Grapes and wine are widely consumed in the world, yet their mineral content can be influenced by many factors such as the mineral composition of soils, viticulture practices and environmental conditions. In this context, considering the importance of Zn in the human physiology, the enrichment of Moscatel and Castelão grapes (white and red variety, respectively) with this nutrient prompted this study; further assessment of tissue deposition and some implications for wine production. Using two foliar fertilizers (ZnO or ZnSO₄, at 150, 450 and 900 g ha⁻¹), decreases in net photosynthesis and stomatal conductance occurred in both varieties, suggesting that the physiological threshold of Zn toxicity was reached without visible symptoms. Following foliar spraying with both fertilizers, the content of Zn in leaves of the Castelão and Moscatel varieties showed higher values in all treatments relative to the control. Moreover, in grapes this tendency occurred only in Castelão. Concerning Cu, Fe, Ca, K, S and P, some significant differences also happened in leaves and grapes among treatments. At harvest, the indexes of Zn enrichment in grapes increased between 2.14- and 8.38-fold and between 1.02- and 1.44-fold in Castelão and Moscatel varieties, respectively. Zinc in the dried skin of Castelão only increased with ZnO and ZnSO₄ sprayed at 900 g ha⁻¹ (ca. 2.71- and 1.5-fold relative to the control, respectively), but in Moscatel a clear accumulation trend could not be found. The dry weight of grapes ranged (in %) between 16 and 23 (but did not vary significantly among treatments of each variety or in each treatment between varieties), and total soluble solids (e.g., mainly soluble sugars and proteins) and color parameters showed some significant variations. Through winemaking, the contents of Zn increased in both varieties (1.34- and 3.57-fold, in Castelão and Moscatel, respectively) and in all treatments, although non-significantly in Castelão. It is concluded that, to increase the contents of Zn in grapes without reaching the threshold of toxicity, ZnO or ZnSO₄ can be used for foliar spraying of Castelão and Moscatel varieties until 900 g ha⁻¹ and that winemaking augments the level of this nutrient.

Nowadays, there is a growing concern about micronutrient deficits in food products, with agronomic biofortification being considered a mitigation strategy. In this context, as Zn is essential for growth and maintenance of human health, a workflow for the biofortification of grapes from the Vitis vinifera variety Fernão Pires, which contains this nutrient, was carried out considering the soil properties of the vineyard. Additionally, Zn accumulation in the tissues of the grapes and the implications for some quality parameters and on winemaking were assessed. Vines were sprayed three times with ZnO and ZnSO₄ at concentrations of 150, 450, and 900 g ha⁻¹ during the production cycle. Physiological data were obtained through chlorophyll a fluorescence data, to access the potential symptoms of toxicity. At harvest, treated grapes revealed significant increases of Zn concentration relative to the control, being more pronounced for ZnO and ZnSO₄ in the skin and seeds, respectively. After winemaking, an increase was also found regarding the control (i.e., 1.59-fold with ZnSO₄-450 g ha⁻¹). The contents of the sugars and fatty acids, as well as the colorimetric analyses, were also assessed, but significant variations were not found among treatments. In general, Zn biofortification increased with ZnO and ZnSO₄, without significantly affecting the physicochemical characteristics of grapes.

The current trend of large-scale bread production is to facilitate processing at an industrial level, considering the use of flour mixtures with different chemical and technological parameters and incorporating food additives. Accordingly, costs can be minimized, whereas the quality and the shelf-life of the final product might increase, but a full characterization of the flours that must be used and the selection of the food additives to be incorporated into the dough is required. In this context, three Portuguese wheat flour varieties were evaluated (FariRamos, Nacional and AJMiranda), as well as two types of food additives with the aim to increase bread shelf-life. In these flours, the levels of K, S, P, Ca and Cl prevailed, but the moisture and ash contents of FariRamos were the highest and lowest, respectively. The colour of all flours was generally within the desired standard values. Nacional flour contained a higher fat content, but all the flours showed a higher relative abundance of linoleic acid (C18:2), followed by palmitic acid (C16:0) and oleic acid (C18:1). AJMiranda flour revealed a higher content of wet gluten and protein, but the SDS sedimentation index showed a higher value in the FariRamos flour. The fall index, which directly monitors the activity of the α-amylase enzyme, showed a lower value in AJMiranda and Nacional. Through farinograph and alveographyc analysis it was found that FariRamos has a tenacious gluten, but AJMiranda and Nacional had a balanced gluten, yet all of them can be classified as medium flours. Bread making with a mix of FariRamos, AJMiranda and Nacional flours and incorporating preservative food additives revealed the highest shelf-life (11-days) with methyl p-hydroxybenzoate [0.05 %] and benzoic acid [0.1 %], but the colour of the breads showed a relationship of intensity of white colour that depended on the additive used. At the end of the shelf-life, molds of the Eurotium, Trichoderma and Cladosporium genera developed in the bread. It was concluded that the chemical and technological approach applied in the characterization of the flour varieties, can be directly used to define the quality and shelf-life in the bakery industry, allowing the establishment of minimum commercialization prices.

