Ultrasound Assisted Extraction of Bioactive Compounds Rich Extract from Immature Dropped Kinnow Fruit

Ultrasound-assisted extraction process parameters of bioactive compounds extraction from immature dropped kinnow fruit were optimized using response surface methodology. Box–Behnken design of the experiments was used to optimize the independent extraction variables: amplitude (30% to 70%), extraction time (3 to 9 min), and pulse cycle (2 to 6 s) for maximizing extraction of bioactive (total phenolics, total flavonoids, antioxidant activity such as 2, 2-diphenyl-1-picrylhydrazyl (DPPH) inhibition and ferric reduction activity potential (FRAP) activity) compounds from immature dropped kinnow fruits. Optimized conditions for ultrasonication bioactive extraction using 45.80% amplitude, 6.63 min extraction time and 4.24 s pulse cycle yielded 5.02 g GAE 100g-1 total phenolics, 9.41 g QE 100g-1 flavonoid content, 302.88 mg AAE 100g-1 DPPH, 6.95 g TE 100g-1 FRAP activity, 0.76 g DE 100g-1 saponins and 6.29 mg AE 100g-1 alkaloids. These optimized conditions could be used for pilot scale extraction of bioactive compounds from immature dropped kinnow fruits.