Efficiency of Fruit Coating Wax from Palm Oil Industry’s Wastewater Fat (TH-ENV wax) on Banana Fruits Preservation

Abstract

The objectives of this study were to: (1) observe microstructure of grease in palm oil industry’s wastewater, (2) create the processes of separating and cleaning fat from grease by non-toxic solvent, (3) compare metallic contaminants in cleaned fat, crude fat and wastewater, (4) formulating the fruit coating wax (TH-ENV wax) from cleaned fat and (5) test the efficiency of TH-ENV wax on weight loss and sweetness increasing in banana. Twenty liters of palm oil industry’s wastewater was collected from grease trapping. Microstructure observation showed that base oil surrounded metallic skeleton in grease molecule, molecular size was 0.8x1.1 μm2. Crude fat was separated from grease of wastewater by mixing to 5% acetic acid then centrifuged at 3,000 rpm for 15 minutes.. The resulted suspension can be visually identified into 3 layers, fat layer on top, liquid layer in the middle and sludge layer at bottom. Fat was collected, cleaned and used as raw material for TH-ENV wax production. Metallic contaminants in the fat decreased after the separating and leaning processes. TH-ENV wax is a bi-layered composite wax (fat/polysaccharides) composed of fat, Siam weed extracts, Tacca’s starch in water (3:1), chitosan and water at 30, 5, 10, 5, 50 % v/v respectively. Triton X-100 was added as emulsifier when testing the TH-ENV wax on banana. Results showed that TH-ENV wax coated bananas’ weight loss was significantly less than unwaxed bananas on day 1 of storage and its sweetness increasing was significantly less at day 5 of storage.