3.1. Apple Pomace Flour Characteristics as an Ingredient
Proximate composition of the APF, including the contents for protein, fat, ash, dietary fibre, and carbohydrate content is shown in
Table 4. As notable features, APF includes high contents of dietary fibre and carbohydrates from fruit and low-fat content. According to this, APF is an interesting ingredient to substitute part of the wheat flour in sweet bakeries. It allows incorporating fibre to reduce sucrose content. In the same way, the authors of [
32] used APF as an ingredient with high levels of polyphenols and also phytate-free dietary fibre to develop gluten-free cakes. The authors of [
23] developed a systematic review of apple pomace as a food fortification ingredient. They concluded from analysing data from 2007 to 2019 that APF has a beneficial nutritional profile and is an ecological issue.
For the above-mentioned reasons, we decided to use apple pomace as a functional ingredient in the development of a bakery pre-mixes, evaluating its acceptability and the effect of information on consumers’ response in comparison with commercial pre-mixes.
3.2. Acceptability of Cakes in Blind and Informed Conditions
Means of acceptability for the regular and fibre-enriched cakes in blind and informed conditions are shown in
Table 5. In the blind condition, when consumers only tasted samples, mean of liking scores for the fibre-enriched cake was significantly lower than for the regular cake. This difference in liking may have been due not only to the presence of fibre but also to the fact that regular cake was higher in fat and sugar content, which are usually related to higher overall acceptability [
33]. The amount of added sugar was kept lower than in regular cake because it was expected that there would be a contribution of apple pomace to sweetness due to its high sugar content and because we were trying to develop a healthier product.
By comparing blind and informed conditions, we found that label presence significantly increased consumers’ liking for the fibre-enriched cake, while for the regular cake, label presence only caused a slight increase in acceptability that was not significant. This indicates claims that “fibre source” and “apple fibre” increase acceptability for cake. According to [
34], product information may influence consumer’s expectation and choice. The authors found a positive effect of nutritional information on consumers’ acceptability of pasta produced with the addition of wheat bran, and similar results were obtained by [
22], who observed that overall acceptability increased when information was provided for a wholemeal muffin.
Despite the increase observed for fibre-enriched cake, we found a lower liking score than the regular cake. However, the percentage of consumers buying fibre-enriched cake (53%) was close to that observed for regular cake (63%).
3.3. Individual Variability in Consumers’ Response to Apple Fibre-Enriched Cake
Cluster analysis was applied to identify segments of consumers with different patterns of preference with respect the regular and fibre-enriched cakes (evaluated in the presence of the label). Three clusters were identified (
Table 6). Consumers in cluster 1 (29%) showed high liking scores for regular cake and low liking scores for the fibre-enriched cake. Only 13% of them would buy the fibre-enriched cake and 56% would buy the regular cake. Cluster 2 (31%) preferred the fibre-enriched cake than the regular cake. A total of 81% of these consumers would buy the fibre-enriched cake and 41% would buy the regular cake. Finally, cluster 3 (40%), despite showing high liking scores for both cakes, liked the regular cake more. Thus, while a high percentage of consumers would buy the regular cake, many of them would also buy the fibre-enriched cake (59%).
Previous studies have shown that inter-individual differences are especially relevant in the response of consumers to fibre-related information and claims in products such as bread, muffins, yogurt, and cakes [
22,
35,
36]. In the same way, the authors of [
35,
36] found culture-related differences in the impact of fibre information on liking and/or sensory properties of food, and the authors of [
22] found that fibre-related information was more effective in increasing liking of muffins for health-conscious consumers. In the present study, clusters did not significantly differ in terms of gender (
p = 0.360) and health interest (
p = 0.861), but they differed in terms of age (
p = 0.019). Cluster 1 and 3 were mainly composed of people younger than 35 (66% and 61%), and cluster 2 showed more people older than 35 (58%). It seems that in the case of fibre, older people show more willingness to accept a new product than young people. Similarly, the authors of [
20] found a significant age effect on the willingness to pay for high-fibre bread. According to these authors, young consumers are more influenced than the older consumers by the hedonic value of the bread more than health concerns and they are not willing to sacrifice pleasure for health.
