INTRODUCTION

The preceding chapter introduced dietary analysis and discussed physical aspects of potential foods as they might influence feeding behaviour. Here, we deal with chemical aspects of potential foods. From the outset though, we should point out that attempts to explain the influence of chemical factors on primate nutrition, and the dietary factors that promote or deter the uptake of nutrients, are limited by our understanding of how the primate gut operates. It is unclear what the optimal dietary requirements are even for humans. Gut research is developing on both theoretical (see, for example, Jumars, 2000) and practical levels (Dominy et al., 2004), but it is important to point out that the effective rate of uptake is not simply a question of enzymatic action. The quantity of plant fibre that a primate ingests has a major influence on the rate of passage of food through the gut and thus digestibility (Lambert, 2002). Variable gut populations of microorganisms and parasites also play a large positive or negative role, particularly in relation to specializations in the stomach or large intestine. The situation is even less clear when it comes to chemical compounds that act as feeding deterrents, toxins or anti-nutritional factors. These have largely been bred or processed out of the agricultural products on which humans feed, so they have received relatively little attention in food science.