Qualitative and Quantitative Characteristics of the Grapes of Different Biotypes of Grapevine Cultivar Assyrtiko in Santorini

The aim of the present study was to assess the qualitative and quantitative characteristics of the grapes and berries of seven different biotypes (A1–A7) of grapevine cultivar Assyrtiko, cultivated in Santorini. All biotypes of grapevine cultivar Assyrtiko are cultivated in the same soil and climatic conditions in the area of Akrotiri. Grapes from the different biotypes were collected during technological maturity. In the must of all samples, the following measurements were carried out: total soluble solids concentration, active acidity (pH), and total titratable acidity. Also, mechanical analyses of the grapes and berries of all the biotypes under study were performed. Moreover, using a spectrophotometer, the content of grape’s skin in total phenolics, condensed tannins, total ortho-diphenols, total flavonoids, total flavanols, total flavonols and flavones, and their antioxidant capacity with the use of FRAP and DPPH methods were quantified, while high-performance liquid chromatography (HPLC) identified the most important individual acids and individual sugars. The same measurements were also carried out for the grape seeds. The results of the present study revealed the effect of the biotype both in the qualitative and the quantitative characteristics of grape cultivar Assyrtiko, with statistically significant differences being observed among the different biotypes.