Luigi Bavaresco

Cancer prevention in Europe: The Mediterranean diet as a protective choice

In the coming years, European death rates because of cancer will further decline, but the overall number of cases will increase, mostly as a consequence of the ageing of the population. The target for cancer prevention in Europe will remain a healthy diet and control of obesity in addition to a decrease in smoking. A healthy diet model in European countries is the traditional Mediterranean diet, which is based on abundant and variable plant foods, high consumption of cereals, olive oil as the main (added) fat, low intake of (red) meat and moderate consumption of wine. The Mediterranean diet is associated with a reduced risk of cardiovascular disease and cancer. The biological mechanisms for cancer prevention associated with the Mediterranean diet have been related to the favourable effect of a balanced ratio of omega 6 and omega 3 essential fatty acids and high amounts of fibre, antioxidants and polyphenols found in fruit, vegetables, olive oil and wine. The Mediterranean diet also involves a ‘Mediterranean way of drinking’, that is, regular, moderate consumption of wine mainly with food. This pattern of drinking increases longevity, reduces the risk of cardiovascular disease and does not appreciably influence the overall risk of cancer. However, heavy alcohol drinking is associated with digestive, upper respiratory tract, liver and breast cancers; therefore, avoidance or restriction of alcohol consumption to two drinks/day in men and one drink/day in women is a global public health priority.

Advanced knowledge of three important classes of grape phenolics: anthocyanins, stilbenes and flavonols

Grape is qualitatively and quantitatively very rich in polyphenols. In particular, anthocyanins, flavonols and stilbene derivatives play very important roles in plant metabolism, thanks to their peculiar characteristics. Anthocyanins are responsible for the color of red grapes and wines and confer organoleptic characteristics on the wine. They are used for chemotaxonomic studies and to evaluate the polyphenolic ripening stage of grape. They are natural colorants, have antioxidant, antimicrobial and anticarcinogenic activity, exert protective effects on the human cardiovascular system, and are used in the food and pharmaceutical industries. Stilbenes are vine phytoalexins present in grape berries and associated with the beneficial effects of drinking wine. The principal stilbene, resveratrol, is characterized by anticancer, antioxidant, anti-inflammatory and cardioprotective activity. Resveratrol dimers and oligomers also occur in grape, and are synthetized by the vine as active defenses against exogenous attack, or produced by extracellular enzymes released from pathogens in an attempt to eliminate undesirable toxic compounds. Flavonols are a ubiquitous class of flavonoids with photo-protection and copigmentation (together with anthocyanins) functions. The lack of expression of the enzyme flavonoid 3′,5′-hydroxylase in white grapes restricts the presence of these compounds to quercetin, kaempferol and isorhamnetin derivatives, whereas red grapes usually also contain myricetin, laricitrin and syringetin derivatives. In the last ten years, the technological development of analytical instrumentation, particularly mass spectrometry, has led to great improvements and further knowledge of the chemistry of these compounds. In this review, the biosynthesis and biological role of these grape polyphenols are briefly introduced, together with the latest knowledge of their chemistry.

Study of Grape Polyphenols by Liquid Chromatography-High-Resolution Mass Spectrometry (UHPLC/QTOF) and Suspect Screening Analysis

Suspect screening analysis is a targeted metabolomics method in which the identification of compounds relies on specific available information, such as their molecular formula and isotopic pattern. This method, coupled to liquid chromatography-high-resolution mass spectrometry, is effective in the study of grape metabolomics, in particular for characterization of flavonols, stilbene derivatives, and anthocyanins. For identification of compounds expected in the samples, a new database of putative compounds was expressly constructed by using the molecular information on potential metabolites of grape and wine from the literature and other electronic databases. Currently, this database contains around 1,100 compounds. The method allows identification of several hundred grape metabolites with two analyses (positive and negative ionization modes), and performing of data reprocessing using “untargeted” algorithms also provided the identification of some flavonols and resveratrol trimers and tetramers in grape for the first time. This approach can be potentially used in the study of metabolomics of varieties of other plant species.

