THE LACTIC ACID FERMENTATION OF THREE DIFFERENT GRAPE LEAVES GROWN IN TURKEY

Abstract

Leaves of three different cultivars of Vitis vinifera L., Ekşikara, Hesapali and Siyah pekmezlik were fermented in 10% brine and 10% brine + 1% citric acid concentration for 5 weeks. Percent dry matter, average weight, protein and dimethyl sulfide content of fresh leaves were determined. During the fermentation time, chemical properties of brine (titratable acidity, pH, salt content) were determined at certain intervals. Fresh leaves of Ekşikara had the highest amount of dry matter (31.69%), followed by Siyah pekmezlik (27.89%) and Hesapali (25.36%).The protein content of fresh leaves decreased approximately 50% as a result of the fermentation. Fermented Hesapali leaves had the highest (2,955 kcal/100 g), while Siyah pekmezlik leaves had the lowest (2,384 kcal/100 g) energy values. Ekşikara leaves in 10% brine + 1% citric acid had the lowest pH value (2.09), while Siyah pekmezlik had the highest pH value (2.57) on the fifth week of the fermentation. The highest titratable acidity was measured in Hesapali (10% brine + 1% citric acid). Hesapali leaves in both types of brine showed the highest taste scores, while Ekşikara leaves were preferred for their more acceptable odor. Siyah pekmezlik leaves are not recommended for brining as the fermented leaves of this cultivar obtained the lowest sensory scores.