solubilization into the yogurt, probably due to the decrease of pH during storage (Stalikas, 2007), followed by major extraction in water. Statistically significant variations in procyanidin B1 and protocathechuic acid were found among the HS varieties at each sampling time. The lowest concentrations were detected in San Giovanni HS, whereas the highest were observed in Georgia HS. Statistically significant differences for gallic acid were found among the HS varieties at each storage time. The lowest concentration was detected in Georgia HS, while the highest was observed in TGT HS.
The highest rutin concentrations were detected at days 7 and 21 inyogurts with 6% San Giovanni HS, while the lowest were found in yogurts made with 3% San Giovanni and TGT HS (< LOQ).