Author
Kahlon, Talwinder | |
SHAO, QIMING - UC DAVIS, CA |
Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/16/2003 Publication Date: 4/1/2004 Citation: Kahlon, T.S., Shao, Q. 2004. In vitro binding of bile acids by soybean (glycine max), black eye bean (vigna unguiculata), garbanzo (cicer arietinum) and lima bean (phaseolus lunatus). Food Chemistry. Vol 86: 435-440. Interpretive Summary: The healthful potential of soy bean, black eye bean, garbanzo and lima bean was evaluated by determining their in vitro bile acid binding. Relative bile acid binding considering cholestyramine (a cholesterol lowering drug) as 100% bound, on equal dry matter, total dietary fiber and insoluble dietary fiber basis was soy bean 2, 10 and 12%, black eye bean 3, 21 and 25%, garbanzo 10, 68 and 80%, and lima bean 4, 19 and 23%, respectively. The difference in bile acid binding between various beans tested may relate to the variability in their phytonutrients (flavonoid, tannin, estrogenic content), non-protein composition, structure, hydrophobicity of undigested fractions, anionic or cationic nature of the metabolites produced during digestion or their interaction with active binding sites. Higher bile acid binding by black eye bean, garbanzo and lima bean than soy bean suggest that animal and human studies should be conducted to explore their potential for lowering blood lipids, lipoprotein and atherosclerosis risk and other healthful properties. Technical Abstract: The in vitro binding of bile acids by soy bean (Glycine max), black eye bean (Vigna unguiculata), garbanzo (Cicer arietinum) and lima bean (Phaseolus lunatus) was determined using a mixture of bile acids secreted in human bile at a duodenal physiological pH of 6.3. Six treatments and two blank incubations were conducted testing substrates on an equal protein basis. Considering cholestyramine as 100 bound, the relative in vitro bile acid binding for the soy bean, black eye bean, garbanzo and lima bean on equal protein basis was 6, 14, 47 and 17%, respectively. Relative bile acid binding on equal dry matter (DM), total dietary fiber (TDF) and insoluble dietary fiber (IDF) basis for soy bean 2, 10 and 12%, black eye bean 3, 21 and 25%, garbanzo 10, 68 and 80%, and lima bean 4, 19 and 23%, respectively. Except for garbanzo where values were much higher, bile acid binding by soy bean, black eye bean and lima bean appear to be related to their DM content. These results point to bile acid binding by garbanzo > black eye beans = lima beans > soy beans as indicative of their health-promoting potential. Incorporation of garbanzo, black eye and lima bean in diets should be encouraged. Data suggest that of all four kinds of beans tested, bile acid binding may be related to phytochemical (falvonoid, tannin, estrogenic content), anionic, cationic, physical and chemical structure, composition, metabolites, or their interaction with active binding sites. Higher bile acid binding by black eye bean, garbanzo and lima bean than soy bean suggest that animal and human studies should be conducted to explore their potential for lipid, lipoprotein and atherosclerosis risk lowering and other healthful properties. |