Indirect Estimation of Mass and Shape Ratio Changes of Aloe vera gel Coated Cherry Tomatoes Using Image Processing Technique

Mass and shape ratio changes estimation of fruits and vegetables using image processing technique is one of the latest advances in post-harvest technology. In this study, changes in mass and shape ratio of cherry tomatoes coated with different concentrations of aloe vera gel (0, 25, 50, 75 and 100%) during storage time at ambient temperature were investigated. For this purpose, after pre-processing of the images, dimensional features (area, main and sub-diameter) as well as the shape ratio were extracted. Then, the relationship between the extracted features of the images and the actual mass was determined using linear and power curve models. The results showed that the linear model well fitted the mass changes in term of the area of the image (R2 = 0.9895) with the accuracy of 0.9729. The results also revealed the efficiency of this system to estimate mass changes during storage with an average relative error of 3.359%. This indicates a very strong relationship between dimensional and mass characteristics. Shape ratio estimation based on the longitudinal and transverse diameters showed that the shape of the coated cherry tomatoes changes due to the loss of moisture from the spindle to the cylindrical shape (shape ratio from 1.1 to 1.7) which this trend decreased with increasing the percentage of aloe vera gel concentration.