Impact of Coconut Copra Byproducts Incorporation on Granola Quality Characteristics

Abstract

This study investigated coconut copra’s (CC) potential as a key ingredient in granola formulations, examining its antioxidant activity, techno-functional, rheological, and sensory properties. Copra exhibited a significant antioxidant capacity across multiple assays: DPPH (1.40–1.58 mg TE/g DM), ABTS (0.49–1.41 mg TE/g DM), and FRAP (0.50–1.43 mM FeSO4/g DM). Techno-functional analysis revealed a high water holding capacity (6.83–7.18 g H2O/g DM) and water absorption capacity (3.47–4.44 g H2O/g DM). When blended with banana flour (BF), the CC75/25BF (3:1 CC:BF ratio) mixture demonstrated optimal foaming stability (95.2–97.4%) and emulsifying properties. Rheological studies showed that increasing copra content reduced paste viscosity, with pure banana flour exhibiting the highest peak viscosity (5249 mPa·s) compared to the CC75/25BF blend (253 mPa·s). Storage stability testing over two weeks revealed minimal changes in lightness (L*: 36.53 to 35.64) and redness (a*: 15.79 to 16.12), though yellowness increased significantly (b*: 21.29 to 25.57). Texture analysis showed a progressive decrease in biting force from 37.7 N (day 0) to 16.2 N (week 2). Preliminary assessment of the final granola formulation demonstrated high consumer acceptance, with the nut-free version (Product A) receiving superior ratings for texture (4.00/5.0), crunchiness (4.00/5.0), and taste (4.06/5.0) compared to the nut-containing version. These findings suggest that coconut copra is a promising functional ingredient for granola production, offering both nutritional benefits and favorable sensory characteristics.