Valorization of algerian leguminous: extraction and characterization of galactomannans

Abstract

This study has an environmental objective based on the valorization of the seeds of legumes in order to obtain a clean nature, its seeds are considered as a good source of galactomannans which can replace other synthetic polysaccharides.They consists on the evaluation of physicochemical properties of galactomanans isolated from different seeds parts of two leguminous species widely known in Algeria: Gleditsia triacanthos and Ceratonia siliqua (carob), which represent an important source of polyscharids. The extraction gave an appreciable yield assessed at 12.97% of Gleditsia triacanthos and 11.45% of Ceratonia siliqua; values witch encourage their valorization. The physicochemical composition of the extracted galactomanans showed comparable characteristics in term of humidity; pH; °Brix and ashes. While; rheologic properties revealed that galactomanans solutions have a pseudo plastic nature. In the other hand; the functional properties analysis showed that the galactomanans obtained are soluble in water; the water absorption capacity was higher for Gleditsia triacanthos than Ceratonia siliqua with 20.62 and 5.98 respectively. Infrared analysis demonstrate that the same chemical structures of galactomanans were extracted from the two spices. NMR analysis allowed us to estimate the galactose / mannose ratio of the two extracts. This ratiois 1.25/1 and 3.63/1 of Gleditsia triacanthos and Ceratonia siliqua respectively