Investigations on iron uptake and reduction by excised roots of different grapevine rootstocks and a V. vinifera cultivar

Roots from cuttings of grapevine rootstocks V. Berlandieri × V. rupestris 140 Ru, V. Berlandieri × V. riparia SO4, V. riparia × V. rupestris 101–14 and a V. vinifera cultivar (Pinot blanc), with a decreasing degree of chlorosis resistance, were excised and tested to quantify physiological and morphological parameters, as follows: 59Fe uptake from an FeEDTA solution; reducing capacity; root diameter and root hair occurrence.The most significant findings are that: a) 59Fe uptake and FeEDTA reduction decreased from the most chlorosis resistant rootstock (‘140 Ru’) to the most susceptible one (‘101–14’) and to Pinot blanc; b) 59Fe uptake and reducing capacity were closely related; c) iron uptake and reduction were closely related to the root diameter and root hair occurrence, within the rootstocks.

Why climate change will not dramatically decrease viticultural suitability in main wine-producing areas by 2050

Hannah et al. (1) recently published a comprehensive study showing substantial impacts of climate change on viticultural suitability, leading to potential ecological issues. We agree that expansion of viticulture into new areas can lead to a decrease in biodiversity and that an increase in water use for irrigation might lead to major freshwater conservation impacts. However, we disagree with the alarming statement that suitability for winegrowing of main wine-producing areas worldwide will dramatically decrease over the next 40 y. We point out major methodological flaws in ref. 1, mostly linked to (i) the misuse of bibliographical data to compute suitability index, (ii) underestimation of adaptations of viticulture to warmer conditions, and (iii) the inadequacy of the monthly time step in the …

Grapevine Rootstock Effects on Lime‐Induced Chlorosis, Nutrient Uptake, and Source–Sink Relationships

Abstract The experiment considered Vitis vinifera L. cv. “Pinot blanc” clone VCR5 grafted on a lime‐susceptible (3309 C) and a lime‐tolerant (41 B) hybrid rootstock and grown in 45 L pots of a calcareous and a non‐calcareous soil. Each treatment included plants bearing clusters and plants without clusters; in the latter case the bunches were removed 15 days before blooming. During the third growth year, shoot length, leaf chlorophyll (Chl), and mineral element concentrations were recorded. At the end of the growing cycle the grapevines were divided into leaves, shoots, berries, cluster stems, trunk, roots, and dry matter and mineral element composition per organ were analyzed. The 41 B rootstock showed its lime‐tolerance by exhibiting little reduction of shoot length when grown in the calcareous soil as compared to the non‐calcareous one, while 3309 C growing in the calcareous soil induced a dramatic shoot length reduction. The rootstock also affected the leaf chl concentration according to the known degree of lime‐tolerance/susceptibility: “Pinot blanc” grafted on 3309 C and growing on the calcareous soil showed chlorotic leaves while the plants grafted on 41 B had green leaves; cluster removal did not affect leaf chl. The fruit load (expressed as berry dry matter) was strongly affected by the soil and the rootstock; in the calcareous soil 41 B rootstock produced twice as high cluster dry matter than did 3309 C. A higher macronutrient uptake for the plants growing under lime‐stress conditions was affected by 41 B rootstock. Cluster removal in plants grown on calcareous soil produced different effects, as follows: in the case of 41 B rootstock, a redistribution of photosynthate to other sinks like shoot tip and roots occurred, while in the case of 3309 C only the roots benefited. Under lime‐stress condition the plants grafted on 41 B took up more iron (recorded as total amount in the leaves) than did those grafted on 3309 C.

