STUDY OF THE CRACKING ENERGY DYNAMICS WITH NOMINAL DIAMETER AND MASSES OF PALM KERNEL NUT DURING CRACKING

This study sought to determine the relationship between cracking energy and palm kernel nut nominal diameter and their masses. Large sample of palm kernel nut were cracked using the static impact method, after characterization of the kernel based on the nominal diameter into d<12mm; 12mm?d<15 mm; 15mm?d<17mm; 17mm?d<19mm; 19mm?d? 20mm and d>20mm. The moisture content of the bulk sample at the time of cracking was 10.42%wb. Cracking was carried out using the energy cracking equipment with different hammer masses against various drop heights, while visual observation was used to assess the level of cracking as follows; completely cracked (CCR), completely cracked with slight damage (CCD), cracked without nut separation (CWS), unable to crack (UCR) and smashed (SMD). The best efficiency of the whole kernels obtained for the various size ranges were 100%, 100%, 90%, 100% and 90% respectively, with the cracking energies varying between the size ranges. Results indicate that cracking energy correlated positively with palm kernel nut masses for size ranges, 12mm?d<15mm, 15mm?d<17mm and 19mm?d?20mm with low sample correlation coefficient, except for size range 19mm?d?20mm which had a 59.62% proportional variability. Cracking energy also had a positive correlation with palm nut nominal diameter for size ranges 15mm?d<17mm; 17mm?d<19mm and 19mm?d?20mm, with low sample correlation coefficient, except for size range 15mm?d<17mm with a proportional variability of 59.64%. Though the energy required to crack palm kernel nut increased as the nut masses and nut nominal diameter increased, cracking energy is unlikely to be influenced by nut mass and its nominal diameter, as the proportion of the cracking energy variability attributed to nut masses and nut nominal diameter for the entire sample is low leading to a weak linear relationship between cracking energy and nut nominal diameter and cracking energy and nut masses.