Extraction and characterization of chickpea (Cicer arietinum) albumin and globulin.

Albumin and globulin fractions of 1 Desi and 2 Kabuli varieties of chickpeas (Cicer arietinum) were extracted with water and salt solutions (K(2)SO(4) and NaCl). The extractable yields and particularly the albumin-globulin ratio varied greatly with the extraction medium and chickpea variety. Depending on the procedure employed, albumin could be extracted as a major fraction of chickpea proteins. Higher levels of essential amino acids and sulfur containing amino acids were found in albumins than in globulins of all chickpeas investigated. The common structural characteristics of both Kabuli and Desi chickpea albumins and globulins were clearly identified by densitometric profiles of their sodium dodecyl sulfate polyacrylamide gel patterns. Albumins contained subunits with higher molecular weights than those of globulins. The in vitro digestibility of the chickpea proteins by papain, pepsin, chymotrypsin, and trypsin indicated that globulins were more susceptible to proteolytic hydrolysis.