effects on kefir properties and antioxidant activity during 4 weeks cold (4 °C) storage. Carob flours differed in composition, mucilage yield, antioxidant activity and phenolic components analyzed by HPLC. Bacterial count increased during the first week of kefir storage with carob supplementation stimulating bacterial growth similar to inulin. Bacterial viability and titratable acidity of carob supplemented kefir increased, whereas pH decreased during storage. The antioxidant activity of kefirs generally increased during storage attaining maximum level at 14 days with the supplemented kefirs exhibiting higher activity compared to the control plain kefir.