# A Preliminary Study on the Potential of the New Red-Fleshed 'JB' Clone Apple for Cider Production
## 3 Results and Discussion
Comparing these findings with the results obtained in the study of the new clone 'JB', it can be concluded that it had a relatively low total sugar content. However, the proportion of fructose was high, exceeding the literature-reported average. According to our study, the glucose content was also very low--only 0.63 g/L higher than in juice from the 'Florina' cultivar, which had the lowest glucose content. Similarly, the sucrose level was only 4.43 g/L higher than in the 'Karmina' cultivar. [PERSON] et al. [33] compared the sugar content of apple juice (results obtained by liquid chromatography, HPLC) from 12 different cultivars. The publication included the average concentrations of sucrose (25.56 g/L), glucose (24.27 g/L), fructose (70.32 g/L), sorbitol (3.55 g/L), and total sugars (123.70 g/L). Comparing these data with our findings on the new apple cultivar, it can be seen that the average concentrations of sucrose, glucose, and fructose differ from those reported in the study. However, in both studies, fructose is the predominant sugar in apple juice, while glucose is the least abundant. The total sugar content determined by the DNS method and the value measured using the Megazyme test were below the literature-reported average (123.70 g/L) but did not deviate significantly from this value. These differences may result from the lack of sorbitol determination for the red-fleshed cultivar or differences in the analytical methods employed. It was observed that the sugar content in the juice from apples of the red-fleshed clone 'JB' was slightly lower than in the juices of the other cultivars examined in the cited studies. Based on the aforementioned literature sources, it can also be concluded that this new cultivar is characterized by a high fructose content and a low glucose content. Active acidity (pH) is one of the most important distinguishing features of the quality of fresh juices, as it influences the biochemical reactions occurring within them. In apple juices, pHs usually range from 3.0 (cultivars containing a high amount of acid) to 4.5 (less acidic cultivars) [13]. In contrast, the must from the new red-fleshed cultivar exhibited significantly lower active acidity, measured at 2.53 \(\pm\) 0.00 (Table 2). [PERSON] et al. [29] determined the pH of eight apple juices from the following cultivars: 'Delicious', 'Golden Delicious', 'Ralls', 'Fuji', 'Qin Guan', 'Jonagold', 'Granny Smith', and 'Orin'. They obtained the following results: 4.15, 3.79, 3.59, 3.91, 4.16, 3.40, 3.82, and 4.12. Juice squeezed from apples of the red-fleshed clone 'JB' had an even lower active acidity. However, this does not preclude its use in juice or cider production due to its other quality parameters and sensory attributes. [PERSON] et al. [34] determined the pH of freshly pressed juices made in a laboratory from raw materials stored in a cold room (at temperatures ranging from 1.6 to 2.2 \({}^{\circ}\)C) with a controlled atmosphere. Eight apple cultivars--'Boiken', 'Elise', 'Gloster', 'Golden Delicious', 'Idared', 'Jonagored', 'Ligol', and 'Pinova'--were analyzed from the 2011-2012 harvest season. The lowest pH was obtained in juice from 'Boiken' apples (2.51), while the highest was recorded in 'Ligol' apple juice (3.58). The active acidity of the red-fleshed cultivar juice analyzed in this study (2.53) closely resembles that of the 'Boiken' cultivar, differing by only 0.02 units. Summarizing the above literature data, it can be concluded that the studied juice from the red-pulp cultivar has a very low active acidity compared to apple juices from other cultivars; only the juice from the 'Boiken' cultivar had a similar value. Acidity is a significant characteristic of apple juice and should be measured. It mainly affects taste. The total acidity of the juice from the new cultivar was 8.78 \(\pm\) 0.05 g/L in terms of malic acid, so it was high (Table 1). In ciders, excessively low acidity can result in a lack of freshness, while excessively high acidity makes the beverage harsh, too pronounced, and unpleasant.