Understanding aroma and flavour formation in baked confectionery products, as influenced by sugar and fat
Loading...
Files
Full Text E-thesis
Date
2020-12-18
Authors
Garvey, Emer
Journal Title
Journal ISSN
Volume Title
Publisher
University College Cork
Published Version
Abstract
This thesis directly addresses consumer demands for ‘clean-label’, sustainable and natural ingredients in baked confectionery products. Baked confectionery products are a prime matrix to explore alternative sucrose replacers due to the critical functionality of sucrose and fat in relation to desirable structural and organoleptic properties. The primary objective of this research was to elucidate the impact of modifying sugar and butter on the aromatic and sensory properties of selected baked confectionery products. Chapter 1 provides an updated review of reduced fat and sucrose research in baked confectionery products focussing on the association of aromatic volatiles and sensory perception. Chapter 2 outlines the development and optimisation of a headspace solid-phase microextraction gas-chromatography mass-spectrometry (HS-SPME-GC-MS) method for the extraction, separation and identification of volatile compounds from a baked confectionery matrix. Extraction parameters were optimised and the method was validated and applied throughout all subsequent volatile analysis in this thesis. Chapter 3 explored the influence of clean-label sucrose replacers on the sensory quality and volatile aroma of sponge cakes. Gas-chromatography-olfactometry (GC-O) was applied to assess the impact of sucrose replacers on aroma perception, in combination with consumer evaluation and ranking descriptive analysis (RDA) to better understand changes in sensory perception. The influence of sucrose particle size, and sucrose source (beet or cane sugar) in sponge cakes was explored in Chapter 4. Chapter 5 investigated if butter produced from pasture and non-pasture bovine diets, had different sensory characteristics, in a cross-cultural context. Consumer studies were conducted in Ireland, Germany and the USA, and, RDA was conducted in Ireland and Germany, with descriptive analysis (DA) carried out in the USA. The butters produced from these same bovine diets were incorporated into shortbread biscuits, and liking was evaluated using consumers, in additional to temporal assessment, using temporal-check-all-that-applies (TCATA) to further understand the impact on the sensory properties of the shortbread biscuits (Chapter 6).
In summary this research demonstrated that the composition of sucrose replacers (particularly when containing reducing sugars), can accelerate Maillard (MR) and Caramelisation (CR) reactions, influencing sensory perception. ‘Spicy/bready’ furfural contributed most to the overall aroma of the sponge cake samples, and that ‘fatty cake crust’ heptanal and ‘potato damp’ methional, varied most between the control (100% sugar) and the 30% w/w reduced sugar sponge cakes with apple pomace powder and oligofructose, respectively. Sucrose source did not significantly affect (P < 0.05) the volatile profile of sponge cakes; however, reduced sugar crystal size positively influenced MR and CR compounds. No significant difference (P < 0.05) was identified in the overall liking, among USA, German and Irish consumers, of the experimental butters-although cross-cultural preferences were clearly evident. Sensory attribute differences based on cow diet were likely influenced by familiarity. The colour of shortbread biscuits formulated with pasture was perceived more favourable by consumers due to the golden colour, as a result of higher β-carotene content. The temporal profile of the shortbread biscuits, evaluated during the stages of oral processing; orthonasal, in-mouth and aftertaste, differentiated mainly due to variations in the fatty acid composition of the butter, which highlights that relatively minor changes in the fatty acid profile of butter can impact on the sensory characteristics of baked confectionery products where it is used as an ingredient
This PhD thesis has highlighted the potential of combining sensory techniques, volatile profiling and olfactometry to provide in-depth information to aid in understanding aroma development in baked confectionery products. This approach can evidently be used to improve the sensory quality of baked confectionery products and especially products with modified sucrose and fat contents; however it is also very applicable to improving the quality of any food type and in new product development.
Description
Keywords
Sponge cake , Biscuit , GC-MS , Flavour chemistry , Sensory analysis , Gas chromatography-olfactory
Citation
Garvey, E. 2020. Understanding aroma and flavour formation in baked confectionery products, as influenced by sugar and fat. PhD Thesis, University College Cork.