THE EFFECTS OF DIFFERENT ALTITUDES ON THE PHENOLIC CONTENTS AND ANTIOXIDANT ACTIVITIES OF SOME WHITE GRAPE (Vitis Vinifera L.) VARIETIES
Turkey is one of the most suitable places for viticulture in the economic sense with its climate conditions, soil properties and location. This study aimed to present the phenolic profiles of the seeds of 5 different table grape varieties grown at different altitudes (800 m, 1000 m and 1200 m) and the relationship of these phenolic contents with antioxidant activity, as well as determining the effects of the different altitudes on the values obtained at the end of the study. A high-performance liquid chromatography device (HPLC-UV, Shimadzu) was used to analyze the phenolic compounds of the grape seeds, while antioxidant activity (radical scavenging activity (DPPH)) was measured with a spectrophotometer.
According to the results we obtained, as altitude increased, phenolic acid quantities increased, while it was determined that, among the studied phenolic compounds, the quantity of vanillic acid was found to be higher than the quantities of caffeic and ferulic acids (p<0.001). DPPH, which is a marker of antioxidant activity, was directly proportional to the increase in altitude (p<0.001). In this study, it was shown that the phenolic contents of the seeds of grape varieties grown at different altitudes varied based on the varieties and the altitudes, and based on this chance, antioxidant activity was also positively affected.