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United States Department of Agriculture

Agricultural Research Service

Research Project: Dietary Modulation of Immune Function and Oxidative Stress

Location: Immunity and Disease Prevention Research Unit

Title: Release and bioaccessibility of ß-carotene from fortified almond butter preparations during in vitro digestion

Authors
item Roman, Maxine -
item Burri, Betty
item Singh, R. Paul -

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 8, 2012
Publication Date: September 17, 2012
Citation: Roman, M.J., Burri, B.J., Singh, R. 2012. Release and bioaccessibility of ß-carotene from fortified almond butter preparations during in vitro digestion. Journal of Agricultural and Food Chemistry. 60(38).

Interpretive Summary: Beta-carotene forms vitamin A, and is a major source of this nutrient. However, beta-carotene is poorly digested from foods. Thus, it has poor bioaccessibility. Fat increases beta-carotene bioaccessibility, so it may be well-absorbed from almond butter spreads. The bioaccessibility of beta-carotene-rich foods in humans can be estimated by in vitro digestion models. We measured the absorption of beta-carotene from fortified almond butter using two different in vitro digestion models, one was a typical static model and the other was a dynamic model called a Human Gastric Simulator (HGS). The HGS mimics gastric peristalsis. Two types of fortifiers were investigated, beta-carotene in oil, and beta-carotene encapsulated in alginate-chitosan microcapsules. The encapsulated beta-carotene is made to be released in the intestine, not in the stomach. Foods digested in the HGS released more beta-carotene from the unencapsulated oil. Also, the beta-carotene in the oil was more accessible than the encapsulated beta-carotene. Unencapsulated beta carotene in oil appears to be the preferred method of fortification of almond butter.

Technical Abstract: The objective of this study was to determine the release and bioaccessibility of ß-carotene from fortified almond butter using in vitro digestion models. Two types of fortifiers were investigated: ß-carotene oil (non-encapsulated) and alginate-chitosan capsules containing ß-carotene oil (encapsulated). Shaking water bath and Human Gastric Simulator (HGS) digestion models assessed the impact of gastric peristalsis on the release of ß-carotene. Bioaccessibility of ß-carotene was measured as percent recovered from the micelle fraction. There was greater release of ß-carotene from non-encapsulated fortified almond butter in the HGS model (87.1%) due to peristalsis than the shaking water bath model (51.0%). More ß-carotene was released from encapsulated fortified almond butter during intestinal digestion. However, more ß-carotene was recovered from the micelle fraction of non-encapsulated fortified almond butter. Non-encapsulated ß-carotene oil appears to be the preferred method of fortification of almond butter due to its higher bioaccessibility.

Last Modified: 11/20/2014
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