Valeriu Cotea

Valeriu Cotea
Iasi University of Life Sciences (IULS) · Horticultural Technologies

PhD

About

173
Publications
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493
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Publications

Publications (173)
Article
Wine’s chemical structure is affected by many biochemical transformations during the winemaking process, which are catalysed by specific enzymes. These compounds participate in the formation of amino acids, which also have fundamental functions in the sensory quality of wine. Therefore, this research focuses on monitoring the effect of enzymes on a...
Article
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Botrytis cinerea is a necrotrophic fungus that affects over 200 plant species. In vineyards, this pathogen is responsible for one of the most important diseases, commonly known as botrytis bunch rot or grey mould. Keeping infection under control with synthetic fungicides leads to an increased biological resistance of pathogen populations. An altern...
Article
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The present study evaluated the chemical composition and the in vitro and in vivo antioxidant potential of Ammi visnaga L. essential oil to provide a scientific basis for the use of this plant in the traditional pharmacopoeia. Gas chromatography-mass spectrometry was used to identify the volatile constituents present of the oil. The in vitro antiox...
Article
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Two wild-type Saccharomyces cerevisiae yeast strains (Sa and Sb) were tested for white wine production using Assyrtiko grape of Santorini. A third commercial Saccharomyces strain was also studied for comparison reasons. Two concentrations of yeast extract and diammonium phosphate (DAP) were added to the must (150 and 250 mg/L) in order to evaluate...
Article
Unfavourable trends have been identified in the evolution of climate factors (temperatures, precipitation, etc.) over the past years, with a direct impact on the vegetative and productive potential of the vine. This calls for a reassessment of climate resources and the adaptation of cultivation technologies to the new conditions. Our paper analyses...
Article
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Organic acids represent naturally occurring compounds that are found in many types of food and beverages, with important functions in defining products’ final quality. Their proportions in wine are dependent on grape composition and winemaking conditions (temperature, pH levels, oxygen, and carbon dioxide concentration). Therefore, this article stu...
Article
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Excessive alcohol consumption has many negative effects on human health and society itself. Climate change and the improvement of viticultural technologies have gradually led to an increase in the alcoholic concentration of wines, a trend that has become contrary to the current requirements of consumers inclined to a healthy diet. The aim of the st...
Chapter
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Grapevine (Vitis vinifera L.) represent an important crop, being cultivated in 2018 on 7.4 million hectares worldwide, and with a total production of 77.8 million tonnes. Grapes are susceptible to a large number of fungal pests and insects that may cause important economic losses, reduction of quality and undesired sensory characteristics in wines....
Article
Wine contamination with heavy metals may pose long-term human health risks and environmental damages. This study evaluated the frequently detected heavy metals (HMs): Cr-Chromium, Fe-Iron, Cu-Copper, Mn-Manganese, Ni-Nickel and Zn-Zinc in the winemaking stages of white (Grasă de Cotnari) and red (Fetească neagră) wine varieties. Samples from wines...
Article
Grapes, the quintessential quality factor in winemaking, are found in certain areas of the globe where viticulture thrives. The quality of wine products is directly influenced by the quality of the grapes, their process technology, the care and the quality of the premises and equipment used, as well as the conditions for the storage and use of the...
Article
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In this study, a complete physical–chemical analysis was performed for Fetească neagră wine, aged with oak staves. Red wine samples were taken from grape varieties grown in Northeast Romania and produced during 2013 vintage. At the end of the fermentation process, four oak mini staves (1 cm width × 10 cm length × 1 cm thickness) from heavy toasted...
Article
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The aim of this work was to examine the potential of High Pressure (HP) technology as an alternative technique for red wine preservation, focusing on the production of reduced SO2 wines while simultaneously adding glutathione (GSH), as a natural antioxidant. Selected quality parameters of red wine samples from Mouchtaro grapes, treated by HP under...
Article
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Authenticity and the methods for determining fraud are two of the most important issues in the field of quality control and food safety. In the winemaking field, the study of authenticity is all the more necessary, with wine being one of the most adulterated foods, as the monthly reports of the European Commission show. This results in a two-fold p...
