P.V. Munasinghe¹, R.M. Dharmadasa^2,, W.C.P. Egodawatta¹, G. Liyanaarachchi², Udayani Binduhewa²

King coconut (Cocos nucifera var. Aurantiaca) water is considered a healthier beverage option, yet the remaining parts of the nut, namely the mesocarp and endocarp, often become king coconut waste (KCW), which decomposes over two to three years. This study aimed to transform KCW into a nutritious ready-to-serve (RTS) beverage to support zero waste management. The KCW was divided into components, and their proportions were calculated. Total antioxidant activity (TAC), total phenol content (TPC), and total flavonoid content (TFC) were assessed using Folin-Ciocalteu method and modified AlCl₃ method respectively, while total antioxidant activity was determined using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) Free Radical Scavenging Assay, and Oxygen Radical Absorbance Capacity (ORAC) Assay. The mineral content was determined using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Quality parameters such as pH, titratable acidity, and colour were measured through established analytical techniques. RTS beverages were formulated with 10%, 15%, and 20% concentrations of king coconut waste extract (KCWE) and evaluated by twenty trained panelists. Anti-inflammatory activity was performed using Arachidonate 5-Lipoxygenase (A5-LOX) inhibition assay. Proximate analysis of king coconut mesocarp extract-based drink was performed using AOAC methods. Data analysis was conducted with SPSS software. Results indicated that KCW consists of 7.82% mesocarp, 7.33% endocarp, 14.34% coir dust, 10.18% fiber, 4.33% perianth, and 16.29% king coconut mesocarp extract (KCME). The final beverage formulation yielded TPC of 880.65±12.8 mg GAE 100 mL-1, TFC of 8.11±0.17 mg QE mL-1, DPPH of 75.42±1.48 μg mL-1, and ORAC of 232.84±67.75 mg TE 100 mL-1. Color values (L*, a*, b*) were 16.57±0.19, 5.91±0.20, and 7.98±0.08, respectively, with pH at 2.94±0.02 and titratable acidity at 18.34±0.12. The RTS beverage, with 10% KCWE achieved significantly higher scores for all sensory attributes, and overall acceptability. Additionally, KCWE-based beverages exhibited 88±0.71% anti-inflammatory activity, reinforcing traditional claims regarding their health benefits. The findings suggest that KCWE is a valuable source of wellness beverages, promoting the zero-waste concept in the king coconut industry.

Keywords: King Coconut, Cocos nucifera Antioxidants, Minerals, Phytochemicals, RTS beverage, Zero waste management