Antioxidative defence mechanisms in two grapevine (Vitis vinifera L.) cultivars grown under boron excess in the irrigation water

The aim of this study was to investigate the impact of B excess on the antioxidative defence system in two grapevine cultivars differently sensitive to B, in order to evaluate in which way the different sensitivity was correlated to the activation of defence mechanisms. Two-year-old Vitis vinifera L. plants (‘Merlot’ and ‘Sangiovese’), grafted on the same rootstock, were subjected to B treatment as potted vines, and biochemical determinations were employed to evaluate the antioxidative response. Compared to ‘Sangiovese’, ‘Merlot’ showed a much higher B accumulation and both leaf and peroxidative damages. In B-treated ‘Sangiovese’ the activity of superoxide dismutase did not change compared to control leaves, whereas in ‘Merlot’ a dramatic decrease in the enzyme activity was observed. B increased reduced ascorbate pools in both cultivars, but ascorbate peroxidase activity was enhanced only in ‘Merlot’. In this latter cv. an enhancement of total phenols was also observed. ‘Merlot’ showed a lower ability to contrast B accumulation in leaves than ‘Sangiovese’ evidencing a higher oxidative stress. Even if defence mechanisms were generally activated in ‘Merlot’, they did not counteract efficiently metabolic damages likely due to the dramatic decrease in superoxide dismutase, the first enzyme involved in the detoxification of oxygen radicals

A Mathematical Model to Evaluate the Kinetics of D-glucose and D-fructose Fermentations by Saccharomyces bayanus at Increasing Ethanol Concentrations

In the cellar, slow and stuck fermentations occurring during winemaking are often successfully solved bythe addition of yeast strains like Saccharomyces bayanus. The kinetic behaviour shown by S. bayanus duringalcoholic fermentation was investigated using a mathematical model previously tested for S. cerevisiae, inorder to show which of the six functional parameters of the model differed significantly with the yeastpopulation. Although some parameters (hexose fractions converted to ethanol and glycerol) did not change,the kinetic constant related to the inactivation rate of the yeast population showed by S. cerevisiae assumeda value significantly higher (approximately 50-fold) than that observed for S. bayanus, while this latterpopulation was ten times less affected by ethanol than S. cerevisiae. Although no remarkable differencescould be found between the ability shown by the two yeast populations to convert hexoses (D-glucose andD-fructose), the tolerance for ethanol accumulation changed strongly. The conversion rate of these twohexoses by S. bayanus was affected less (about ten thousand-fold) by ethanol than that of S. cerevisiae

The Kinetic Effect of Some Wine Components on the Enzymatic Hydrolysis of β-glucan

Enzymatic preparations containing β-glucanases are utilised extensively in winemaking to facilitate the filtration ofmusts and wines coming from grapes affected by Botrytis cinerea, and to induce the release of mannoproteins andoligosaccharides from the cell walls of yeasts. The aim of the present work was to investigate the possible inhibitoryeffect of some wine components, and in particular of ethanol, on β-glucanase activities. For this purpose, the kineticactivity of a commercial enzymatic preparation containing β-glucanases was tested utilising both model solutions(buffer solution having a pH value similar to a must/wine with or without 13% v/v of ethanol added) and a redwine. When ethanol was added to the model solution, both the kinetic constant k and glucose production suffered adecrease of about 50% compared to the values detected in the absence of ethanol. A further loss of activity (about87%) was found using red wine as reaction medium, suggesting, as already reported in the literature, that phenolscould add their inhibitory effect to that of ethanol. The results obtained provide useful suggestions that can beadopted during winemaking. To promote the hydrolysis of the possible excess of β-glucan coming from grapesaffected by Botritis cinerea, it would be more convenient to add β-glucanases before a significant amount of ethanolaccumulates in the must/wine, while it is not possible to avoid the negative impact of ethanol or other possibleinhibitors (phenols) to promote yeast degradation in wine left on lees

A Mathematical Model to Evaluate the Kinetics of D-glucose and D-fructose Fermentations by Saccharomyces bayanus at Increasing Ethanol Concentration

In the cellar, slow and stuck fermentations occurring during winemaking are often successfully solved by the addition of yeast strains like Saccharomyces bayanus. The kinetic behaviour shown by S. bayanus during alcoholic fermentation was investigated using a mathematical model previously tested for S. cerevisiae, in order to show which of the six functional parameters of the model differed significantly with the yeast population. Although some parameters (hexose fractions converted to ethanol and glycerol) did not change, the kinetic constant related to the inactivation rate of the yeast population showed by S. cerevisiae assumed a value significantly higher (approximately 50-fold) than that observed for S. bayanus, while this latter population was ten times less affected by ethanol than S. cerevisiae. Although no remarkable differences could be found between the ability shown by the two yeast populations to convert hexoses (D-glucose and D-fructose), the tolerance for ethanol accumulation changed strongly. The conversion rate of these two hexoses by S. bayanus was affected less (about ten thousand-fold) by ethanol than that of S. cerevisiae

Lipid composition of pea (Pisum sativum L.) and maize (Zea mays L.) root plasma membrane and membrane-bound peroxidase and superoxide dismutase

