Fruit growing
and viticulture of South Russia

Annotation

The problem of using the grape pomaces from grape varieties of Merlot and Cabernet Sauvignon is discussed in the article. Experiments on extraction of biologically active substances and anthocyanins from sweet and fermented pomace by water and solutions of hydrochloric acid have been carried out. Data on the qualitative and quantitative composition of extracts of grape pomace were obtained. It was established that the content of acetic acid should be considered as the determining criterion for the quality of extracts from the pomace of red grapes. For the quality of the fermented pomace, also the ethanol content has a certain value. Extraction of extractive substances of various classes, and especially of potassium, magnesium, calcium, tartaric acid, significantly increases when using an acidic medium during extraction of sweet or fermented pomace. The applicability of the proposed extraction method for dry pomace is evaluated. The obtained results of the research confirm the possibility of using grape pomace of red grape varieties as a raw material for obtaining an extract enriched with various biologically valuable components. It is recommended to concentrate water extracts obtained from fermented grape pomace in order to ensure their stability. Extracts did not exceed the maximum permissible concentration limit for toxic metals. The extracts obtained had a saturated red color in a slightly acidic medium, which suggests their use as a corrective natural dye in the technology of functional or non-alcoholic beverages.

Annotation

Evaluation of grape resistance to low negative temperatures is relevant in connection with the increasing climate instability in the Anapo-Taman viticulture zone. An important metabolite associated with resistance to low temperatures is ascorbic acid. The purpose of this work is to conduct a comparative study of grape varieties of different ecological and geographical origin in terms of the dynamics of ascorbic acid content in the autumn-winter period and to identify varieties with increased resistance to low temperatures in terms of this indicator. The objects of research are grape varieties of various ecological and geographical origin: Kristall (control) � Euro-Amur-American origin; Krasnostop AZOS, Dostoynyi � Euro-American origin; Vostorg � Amur-American origin; Zarif � Eastern origin; Aligote � Western European origin. It was found that during t he autumn-winter period in the buds of grapes there was an accumulation of ascorbic acid. Its greatest increase was noted in the varieties Dostoynyi and Krasnostop AZOS � 3.6 and 3.9 times, respectively, in other studied varieties, this increase was 1.2-2.9 times. After artificial freezing, the least damage of cell membranes, determined by the accumulation of malondialdehyde (MDA), was noted in the Krasnostop AZOS variety � an increase in the content by 1.09 times. The varieties Kristall and Dostoynyi were next in terms of resistance � an increase in the level of MDA by 1.15 and 1.36 times, respectively. In other studied varieties, identified as unstable, this increase was 2.2-2.93 times. In varieties Krasnostop AZOS, Kristall, Dostoynyi after freezing, the content of AA increased � by 6.7-9.6%, i.e. ascorbic acid played the role of a low molecular weight antioxidant in suppressing the development of oxidative stress. According to the content and accumulation of ascorbic acid in the buds, the Krasnostop AZOS variety was identified out as the most resistant to extremely low temperatures. Next in terms of resistance were the varieties Dostoynyi, Kristall. The content of ascorbic acid in grape buds can be used as a diagnostic criterion in the selection of frost-resistant varieties for breeding purposes.