Bioactive (Poly)phenols, Volatile Compounds from Vegetables, Medicinal and Aromatic Plants.

Polyphenols, as well as volatile compounds responsible for aromatic features, play a critical role in the quality of vegetables and medicinal, and aromatic plants (MAPs). The research conducted in recent years has shown that these plants contain biologically active compounds, mainly polyphenols, that relate to the prevention of inflammatory processes, neurodegenerative diseases, cancers, and cardiovascular disorders as well as to antimicrobial, antioxidant, and antiparasitic properties. Throughout the years, many researchers have deeply studied polyphenols and volatile compounds in medicinal and aromatic plants, particularly those associated with consumer's choices or with their beneficial properties. In this context, the purpose of this review is to provide an overview of the presence of volatile and nonvolatile compounds in some of the most economically relevant and consumed vegetables and medicinal and aromatic plants, with an emphasis on bioactive polyphenols, polyphenols as prebiotics, and, also, the most important factors that affect the contents and profiles of the volatile and nonvolatile compounds responsible for the aromatic features of vegetables and MAPs. Additionally, the new challenges for science in terms of improving polyphenol composition and intensifying volatile compounds responsible for the positive characteristics of vegetables and medicinal and aromatic plants are reported.

Effect of agricultural practices, conventional vs organic, on the phytochemical composition of 'Kweli' and 'Tulameen' raspberries (Rubus idaeus L.).

Raspberries are rich in polyphenols but the impact of organic versus conventional agricultural practices on their phytochemical composition is not well known. This study aimed to analyse and compare the polyphenol accumulation in raspberries grown under both agricultural practices in the same edaphoclimatic conditions. Two raspberry cultivars 'Kweli' and 'Tulameen' were used. Under organic agricultural practices, the polyphenols levels increased for the 'Kweli' cultivar but decreased for the 'Tulameen' cultivar. 'Tulameen' cultivar grown under conventional agricultural practices contained higher anthocyanins levels than grown under organic agricultural practices while for the 'Kweli' cultivar no significant differences were observed between the two agricultural practices. 'Kweli' cultivar presented a significantly higher amount of ellagitannins and ellagic acid derivatives when compared to the 'Tulameen' cultivar under both agricultural practices. The effect of the agricultural practices on the raspberries' chemical profile was dependent on the cultivar and cannot be generalised.

Silicates of Potassium and Aluminium (Kaolin); Comparative Foliar Mitigation Treatments and Biochemical Insight on Grape Berry Quality in Vitis vinifera L. (cv. Touriga National and Touriga Franca).

Grapevine physiology is influenced by several environmental factors, such as temperature, precipitation, potential evapotranspiration, and sunshine hours. Due to climatic changes, effects in grapevine physiology and consequently on the grape berry composition and quality have been observed. This work aims to make a comparative study of the effect of foliar mitigation treatment with kaolin (5%) and potassium silicates (0.1% and 0.05%) on the grape berry quality; namely on berry weight, pH, probable alcohol, total phenolics, tannins, total anthocyanins, monomeric anthocyanins, calcium, potassium, and magnesium composition from Portuguese grapevines (Vitis vinifera L. cv. Touriga Nacional and Touriga Franca). The results suggested that the phenolic composition and anthocyanin content differs between treatments while other parameters showed distinct behavior among the different applications. Qualitative parameters observed in the present study suggested non-significant changes upon both the applications.

Chitosan Upregulates the Genes of the ROS Pathway and Enhances the Antioxidant Potential of Grape (Vitis vinifera L. 'Touriga Franca' and 'Tinto Cão') Tissues.

Chitosan is an environmentally-friendly active molecule that has been explored for numerous agricultural uses. Its use in crop protection is well-known, however, other properties, such as bioactivity, deserve attention. Moreover, the modes of actions of chitosan remain to be elucidated. The present study assessed the levels of total phenolic compounds, the antioxidant potential, and the expression of reactive oxygen species (ROS) scavenging genes in the berries (skins and seeds), leaves, cluster stems, and shoots upon chitosan application on two red grapevine varieties (Touriga Franca and Tinto Cão). The application of chitosan on the whole vine before and after veraison led to the increased levels of polyphenols, anthocyanins, and tannins in Tinto Cão berries, and polyphenols and tannins in Touriga Franca berries, respectively. CUPric Reducing Antioxidant Capacity (CUPRAC) and Ferric Reducing Antioxidant Power (FRAP) assays indicated an increase in the antioxidant potential of berries. With the exception of ascorbate peroxidase (APX), all the ROS pathway genes tested, i.e., iron-superoxide dismutase (Fe-SOD), copper-zinc-superoxide dismutase (Cu/Zn-SOD), catalase (CAT), glutathione reductase (GR), glutaredoxin (Grx), respiratory burst oxidase (Rboh), amine oxidase (AO), peroxidase (POD) and polyphenol oxidase (PPO), were found up-regulated in chitosan-treated berries. Results from the analyses of leaves, stems, and shoots revealed that chitosan not only induced the synthesis of phenolic compounds but also acted as a facilitator for the transfer of polyphenols from the leaves to the berries.

Influence of cultivar and of conventional and organic agricultural practices on phenolic and sensory profile of blackberries (Rubus fruticosus).

BACKGROUND: Consumer demand for organic products is increasing because of their claimed health benefits. Blackberries are a rich source of polyphenols, with high antioxidant activity; nevertheless, the impact of organic versus conventional agricultural practices on its phytochemical composition is unknown. 'Loch Ness' and 'Chester Thornless' were selected as blackberry cultivars for this study because of their desired sensory and technological properties, which make them more suitable for export. RESULTS: 'Loch Ness' variety presented a higher amounts of polyphenols and higher antioxidant activity when compared to the 'Chester Thornless' variety. The impact of agricultural practices on the phytochemical composition of the two varieties was contradictory. Under organic agricultural practices, levels of polyphenols increased for 'Loch Ness' and decreased for 'Chester Thornless', whereas the soluble solids content increased in both varieties. These changes in composition were correlated with changes observed in the blackberries' sensory profile. CONCLUSION: The effect of agricultural practices on the blackberries' chemical and sensory profile was dependent on the variety and cannot be generalized. © 2018 Society of Chemical Industry.

General phenolic characterisation, individual anthocyanin and antioxidant capacity of matured red wines from two Portuguese Appellations of Origins.

BACKGROUND: The main aim of this work was to evaluate the general phenolic composition, individual anthocyanin content and total antioxidant capacity from 20 commercial matured red wine samples (vintage from 2005 to 2008) produced in two Appellations of Origin from the north of Portugal: Douro and Dão. RESULTS: The results showed that the levels of general phenolic compounds, individual anthocyanins and antioxidant capacity in the 20 matured red wine samples analysed differed significantly. In addition, matured red wine samples aged in oak wood had a lower total individual anthocyanin content (from 13.85 to 56.79 mg L(-1), averaging 46.13 mg L(-1)) than wines aged in bottle (from 25.93 to 252.82 mg L(-1), averaging 94.17 mg L(-1)). The total antioxidant capacity values of the analysed wines showed quantitative differences among the values obtained from each antioxidant method applied as well as differences in the range of variation, especially for the values obtained by the DPPH method. CONCLUSION: The wines used in this study constitute quite a heterogeneous group, made from different Portuguese red grape varieties, with diverse ages and two ageing processes (bottle and oak wood barrels); and accordingly, they showed important differences, especially in their phenolic composition. Finally, the oak wood ageing process before bottling had a negative effect in individual anthocyanins content in contrast to matured red wines submitted only to a bottle ageing process.