Development of a system to measure color in fresh and microwave dried banana slices.

The main focus of this study was to develop and calibrate a computerized image analysis system in order to measure the color of banana (Musa Cavendish) under microwave treatment. Bananas were cut into 2 mm slice thickness and dried at two different microwave power level; 540 W and 180 W. An algorithmic was developed which converted RGB color value from a color image into CIE L*a*b* values very well (ErrorL* = 2.163%, Errora* = 4.458%, Errorb* = 5.224%). Once the calibration is completed, it was applied to measure the color change in the banana slice during drying. The value of L* decreased from 89.01 to 71.17 and from 82.60 to 72.53 for both microwave treated samples suggesting browning is taking place during the drying operation. The value of a* increased from - 0.80 to 11.50 and from - 3.90 to 5.18 for 540 and 180 W microwave treated banana slices respectively suggesting tendency of redness increased. The same type of increment was observed for b* value. It changed from 36.46 to 60.51 and 34.02 to 72.82 for 540 and 180 W microwave treated banana slices, respectively. Artificial Neural Network (ANN) modeling was used for prediction of the developed CVS's values.

Study of color kinetics of banana (Musa cavendish) under microwave drying by application of image analysis.

Microwave drying works on the volumetric heating concept promoted by electromagnetic radiation at 0.915 or 2.450 GHz. In this study, banana (Musa Cavendish) was taken as the sample and treated under microwave drying. The effect of two process variables, namely slice thickness (2, 3.5, and 5 mm) and microwave power (180 W, 360 W, and 540 W), were studied on drying kinetics and color kinetics. It was observed that the inverse variation relationship exists between drying time and microwave power level while drying time and slice thickness exhibited a direct variation relationship. A Computer Vision System (CVS) was developed to measure the color values of banana in CIELab space using an algorithm written in MATLAB software. Once the color parameters were obtained, they were fitted in First and Zero-order kinetic models. Both models were found to describe the color values adequately. This study concludes that microwave drying is a promising dehydration technique for banana drying that reduces the significant time of drying. Application of CVS is an excellent approach to measure the surface color of banana.