Article
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Abstract: The occurrence of aroma constituents in sparkling wines, with direct impact on their organoleptic characteristics, is affected by several factors, for example the base-wine particularities, grapes cultivar conditions, inoculated yeasts, the aging stage, and wine-making practices. This study evaluated the influence of different four commer...
Preprint
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Sparkling wine producing and consumption are in constant increase in the last decade and show no sign of slowing. Prior consumption, origin, grape variety, occasion, price and sensorial perception are factors that typically influence wine consumers’ purchasing and consumption behavior. The presence of volatile compounds in sparkling wines, with dir...
Article
The aim of this study is to monitor the evolution of the principal phenolic compounds throughout the fermentation stage of white wines treated with different enzymes. The effect of five commercial enzymes on the evolution of the phenolic profile during the alcoholic fermentation of white wines obtained from Fetească regală and Sauvignon blanc varie...
Article
Expert winemakers demand an objective methodology based on the volatile metabolome that provides a scientific basis for technology enhancements. In this study, thirty-seven volatile metabolites are quantified in nine wines: one obtained by spontaneous fermentation and eight by using pure starter cultures of eight different Saccharomyces cerevisiae...
Article
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The influence on aroma compounds chips or staves and toasting degree have been analyzed in red wines aged for two periods of time. Ethyl propanoate, ethyl butanoate, ethyl octanoate, ethyl acetate, isoamyl acetate, isobutanol, 2-methyl-1-butanol, 2-phenylethanol, E-2-hexenol, octanal, nonanal, decanal, γ-nonalactone, furfural, 5-methylfurfural, 2-m...
Article
Full-text available
Wine aroma plays an essential role and can be considered one of the most important attributes of the overall wine quality. Generally, aroma is a remarkable complex chemical matrix comprising compounds from various chemical classes (alcohols, esters, acids, aldehydes, lactones, phenols, terpenes, ketones, norisoprenoids, etc.). Although some studies...
Article
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Many modern alcoholic beverages are subjected to ageing processes during which compounds extracted from wood contribute decisively to the overall beverage character. Wines represent a perfect example of beverage in which ageing is a crucial technological manufacturing step. During winemaking, producers accelerate chemical changes in wine compositio...
Article
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Heavy metals in beverages can constitute serious problems to human health. Consumption of wine may contribute to the daily dietary intake of pollutants, especially of toxic (heavy) metals. These compounds are also known as priority pollutants due to their potential toxic effects, if concentrations are not kept under allowable limits. Many character...
Article
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Byproducts obtained after wine production constitute an important source for the extraction of antioxidant compounds. Phenolic compounds showed a wide spectrum of biological actions for the human health, often associated with neuroprotective, cardioprotective, antimicrobial and other health-related effects. The aim of the present study was to deter...
Article
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Romania has a long tradition regarding the production of wine rustically or household products. Each householder has the possibility for making its own wine from its own grape vines. Most of them are made and kept using almost no interventions or treatments no corrections or added substances, which could protect them from eventual diseases, which m...
Article
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Astringency is a parameter of great importance for wine quality. During wine maturation in wooden barrels it can be enhanced by tannins extracted by the wood. However, their concentration is not directly correlated with astringency. Mean Degree of Polymerization (mDP) is often employed to characterize the structural characteristics of tannins in wi...
Article
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The use of antioxidants and antibacterials in food industry has become increasingly necessary to ensure the high quality of food. Grape pomace is the main by-product of winemaking industry that concentrates bioactive metabolites with more studied antioxidant activity and possible antibacterial activity. The grape pomace contains fragmented skin, br...
Article
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Most biochemical reactions involved in the wine-making process are catalyzed by enzymes. The use of enzymes of exogenous origin in wine production is due to the numerous technological and economical advantages demonstrated over time in the winemaking process. Understanding the important role played by enzymes in wine making technology contributes t...
