Determining the pectinesterase enzyme activity when storing table grape varieties depending on the degree of ripening

Abstract

Grapes are rich in easily digestible carbohydrates, mineral compounds, vitamins, phenolic compounds. and other vital components. It is known that fresh grapes can be used from September to December. To prolong the terms of consumption of this valuable raw material, the most appropriate varieties and conditions for storing grapes have been determined. White, pink, and red grape varieties were taken as the object of research. The changes in the activity of the pectinesterase enzyme were determined depending on the degree of ripening of table grape varieties, the change in the pectinesterase enzyme during storage of table grape varieties in various variants was investigated. Statistical processing and calculation of variations in the indicators of changes in the activity of the enzyme pectinesterase were performed, depending on the degree of ripening of grapes of the Shamakhi Marandi variety. During the study, the pectinesterase enzyme remained more stable in mature varieties. This means that in ripe table grape varieties, the absorption of nutrients in the respiratory process is significantly slowed down. However, as they mature, the activity of the pectinesterase enzyme gradually increases. Therefore, for long-term storage in refrigerated chambers, fully ripe varieties of table grapes were used; to this end, grapes of the white Ganja table variety, the pink Shamakhi Marandi variety, and the red Black Asma variety are more suitable. The comparison of the investigated variants showed that table grape varieties, when stored in a refrigerated chamber in a controlled atmosphere, at 3–4 % CO2 and 2–3 % O2, retain better quality than other variants. When storing table grape varieties of various variants in the refrigerator, the enzyme activity decreases but is not completely suppressed.

Development of improved technology for the production of strong wines of marsala type on the basis of enzymatic catalysis

“…These variants, which are characterized by the course of most of the extraction processes under conditions of excess CO 2 and trace amounts of oxygen, are characterized by "moderate oxidation" of phenolic substances, which, however, are marked by enzyme preparations. The presence of cellulolytic preparations is apparently accompanied by accelerated oxidation and condensation of phenolic substances [23], as a result of which the level of phenolic substances in wine materials obtained with glucanex turned out to be minimal. The most promising is the preparation of mixed-type action -Vinozyme and PEC 1 (Table 1), in the presence of which the mass concentration of phenolic substances in the wine material exceeds the control by more than 50 %.…”

Improvement of technology for producing wine material for Tokaj wine

“…The content of methyl alcohol in wines prepared from white grape varieties was 0.22÷0.23 g/dm 3 , and in wines prepared from red grape varieties this figure was relatively higher -0.34÷0.37 g/dm 3 . This means that red grape varieties have higher pectin content than white varieties [30].…”

Determining biochemical qualitative indicators of grapes during long-term storage

“…As a result of research [13], it was found that table grape varieties are rich in nutrients necessary for the human body, mainly simple sugars, organic acids, phenolic compounds, minerals, and iodine. Before storing fully ripened grape varieties, it was established that the enzymes ascorbate oxidase, o-diphenol oxidase, peroxidase, and catalase in their composition are constantly active and change differently.…”