2.5.3.i Purees
All target vegetables were selected on the basis of being relatively novel to the designated age group of participating children. They were identified using results from the vegetable survey used in Study 2 and chosen based the following inclusion criteria. Vegetables must not have been offered to more than 60% of children, must not have been offered more frequently than 1-3 times per month and/or must not have been rated as well liked by mothers. For the purpose of assessing associative conditioning and to permit the easy addition of other flavours and/or energy it was decided that presenting the vegetables as purees would be most appropriate. This also allowed the influence of sensory properties other than flavour to be limited.
Artichoke puree
Artichoke was identified as an extremely novel vegetable as it had only been offered to 12.5% of UK pre-school children and on average was offered approximately once per month. Artichoke purees were produced using baby food grade frozen artichoke hearts
(France Recherche & Developpement), water, sucrose (Vermandoise), sunflower oil (Huileries de Lapalisse) and salt (Vermand). All recipes were developed in the Centre des Sciences du Gouˆt et de l’Alimentation. For the RE condition a basic puree was produced using minimal amounts of oil, salt and sugar. To examine the effectiveness of associative condition two further purees were produced incorporating the chosen unconditioned stimuli. For FFL this was sweetness and was achieved by increasing the amount of sucrose in the original recipe. To investigate FNL energy density was increased by adding more sunflower oil. In order to avoid other conflicting properties recipes were developed so that the energy content of the RE and FFL versions were comparable and the sensory properties of the RE and FNL versions were not significantly different.
Figure 2:2: Vegetable purees used in Study 3; clockwise from top, FFL artichoke, RE artichoke, FNL artichoke and carrot
Purees were produced by Freshinov, a company experienced in the production of purees and children’s products and accredited to prepare baby foods. Following a test of
industrial production recipes were adjusted. Final purees were produced from the same batch of fresh vegetables as were initially used to reduce the chance of seasonal variation. For all purees ingredients were steamed for 20 min at 90ºC, mixed, conditioned in a 100 (SEM 2) g jar with lid and sterilised at 1208C for 75 min at 2 bars. The Departmental
Laboratory of Analysis and Research (Barenton- Bugny) conducted bacteriological analyses on the final products and the nutritional composition was assessed by a certified
laboratory (INZO) (Table 2.2).
Table 2:2: Nutritional composition and recipes of artichoke purees: repeated exposure (RE), flavour–flavour learning (FFL), flavour–nutrient learning (FNL) and carrot (adapted from Caton, Ahern et al. 2012)
Nutritional Composition per 100kcal RE FFL FNL Carrot
Protein (g) 1·1 1·1 1·2 0·3 Carbohydrates (g) 8·9 11·1 10·7 4·5 Fat (g) 1·0 0·3 10·7 0·4 Sodium (g) 182·3 135·0 136·0 40·0 Energy kcal 48 51 144 27 KJ 201 213 602 113 Recipe (g/100g) Artichoke 78·9 76·2 78·3 Water 19·0 20·1 9·0 Sunflower Oil 1·0 0·0 11·6 Sugar 1·0 3·6 1·0 Salt 0·1 0·1 0·1
Purees were presented in clear plastic pots and stickers with each child’s name on were placed on both the pots and the lids (Figure 2.2).
Carrot puree
A baby food carrot purée, used as a control, was supplied by the Nestle´ group (NaturNes; Nestlé; Figure 2; Table 2.2).
Root vegetable purees
Four root vegetables were initially selected for use in Study 4 based on the inclusion criteria (Table 2.3). Celeriac, swede and turnip were then selected for use in the study based on sensory profiling (see section 6.2).
Table 2:3: Familiarity of root vegetables based on results from vegetable survey: percentage of children offered, mean frequency of offering, mean liking scores.
Familiarity of Vegetables Beetroot Celeriac Swede Turnip
Children Offered (%) 40.3 15.3 54 38.9
Frequency of Offering (mean score) 1.5 1.2 1.4 1.4
Liking (mean score) 3.3 3.2 3.4 3.4
Purees were produced using organic frozen celeriac, swede and turnip (JE Hartley, York), boiled and blended using a hand blender and with no other ingredients added. Purees were prepared in 5 to 10 kg batches and refrozen as individual 100g portions in small freezer bags. Sufficient portions for each test visit were defrosted while being refrigerated overnight. For the RE condition children received the basic plain puree with nothing added. To assess the effectiveness of FFL a pre-liked flavour in this case, apple puree was added. For the FFL recipe 21.5g of Ella’s Kitchen© First Taste apple puree (Table 2.4) was added to 100g of vegetable puree and stirred until fully mixed. For a portion, 100g of this mixed puree was then extracted (18% apple). The concentration of apple puree for the FFL recipes was selected using earlier sensory profiling (see section 6.2).
Before testing sessions purees were transferred from freezer bags to identical Tommee Tippee™ Pop Up Weaning Pots (Figure 2.3) to ensure that they were visually similar and stickers with each child’s name were placed on the pots and lids.
Table 2:4: Nutritional composition and recipe of Ella's Kitchen Apples Apples Apples (apple puree) taken from www.ellaskitchen.co.uk and approximate nutritional composition of root vegetable purees (values calculated from www.fondation-louisbonduelle.org) with recipes per 100g
Nutritional composition per 100g Apple puree RE celeriac puree FFL celeriac puree RE swede puree FFL swede puree RE turnip puree FFL turnip puree Protein (g) 0.4 1 0.9 1.3 1.2 0.8 0.7 Carbohydrates (g) 11.1 2.8 4.3 8.7 9.1 2.9 4.4 Fat (g) 0.1 0.3 0.3 0.2 0.3 0.1 0.1 Sodium (g) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 Energy kcal 46 18 23 39 40 15 21 KJ 161 75 91 163 163 63 81 Recipe (%/100g) Organic apples 100 0 18 0 18 0 18 Organic celeriac 0 100 92 0 0 0 0 Organic swede 0 0 0 100 92 0 0 Organic turnip 0 0 0 0 0 100 92
2.5.3.ii Raw vegetable snacks
When raw vegetables were selected for tasks within the experiments presented here, the survey data was used to identify suitable candidate items (Chapter 6). This reduced a list of 54 to 25. This list was then reduced further by excluding those vegetables that cannot feasibly be offered as a finger food, such as leaf vegetables. From this list of 10 another 3 were excluded on the basis of them already being offered an average of 1-3 times per week. Discussions were then held with two nursery managers and a group of five mothers with relation to the remaining 7 vegetables and their suitability as nursery snack foods and further suggestions were given. A final list of 5 vegetables was produced; baby sweet corn, celery, green pepper, red pepper and radish.
All vegetables were supplied by Country Fresh FoodsLtd a British Retail Consortium accredited company supplying both whole and pre-prepared vegetables. All vegetables were sterilised in the HARU using Milton Sterilising Fluid (half cap/2.5L) and rinsed
thoroughly before the snacks were prepared. Vegetable snacks were prepared as crudités so as to be easily handled and eaten by young children. The peppers and celery were cut into batons, the baby sweet corn was halved lengthways and the radishes were halved. Snacks were presented as 100g portions in Sainsbury’s small zip-lock clear plastic freezer bags; for RE 100g of a single vegetable and for Variety 20g of each vegetable. Stickers depicting a “Veggiesaurus” dinosaur and with each child’s name on were placed on the bags to make them more attractive to the children (Figure 2.4).
Figure 2:4 Variety vegetable snack used in Study 5; baby sweet corn, celery, green pepper, red pepper and radish