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CNAA / Theses / 2016 / July /

The influence of physico-chemical factors on the complex stabilization of young wines


Author: Covaci Ecaterina
Degree:doctor of chemistry
Speciality: 02.00.04 - Physical chemistry
Year:2016
Scientific adviser: Gheorghe Duca
doctor habilitat, professor, Moldova State University
Scientific consultant: Rodica Sturza
doctor habilitat, professor, Technical University of Moldova
Institution: Institute of Chemistry of the ASM

Status

The thesis was presented on the 5 July, 2016
Approved by NCAA on the 6 October, 2016

Abstract

Adobe PDF document1.23 Mb / in romanian

Thesis

CZU [50044.36:50044.36]:663.2(043.2)

Adobe PDF document 5.25 Mb / in romanian
150 pages


Keywords

physico-chemical factors, complex stabilization processes, tartrate precipitation, protein absorption, young wines

Summary

The thesis consists of introduction, four chapters, general conclusions and recommendations, bibliography with 217 sources, 11 annexes, 115 pages of main text, 46 figures, and 22 tables. The obtained results are exposed in 11 articles, 8 abstracts and two national invention patents.

Field of study: 144.01 – Physical chemistry

The aim of the research was to establish the type and the nature of the processes, to calculate the variation of thermodynamic and kinetic parameters in the process of proteins sorption and tartaric salt precipitation, as finality the optimal conditions for complex stabilization of white and red young wines were established. Proposed objectives: investigation of colloidal and crystalline stabilization through the prism of kinetics and thermodynamics, in aim to elucidate the type and the nature of processes that occur; to establish the influence of applied temperature, stabilization procedures, pre-fermentatives and conditioning operations to the physico-chemical and stability parameters changes in young wines; mathematical processing of the experimental data to establish general regression equations that describe the studied processes under the influence of determinant factors.

Novelty and scientific originality lies on the elucidation of physico-chemical factors that influence the complex stabilization of young wines. For the first time, was determined the change of thermodynamic and kinetic parameters in processes of proteins sorption and tartaric salt precipitation in a real system as young wine. It was possible, for the first time, to develop a sulphitation agent based on potassium metabisulphite that keeps the crystalline stabilization of wines and present a low toxicity level to human body. Results of the study allowed, for the first time, development and testing two technological schemas of wines complex stabilization in practice at a wine factory.

The solved scientific problem consists in the scientific argumentation of complex stabilization schemes recommended for young wines by minimum technological operations. The establishment of the thermodynamic and kinetic parameters variation during stabilization, study of the biochemical and colloidal changes that occur in this process allowed to elucidate the influence of physico-chemical factors on the quality and specific characteristics of young wines.

The theoretical significance and practical value of thesis is based on establishing the influence of temperature, production schemes, stabilization processes and chemical inhibitors on the stability of young wines, which allowed identifying the optimum for obtaining stable and quality young wines. Recommended technological processes may be applied to wineries without reguiring special equipment and the reuse of tartar collected in winemaking solved global environmental problems. The mathematical model of white and red wines complex stabilization was developed.

Implementation of scientific results was done at „Cricova” S.A. winery on seven young wine lots in a total volume of 17 thousand dal through complex stabilization schemes developed in the study, during December 2014 – January 2015.