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 studied the influence of different fermentation conditions (200 hL tanks vs. 50 L glass demijohns) and various yeasts on the evolution of the main organic acids during alcoholic fermentation of “Aligoté” wines. The fermentation lasted 22 days and samples were collected daily. Laboratory analyses were quantified according to the International Organization of Vine and Wine recommendations. High-performance liquid chromatography for the identification and quantification of organic acids was used. The data showed the important effect of winemaking conditions on sugar consumption, density or acidity values, and sensory characteristics. Significant differences in organic acid concentrations (especially for tartaric acid) were obtained for all variants, depending on the fermentation conditions, inoculated yeast and the sampling moment. The quantities of most of the identified organic acids were generally significantly increased when glass vessels were used, compared to those fermented in tanks. Most organic acids concentrations were favored by lower pH and showed higher values at lower temperatures.
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 problem: consumer expectations are not met and there is a disloyal competition among wine producers in the field. Authenticity has been a priority research direction worldwide for centuries. Today, researchers are working on improving already existing methods of authenticity monitoring, but also on creating new ones. The intention is to have results that are as accurate, fast and inexpensive as possible for confirmation or rejection of the hypothesis. The bibliographic study of the literature undertaken for the development of this article aims to identify the classical methods of establishing authenticity, describe them and establish their degree of efficiency. Moreover, a review of the current research trends is presented in this work.
Over the past few decades, there has been a notable paradigm shift worldwide, affecting people’s preferences and decisions regarding both food and beverage options. These factors have sparked a newfound fascination among winemakers, wine enthusiasts, and consumers alike, as they explore the notion of reconnecting with a bygone era and embracing a lifestyle reminiscent of the past. “Orange” wine, a product derived from white grapes, encapsulates the intriguing allure of ancient winemaking methods that trace their roots back to Georgia. The method enables an elevated presence of phenolic compounds, which can have a favorable influence on the sensory characteristics of the wines or their behavior during oxidative processes. Given the scarcity of widespread knowledge, this overview aims to provide a comprehensive understanding of the historical evolution of winemaking and its various transformations over the years. It delves into the intricacies of winemaking technology, particularly focusing on the unique utilization of qvevri vessels. In addition to traditional sources, this review examines the influence of winemaking technology and the utilization of special vessels on the characteristics of “orange” wines. It explores the unique traits that develop in these wines as a result of prolonged maceration. By considering the impact of these factors, the review offers insights into the distinct qualities and attributes that emerge in “orange” wines during the winemaking process.
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 commercial yeasts (IOC FIZZ™, IOC DIVINE™, LEVULIA CRISTAL™, and IOC 18-2007™) on the volatile composition of experimental sparkling wines. For this, five sparkling wines variants from the Muscat Ottonel grape variety were obtained. The base-wine was obtained through reverse osmosis and had a predetermined alcoholic concentration (10.5% vol.). In order to fulfill the proposed purpose, the experimental sparkling wines were characterized by the physical–chemical parameters (according to International Organization of Vine and Wine methods of analysis), volatile fraction (using gas-chromatography coupled with mass spectrometry technique), and sensory descriptors. Data showed a key impact on the concentration of the volatile constituents (p < 0.05), depending on the type of inoculated yeast for the second fermentation. Regarding the sensory analysis, important differences can be observed due to the type of inoculated yeast. Only a minor influence on the physical–chemical parameters was registered.
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 amino acid concentration during the fermentation of Fetească regală and Sauvignon blanc wines. A total of 22 amino acids were quantified using an ultra-high liquid chromatography system coupled with mass spectrometry detection. Data indicated a major impact of the analysed variables (enzyme type and grape variety) on wine’s characteristics. Considerable amounts of some essential amino acids, such as histidine, isoleucine, phenylalanine, and tryptophan, were found in samples treated with pectinases preparations. The administration of pectinases was more effective in the Fetească regală wines in the applied work conditions, although the β-glycosides generated the highest values for most amino acids in the Sauvignon blanc. Pectinases can provide more acceptable sensory characteristics of wine compared to β-glycosides in the applied work conditions (when they are applied in the pre-fermentation stage), while these samples generally showed the lowest intensity for some negative descriptors, such as phenolic, mineral or a bitter taste.