Assessing traits in bread using image analysis and machine learning

Food quality depends on both consumer expectations and industry standards. Sensory assessment is one dimension of food quality. The current method of food industry to assess quality of food is product testing through trained sensory panels or consumer panels. These evaluations are effective, but very time consuming in time and human resources. So, food industry is interested in the development of new faster and cheaper methods. This paper proposes a complete computer system to predict quality of bread from color images of its crust and crumb. The proposed method encloses an algorithm to extract the crust and crumb from the bread image, a module to calculate color texture features from images and a machine learning module to predict the sensory traits, using support vector regression among other methods. Statistical evaluation comparing the Pearson correlation (R) between the scores provided by the trained panel and the computer prediction is presented for 24 sensory traits on 54 bread samples. The prediction achieved high reliability for 7 out of 24 traits (R≥0.75), 14 traits with moderate to good reliability (0.5≤R<0.75) and only 3 traits are predicted with bad to moderate reliability (R approximately 0.4). These results are very encouraging for the bread industry, although still subject to some limitations due to the small size of the dataset, due to its application in quality control and product categorization.