An innovative approach to grape metabolomics: stilbene profiling by suspect screening analysis

Suspect screening analysis is a targeted metabolomics approach in which identification of compounds relies on specific available information such as their molecular formula and isotopic pattern. This method was applied to the study of grape metabolomics with an UPLC/MS high-resolution Q-TOF mass spectrometer (nominal resolution 40,000) coupled with a Jet Stream ionization source. The present paper describes the detailed qualitative and quantitative study of grape stilbenes, the principal polyphenols associated with the beneficial effects of drinking wine. For identification of compounds, a new database was expressly constructed from the molecular information of potential metabolites of grape and wine from the literature and other electronic databases. Currently, GrapeMetabolomics contains about a thousand putative grape compounds. If untargeted analysis of a sample provides identification of a new compound with a sufficiently confident score, it is added to the database. Thus, by increasing the number of samples studied, GrapeMetabolomics can be expanded. This method is effective for identification of the molecular formulae of several hundred metabolites in two runs (positive and negative ionization) with minimal sample preparation, and can also be used to analyse some single classes of compounds involved in cell and tissue metabolism. With this approach, a total of 18 stilbene derivatives was identified in two grape samples (Raboso Piave and Primitivo) on the basis of accurate mass measurements and isotopic patterns, and identification was confirmed by MS/MS analysis. The approach can also potentially be applied to the metabolomics of other plant varieties.

Iron chlorosis paradox in grapevine

Abstract Vitis vinifera L. cv. Pinot blanc was grown in both pot and commercial vineyard under lime‐stress conditions. Dark green to very chlorotic young leaves were sampled in order to analyze chlorophyll and iron (Fe) concentration and content, area, fresh and dry weight, specific weight per area. Iron content per individual leaf was a good parameter to separate dark green leaves from chlorotic ones in both trials, while Fe concentration on DW basis was not. Chlorosis occurrence always decreased leaf dry weight and specific weight per area.

Effects of Elicitors, Viticultural Factors, and Enological Practices on Resveratrol and Stilbenes in Grapevine and Wine

The ability of grapevine to activate defense mechanisms against some pathogens has been shown to be linked to the synthesis of stilbenes by the plant (inducible viniferins). Metabolized viniferins may also be produced or modified by extracellular enzymes released by the pathogen in an attempt to eliminate undesirable toxic compounds. Due to the important properties of resveratrol, there is increasing interest in producing foods with higher contents of this compound and higher nutritional value. The production of high resveratrol-containing grapes and wines relies on quality-oriented viticulture (suitable terroirs, sustainable cultural practices) and wine-making technologies which avoid degradation of the compound. The technique of skin extraction and enzymatic hydrolysis of glucoside forms in wine-making plays an important role in resveratrol wine concentration. Other factors affecting its final concentration and balance in wine are conditions for promoting trans-cis isomerization of aglycones, the type of yeast used, and the presence of lactic bacteria with β-glucosidase activity. In general, the enological practices commonly used to stabilize wine after fermentation do not significantly affect resveratrol concentrations, which show considerable stability.

Effect of the rootstock on the occurrence of lime-induced chlorosis of potted Vitis vinifera L. cv. ‘Pinot blanc’

The chlorosis susceptible Vitis vinifera L. cv. ‘Pinot blanc’ was grafted on two hybrid rootstocks with different iron efficiency, as follows: V. Berlandieri × V. rupestris ‘140 Ru’ (iron-efficient) and V. riparia × V. rupestris ‘101-14’ (iron-inefficient). The grafted vines were grown in pots of a calcareous and a non-calcareous soil. The shoot growth was periodically checked and leaves, selected at two different times (at the middle of the annual growing period), were assayed for total chlorophyll, ferrous iron, ash alkalinity, percentage of dry matter and chlorosis score. At the end of the growing cycle the roots were oven-dried and weighed. The most significant findings of the trial were: (a) the soil strongly affected the shoot growth, with canes about twice as long in the non-calcareous soil; (b) the iron-efficient rootstock (‘140 Ru’) did not induce chlorosis when growing on the calcareous soil, while the opposite occurred with the iron-inefficient rootstock (‘101=14’); and (c) a high ash alkalinity occurred in light chlorotic leaves compared to green ones, under the same iron concentration.