In vitro human digestion models for food applications

In vitro digestion models are widely used to study the structural changes, digestibility, and release of food components under simulated gastrointestinal conditions. However, the results of in vitro digestion models are often different to those found using in vivo models because of the difficulties in accurately simulating the highly complex physicochemical and physiological events occurring in animal and human digestive tracts. This paper provides an overview of current trends in the development and utilisation of in vitro digestion models for foods, as well as information that can be used to develop improved digestion models. Our survey of in vitro digestion models found that the most predominant food samples tested were plants, meats, fish, dairy, and emulsion-based foods. The most frequently used biological molecules included in the digestion models were digestive enzymes (pancreatin, pepsin, trypsin, chymotrypsin, peptidase, α-amylase, and lipase), bile salts, and mucin. In all the in vitro digestion models surveyed, the digestion temperature was 37 °C although varying types and concentrations of enzymes were utilised. With regard to digestion times, 2 h (the stomach, small intestine, and large intestine each) was predominantly employed. This survey enhances the understanding of in vitro digestion models and provides indications for the development of improved in vitro digestion models for foods or pharmaceuticals.