Bioavailability of nutrients

Gibson, R. S., Perlas, L., Hotz, C. (2006). Improving the bioavailability of nutrients in plant foods at the household level. Proc. Nutr. Soc., 65, 160-168. 

The biochemical stability of food colloids is now attracting considerable research interest because of its obvious relevance to the delivery and bioavailability of nutrients and nutraceuticals in vivo. In particular, the processes of enzymatic hydrolysis occurring at the triglyceride-water interface appear important because most dietary lipids are present in the human stomach at some stage in the form of emulsified droplets (size 20-40 pm) (Armand et al., 1994 McClements et al., 2008 Dickinson, 2008 Singh et cil, 2009 McClements and Decker, 2009). 

Bioavailability can be influenced directly or indirectly by many physiological, pathological, chemical, nutritional, and processing conditions. Discussion in this chapter will be limited to unit food processing effects upon the bioavailability of nutrients from plant protein foods. The bioavailability of amino acids, carbohydrates, lipids, vitamins and minerals from processed foods will be selectively reviewed. Amino Acids... 

Acording to the FDA (1982A), an imitation food is a product that substitutes for and resembles a traditional food but is nutritionally inferior to that food. That is, the term imitation denotes nutritional inferiority. On the other hand, FDA has determined that if a food substitutes for and resembles another food but is not nutritionally inferior to that food, it need not be called an imitation. Rather, by FDA definition, such a substitute food may be called nutritionally equivalent. This term implies that the nutrients in the substitute food are identical in quantity, biological activity, and bioavailability to those found in the traditional food. However, examination of FDA s nutrient profile for nutritional equivalency and consideration of the differences in the biological activity and bioavailability of nutrients, as well as the possibility that traditional foods may contain beneficial factors, reveal seri-... 

Bioavailability of nutrients may be influenced beneficially or adversely by pelleting. For example, the availability of phytate phosphorus in grains was found to be increased by steam-pelleting (Bayley et al., 1975). On the other hand, there may be destruction of heat-labile nutrients and components, such as phytase enzyme in wheat or vitamin A. 

There is enough published microscopy of foods (Aguilera and Stanley, 1999) to indicate that their structures are enormously variable and complex. The physical property of appearance is derived from the structure itself, and texture, flavour, taste, and subsequent bioavailability of nutrients are derived from the manner in which the structure collapses or breaks down. Simple theories of composite solids tell us that the spatial organisation of components and materials, their own physical properties and the interfacial interactions between them will determine overall properties. The components and materials themselves consist of molecular assemblies. This hierarchy of structure suggests we will need measurement at all length scales from molecular to macro structure and over timescales relevant to processing (milliseconds to hours) and product stability (minutes to months). 

The impact of plant products on the metabolism of synthetic dmgs results from the inhibition or activation of cytochrome P-450 (CYP) enzymes. Evaluation of the potential activation of CYP by administration of natural plant products or dietary supplements is important for prediction of interactions between their components and dmgs. Therefore, attention is directed to research on the impact of products available on the food market known as natural non-nutritive substances on dmg absorption. Non-nutritive dietary components are mainly secondary plant metabolites, which include, among others, phenolic compounds such as phenolic acids and flavonoids. The health effects of non-nutritive substances are not yet known. So far, there is no answer on the extent to which they are absorbed and metabolized by the body, and there is no information on the permitted daily intake for these compounds. This information is particularly important because certain non-nutritive natural substances are simultaneously considered to be anti-nutritional factors, mainly because they inhibit digestion and reduce the bioavailability of nutrients or dmgs. It is also possible that they form undesirable interactions with dmgs. The positive health effects of non-nutritive natural substances are not only attributed to their antioxidant properties. These substances are involved in various metabolic... 

Stevia used in small amounts has no negative consequenses for the bioavailability of nutrients from the diet and it does not have adverse physiological effects. This can be deduced from the data used to determine the ADI (see above) and from the use of Stevia in countries as Paraguay (used since more than 500 years), Brasil, China, Japan (more than 25 years) and even in the USA Stevia allowed as dietary supplement). 

The possible chelating effect of pectin on the bioavailability of nutrients, other than carbohydrates and lipids, is a concern. Despite extensive investigations in both animals and humans, there are no final conclusions because of the conflicting results. 

The physiological interaction between different essential trace elements and also with the other essential major minerals can have significant effects on health. Such interactions are mostly considered as affecting the intestinal bioavailability of nutrients from various diets. The complex interactions that were investigated systematically in animal studies have been important in trying to understand the mechanisms of... 

Integration of in vitro results and pharmacokinetic modeling is also used to assess the bioavailability of nutrients [85] using TNO s gastrointestinal model TIM [www. tno.nl/pharma]. 

Improves digestibility and bioavailability of nutrients in the digestive system... 

Ammerman C. B., Baker D. H., Lewis A. J., 1995. Bioavailability of nutrients for animais amino acids, minerais, and vitamins. Academic Press, San Diego, CA. 

Effect of fermentation on phytochemical profiles of plant foods and the bioavailability of nutrients... 

Russell RM (2001) Factors in aging that affect the bioavailability of nutrients. Journal of Nutrition 131 1359S-1361S. 

---