Nutraceuticals compounds extraction optimization from open air and swell-dried banana peel powders

The aim of this study was to optimize the operating conditions of two drying processes on banana peels: open air and Instant Controlled Pressure Drop technique (DIC) assisted Swell-Drying at 40 degrees C in order to obtain high quality final powders. The optimization of three extraction conditions including extraction temperature (40-100 degrees C), extraction time (10 - 60 min) and particle size (60 - 363 mu m) from open air banana peel powder was investigated). Additionally, three DIC texturing conditions were improved. DIC involves maintaining banana peels at a high temperature for 20 to 220s, high steam pressure (p=0.3 to 0.6 MPa) and varying the Number of cycles from 1 to 7. Modelling of some nutraceutical compounds (Total Flavonoids Content and carotenoids) from open air and Swell-Dried banana peels powders by applying experiments design using Response Surface Methodology and Desirability Function. The antioxidant activity was also investigated by the determination of the % of DPPH inhibition. The optimal conditions derived from the multi-Responses-Desirability Function were as follows: 60.47 degrees C; 10min; and particle size phi= 348.648 mu m yielding a TFC=5.13 (mg QE/g d.b), TCC=0.48 (mg /g d.b) and % of DPPH inhibition=73.05%, with an optimal desirability coefficient d=0.7 (open air process). The following optimized DIC operating parameters with maximum desirability coefficient d=1, t=24.46s P=0.59MPa and number of cycles N=6.38 yielding a TFC=4.07 (mg QE/g d.b), a TCC= 1.37 (mg /g d.b) and a % of DPPH inhibition=75.97 %. Banana peel could be a good source of bioactive substances, which could be further used as a natural antioxidant.