shoots remained stable, except for the significant increase in the S content and the rise in Ca accumulation accompanied by an increase in N and K accumulation recorded at the S dose 6 mM. Ni-bioaccumulation did not change markedly with the exception of its increase in roots at the 6 mM S level.

In recent years an increased interest in healthy lifestyle caused that other types of tea, e.g. Pu Erh, are also increasingly selected by the consumers. Currently, Pu Erh tea is considered to promote weight loss, as well as support the treatment of numerous diseases, by neutralizing free radicals activity in the human body. Present research aimed at the evaluation of antiradical capacity of Pu Erh tea leaves available on the Polish market. The research was conducted on seven Pu Erh teas produced according to the accelerated ripening method (wo dui), supplied by Polish dealers. Pu Erh tea was subjected to traditional brewing methods, followed by DPPH and ABTS radical reducing activity assays. Tea leaves and its brews were also characterized according to the commodity value. The antiradical capacity of Pu Erh tea leaves showed that examined teas exhibited antiradical properties, however in a varied degree, not conditioned by the type of tea and brewing time. The quality of tea had no significant effect on the ability to reduce the DPPH and ABTS radicals, whereas it affected the extraction process efficiency. Pu Erh tea may be a dietary source of antioxidants, helping with the treatment of diseases caused by free radicals activity, such as diabetes or coronary heart disease.