Citation: Daccak, D.; Lidon, F.C.; Luís, I.C.; Marques, A.C.; Coelho, A.R.F.; Pessoa, C.C.; Caleiro, J.; Ramalho, J.C.; Leitão, A.E.; Silva, M.J.; et al. Zinc Biofortification in Vitis vinifera: Implications for Quality and Wine Production. Plants 2022, 11, 2442. https://doi.org/10.3390/ plants11182442 Academic Editor: Sampson Agyin- Birikorang Received: 28 July 2022 Accepted: 15 September 2022 Published: 19 September 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). plants Article Zinc Biofortification in Vitis vinifera: Implications for Quality and Wine Production Diana Daccak 1,2, * , Fernando C. Lidon 1,2 , Inês Carmo Luís 1,2 , Ana Coelho Marques 1,2 , Ana Rita F. Coelho 1,2 , Cláudia Campos Pessoa 1,2 , João Caleiro 1 , José C. Ramalho 2,3 , António E. Leitão 2,3 , Maria José Silva 2,3 , Ana Paula Rodrigues 3 , Mauro Guerra 4 , Roberta G. Leitão 4 , Paula Scotti Campos 2,5 , Isabel P. Pais 2,5 , José N. Semedo 2,5 , Nuno Alvarenga 2,5 , Elsa M. Gonçalves 2,5 , Maria Manuela Silva 2,6 , Paulo Legoinha 1,2 , Carlos Galhano 1,2 , José Carlos Kullberg 1,2 , Maria Brito 1,2 , Manuela Simões 1,2 , Maria Fernanda Pessoa 1,2 and Fernando H. Reboredo 1,2 1 Earth Sciences Department, Faculdade de Ciências e Tecnologia, Campus da Caparica, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal 2 GeoBiotec Research Center, Faculdade de Ciências e Tecnologia, Campus da Caparica, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal 3 PlantStress & Biodiversity Laboratory, Centro de Estudos Florestais (CEF), Instituto Superior Agronomia (ISA), Universidade de Lisboa (ULisboa), Quinta do Marquês, Av. República, 2784-505, Oeiras and Tapada da Ajuda, 1349-017 Lisboa, Portugal 4 LIBPhys, Physics Department, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, 2829-516 Caparica, Portugal 5 Instituto Nacional de Investigação Agrária e Veterinária, I.P. (INIAV), Avenida da República, Quinta do Marquês, 2780-157 Oeiras, Portugal 6 Escola Superior de Educação Almeida Garrett (ESEAG-COFAC), Avenida do Campo Grande 376, 1749-024 Lisboa, Portugal * Correspondence: d.daccak@campus.fct.unl.pt Abstract: 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 ZnSO 4 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 ZnSO 4 in the skin and seeds, respectively. After winemaking, an increase was also found regarding the control (i.e., 1.59-fold with ZnSO 4 -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 ZnSO 4 , without significantly affecting the physicochemical characteristics of grapes. Keywords: grape’s quality; variety fernão pires; winemaking; zn agronomic biofortification 1. Introduction Zinc is the second-most-common transition metal in living organisms [1], being es- sential for the metabolism of humans and crops. Zinc has several physiological functions, namely in enzyme kinetics, cell membrane integrity, control of oxy radicals, and synthesis of sugars and chlorophylls [2,3]. Regarding enzymes, Zn is a cofactor of carbonic anhydrase, carboxypeptidase, RNA polymerase, and Zn-superoxide dismutase [2,4]; these enzymes are involved in the proteosynthesis and metabolism of carbohydrates, lipids, and nucleic Plants 2022, 11, 2442. https://doi.org/10.3390/plants11182442 https://www.mdpi.com/journal/plants