Changes in the chemical composition of apple juice during maturation and storage

The chemical composition of apples is not constant. It depends on a number of factors: variety, climate and weather, soil and fertilizers, on the degree of ripening, the size of the fruit, storage conditions, etc. less constant for certain periods of development of certain commercial varieties. One of the most important indicators by which the quality of processed raw materials and harvesting time is judged is the accumulation of dry substances in fruits, on which the efficiency and direction of biochemical processes, including juice fermentation, depend. Most of the dry matters contained in the fruits are carbohydrates - sugars, starch, cellulose, pectin. The aim of the work was to study changes in the chemical composition of apples in different phases of ripeness during ripening and maturation. The winter variety of apples Idared served as the objects of research. Studies of apple fruits in different phases of maturity show that the amount of phenolic substances in fruits decreases as they ripen. Studies conducted on the study of changes in organic acids in Idared apples during cold storage in a chamber showed that, regardless of the period of removal of apples, weight loss and the intensity of acid decay were the same. In more mature fruits, decay developed earlier. It was found that the decrease in titratable acidity is similar to the decrease in the content of malic acid. Studies of apple fruits in different phases of maturity show that the acidity and the amount of phenolic substances decrease as they ripen, while the sugar content increases. When pectin is dissolved, apples can become mealy and acquire a granular texture, which negatively affects the efficiency of juice extraction. During the storage of apples, aging of the fetus occurs, accompanied by a decrease in the molecular weight of proteins.