Tissue accumulation and quantification of Zn in biofortified Triticum aestivum L. grains – development of a functional food
With the growth of the world population, there is an urgent need to increase the production of staple foods. Zinc deficiency is the fifth leading cause of mortality and disease in developing countries, leading 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. One way to make up for these deficiencies may involve 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. Thus, the biofortification of wheat will allow the development of functional foods with added value and differentiators in the market. 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 average biofortification index of Zn varied between 24 - 73% for Paiva and Roxo varied between 29 and 44 % in field 1. In field 2, the results varied between 134 - 146% for Paiva and between 108 - 143% for Roxo. The µ-EDWRF analyses revealed that Zn was preferentially localized in the embryo and aleurone in both varieties.