Environmental Waste Management: Effect of Debittered-defatted Orange Seed Flour on the Proximate, Anti-nutritional and Sensory Properties of Biscuit

Orange seeds were extracted from orange fruits and sundried at 30 ± 2˚C for 8 hours. The orange seeds (20kg) were steeped in water for 12 hours and cooked for 120 minutes. The boiling seeds were dehulled, oven dried at 60°C for 14 hours, ground and defatted with 100% ethanol, milled, and sieved. Debittered orange seed flour was used to substitute 10, 20, 30, 40, and 100% in biscuits to test its proximate composition, physical, and sensory qualities. The results revealed that the proximate composition of the biscuits ranged from 12.49% to 17.17% protein, 9.38% - 12.14% fat, 1.55 - 9.84% crude fiber, 1.07% - 4.01% ash, 6.37% - 11.00% moisture content, and 45.83% - 64.46% carbohydrate. With increased orange seed flour content, the biscuits' weight, volume, break strength, and thickness reduced, while their spread ratio and density increased. The anti-nutrient composition of the biscuits revealed oxalate (20.06 – 77.21 mg/100g), phytate (61.03 – 99.91 mg/100g), and tannin (0.07 – 2.09 mg/100g). Biscuits made with up to 30% orange seed flour were generally acceptable throughout sensory evaluation. Orange seeds are commonly disposed improperly during the manufacturing of juice along with other orange fruit products, causing a severe environmental impact and posing a health risk. Orange seed flour production would not only provide a novel source of flour for food manufacturing, but would also serve as an environmentally friendly recycling option.