Nutrient Content, Functional Properties and Acceptability of Rock Buns Formulated From Freeze‐Dried Detroit Dark Red Beetroot Pomace Flour

Beetroot pomace is an underutilised food by-product obtained from the processing of beetroots. However, its rich source of nutrients makes it a potential ingredient for utilisation in rock bun development. The aim of the study was to investigate the nutrient composition and functional properties of freeze-dried beetroot pomace and wheat composite flours, as well as the sensory acceptability of rock buns formulated from these flours. Rock buns were formulated with 95:5, 90:10, 85:15 and 80:20 for wheat flour:freeze-dried beetroot pomace flour (BPF) and 100:0 for the control, respectively. Functional properties and proximate analysis of the flours were determined using standard methods. Sensory evaluation was carried out using a 100 mm visual analogue scale. One-way ANOVA was used to determine significant differences in the mean of the parameters evaluated. Principal component analysis and agglomerative hierarchical clustering exploiting Ward linkage and Euclidean distances were used to establish a visual relationship between the flour samples and some outcome variables. The nutrient composition of composite flour enriched with 20% of BPF showed high fibre, protein and ash content of 1.79%, 11.71% and 2.19%, respectively, compared to the control sample. The swelling power, oil absorption capacity and water absorption capacity increased with increased incorporation of BPF, whilst dispersibility and solubility decreased. The sensory acceptability of the rock buns enriched with 5% and 10% freeze-dried BPF was comparable to the control rock buns formulated from wheat flour only. Rock buns enriched with 10% freeze-dried BPF are nutrient-dense and can compete with control rock buns commercially.