The control of food processing is becoming more and more important every day, and the search for sensing and measurement of parameters is of utmost importance. In this sense, the present work was developed with the objective of evaluating the color change by means of image analysis in the thermal process of blanching green plantain slices (5 mm) (San Martin region, Peru). Color changes in "ingiri" plantain (Musa paradisiaca Var. Harton) during blanching at different times were monitored by cell phone images, which were processed using ImageJ project software (ImageJ-win64 software, USA), and the Color Grab application (Loomatix Team, version 3.9.2), using a Samsung cell phone (Android) with a 13 megapixel front-facing triple camera. Temperatures evaluated were at 55, 75 and 93 ºC, heat treatment was three and six minutes, along with an unprocessed control. The banana slices were evaluated taking into account an angle of 90º (direction of the photo with the plane where banana was placed) and a distance of seven centimeters between the slices and the smartphone. Statistical processing was performed with Statgraphics Centurion XV.I. The results showed: significant differences in the "B" (RGB system), in agreement the amount of integrated density when the image was processed (monochromatic) also followed this kinetics, these results suggest that the processing of the banana during blanching followed a first order kinetics, with an activation energy of 5.89 J/mol. On the other hand, the parameters Cielab also measured, showed significant changes in the white/yellow ratio (L*/b*). These changes, taken together, show that by image analysis it is possible to effectively control color changes during blanching in banana slices. There are several applications and mechanisms for color control in the literature; however, the present study shows that image analysis using a smartphone could be efficient to control thermal processes at low cost.