Determination of Chemical Composition of Carob (Ceratonia siliqua): Protein, Fat, Carbohydrates, and Tannins

Carob pod, germ, and seed were analyzed for moisture, ash, protein, fat, carbohydrates, and particularly for their tannin content. Recovery of tannins as affected by various solvent extraction systems was investigated. Carob pod meal contained high levels of carbohydrates (45%), appreciable amounts of protein (3%), and low levels of fat (0.6%). Germ and seed meal contained more fat and less carbohydrates compared to the carob pod. Seventy percent acetone was the most effective solvent for the extraction and recovery of tannins. Carob pod contains a mean value of 19 mg of total polyphenols/g, 2.75 mg of condensed tannins (proanthocyanidins)/g, 0.95 mg of hydrolysable tannins (gallo- and ellagitannins)/g. Germ contained higher concentration of total polyphenols (40.8 mg/g) and tannins (16.2 mg of condensed tannins/g and 2.98 mg of hydrolysable tannins/g) while only traces of these compounds were detected in carob seed.