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Natural processing for beverages: from a Hibiscus sabdariffa (Roselle) beverage perspective

Omoarukhe, E. D. (2017) Natural processing for beverages: from a Hibiscus sabdariffa (Roselle) beverage perspective. PhD thesis, University of Reading

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The beverage industry is tending towards the production of healthier, low calorie beverages containing only naturally derived ingredients. The use of these ingredients presents an opportunity for a rise in functional beverages but could also present beverage quality challenges. Using Hibiscus sabdariffa (Roselle) extracts, known for its functional properties, this research investigates some quality considerations that may result due to relevant changes to the production, storage and consumption of the beverage to suit clean label considerations. These issues relate to processing, calories reduction and stability. Several research questions have been generated under these categories and addressed in subsequent chapters of the thesis. From a Roselle beverage perspective, pasteurisation (in-bottle, 85oC for 20 minutes) and cold storage (below 4oC) were satisfactory for processing of the beverage. Stevia Rebaudioside A (SRA) was explored as a sugar replacer and displayed promising results such as improving the sensory attributes of the unsweetened Roselle extract. In physical and chemical tests, it matched the attributes of unsweetened beverages. However, it did not perform as well as sugar in either consumer studies and when combined with spice flavours. The spices (cinnamon, ginger and cloves) used for their flavouring and preserving properties did not improve consumer liking of the beverages in general but cinnamon demonstrated stabilising effects on the anthocyanins in a sugar sweetened Roselle beverage through a suspected co-pigmentation mechanism. Furthermore, cinnamon and ginger were deemed congruent with the Roselle flavour profile based on their performance in the consumer study. Further investigative work on spice and sweetener synergies and the understanding of their mechanisms were recommended.

Item Type:Thesis (PhD)
Thesis Supervisor:Jauregi, P. and Harbourne, N.
Thesis/Report Department:School of Chemistry, Food and Pharmacy
Identification Number/DOI:
Divisions:Life Sciences > School of Chemistry, Food and Pharmacy > Department of Food and Nutritional Sciences
ID Code:78761


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