3.4. Consumer Drivers of Liking and Reasons to Purchase
Consumers also described (CATA questionnaire) the cakes after tasting them and observing the labels. For 15 of the 21 terms in the list, significant differences were observed in terms of the frequency of mention.
Figure 2 shows the frequency of mention of the two cakes compared to the ideal cake, which was described by most of the participants as being homemade, tasty, moist, sweet, soft, spongy, and healthy. The fibre-enriched cake showed a higher frequency for some of these terms, such as being homemade and healthy, while the regular cake showed higher frequency in terms of being sweet and soft. Both cakes were described as tasty and easy to chew. Among the terms not cited for the ideal cake, dry and tasteless were used similarly for both cakes by some consumers (15–18%), and fibrous and sandy were used by some consumers only for the fibre-enriched cake.
To understand the variability in consumers response, we applied a penalty lift analysis to determine the attributes that explain the differences in consumers liking scores for the same product (
Figure 3). For the fibre-enriched cake, the acceptability was higher for consumers that described it as tasty, homemade, and healthy, and lower for consumers that found it tasteless or dry. For the regular cake, the variation in liking scores among consumers was mainly associated with positive terms; the consumers who found the cake tasty, homemade, easy to chew, soft, and spongy gave it a higher liking score, while those who found the cake dry gave it a lower liking score (
Figure 3).
Figure 3 shows global results in which most attributes had a positive connotation in cakes. As expected, the attributes tasty, soft, homemade, easy to chew, and moist were found to be the most important drivers of liking, increase liking by around 1 point on the nine-point scale when they were present. On the other hand, the worst impact in acceptability was given by the attributes flattened, distasteful, and bitter.
In sponge cakes enriched with fibre from different sources, the authors of [
37] reported a similar positive impact of easy to chew, spongy, soft, and sweet on liking. Negative impact of dry and tasteless sensations on liking were also found by these authors, but they also found a negative impact of soft, odd flavour, and fruity flavour (especially for blackcurrant fibre cake) that was not found in this work for the cake enriched with apple fibre. This seems to be an advantage for apple fibre because, as reported by [
38], certain flavours provided by the addition of fruit fibre can make the product too different from original to be acceptable. It is important to note that while in this work, homemade and healthy were relevant attributes with positive impact for the fibre-enriched cake, they were not found to be relevant in the study of [
37]; one possible explanation for this difference is that in this study, cakes were evaluated without any product information.
As expected, the reasons that consumers linked to their buying decisions were in agreement with the drivers of linking. Among consumers buying the fibre-enriched cake (53%), the main reasons were that it is healthy (27%) and tasty (35%) (
Figure 4). As observed in
Figure 4, being healthy and tasty were relevant reasons for consumers in cluster 2, but for consumers in cluster 3, being tasty was more relevant. Among those buying regular cake (67% of consumers), being tasty was the reason indicated for almost all of them (60% of consumers). For both fibre-enriched and regular cake, the main reasons for not buying the cake were that it was not tasty (23% and 11%, respectively), but also to prevent weight gain (8%). Additionally, some consumers did not buy the fibre-enriched cake because it was not the same as what they were used to, and some consumers did not buy regular cake because they consider it unhealthy.
In the same way, the authors of [
39] studied fibre-enriched breads and found two groups of consumers with different consumption choices: hedonistic consumers whose motives were driven mainly by “mood” and “price”, and traditional consumers driven by “natural content”, “familiarity”, and “health concern” claims.
Regarding reasons to buy, the authors of [
40] found that price, sensory appeal, convenience, and health were strong motives contributing to food choices. These authors also reported that young adults who value the food choice motives of weight control and natural content are likely to have a very positive attitude towards functional food. As the authors of [
41] proposed, young adults experience many barriers to living a healthy lifestyle—high stress, poor sleep, and challenges in time balance—which may increase the need for convenience in food choices.
APF was used as a fibre enrichment strategy, and as
Figure 1 shows, consumers were able to notice that the product contained apple fibre, but they did not have information about the apple fibre origin. Consumers did not have explicit information about fibre-enriched cake sustainability. Kaczorowska et al. (2019) [
42] found that sustainability labels influence consumer buying behaviour in spite of the fact that consumers perceive the benefits of buying them differently. In these ways, it should be explored whether sustainability should be a valuable reason to rise up the lower acceptability of fibre-enriched cake.