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ARS Home » Plains Area » Grand Forks, North Dakota » Grand Forks Human Nutrition Research Center » Dietary Prevention of Obesity-related Disease Research » Research » Publications at this Location » Publication #134420
Title: BIOAVAILABILITY OF ZINC FROM COOKED PHILIPPINE MILLED, UNDERMILLED, AND BROWN RICE, AS ASSESSED IN RATS BY USING GROWTH, BONE ZINC AND ZINC-65 RETENTION

Author
item Hunt, Janet
item JOHNSON, LUANN - UNIV OF NORTH DAKOTA
item JULIANO, BIENVENIDO - PHILIPPINE RICE INSTITUTE

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/6/2002
Publication Date: 8/3/2002
Citation: Hunt, J.R., Johnson, L.K., Juliano, B.O. 2002. Bioavailability of zinc from cooked philippine milled, undermilled, and brown rice, as assessed in rats by using growth, bone zinc and zinc-65 retention. Journal of Agricultural and Food Chemistry. 50(18):5229-35.

Interpretive Summary: The nutritional bioavailability of zinc from cooked milled, undermilled, and brown PSB Rc14 rice was evaluated in a rat model, comparing results based on weight gain, tibia zinc incorporation (slope ratio analyses) and zinc radiotracer retention. Milling reduced the phytic acid, fiber, and mineral content of the rice, resulting in zinc concentrations of 16.5, 19.4, and 27.2 µg/g and phytate/zinc molar ratios of 4, 20, and 28 for milled, undermilled, and brown rice, respectively. Measured zinc bioavailability was similar whether using growth, bone zinc or radioisotope retention as criteria, at approximately 92, 86, and 77% of zinc sulfate, for milled, undermilled, and brown rice, respectively. However, the higher percent bioavailability of the zinc in rice after milling was insufficient to compensate for the lower zinc content of the milled rices. Brown rice provided the greatest zinc nutritional value, in comparison with milled or undermilled rice of this variety.

Technical Abstract: The nutritional bioavailability of zinc from cooked milled, undermilled, and brown PSB Rc14 rice was evaluated in a rat model, comparing results based on weight gain, tibia zinc incorporation (slope ratio analyses) and zinc radiotracer retention. Milling reduced the phytic acid, fiber, and mineral content of the rice, resulting in zinc concentrations of 16.5, 19.4, and 27.2 µg/g and phytate/zinc molar ratios of 4, 20, and 28 for milled, undermilled, and brown rice, respectively. Measured zinc bioavailability was similar whether using growth, bone zinc or radioisotope retention as criteria, at approximately 92, 86, and 77% of zinc sulfate, for milled, undermilled, and brown rice, respectively. However, the higher percent bioavailability of the zinc in rice after milling was insufficient to compensate for the lower zinc content of the milled rices. Brown rice provided the greatest zinc nutritional value, in comparison with milled or undermilled rice of this variety.