Understanding and changing children’s sensory acceptance for vegetables

Vegetable intake of children is well below recommendations in Australia and in most other western countries. Vegetables are the food category least liked by children. As acceptance is a key driver of intake, strategies are needed to increase children’s acceptance of vegetables. The present thesis was directed at understanding and changing children’s acceptance for vegetables, focusing on strategies that could be employed by parents in the home environment. The research was conducted with 4-6 year old Australian children. To gain understanding of vegetable sensory properties, these were compared to sensory properties of other core food groups representative of the diet of Australian children, through the use of trained sensory panel. To increase vegetable acceptance and intake, two types of strategies were investigated. Preparation was investigated as a strategy to create vegetable sensory properties that were more accepted by children. Two experimental taste tests with children and a survey amongst parents together explored a range of vegetables (both across and within vegetable categories) and preparation (including cooking methods such as boiling, steaming, baking, use in mixed dishes, the use of an atypical colour, and cooking time), and sensory evaluation was used to measure the vegetable sensory properties. A behavioural sensory learning intervention strategy was investigated as a strategy to increase children’s acceptance of vegetable sensory properties per se, in which repeated exposure to a single and to multiple target vegetables were compared in their effectiveness to increase acceptance and intake. Compared to other core foods, vegetables were more bitter in taste, amongst the hardest foods, and were low in sweet, salty and sour taste as well as fatty mouthfeel. Unlike the other core food groups, vegetables had no known drivers of liking as well as a known driver of dislike. The preparation studies showed several results generic across the vegetables tested. An atypical colour (e.g. green cauliflower) increased willingness to try vegetables. Despite a more intense flavour profile, boiling and steaming were equally accepted by children. Use in mixed dishes was also well accepted by children. Other effects of preparation method were mostly vegetable specific, and a non-linear combination of flavour and texture properties were driving acceptance. The behavioural intervention study showed that repeated exposure to both single and multiple target vegetables increased acceptance. Exposure to multiple target vegetables increased usual daily vegetable intake from 0.6 to 1.2 serves per day, whereas exposure to a single vegetable did not. This study showed that vegetable sensory properties predispose to low acceptance based on innate likes and dislikes, and food preferences acquired within the first few months of life. Preparation strategies and sensory learning strategies are both effective to increase vegetable acceptance amongst children in their peak of food neophobia. The results of this research can be used by health professionals to support parents with strategies and advice to increase children’s enjoyment and intake of vegetables.