Conference Paper
Background: Wine may be an important source of human exposure to mycotoxins [1], of which aflatoxins represent biological risk factors for the public health by considering their nephrotoxic, hepatotoxic, teratogenic and carcinogenic action. The best methods for reducing mycotoxins contamination of the wines consist in efficient preventive control m...
Article
Background: Wine may be an important source of human exposure to mycotoxins [1], of which aflatoxins represent biological risk factors for the public health by considering their nephrotoxic, hepatotoxic, teratogenic and carcinogenic action. The best methods for reducing mycotoxins contamination of the wines consist in efficient preventive control m...
Conference Paper
Wine aroma plays an essential role and can be considered one of the most important attribute of the overall wine quality. Generally, aroma is an remarkable complex chemical matrix comprising compounds from all chemical classes (alcohols, esters, acids, aldehydes, lactones, phenols, terpenes, ketones, norisoprenoids, etc.). Nevertheless, the composi...
Article
Aroma compounds represent an important part in the final wine quality; therefore wine scientists are continuously looking for alternative techniques to handle this aspect. Current techniques include the use of oak staves, which produce chemical and sensory properties similar to those of oak wood barrels. The effect of this technique on the major vo...
Article
Full-text available
Red wines maturation is considered a crucial stage of refinement, in which a series of physical, chemical and biological transformations take place, which improve wines stability and also modify the compositional and organoleptic characteristics. Research related to this paper was conducted in order to study the effects of different maturation proc...
Article
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Nowadays the clarification and stabilization of red wines is generally done with conventional fining agents, like bentonite and activated coal, which pose a major challenge to environmental security and wastes management. This stimulated the use of many new techniques in order to discover alternative fining agents that don’t have negative influence...
Article
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There is an increasing interest in the food industry and in protective health care for the expansion of natural antioxidants from plant materials. The solid wastes generated by the winemaking industry represent about 30% of the material used and it consists mainly of grape pomace (containing seeds, pulp, stem and skin). It is well known that high q...
Article
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Mesoporous nanomaterials were used to prevent protein haze in Muscat Ottonel and Pedro Ximénez wines. Major volatile compounds, polyols and turbidity were analyzed in fined wines and the results were compared with untreated and fined with bentonite wines. Two commercial mesoporous nanomaterial labelled as SBA-15 and MCM-41 provided a notable turbid...
Article
Volatile aroma compounds of Fetească neagră wines, aged for 1.5 and 3 months in oak barrels with different toast degree, have been analyzed using stir bars sorptive extraction and gas chromatography coupled to mass spectrometry. Principal components analysis of the volatile aroma permits wine differentiation according to the toast degree of the bar...
Article
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The distillates obtained from wine, both raw and aged, are highly appreciated alcoholic beverages due to the refinement and fineness that characterizes them. Romania’s viticultural conditions are very favourable for these products - which in the last centuries have made regions such as Cognac and Armagnac in France famous. In Romania the aged disti...
Article
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Free radicals have an important role in food and in chemical material degradation, contributing to the occurrence of many human health problems, but the antioxidants can considerably delay or prevent the oxidation of easily oxidable substrates. The present research aimed to assess the antioxidant activity, expressed by the presence of polyphenols,...
Article
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‘Fetească regală’, the most cultivated white Romanian grape variety produces elegant wines with flowery notes and white fruits (especially apricot and citrus) hues, with a good acidity. Its volatile profile (esters, terpenes, higher alcohols) and phenolic compounds are of great interest to the wine industry, especially regarding the influence pre-f...
Article
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This paper’s objectives were to determine the anthocyanic extraction level and their distribution by correlating the total phenolic content with different thermic maceration techniques applied to ‘Merlot’ grapes. In this study, three maceration processes were employed: thermoflash maceration (thermobaric), thermomaceration, and also classical macer...
Article
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https://www.bio-conferences.org/articles/bioconf/abs/2017/02/bioconf-oiv2017_01026/bioconf-oiv2017_01026.html
Article
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Austenitic stainless steel alloys are used in different food industry applications, including the preparation and storage of acidified carbonated soft drinks. Yet, austenitic stainless steels are not inert materials in contact with these drinks, and eventual modifications of these alloys must be investigated. Three carbonated soft drinks were inves...
