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.
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, broken cells, pulp remains, stalks and seeds with high amount of phenolic compounds due to their poor extraction during the winemaking process. Anthocyanins, catechins, flavonol glycosides, phenolic acids, alcohols and stilbenes have been identified among the compounds present in grape pomace. In this study, antibacterial activity against different pathogens (Escherichia coli ATCC 25922, Candida albicansATCC 90028, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923) was evaluated and the relation with polyphenols content and antioxidant activity of grape pomace from selected grapes from Iaşi vineyard was studied. The grape pomace samples were obtained after the fermentation process from the 2017 harvest of Sauvignon Blanc, Traminer, Busuioacă de Bohotin, Cabernet Sauvignon, Merlot, Fetească Neagră and Fetească Regală grape varieties. The antioxidant properties were evaluated using the DPPH method, FRAP assay and Folin Ciocalteu method. The content of resveratrol was quantified using an HPLC method. Samples with antioxidant activity showed the highest phenolics content. This study reveals that grape pomace is a potential source of natural antioxidant agents. The pomace extracts were tested to establish the effects on Gram-positive and Gram-negative bacteria. The analysed samples exhibited insignificant antibacterial activity and the method requires optimization. Grape marc represents an important source of resveratrol and other bioactive compounds that could be a valuable source of antioxidants for further utilization in food and pharmaceutical industry.
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.