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United States Department of Agriculture

Agricultural Research Service

Research Project: KNOWLEDGE OF SOIL-PLANT-HUMAN FOOD SYSTEMS TO ENHANCE IRON AND ZINC BIOAVAILABILITY IN PLANT FOODS

Location: Plant, Soil and Nutrition Research

Title: Hydrolysis of soybean protein improves iron bioavailability

Authors
item Lv, Ying -
item Shuntang, Guo -
item Zhiqiang, Cheng -
item Glahn, Raymond
item Tako, Elad

Submitted to: Food and Nutrition Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 24, 2014
Publication Date: May 3, 2014
Citation: Lv, Y., Shuntang, G., Zhiqiang, C., Glahn, R.P., Tako, E.N. 2014. Hydrolysis of soybean protein improves iron bioavailability. Food and Nutrition Research. 2(4):162-166. DOI: 10.12691/jfnr-2-4-5.

Interpretive Summary: Iron is an important mineral in human body. Iron deficiency affects human health, especially pregnant women and children. Soybean protein is a popular food in Asia and can contain a high amount of iron (145.70+/-0.74 ug/g); however, it is usually reported as an inhibitor of iron absorption. In this study, the effect of hydrolysis (water separation) on iron bioavailability (absorption) of soybean protein was investigated in a cellular model. The result showed that hydrolysis of soybean protein significantly enhanced the bioavailability of extrinsically added iron. Also, infant formula containing hydrolyzed soybean protein (SPH) exhibited greater iron bioavailability than intact soybean protein based infant formula. Furthermore, the SPH was ultrafiltered to different sizes of SPH (<1 kDa), SPH (1-3 kDa), SPH (3-10 kDa), SPH (10-30 kDa), and SPH (>30 kDa); and intrinsic iron content of them, as well as the iron uptake by the intestinal cells, were shown increasing tendency with the increasing of molecular weight. However, when extrinsic iron was added, the SPH (<1 kDa) were presented with highest iron bioavailability. These results indicated that hydrolysis of soybean protein improves iron absorption, and some low molecular weight of SPH might play an important role.

Technical Abstract: Iron is an important trace metal element in human body. Iron deficiency affects human health, especially pregnant women and children. Soybean protein is a popular food in Asia and can contain a high amount of iron (145.70±0.74 ug/g); however, it is usually reported as an inhibitor of iron absorption. In this study, the effect of hydrolysis on iron bioavailability of soybean protein was investigated with an in vitro digestion/Caco-2 cell model. The result showed that hydrolysis of soybean protein significantly enhanced the bioavailability of extrinsically added iron. Also, infant formula containing hydrolyzed soybean protein (SPH) exhibited greater iron bioavailability than intact soybean protein based infant formula. Furthermore, the SPH was ultrafiltered to SPH (<1 kDa), SPH (1-3 kDa), SPH (3-10 kDa), SPH (10-30 kDa), and SPH (>30 kDa); and intrinsic iron content of them, as well as the iron uptake by Caco-2 cells, were shown increasing tendency with the increasing of molecular weight. However, when extrinsic iron was added, the SPH (<1 kDa) were presented with highest iron bioavailability. These results indicated that hydrolysis of soybean protein improves iron absorption, and some low molecular weight of SPH might play an important role.

Last Modified: 8/1/2014
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