Plasma membrane was isolated from roots of pea and maize plants and used to analyze POD and SOD isoforms, as well as lipid composition. Among lipids, phospholipids were the main lipid class, with phosphatidylcholine being the most abundant individual component in both pea and maize plasma membranes. Significant differences between the two plant species were found in the contents of cerebrosides, free sterols, and steryl glycosides. Most maize POD isoforms were with neutral and anionic pI values, but the opposite was observed in pea. While both anionic and cationic SOD isoforms were isolated from maize, only two anionic SOD isoforms were detected in pea

Nutraceutical Oils Produced by Olives and Citrus Peel of Tuscany Varieties as Sources of Functional Ingredients

The essential oils extracted from the peels of two Tuscany Citrus of the Massa province have been characterised. Moreover, the flavedo of these species has been used in the production of two Citrus olive oils (COOs) obtained with an innovative method in which the citrus peels are cryomacerated and then pressed with the olives. The presence of functional compounds, such as carotenoids, naringenin and minor phenolics, classifies these COOs as nutraceuticals with the potential to develop enriched foods able to promote a healthy diet. Moreover, the increased presence of tyrosol and hydroxytyrosol, compared to the unflavoured oil, further highlights the nutritional value to the two COOs, being these phenolic compounds recognized as good possible therapeutic candidates for the inhibition of neurodegenerative diseases as the Parkinson's disease. In this perspective, the citrus peels, rich in bioactive compounds, have been valued transforming their waste nature in an innovative resource

The effects of packaging and storage temperature on the shelf-life of extra virgin olive oil

This research aimed to study the effects of packaging and storage temperature on the shelf-life of an extra virgin olive oil (EVOO) as it can occur in most points of sale. The evolution of the chemical and sensory characteristics of an EVOO, initially stored in stainless steel silos under nitrogen at 12–18 °C, was evaluated after packaging. Tinplate tin (TT) and greenish glass (GG), the most used packaging containers, and temperatures of 6 and 26 °C were taken into consideration. After 125 days from packaging all the samples maintained clearness, green and yellow reflections and the positive sensory notes of bitterness and pungency of the starting EVOO. Shelf-life of EVOO was significantly affected by different storage conditions: oil samples stored in GG at 6 °C preserved for the most part the positive attributes, whereas those stored in TT at 26 °C showed a significant presence of the rancid flavor due to oxidative processes. Moreover, samples stored in GG at 6 °C maintained the highest bitterness intensity and did not show defects at the end of the storage period. The results suggest that storage in GG at a low temperature could represent a promising storage condition to slow-down the oil degradation during market storage

The Kinetic Effect of Some Wine Components on the Enzymatic Hydrolysis of β-glucan

Enzymatic preparations containing β-glucanases are utilised extensively in winemaking to facilitate the filtration of musts and wines coming from grapes affected by Botrytis cinerea, and to induce the release of mannoproteins and oligosaccharides from the cell walls of yeasts. The aim of the present work was to investigate the possible inhibitory effect of some wine components, and in particular of ethanol, on β-glucanase activities. For this purpose, the kinetic activity of a commercial enzymatic preparation containing β-glucanases was tested utilising both model solutions (buffer solution having a pH value similar to a must/wine with or without 13% v/v of ethanol added) and a red wine. When ethanol was added to the model solution, both the kinetic constant k and glucose production suffered a decrease of about 50% compared to the values detected in the absence of ethanol. A further loss of activity (about 87%) was found using red wine as reaction medium, suggesting, as already reported in the literature, that phenols could add their inhibitory effect to that of ethanol. The results obtained provide useful suggestions that can be adopted during winemaking. To promote the hydrolysis of the possible excess of β-glucan coming from grapes affected by Botritis cinerea, it would be more convenient to add β-glucanases before a significant amount of ethanol accumulates in the must/wine, while it is not possible to avoid the negative impact of ethanol or other possible inhibitors (phenols) to promote yeast degradation in wine left on lees

Foliar and root comparative metabolomics and phenolic profiling of Micro-Tom tomato (Solanum lycopersicum L.) plants associated with a gene expression analysis in response to short daily UV treatments

Tomato (Solanum lycopersicum L.) is globally recognised as a high-value crop both for commercial profit and nutritional benefits. In contrast to the extensive data regarding the changes in the metabolism of tomato fruit exposed to UV radiation, less is known about the foliar and root metabolome. Using an untargeted metabolomic approach through UHPLC-ESI-QTOF-MS analysis, we detected thousands of metabolites in the leaves (3000) and roots (2800) of Micro-Tom tomato plants exposed to 11 days of short daily UV radiation, applied only on the aboveground organs. Multivariate statistical analysis, such as OPLS-DA and volcano, were performed to allow a better understanding of the modifications caused by the treatment. Based on the unexpected modulation to the secondary metabolism, especially the phenylpropanoid pathway, of which compounds were down and up accumulated respectively in leaves and roots of treated plants, a phenolic profiling was carried out for both organs. The phenolic profile was associated with a gene expression analysis to check the transcription trend of genes involved in the UVR8 signalling pathway and the early steps of the phenolic biosynthesis. The retention of the modifications at metabolic and phenolic levels was also investigated 3 days after the UV treatment, showing a prolonged effect on the modulation once the UV treatment had ceased