Moisture‐dependentengineering properties of arugula seed relevant in mechanical processing and bulk handling

Abstract

Knowledge of the engineering properties of seeds, grains, nuts, kernels, and fruits is vital in the design of planting, harvesting, and postharvesting machines. This study investigates moisture‐dependent geometrical, gravimetrical, frictional, rheological, and aerodynamical properties of arugula seed. The length, width, and thickness of the seed distributions were modeled by the Normal, Log‐normal, and Weibull probability density functions. In the moisture ranges of 4.68–20.50%, the major, intermediate, and minor seed dimensions increased from 2.01 to 2.35 mm, 1.60 to 1.98 mm, and 1.17 to 1.33 mm, respectively. The results indicated that Log‐normal distribution had the best performance in most cases. Values of 1,000‐seed mass, bulk density, particle density, and porosity ranged between 1.33 to 1.77 g, 703.07 to 644.37 kg m−3, 1,160 to 1,392 kg m−3, and 39.39 to 53.71% as in the above moisture ranges. The filling and emptying angles of repose increased from 29.21° to 34.78° and 37.95° to 39.75°, respectively, as the moisture content increased. Incremental trends were observed for terminal velocity in water and air and residual stress during relaxation tests. Decreasing trends were observed for drag coefficient, modulus of elasticity, maximum contact stress, toughness, hardness, rupture force, and reduced stress during relaxation tests.Practical ApplicationsArugula (Eruca vesicaria L. or Eruca sativa Mill L.) is a popular worldwide vegetable. Besides consuming its leaves as a vegetable, the oil extracted from its seeds has industrial uses. This study investigated properties of arugula seeds with varying moisture contents with a view to understand their relevance in mechanical processing and bulk handling. The results presented in the current work would contribute to designing the metering devices (distributors), sorters, separators, cleaners, transportation systems, conveyors, oil extractors, etc.

Physico‐mechanical properties of unripe grape berries relevant in the design of juicing machine

“…Similar results have been reported for comparing friction angles on galvanized, iron, and rubber surfaces at different moisture levels (Fadavi, Mirzabe, & Mansouri, 2015;Mirzabe, Taheri, Pouyesh, & Bavani, 2016;Taheri et al, 2015). Furthermore, in all moisture levels, the emptying angle of repose had higher values than the filling angle of repose reported by (Mirzabe et al, 2016(Mirzabe et al, , 2021bTaheri et al, 2015).…”

“…Thereupon, dimensions and coordinates of the four contours of each bounding box of berry were measured in pixels. Pixel values were converted to the mm by multiplying these measured amounts into a size of pixel measured by a reference value (Mirzabe et al, 2021b).…”

“…The berries were assumed to be ellipsoid before starting the test, and by lowering the jaw of the device, they started to deform and formed the shape of the incomte ellipsoid. After tests, the Python programming language was used to capture desirable images from the videos at a rate of 2.5 s. After that, as explained in previous section, measurements of the berries' height, width, and thickness were performed (Mirzabe et al, 2021b).…”

“…Pixel values were converted to the mm by multiplying these measured amounts into a size of pixel measured by a reference value (Mirzabe et al, 2021b).…”

“…Due to the importance of the physical, mechanical, and thermal properties of agricultural products in the field of the development of automatic processing equipment (Wang, Ma, Fu, Cui, & Majeed, 2020), much research has been done to determine these properties for seeds (Bajpai, Kumar, Singh, Prabhakar, & Meghwal, 2020; Gade, Meghwal, & Prabhakar, 2020; Rokhbin, Azadbakht, & Asghari, 2021; Singh & Meghwal, 2020) grains (Carvalho, Polachini, Augusto, Telis‐Romero, & Bon, 2021; Pohndorf et al, 2018), nuts (Kilanko et al, 2020; Kumar, Prabhakar, Srivastav, & Bhowmick, 2016), kernels (Habibiasr, Mokhtar, Ibrahim, Md Yunos, & Ibrahim, 2020; Razavi & Edalatian, 2012), and fruits (Tan, Tan, Ghazali, & Tan, 2021; Vahedi Torshizi, Khojastehpour, Tabarsa, Ghorbanzadeh, & Akbarzadeh, 2020). Although determining physical properties is more common than mechanical properties, there are reports that investigate the rupture force (Akar & Aydin, 2005; Sirisomboon, Kitchaiya, Pholpho, & Mahuttanyavanitch, 2007), rupture energy (Kılıçkan & Güner, 2008; Sirisomboon et al, 2007), toughness (Lucas et al, 2012; Sirisomboon et al, 2007), hardness (Nwanjika, Onuegbu, & Amaefule, 2017), modulus of elasticity (Mirzabe, Hajiahmad, & Asadollahzadeh, 2021b; Nwanjika et al, 2017), maximum normal contact stress (Mirzabe et al, 2021b; Nwanjika et al, 2017), and Poisson's ratio (Gładyszewska & Ciupak, 2009; Grotte, Duprat, Piétri, & Loonis, 2002) for agricultural crops. However, the conducted literature review showed no conducted research on measuring the physical properties of unripe green grape berries.…”