Dissertation for the degree of Doctor of Philosophy in the field of knowledge 18 “Production and Technology” in specialty 181 “Food Technologies”. – Odesa National University of Technology. – Odesa, 2026.
The dissertation is devoted to the theoretical and experimental substantiation of the use of oak alternatives in table wine technology. Traditionally, the formation of a complex aromatic and flavour profile of wines is associated with oak ageing; however, oak alternatives make it possible to achieve similar effects at lower cost and within a shorter production cycle. The relevance of the study is determined by the need for a scientific substantiation of the influence of oak alternatives on the physicochemical, phenolic, and sensory characteristics of wines.
The introduction substantiates the relevance of the research topic and defines the aim, object, subject, and objectives of the study. The scientific novelty of the work lies in establishing the patterns of influence of the toasting level, dosage, and form of oak alternatives on the formation of the phenolic, colour, and sensory profiles of Chardonnay and Merlot wines. The practical significance of the obtained results consists in the development of recommendations for the use of oak alternatives in the production of table wines.
The first chapter summarizes current scientific knowledge regarding the role of oak wood in wine quality formation. The main oak species, their chemical composition, and their influence on wine quality are analysed. The effects of wood seasoning and toasting on the formation of aroma-active and phenolic compounds are considered. Modern approaches to the use of oak alternatives are systematized, and their ability to provide an effect similar to barrel ageing is demonstrated, provided that the form, dosage, and toasting level are selected appropriately.
The second chapter presents the research programme and methodology developed to investigate the influence of oak alternatives on the formation of physicochemical and sensory parameters of Chardonnay and Merlot wines during alcoholic fermentation and ageing. The studies were conducted using oak alternatives with different toasting levels (UN, L, M, M+, H) and dosages ranging from 1 to 5 g/dm³. The research included the determination of oenological parameters, phenolic composition, ellagitannins, organic acids, and colour characteristics using standardized OIV methods, spectrophotometric techniques, and chromatographic analyses. Sensory evaluation was performed using the OIV 100-point scale, descriptive analysis, and profile analysis. Statistical data processing was carried out using analysis of variance (ANOVA) and the PanelCheck software.
The third chapter investigates the influence of oak ageing on the sensory characteristics of varietal wines from different wine-producing regions of Ukraine. Contact with oak wood was shown to improve tasting scores, aromatic complexity, and flavour harmony. The characteristics of oak alternative production using the “le Bousinage” technology are summarized, and the influence of wood heat treatment on the formation of phenolic and aromatic compounds is identified. It is demonstrated that the use of oak alternatives enhances sensory complexity, stabilizes colour, and enables controlled formation of the organoleptic profile of wines.
The fourth chapter presents the results of experimental studies on the influence of oak alternatives on the chemical and sensory profiles of Chardonnay and Merlot wines. Their application during fermentation did not disrupt process stability or significantly affect acid balance; however, it enhanced the extraction of phenolic compounds and increased the content of tannins and ellagitannins. Untoasted wood provided the greatest enrichment of the phenolic composition, whereas light and medium toasting levels resulted in the most harmonious sensory profile. During ageing, oak alternatives improved colour stabilization, aroma development, and wine structure. For red wines, their role in stabilizing anthocyanin–tannin complexes and increasing colour intensity was demonstrated.
Optimal parameters for the use of oak alternatives were determined: for wines produced from Chardonnay grapes, lightly toasted oak alternatives at a dosage of 2–3 g/dm³ are recommended; for wines produced from Merlot grapes, medium-toasted oak alternatives at a dosage of 3–4 g/dm³ are recommended. The use of oak alternatives was found to be an economically feasible solution that reduces production time and costs while increasing winery competitiveness.
Keywords: oak alternatives, table wines, alcoholic fermentation, wine ageing, phenolic composition, sensory analysis, aromatic profile, toasting level, Chardonnay, Merlot, economic efficiency.
