ARS | Publication request: IN VITRO IRON BIOAVAILABILITY AND ANTIOXIDANT ACTIVITY OF RAISINS

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 31, 2002
Publication Date: February 1, 2003
Citation: Yeung, C.K., Glahn, R.P., Wu, X., Liu, R.H., Miller, D.D. 2003. In vitro iron bioavailability and antioxidant activity of raisins. Journal of Food Science. 68(2):701-705.

Interpretive Summary: Iron bioavailabilities and antioxidant activities of three common generic raisin types, Golden Thompson, Dipped Thompson and Sun dried Thompson, were quantified and compared. Iron bioavailability was assessed with a simulated digestion/cell culture model. Antioxidant activity of the raisins was also determined. Iron bioavailability from the raisins was low for all three raisin types, indicating high levels of iron absorption inhibitors in raisins. Furthermore, these high levels of iron uptake inhibitors may inhibit iron availability from other sources consumed simultaneously with the raisins. Antioxidant activity was significantly higher in Golden Thompson than Dipped Thompson and Sun dried Thompson. The lower antioxidant activities of the latter two suggest that enzymatic browning due to processing practices negatively affects antioxidant activity.

Technical Abstract: Iron bioavailabilities and antioxidant activities of three common generic raisin types, Golden Thompson, Dipped Thompson and Sun dried Thompson, were quantified and compared. Iron bioavailability was assessed with an in vitro digestion/Caco 2 cell culture model using cell ferritin formation as an index of iron bioavailability. Antioxidant activity was determined using the Total Oxyradical Scavenging Capacity (TOSC) assay. Ferritin formation in Caco 2 cells was low for all three types, indicating low iron bioavailability and high levels of iron absorption inhibitors in raisins. Antioxidant activity was significantly higher in Golden Thompson than Dipped Thompson and Sun dried Thompson. The lower antioxidant activities of the latter two suggest that enzymatic browning negatively affects antioxidant activity.