Abstract/Summary

Research into plant-based milk alternatives (PBBMAs), in particular Oat-based (OMAs) is increasingly important. Existing literature has highlighted sensory, physicochemical, and nutritional challenges – with limited protein quantity and quality, potential for bioactive compounds to hinder absorption of calcium and impart bitter and astringent effects, and issues with processing, stability and appearance – all of which impacting the overall acceptability of OMAs. There are substantial gaps in literature which are necessary to address. The aim of this thesis is to lead to a better understanding of the sensory, physical and nutritional profile of OMAs, to provide a basis on how to optimise future products. This research investigates the physical, chemical, and sensory components of existing commercial OMA’s, and how these correlate with one another, concluding that smaller particle size results in increased whiteness of products, avenanthramides and avenacosides at their current level in OMAs do not correlate with perceived bitterness and astringency, and packing may substantially effect the volatile profile. Following this, the effects of pea and potato protein fortification are investigated, concluding that pea and potato protein fortification as low as 1% significantly affect the physical and sensory properties of OMAs. Next, a study into the effects of processing on oats nutritional components, found processing steps to affect properties differently, with only avenanthramides more susceptible to heat degradation, and only β-glucan lost within decanted solids, whilst the effect of enzymatic hydrolyses differed depending on the enzyme in use. Finally, an investigation into the effect of OMAs on calcium bioavailability discovered no significant reduction in calcium uptake in comparison to cow’s milk, suggesting calcium uptake is not negatively affected by OMA’s. This research on PBMAs is promising for the future of these products, as despite challenges and drawbacks, there are many methods established to address and overcome these. With the highlighted areas addressed in future research, it may be possible to optimise the nutritional, sensorial and physicochemical profile of OMAs.