Physical and Mechanical Properties of Garlic Bulbs and Cloves (Allium sativum L.) Relevant to Development of Garlic Bulb Breaker

摘要

Garlic (Allium sativum) is one of the important bulb crops grown and used as a spice in culinary ingredient as it adds to the taste and flavour in a wide range of food preparations. It also has medicinal properties. Garlic cloves are processed in theform of dehydrated products like flakes, powder, pickles paste, canned and bottled. Processed products of garlic are in good demand in local market for defense and fast food industries and also exported to exotic markets to earn valuable foreign exchange. Garlic is propagated by single clove. For these reasons, garlic bulbs are broken and loosened into garlic cloves. Conventionally, garlic cloves are separated by rubbing the bulb between palms, against jute bags or by beating with a wooden stick. As these methods are very laborious and time consuming, machinery are being developed to break the whole garlic into single cloves. Knowledge of physical, mechanical and mechanical properties of garlic bulb and garlic clove are very important for development of machinery. Hence, study was conducted to determine physical, mechanical and aerodynamic properties at 60.92 per cent moisture content on dry basis. These properties namely polar diameter, equatorial diameter, thickness, geometric mean diameter, shape index, weight of garlic bulbs, bulk density, true density, porosity, angle of repose were found to be 61.25±1.43 mm, 43.21±0.83 mm, 36.00±0.85 mm, 45.70±0.86 mm, 0.74+0.01,3065.59±0.97 g, 453.5+20.7 kg/m3,988.08+20.7kg/m3,53.99+2.40 per cent and 54.16+3.85° for garlic bulbs. The co-efficient of static friction on different surfaces of materials like plywood, glass sheet and mild steel sheet for garlic bulbs were found to be 0.454+0.40,0.321+0.28 and 0.387±0.34. The force required to loosen the garlic cloves from the whole bulb was 40.15+0.1 N. The physical, mechanical and aerodynamic properties of garlic cloves viz., length, width, thickness, geometric mean diameter, sphericity, weight of hundred garlic cloves, bulk density, true density, porosity, and angle of repose were 27..3+1.92 mm, 10.18±0.35 mm, 7.42±024 mm, 12.55±0.04 mm, 0.45± 0.001,181.1+0.2 g, 424.94+7.23 kg/m3,1516.22± 2322 kg/m3,59.02+6.09 per cent and 38.40+3.78°. The co-efficient of static friction on different surfaces of materials like plywood, glass sheet and mild steel sheet were found to be 469+0.006, 0.364±0.003 and 0.394±0.004 for garlic cloves. The terminal velocity of garlic cloves, stems and skins were 11± 0.69, 426+0.56 and 1.32+0.42 m/s.