In vitro digestion procedure

In the in vitro digestion method, the compound of interest is transferred from the food matrix to a bile salt micelle suspension that simulates the in vivo digestion process. This in vitro digestion procedure was first developed to estimate iron availability from meals and since then has been modified and applied to studying carotenoid bioaccessibility from various food matrices. This approach assesses the bioaccessibility of the compound from a certain meal before it is presented to and taken up by intestinal cells. 

One recent report involving the use of the in vitro digestion procedure noted that the micellarization of zeaxanthin from digested foods was dependent on its degree of esterification with transfer efficiency levels of 80, 44, and 11%, respectively, for the free form, monoesters, and diesters of zeaxanthin." In vivo studies" " ... 

Evaluation and Potential Uses of an In Vitro Digestion Procedure... 

We have developed an in vitro digestion procedure, not as a substitute for in vivo studies, but as a useful adjunct. Our initial objective was to develop an in vitro procedure for measuring exchangeability, the fraction of the food mineral which exchanges with an extrinsic isotope tracer added to the food. This was expected to facilitate the measurement of food mineral absorption in humans by the extrinsic tag method. Secondary objectives were to determine if in vitro mineral solubility could be used to estimate potential... 

Figure 1. In vitro digestion procedure. (Reproduced with permission from Ref. 7. Copyright 1982 J. Nutr., American Institute of Nutrition.)...

Experiments were conducted to determine if varying the conditions in the in vitro digestion procedure would affect post-digestion calcium solubility and in some cases, exchangeability. This was done with two purposes to test the use of the in vitro digestion procedure for studying factors which might influence calcium bioavailability and to use the results to modify the standard procedure. 

Fractionation of Digest Calcium. The in vitro digestion procedure provides a means of producing the starting material for a more detailed study of the calcium complexes in intestinal digests. This may be desirable in a number of situations ... 

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