Conference Paper
This paper proposes an overview of the main rituals using wine in the traditional Orthodox Church Eucharistic services in order to explain their usefulness/efficacy/benefits in terms of scientific observations. Sacramental/communion/monastic wine is used in all main rituals of the traditional, Orthodox liturgy. Monasteries produce wine within the s...
Article
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The main objective of the present study is to evaluate the influence of the maceration techniques on the volatile and phenolic compounds content of the wines obtained from an autochthonous aromatic variety from Romania. For this study, a pink biotype of the Busuioacă de Bohotin variety from the Huşi vineyard was used. The wine samples were obtained...
Article
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Eight wines of Pinot gris and five wines of Sauvignon blanc obtained by fermenting grape juices from PGI Dealurile Olteniei with different commercial selected yeast strains and with indigenous microbiota were compared in terms of sensorial characteristics and their composition in minor volatile aroma compounds. An easy handle methodology with dynam...
Article
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Wine is defined as an alcoholic beverage resulted from fermentation of grape must, having ethanol content higher than 8.5% (v/v). Wine consumption has health benefits related to the high concentration of polyphenolic compounds with antioxidant activity and cardiovascular protection effects. However, the alcohol content restricts wine consumption, b...
Article
Full-text available
According to the latest statistics, grapes are one of the largest fruit crops worldwide. In this regard, it is important to consider all factors influencing quality of grapes and wine. In the last years, scientist focused on the study of mycotoxins that can influence the quality of wine. It is considered that toxins produced by moulds, causing sign...
Article
Full-text available
This work is focused on the study of the influence of different strains of yeasts on the concentration of organic acids, metallic content, and other physical-chemical parameters from experimental sparkling white wines produced by traditional method (bottle fermented). This study was required due to climatic conditions varying from year to year, gen...
Article
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Alternative oenological practices are a key factor in sustainable winemaking. The influence of 6 types of chips with different toasting degrees on chromatic parameters, phenolic families and antioxidant activity of Fetească neagră wines has been studied. Brownish hue was highly influenced by the aging time and increased the most in wines treated wi...
Article
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Innovative oenological products and techniques constantly need to be optimized in order to produce high quality wines that are able to fulfill the demanding consumers, with a pleasant colour, astringency, bitterness and a balanced organoleptic profile. New mesoporous materials with viability and environmental safety characteristics, might be a feas...
Article
Full-text available
Aging process in winemaking is a crucial component in defining the quality of resulted products. In the last years alternative practices (oak chips) started to become more useful, due to their benefits. In this paper we study the impacts of various oak chips on the red wines enological parameters and phenolic compounds. Fetească neagră variety grap...
Article
Wine is a product resulting from the crossing of the conditions offered by plantation and the different treatments applied by winemakers in the wine making process. The present study has evaluated the influence of pre- fermentative treatments on the physical- chemical and chromatic features of the analyzed wines, and it was also observed the differ...
Article
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The present study evaluates the influence of some pre-fermentative treatments on the volatile content, the chromatic parameters, the total polyphenol index and Folin-Ciocâlteu index of experimental wines obtained from Fetească albă grape variety. Five experimental samples were produced: FA V0 (control sample), FA V1 (sodium bentonite treatment), FA...
Article
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The aim of this paper is to investigate new possibilities of using carbon based materials in winemaking technology. In this study, Cabernet Sauvignon wine was treated with following materials: graphene (G), graphene oxide (GO) and carbon nanotubes (CNTs). The total polyphenols content expressed as mg of gallic acid showed that carbon based material...
Article
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Nanotechnology is a rapidly evolving field of research with many potentially applications, such as advanced chemistry, medicine, energy production, as well as the food and wine making industry. The aim of this paper is to study the influence of mesoporous materials (MCM-41, SBA-15 and KIT-6) on the white wines physical-chemical parameters, turbidit...