Image processing and physico-mechanical properties of basil seed (ocimum basilicum)

Various physical properties of basil seed (Ocimum basilicum) were investigated at a moisture content of 5.32% (wet basis). In order to present a quick and an accurate method for measuring small seed dimensions, the image processing data was compared with the one measured experimentally, and the correlations between these were determined. The average length, width and thickness obtained by image processing and micrometer methods were 3.216, 3.220, 1.838, 1.840, 1.363 and 1.374 mm, respectively. The average projected area, sphericity and roundness evaluated by image processing were 4.407 mm², 0.95 and 0.54, respectively. However, the average geometric mean diameter, arithmetic mean diameter, surface area and sphericity calculated theoretically based on micrometer data were 2.009, 2.145 mm, 12.796 mm² and 0.62, respectively. The average unit mass, 1,000 grain mass, volume, true density, bulk density and porosity were measured as 0.0020 and 2.23 g; 7.55 mm³; 1,038; 340.24 kg/m³; and 67.2%, respectively. The friction coefficient ranged from 0.300 for basil seed on glass up to 0.547 on plywood surface. The filling and funning angles of repose were established as 14.64° and 12.35°, respectively. The terminal velocity was 4.26 m/s, and textural properties including rupture force, hardness and toughness were determined as 537.4, 926.13 g and 246.32 g/mm, respectively. According to the small size of some seeds, dimension measurement is difficult and time consuming; therefore, developing a rapid, easy, accurate and nondestructive method seems to be necessary. In recent years, computer vision system (CVS) has been increasingly used in the agricultural and food industry. Some examples of CVS application in food industry are: classification of cereal grains, evaluation of pork color, measurement and classification of corn whiteness, automated sorting of pistachio nuts, quality inspection of bakery products, inspection of Golden Delicious apples, detection of pinhole damage in almonds and detection of bones in fish and chicken; therefore, we decided to examine the possibility and accuracy of this technique for measuring seed dimension for the first time. In this study, in addition to introducing the CVS system for dimension measurement, the physico-mechanical properties of basil seed have been determined, which is necessary for the design of equipment for harvesting, transporting, cleaning, packing, processing, etc.