Variation in Organic Acid, Sugar and Phenolic Compounds in Fruits of Historical Apple Cultivars

Abstract

Knowledge about diversity of local apple cultivars is particularly important and helps to ensure that specific cultivars are available when and where farmers need them. The phenolic content, organic acids and sugars were investigated in the four historical apple cultivars ('Aslik', 'Cebegirmez', 'Bey Elmasi' and 'Arapkizi') grown in Van province, located in Eastern Anatolia, Turkey. In the study, ellagic acid (63.034 mg per 100 ml) was found to be higher than other phenolic compounds and followed by vanilic acid, caffeic acid and routine, respectively. When examined the apple cultivars, it has been found that the 'Bey Elmasi' cultivar has the highest content of six phenolic acids (chlorogenic, ferulic, o-coumaric, p-coumaric, catechin and quercetin). The organic acid contents were as follows: malic>fumaric>succinic>citric>tartaric among cultivars. 'Arapkizi' cultivar possessed the highest value of four organic acids except of tartaric acid. It was determined that fructose was the major sugar for all apple cultivars. There was a positive correlation among gallic, ellagic acid and routine. Similarly, the positive correlation was observed among malic, fumaric and succinic acid. However the negative correlation between citric acid and all sugars was observed. As a result, 'Bey Elmasi' and 'Arapkizi' cultivars with higher phenolic content, 'Arapkizi' cultivar with higher organic acid content and 'Aslik' cultivar with higher sugar content comes to the foreground. Results indicated the importance of local apple germplasm to use of them for future apple breeding activities to increase inner quality.