Unveiling moisture effects on physical, fluid, and thermal dynamics of fennel seeds

A phytochemical analysis of three varieties of seeds, AF-1, AF-2, and AF-3, suggested the highest protein content for the AF-2 variety, equivalent to 15.69%. The highest crude nitrogen content was found for the AF-2 variety. The pH value for the AF-1, AF-2, and AF-3 varieties was 5.84, 5.9, and 5.98, respectively. The AF-2 variety was also found to have the lowest a* value of -0.0533; hence, they were greener than the AF-1 and AF-2 varieties. Analysis of physical and thermal properties was done by varying the moisture level of the seeds from 10 to 22%. The gravimetric properties, including bulk density and true density, decreased with the increase in the moisture content from: 379.867 to 312.5, 370.37 to 329.75, and from 348.93 to 306.19 kg m-3 for the AF-1, AF-2, and AF-3 varieties. True density decreased from 1 000 to 666.66 kg m-3. Angle of repose increased from 79.38 to 82.24° for the AF-1 variety, from 79.14 to 82.18° for the AF-2 variety, and from 79.82 to 81.88° for the AF-3 variety. The coefficient of friction increased with the moisture level; however, it was found to be the highest for the wood surface for all three varieties of fennel seeds. Specific heat and thermal conductivity increased significantly with the increase in moisture. The knowledge of the physical properties of the fennel seeds, including their size, shape, volume, and surface area, is helpful in designing machinery for sorting, grading, and sizing. Gravimetric properties like bulk density, true density, and porosity aid in designing storage containers, hoppers, and separation processes based on density. Frictional properties like the coefficient of friction and angle of repose play an essential role in designing storage bins, chutes, and handling equipment, including screw conveyors, threshers, and forage harvesters, to ensure smooth movement and prevent blockages. Drag properties like terminal velocity, drag coefficient, *Corresponding author e-mail: [email protected] and projected area are useful for the design of separation systems, like air classifiers, which sort grains and seeds according to their aerodynamic characteristics. Thermal properties help design the equipment used in heat transfer processes like cooking and drying. It also helps in understanding the heat transfer phenomenon in the food system.