Effects of flavour amplification of Quorn and yoghurt on food preference and consumption in relation to age, BMI and odour perception.

Since the food habits of many elderly people are inadequate, the first experiment of the present study tested whether flavour amplification induces changes in preferences for and consumption of food and thus might result in a nutritional benefit. Two panels, one of 260 and one of 120 subjects, aged 19-98 years, took part in the study in which preferences for flavour-amplified yoghurt and Quorn were measured. For both products, only a few of the young subjects (20%) preferred the high flavour level; the percentage of subjects preferring the high flavour levels increased with age. These changes were highly significant. In a second experiment, participants received, under ad libitum conditions over 2 d in random order, a dish of yoghurt with either a high or a low flavour level. When adjusted for total consumption quantity, consumption of the highly flavoured yoghurt was not significantly correlated with age (r -0.03, P = 0.35). In a third experiment, odour perception was measured by determining the detection threshold for isoamylacetate. BMI values were obtained and the relationships between BMI and odour perception, age, preference and consumption were assessed in the age group 40-65 years. A significant correlation was observed between age and BMI (r 0.51, P < 0.0005). No significant correlation was observed between BMI and relative consumption of highly flavoured yoghurt (r -0.14, P = 0.14). A significant correlation was observed between BMI and preference for flavour-amplified yoghurt (r 0.35, P < 0.001). However, no significant correlation was observed between BMI and odour perception (r 0.07, P = 0.32). With increasing age, a combined influence of age, sex, BMI and odour perception on food preference is to be expected. According to our multiple regression analysis, BMI showed a significant partial regression coefficient (standardized beta 0.36, P = 0.03). In conclusion, flavour amplification of food for older adults deserves attention, but specific approaches, which are tailored to the candidate food systems and older adult target groups, are needed.