Evaluation of Photoshop software potential for food colorimetry: color changes of Mazafati dates during accelerated ripening

Abstract

Color and appearance are among the first parameters perceived by consumers to judge the quality of foods. L*a*b* are used to report foods’ colors quantitatively. In this study the use of digital imaging and Photoshop software was evaluated for measurement of L*, a* and b* color parameters. The results showed that L*, a*, and b* values from Hunter colorimeter and the digital imaging method had a good correlation with R2 more than 0.95, but the values from digital imaging method can be used only to monitor the trend of color changes and the actual numbers of digital imaging L*, a* and b* obtained by digital imaging do not have the same value as the L*, a* and b* given by a Hunter colorimeter. Using two equations for the three parameters the values obtained from digital imaging method can be successfully converted to Hunter Lab color corresponding parameters. The color change of Mazafati date during accelerated ripening using acetic acid solutions was monitored by the proposed method. L*, a*, and b* of the samples all decreased over the ripening. Key words: Colorimetry, Photoshop software, Digital imaging, Mazafati date