Study on some engineering attributes of pine nut (Pinus pinea) to the design of processing equipment

Abstract

Moisture-dependent engineering properties of pine nut were studied at 6.3, 8.2, 10.8, 14.5, 18.9, and 20.1% moisture content (dry basis). The length, width, thickness, and geometric mean diameter increased significantly (P < 0.05) from 21.75 to 21.85 mm, 7.39 to 7.47 mm, 6.07 to 6.14 mm, and 9.89 to 9.98 mm, respectively, with an increase in moisture content from 6.3% to 20.1%, whereas the increase in sphericity from 45.49% to 45.69% was not significant. Similarly, thousand seed mass, true density, porosity, terminal velocity, and angle of repose increased (P < 0.05) from 0.85 to 0.93 kg, 1043.3 to 1071 kg/m3, 41.31% to 44.57%, 8.67 to 8.83 m/s, and 35.4° to 39°, respectively, with an increase in moisture content under the experimental condition. Moreover, the bulk density decreased significantly (P < 0.05) from 612.3 to 593.6 kg/m3. Coefficient of static friction increased (P < 0.05) from 0.251 to 0.292, 0.241 to 0.271, 0.227 to 0.262, and 0.218 to 0.247 on plywood, galvanized iron sheet, stainless steel, and glass surfaces, respectively, with an increase in moisture content from 6.3% to 20.1%.