Tissue Accumulation and Quantification of Zn in Biofortified Triticum aestivum Grains—Interactions with Mn, Fe, Cu, Ca, K, P and S

Zinc deficiency leads to loss of brain function, changes in growth and weakening of the immune system. This micronutrient has a fundamental role at the regulatory, functional and structural levels. Biofortification, which is a process in which there is an enrichment of both content and the bioavailability of micronutrients in edible tissues of staple foods, may be used to overcome these deficiencies. Two wheat crops (fields 1 and 2) located in Beja, Portugal, with two varieties (Paiva and Roxo) of Triticum aestivum, were selected to be part of a zinc biofortification itinerary. Both varieties were sprayed three times with a zinc fertilizer in two different concentrations and were compared to the control samples. To quantify and locate Zn in the wheat flour and within the grains, XRF analyser and μ-EDWRF analyser were used, respectively, at harvest. Applying XRF analyser to wheat flour, the biofortification index of Zn increased between 1,2 – 1,7 times for Paiva and Roxo increased between 1,3 – 1,4 times in field 1. In field 2, the results varied between 2,3 – 2,5 times for Paiva and between 2,1 – 2,4 times for Roxo. The μ-EDWRF analyses revealed that Zn was preferentially located in the embryo and aleurone in both varieties. To sum up, Zn biofortification resulted in a higher accumulation of the mineral in the embryo and aleurone, particularly in the samples with higher levels of Zn applications. Thus, the biofortification of wheat will allow the development of functional foods with added value and differentiators in the market.