Fruit growing
and viticulture of South Russia

Annotation

Apple juice is one of the most popular drinks among the population. The content of physiologically valuable components is one of the most important indicators of juice quality. It is equally important to preserve the healing properties of apple juice during storage with the desirable use of natural preserving agents. An infusion of bracken fern can be used as a natural preserving agent. The objects of the study were apple juices of direct pressing, extracts of bracken fern. Generally accepted and instrumental methods were used for analysis. Experiments related to sensory analysis were carried out in the laboratory. As a result of the work, the composition of several variants of apple juices for preservation, in which fern extract was used, was studied. Fern extract was obtained using hydrochloric, malic, citric acids in molar concentration. It is established that the maximum content of biologically valuable substances is found in extracts of hydrochloric acid. Extracts obtained with malic and citric acids were used to study the canning process of experimental apple juices. It is shown that the use of fern extract with malic or citric acids in dosages of 0.025-0.1 % ensured the stability of apple juices during the guaranteed period of storage. The degustation of apple juices carried out by the expert commissionconfirmed the immutability of their taste characteristics. It was noted that the introduced fern extracts practically did not change the physico-chemical composition of the juice. As a result of experiments, the limiting amount of the dosage of fern extract was found, equal to 0.2 % of the juice volume, which begins to lead to a change in the taste characteristics of apple juice and lower its quality indicators.

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.