Calcium is essential for plants, yet as its mobility is limited, the understanding of the rate of Ca²⁺ accumulation and deposition in tissues of tubers, as well as the interactions with other critical nutrients prompted this study. To assess the interactions and differential accumulation of micro and macronutrients in the tissues of tubers, Solanum tuberosum L. varieties Agria and Rossi were cultivated and, after the beginning of tuberization, four foliar sprayings (at 8–10 day intervals) with CaCl₂ (3 and 6 kg ha⁻¹) or Ca(NO₃)₂ (2 and 4 kg ha⁻¹) solutions were performed. It was found that both fertilizers increased Ca accumulation in tubers (mostly in the parenchyma tissues located in the center of the equatorial region). The functioning of the photosynthetic apparatus was not affected until the 3rd application but was somewhat affected when approaching the end of the crop cycle (after the 4th application), although the lower dose of CaCl₂ seemed to improve the photochemical use of energy, particularly when compared with the greater dose of Ca(NO₃)₂. Still, none of these impacts modified tuber height and diameter. Following the increased accumulation of Ca, in the tubers of both varieties, the mean contents of P, K, Na, Fe, and Zn revealed different accumulation patterns. Moreover, accumulation of K, Fe, Mn, and Zn prevailed in the epidermis, displaying a contrasting pattern relative to Ca. Therefore, Ca accumulation revealed a heterogeneous trend in the different regions analyzed, and Ca enrichment of tubers altered the accumulation of other nutrients.

Calcium is a crucial nutrient for bone development and the normal functioning of the circulatory system, whereas its deficiency can trigger the development of osteoporosis and rickets. On the other hand, Solanum tuberosum L. is one of the most important staple food crops worldwide and is a primary component of the human diet. Accordingly, using this staple food, this study aims to develop a technical itinerary for Ca biofortification of cv. Agria. As such, an itinerary of Ca biofortification was promoted throughout the respective production cycle. Seven foliar sprays with CaCl₂ or chelated calcium (Ca EDTA) were used at concentrations of 12 and 24 kg ha⁻¹. The index of Ca biofortification and the related interactions with other chemical elements in the tuber were assessed. It was found that, relative to the control at harvest, Ca content increased 1.07–2.22 fold (maximum levels were obtained with 12 kg ha⁻¹ Ca-EDTA). Ca(EDTA) at a concentration of 24 kg ha⁻¹ showed the second-highest levels in Ca, S and, P content. By adding CaCl₂, it was also possible to identify a tendency of increasing contents (in Ca, K, S, and P) when the spraying concentration increased (12 kg ha⁻¹ to 24 kg ha⁻¹). Outside of the Ca higher content, dry weight, height, diameter, and the colorimetric parameter L of the tubers did not vary significantly, but minor changes occurred in the colorimetric parameters Chroma and Hue. It was concluded that Ca(EDTA) could trigger a more efficient Ca biofortification of Agria potato tubers with the additional enrichment of K, S, and P.

Calcium is one of the 16 essential elements for plants, being required as Ca²⁺ and being involved in several fundamental processes (namely, in the stability and integrity of the cell wall, the development of plant tissue, cell division, and in stress responses). Moreover, Ca plays an important role in potato production. In this context, this study aimed to monitor the culture development (in situ and using an unmanned aerial vehicle (UAV)) and the mineral content of four essential elements (Ca, P, K, and S) in different organs of Solanum tuberosum L. (roots, stems, leaves, and tubers) during a calcium biofortification process, carried out with two types of solutions (CaCl₂ and Ca-EDTA) with two concentrations (12 and 24 kg∙ha⁻¹). The calcium content generally increased in the S. tuberosum L. organs of both varieties and showed, after the last foliar application, an increase in Ca content that varied between 5.7–95.6% and 20.7–33%, for the Picasso and Agria varieties, respectively. The patterns of accumulation in both varieties during the biofortification process were different between the variety and mineral element. Regarding the quality analysis carried out during the development of the tubers, only the Agria variety was suitable for industrial processing after the last foliar application.