Substitution of wheat flour with whole-grain spelt flour in cakes and its influence on consumer acceptance

Abstract

In typical bakery products, wheat flour is the principal ingredient(1), and wheat gluten has been associated with negative health consequences in individuals with gluten-related disorders(2). Wholegrain spelt flour (WSF) appears to offer a suitable alternative to wheat for some gluten-sensitive individuals. In order to be accepted by consumers, any 'healthy alternative' version of a food product must be of comparable sensory quality to the standard product(3). To date, new product-development (NPD) efforts involving WSF have mainly been focused on breads, with little NPD work in the area of other baked goods such as cakes(1). The aim of this study was to develop WSF versions of sponge cake and butter cake - both popular in Singapore -, with similar baking quality and product acceptability to those of the standard wheat-based versions. In a series of controlled bakery trials, baking performance (specific volume: cm3/g) of WSF- and standard wheat-based versions was compared (seed-displacement method). During a five-day post-baking period, crumb firmness (g) and springiness (%) were compared (TX - XT Plusä Texture Analyzer). All assays were performed in triplicate. Analysis of the resulting data indicated an absence of significant difference (p> 0•05) between WGS- and standard wheat-based sponge cakes and butter cakes, in terms of specific volume, firmness and springiness (Mann-Whitney/Kruskal-Wallis tests used). In consumer testing, the perceptions of 50 mainly Singaporean consumers (aged 19-37 years) regarding the wheat- and WGS-based sponge cake and butter cake products were assessed using a 9-point hedonic scale(4). At the 5% significance level, the wheat-based butter cake scored significantly better than the WGS-based butter cake in terms of overall appearance, overall aroma and texturesoftness, while the wheat-based sponge cake outscored the WGS version in terms of overall appearance and overall aroma. With the remaining attributes ('flavour' and 'overall acceptance', and additionally 'texture-softness' in the case of the sponge cake), no significant differences (p > 0•05) were noted between the wheat-based and WGS-based cakes (Mann-Whitney U test used). The results of the study demonstrate the potential of WGS as a potential substitute for wheat flour in some cake-type products. Although no significant differences were found in terms of specific volume, firmness and springiness between the WGS- and the standard wheat-based cakes, nonetheless the consumer-derived data indicate something of a "preference gap" in favour of the standard wheat-based products. If WGS-based cake products are to be fully successful, it appears that NPD efforts will be required to focus on improving sensory quality.