A technological and physiological integrated approach for appetite control : from identification of novel biomarkers to development of new functional ingredients

A technological and physiological integrated approach for appetite control.

From identification of novel biomarkers to development of new functional ingredients.

Human dietary behaviour is driven by homeostatic, hedonic and environmental factors. Foods can

influence these factors throughout extrinsic (marketing suggestions, portion sizes, form) and

intrinsic characteristics (taste, flavour, smell, texture). In turn biochemical response and

psychological traits influenced food taste, flavour, smell and texture perception determining the

hedonic value of a meal. This interplay between the food and the subjective psychophysiological

response determine the control of energy intake, therefore must be considered in developing food

for appetite control.

In the present thesis four human studies are described. Of these two were conducted to investigate

the role of the saliva and the endocannabinoids system in the food preference and liking during the

cephalic phase of digestion. We found out that salivary enzymes activity are influenced by

nutritional status, food preference and food habits. Moreover, food palatability influenced some

plasma endocannabinoid and N-acylethanolamine concentrations during the cephalic phase

response and indicated that 2-arachidonoylglycerol and pancreatic polypeptide can be used as

biomarkers of food liking in humans. These findings can have interesting implications in designing

foods for appetite control:

­ salivary enzymatic activity must be considered because it influence taste and texture

perception and consequently food choice;

­ the measure of 2-arachidonoylglycerol can offer the possibility to merge the sensory and

biochemical approach to compare the satiating and rewarding capacity of foods.

The other two studies investigated the potential satiating effect on the short term energy intake of

specific food ingredients. As previous in animal studies shown, we demonstrated (chapter 4) that

also in humans the circulating oleoylethanolamide levels can be modulated by the fatty acid

composition of a meal and this can influence the short-term energy intake. Therefore, we

highlighted the anorexigenic effect of the oleoylethanolamide that can be a target of specific food

ingredients. In the study described in the chapter 5, we aimed in assessing the appetite control

capability of bitter compounds. The ingredient was microencapsulated with the double aim to avoid

the (not palatable) taste perception in the mouth and to deliver the compounds directly in the

gastrointestinal tract and target the enteroendocrine bitter taste receptors. We showed that

microencapsulated bitter compounds are effective to reduce daily energy intakes in humans. This

study demonstrated that sense the taste receptors directly in the gastrointestinal tract may be a valid

way to trigger satiety and control appetite.

The general conclusions of the present thesis are that a fine design of ingredients for appetite

control is necessary to develop novel foods for appetite control that has to take in account from one

side the hedonic value from the other side the functionality.