Fernando M. Nunes

By Fernanda Leal, Meriem Taghouti, Fernando Nunes, Amélia Silva, Ana Cláudia Coelho and Manuela Matos

Medicinal and aromatic plants are important sources for plant secondary metabolites. The genetic manipulation of plants associated with in vitro plant regeneration systems facilitates efforts to engineer secondary product metabolic pathways. The fungal infections have been increasing in recent years due to several factors, namely, the increased incidence of high-risk patients, particularly immunocompromised hosts. Aromatic plants have been empirically used as antimicrobial agents, but the mechanisms of action are still unknown. Thyme has a great interest due to the possibility of its use in different applications, in medicine, in the cosmetic industry, or as food additives. Several studies have shown that thyme oils possess antimicrobial activity. Increasingly, plant breeding has taken advantage of molecular biology developments in order to genotype the species of interest to accelerate their selection. These approaches consist in choosing desired genotypes based on molecular markers or the knowledge of the genes involved in a particular trait. The in vitro culture techniques can be used to multiply plants selected after molecular and antifungal studies. The course of the investigation and the current state in relation to micropropagation, molecular studies, and antifungal action of the Thymus genus plants will be presented.

Part of the book: Active Ingredients from Aromatic and Medicinal Plants

By Luís Filipe da Mota Ribeiro, Maria Fernanda Gil Cosme Martins and Fernando Hermínio Ferreira Milheiro Nunes

We recently proposed a simple methodology to improve cork powder waste adsorption properties through vacuum degassing and solvent impregnation, to use this abundant and cheap material as a new wine fining agent. Its applicability was first shown for red wine 4-ethylphenol (4-EP) and 4-ethylguaiacol (4-EG) reduction. Nowadays, the presence of 4-EP and 4-EG is a serious problem in the wine industry, known as “Brett character”, by the negative aroma imparted by these volatile phenols (VPs) to red wine. There are only some curative treatments to remove these compounds without impacting negatively on wine quality. Optimised cork powder was used successfully as a new treatment for the reduction of these negative VPs (41?75% for 4-EP and 40?69% for 4-EG) increasing at the same time wine sensory performance. Wine treated with cork powder reduced 6.9% phenolic acids and catechin and 2.3% monomeric anthocyanins without any significant change in colour intensity. In this chapter, the cork complex structure is discussed, besides the impact of its use in wine containing VPs on physicochemical composition and quality. This new application of this natural, abundant and cheap material has the potential of being a new wine fining agent with low environmental impact.

Part of the book: Advances in Grape and Wine Biotechnology

By Juliana Milheiro, Fernanda Cosme, Luís Filipe-Ribeiro and Fernando M. Nunes

Port wine is a traditional and worldwide renowned fortified wine produced in the Douro Demarcated Region (DDR) Northeast of Portugal by specific and traditional winemaking practices. The final quality and uniqueness of the different Port wine styles are highly dependent on the ageing process, namely time, temperature and oxygen levels that will ultimately dictate the type and extension of the chemical changes that occur during this process. These chemical changes occurring during the Port wine ageing process results in significant changes in colour and aroma according to the different ageing conditions employed for the different Port wine styles. This chapter intends to give a broad and generic overview of the known and potential chemical changes occurring during ageing of Port wine that are responsible for the changes in the sensory profile observed during the ageing process. Also, the known chromatic and aromatic characteristics of the different Port wine styles and the specific ageing processes, reductive or oxidative, are reviewed.

Part of the book: Chemistry and Biochemistry of Winemaking, Wine Stabilization and Aging

By Fernanda Cosme, Luís Filipe-Ribeiro and Fernando M. Nunes

Wine is widely consumed due to its distinctive sensory characteristics. However, during wine production and storage, several defects can appear. These can be the result of unwanted microbiological activity or due to the unbalanced levels of some compounds resulting from an unbalanced grape chemical composition or inadequate winemaking practices and storage conditions. The main purpose of wine stabilisation is the removal of wine defects, either visual, olfactive, gustative, or tactile, the increase in wine safety and stability by fining and filtration operations, avoiding the occurrence of some usual wine precipitations after bottling. Although the best strategy is to prevent the appearance of wine defects, when present, several fining agents or additives, and technologies are available today with different performances and impact on wine quality. By physicochemical and sensory analysis, the defect is detected, and if the objective is removing them, some laboratory trials are performed to achieve a better treatment approach. This review overviews the principal wine defects and treatments available today and in the near future. Generally, the future trend is the use of more sustainable and environmentally friendly fining agents and technologies, looking for treatments with better performance and specificity.

Part of the book: Chemistry and Biochemistry of Winemaking, Wine Stabilization and Aging

By Luís Filipe-Ribeiro, Fernanda Cosme and Fernando M. Nunes

White wine protein instability depends on several factors, where Vitis vinifera pathogenesis-related proteins (PRPs), namely chitinases and thaumatin-like proteins, present an important role. These proteins can be gradually denatured and aggregate during wine storage, developing a light-dispersing haze. At present, the most efficient process for avoiding this wine instability is through the removal of these unstable proteins from the wine before bottling. To remove unstable white wines proteins, the sodium bentonite fining is the most used treatment, however, many alternative techniques such as ultrafiltration, the application of proteolytic enzymes, flash pasteurisation, other adsorbents (silica gel, hydroxyapatite and alumina), zirconium oxide, natural zeolites, chitin and chitosan, carrageenan and the application of mannoproteins have been studied. This chapter overviews the factors that influenced the white wine protein instability and explored alternative treatments to bentonite to remove white wine unstable proteins.

Part of the book: Grapes and Wine

By Fernanda Cosme, Luís Filipe-Ribeiro and Fernando M. Nunes

Part of the book: Global Warming and the Wine Industry

By Fernanda Cosme, Miguel Ribeiro, Luís Filipe-Ribeiro and Fernando M. Nunes

This review explores the presence of mycotoxins in grapes and grape products, focusing on various types such as ochratoxin A (OTA), aflatoxins, fumonisins, patulin, and others. The discussion encompasses multifaceted factors influencing mycotoxin occurrence, including environmental aspects, agricultural practices, and post-harvest handling. Advanced techniques for mycotoxin detection, such as chromatography and immunoassays, are explored, along with the challenges associated with these methods. Mitigation strategies, such as the implementation of good agricultural practices and good manufacturing practices, are presented. Additionally, emerging technologies for mycotoxin control are discussed, highlighting innovative approaches in the field. This overview aims to contribute to the complex realm of mycotoxins in grapes and grape products, offering a holistic understanding from detection to mitigation. The concluding remarks emphasize the significance of proactive measures to ensure the safety and quality of grape products regarding mycotoxin challenges.

Part of the book: Global Warming and the Wine Industry