Selenium enriched vegetables as biofortification alternative for alleviating micronutrient malnutrition

There is a very difficult equation for malnutrition and over-consumption. That means malnutrition even of vitamins and/or minerals (Ca, Cu, Fe, I, Mg, Se and Zn, vitamin A) affects more than two billion people worldwide, largely due to low concentrations or poor bioavailability of the nutrients in the diet. In some developed countries in contrast, over-consumption, particularly of over-refined cerealbased foods, has contributed to the development of an epidemic of metabolic diseases. So, producing nutritious and safe foods sufficiently and sustainably is important target at the same time challenge of modern agriculture. In the past, great efforts have focused only on increasing crop yields, but enhancing the concentrations of mineral micronutrients has become an urgent task. The main daily food source is the staple crops specially in developing countries of the world, i.e., wheat, rice, cassava, beans, sweet potato or maize. These kind of plants are often deficient in some of mineral elements. Thus, the increasing of bioavailable concentration of micronutrients in edible crop tissues (via biofortification) has become a promising strategy in modern agriculture, providing more nutritious foods, to more people, with the use of fewer lands. Biofortification of these trace elements can be achieved application with agronomic process such as soil or foliar fertilization or crop breeding even conventional technic and/or genetic engineering. This review highlight progress to date and identify challenges faced in delivering biofortified vegetable crops as well as the agronomic approaches and tools to improve crop yield and micronutrient content of food crops.

Variation in selenium tolerance among two onion cultivars in closed fortification system

Selenium (Se) is an essential trace element for humans and animals. To consumption of selenium could be good sources the vegetables. Many of them are able to convert the inorganic selenium forms to organic forms, which are more effective for health. To enrich onion with selenium is known however some unclear points are remained. A closed fortification system was conducted to compare the difference of selenium tolerance in two onion cultivars in greenhouse environment. This system was well controlled, eliminating a lot of disturbing factors. The comparative analysis of Makói bronz and Makói lila spring onoins showed that there is difference in selenium tolerance and accumulation not only between plant species but inside it between the different cultivars, too. The Makói bronz seemed to more sensitive to the selenate treatment than Makói lila.

Relationship between zinc and cadmium contents and cultivating conditions of gourmet and medicinal mushroom Agaricus subrufescens

Almoust half of the world’s population is at risk for inadequate zinc (Zn) intake, a strategic trace element that is necessary for a healthy immune system. A lack of zinc can make a person more susceptible to disease and illness. There is a need of defining additional sources of zinc in diet. Cadmium (Cd), however, and its toxicity in food chain receives considerable public and scientific attention. Cd is primarily toxic to kidney and can cause bone demineralization. In many areas in the EU, intake of Cd is not far from maximum tolerable. Mushrooms are well known for accumulating metal ions such as zinc and cadmium. Objective of this study was to define relationship between cultivation systems and conditions on zinc and cadmium content in fruit bodies of Agaricus subrufescens grown on different substrates. Cultivation was performed on mushroom composts based on increasing amount of digestate from anaerobic digestion treatment processes mixed with wheat straw and paper. The Zn and Cd concentration was defined in fruiting bodies, correlated with yield, flush and element concentration in substrates. Results showed percentage of food waste digestate and other components used in experiment had influence on concentration of Zn and Cd in mushroom compost and in A. subrufescens. Zn accumulated in collected mushrooms in amounts reaching from 42.8 to 126.9 mg kg-1 Cd content ranged 2.6 to 17.9 mg kg-1. Significant correlations for Zn concentration between mushrooms and substrates showed increase of Zn in mushrooms when cultivated on substrates with higher amount of digestate.