Understanding and changing children's sensory acceptance for vegetables

166 Pages·2016·4.42 MB·English

Understanding and changing children’s
sensory acceptance for vegetables

Astrid A.M. Poelman
Thesis committee

Promotor
Prof. Dr Kees de Graaf
Professor of Sensory Science and Eating Behaviour
Wageningen University

Co-promotor
Dr Conor M. Delahunty
Group Leader Behavioural and Sensory Sciences
CSIRO Food and Nutrition
Sydney, Australia

Other members
Prof. Dr Maria A. Koelen, Wageningen University
Dr Sylvie Issanchou, Institute National de la Recherche Agronomique, Dijon, France
Dr Koen F.M. Joosten, Erasmus University Medical Center, Rotterdam
Dr Astrid Postma-Smeets, Netherlands Nutrition Center, The Hague

This research was conducted under the auspices of the Graduate School VLAG
(Advanced studies in Food Technology, Agrobiotechnology, Nutrition and Health
Sciences).
Understanding and changing children’s
sensory acceptance for vegetables

Astrid A.M. Poelman

Thesis
submitted in fulfilment of the requirements for the degree of doctor
at Wageningen University
by the authority of the Rector Magnificus
Prof. Dr A.P.J. Mol,
in the presence of the
Thesis Committee appointed by the Academic Board
to be defended in public
on Monday 27 June 2016
at 11 a.m. in the Aula.
Astrid A.M. Poelman
Understanding and changing children’s sensory acceptance for vegetables,
166 pages.

PhD thesis, Wageningen University, Wageningen, NL (2016)
With references, with summaries in English and Dutch

ISBN 978-94-6257-783-1
Voor mijn familie

Abstract
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.
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Contents

Abstract 7
Chapter 1 Introduction 11
Chapter 2 Vegetables and other core food groups: A comparison of key 29
flavour and texture properties
Chapter 3 The effect of preparation method and typicality of colour on 45
children’s acceptance for vegetables
Chapter 4 Cooking time but not cooking method affected children’s 69
acceptance of Brassica vegetables
Chapter 5 Vegetable preparation practices for 5-6 year old Australian 89
children as reported by their parents; relationships with liking
and consumption
Chapter 6 The effect of multiple target versus single target exposure 105
with reward to increase vegetable intake in children. A pilot
study
Chapter 7 General discussion 125
Summary 147
Samenvatting 151
Dankwoord / Acknowledgements 155
About the author 159

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