THE INFLUENCE OF STORAGE CONDITIONS UPON ASCORBIC ACID CONTENT IN JONATHAN AND GOLDEN APPLES

摘要

In this work it has searched the influence of storage conditions upon ascorbic acid content, in Jonathan and Golden apples. The study of ascorbic acid content and pH evolutin for 16 weeks has been carried out using, as biological material, apple samples from Jonathan and Golden varieties, coming from the orchards in the area of F?lticeni. The apples were kept in containers of glass and wood, constituting, for each sample, variants of experiences, in the presence and in the absence of oxygen, at following thermal thresholds: 4°C, 8°C and 15°C. In order to keep the apples in the presence of oxygen, they were placed in wooden boxes. To store apples in an oxygen-free environment, it used glass containers where the fruits were introduced along with a small candle lit, and then the lid of the container was tightly closed. The extinguish of the candle has confirmed that the oxygen in the container was used. The chemical investigations have been carried out on freshly harvested material (week 0) and then every two weeks, for a total of 16 weeks. At the end of the analysed interval (after 16 weeks of storage), the ascorbic acid content has registered different rates of diminution, depending on storage temperature and length, as well as on variety (sucrose concentration and pH). The lower degradation of ascorbic acid in apples from Golden variety, during storage, is due both to higher sucrose content of those ones, and to higher pH values compared to apples from Jonathan variety.