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CNAA / Theses / 2019 / May /

Improving the technology of stabilization of white dry wines


Author: Hristeva Oxana
Degree:doctor of engineering
Speciality: 05.18.07 - Technology of alcoholic and non-alcoholic drinks
Year:2019
Scientific adviser: Nicolae Taran
doctor habilitat, professor, Practical Scientific Institute of Horticulture and Food Technology
Institution: Practical Scientific Institute of Horticulture and Food Technology

Status

The thesis was presented on the 24 May, 2019
Approved by NCAA on the 9 July, 2019

Abstract

Adobe PDF document1.23 Mb / in romanian
Adobe PDF document1.32 Mb / in russian

Thesis

CZU 663.221:663.252

Adobe PDF document 7.78 Mb / in russian
159 pages


Keywords

grape variety, white dry wines, physico-chemical composition, mass concentrations of phenolic substances and proteins, turbidity, stability to protein turbidity, bottling resistance, yeast race, auxiliary materials, stabilization of wines

Summary

"Improving the technology of stabilization of white dry wines", PhD thesis in technical sciences, Chişinău, 2019. The thesis consists of introduction, four chapters, conclusions and recommendations, bibliography with 176 references, 13 anexes, 115 pages of basic content, 34 tables and 11 figures. The results were presented in 14 scientific publications. Keywords: grape variety, white dry wines, physico-chemical composition, mass concentrations of phenolic substances and proteins, turbidity, stability to protein turbidity, bottling resistance, yeast race, auxiliary materials, stabilization of wines.

Field of study: engineering sciences and technology.

Goals and objectives of research. The main goal is to increase the stability of white dry wines on the basis of improving the technological regimes of their processing for stabilization against physicochemical turbidity. Objectives: To study the influence of the quality of the initial grapes, various technological regimes during their processing on physico-chemical parameters, and also the stability of the obtained wine materials to various turbidities. To investigate the effect of different fining agents used for wine processing and develop optimal technological schemes with their use to stabilize white dry wines. To develop and introduce in production at "CRICOVA" JSC new technological regimes for processing wine materials in order to stabilize them against physical and chemical turbidities and improved methods for testing wines for different turbidities.

Scientific novelty and originality. For the first time, studies on the change in the ampeloecological factors of grape growth for further stability of wines to protein turbidities have been carried out. It has been proven that the use of «Nobil Fresh» oak chips or the addition of "Tanin Galalcool" galicl tannin at the stage of grape processing allows us to exclude the use of tannin from the technological schemes of processing wine materials. It also proved the impact of the main physicochemical parameters of white dry wines on the processing of wines, as well as the doses of auxiliary materials necessary to stabilize wines against protein turbidities; and the temperature of white dry wine materials on the process of stabilizing wine against protein turbidities.

For the first time, was used a improved method of stability testing in white dry wines to protein turbidities based on the determination of turbidity as a result of a heat test with the addition of tannin.

A new method was used to determine the presence of pectins, colloids and other high-molecular substances in wort or wine materials. Scientific problem. The thesis has been solved the scientific problem of development and scientific justification of technological regimes of grape processing, preparation and processing of wine materials for production of white dry wines with predictable stability against protein turbidities which allowed to reduce expenses and the sinecost of finished product.

Theoretical significance and practicality applied value. A new technique for determining the stability of white dry wines to protein turbidities has been developed. An instruction has been developed to determine the stability of white dry wines to various turbidities and the effectiveness of auxiliary preparations for the stabilization of white dry wines to protein turbidities based on the determination of turbidity. New technologies have been developed for the processing of white dry wines with the use of the pectolytic enzyme preparation «Zymoclaire CG», as well as «Sil-Flok» silica.

Implementation of scientific results. White dry wines, tested according to the introduced method, have confirmed the stability to protein tubidities during the warranty period of storage (18 months). The samples of production batches of bottled finished products are stored in the warehouse of check samples of the „CRICOVA” JSC winery.

Were produced at "CRICOVA" JSC: