Phenolic extraction from cacao pod husks- a route to waste valorisation Shinta Rosalia Dewi (a,b*), Lee Stevens (a), Derek Irvine (a), Rebecca Ferrari (a), Eleanor Binner (a)
a) Department of Chemical and Environmental Engineering, University of Nottingham, NG7 2RD, United Kingdom
*shinta.dewi[at]nottingham.ac.uk
b) Department of Bioprocess Engineering, Universitas Brawijaya, 65145, Indonesia
Abstract
As a primary waste-by product (ca. 70-75% of the total weight of cacao fruit), ten tonnes of wet cacao pod husks (CPH) are discarded to produce a tonne of dry cacao beans. Without any treatment, CPH can cause environmental problems, such as foul odour and black pod rot disease on cacao plantation. in 2019, Indonesia was estimated discard \pm420,000 tonnes of CPH, which only a small portion was directly used as fertiliser and animal feed or processed into soap and biogas. Meantime, CPH contains bioactive compounds, such as pectin, fibres, and phenolic antioxidant compounds, which can be valorised into added-value products. This study focused on the extraction of phenolic from CPH as an initial step to valorisation. Phenolic compounds were reported to have antioxidant activity to prevent lipid oxidation in food industries. Phenolic extraction was conducted by microwave-assisted extraction (MAE) and conventional solvent extraction (CSE). CPH was collected from Malang, Indonesia and then dried using forced air dryer at 50C. In phenolic extraction, the effect of solvent type and particle size were investigated to obatin high yield. The extract quality was presented as total phenolic content (TPC) which was measured by using UV/Vis Spectrophotometer. The results showed that solvent type and particle size had significant effects \left(p<0.5\right) on TPC yield. The appropriate solvent, 50%ethanol, yielded high TPC from CPH with particle <38micron, was about 101.08\pm1.87 mg GAE/g dw.
Keywords: cacao pod husk, extraction, phenolic, microwave-assisted extraction, valorisation
