Bioaccessibility and Bioavailability of Bioactive Compounds in Food and Plant Determination - Natural Antioxidants and Biocides from Wild Medicinal Plants - page 45

4 Bioaccessibility and Bioavailability
of Bioactive Compounds in Food
and Plant Determination

José Bastias, 1 * Claudia Fuentealba 2 and Ociel Muñoz 2 †
1 Universidad del Bío-Bío, Food Engineering Department, Chillán, Chile;
2 Universidad Austral de Chile, Faculty of Agricultural Sciences, Valdivia, Chile

4.1 Introduction

digestion (Parada and Aguilera, 2007; García-
Sartal et al. , 2011). Alternatively, bioavail-
ability is defined as the fraction of ingested
nutrient or active substance present in foods
that is absorbed and reaches the circulatory
system (Brandon et al. , 2006; Ercan and El,
2011). Bioavailability depends on several pro-
cesses, such as digestion, absorption, trans-
port, use and disposal. Bioavailability is an
important factor in nutrition because it varies
for different foods, food compounds and vari-
ous gastrointestinal conditions (García-Sartal
et al. , 2011). Mechanisms that are observed in
the bioavailability of a given compound are:
the compound released from their matrix dur-
ing digestion in the gastrointestinal tract (bio-
availability); bioaccessible fraction absorption,
and metabolism in bowel and liver (Brandon
et al. , 2006).
To study the bioaccessibility and/or
bioavailability in vitro gastrointestinal
models are used in such a way to subdue
the food product to various processes that
occur in the digestive system. These mod-
els have been used not only for the study
of bioactive compounds, but also to study
the bioavailability of contaminants. The
total amount of a pollutant does not always

The bioactive compounds in foods can have
benefits to human health through different
mechanisms. These compounds must be
acquired through the diet, however, which
implies that together with the bioactive com-
pounds will be found other compounds that
might interfere with nutrient absorption or
availability. The food matrix is one of the
most important factors to consider when
studying the bioavailability of a compound.
In the case of polyphenolic compounds, these
are generally ingested as complex mixtures
immersed in a food matrix, for example fruit
or fruit juice, which then pass through the
digestive process. To exert biological activi-
ties phytochemicals should be available.
Therefore, it is important to determine how
the digestive process can affect the bioactive
compounds and their stability, which could
affect their bioavailability to be absorbed.
There are two important concepts that
have been widely discussed and studied:
bioaccessibility and bioavailability. Bioavail-
ability is defined as the amount of a food com-
ponent that is released from the food matrix
and is available for intestinal absorption after

* E-mail: [e-mail]
† E-mail: [e-mail]