Shelf life of macadamia kernels of different origin

Postharvest factors affect the shelf life of edible kernels. However, it is uncertain to what extent the origin of nuts can influence the shelf life of kernels. We established an accelerated ageing experiment for macadamia cultivar 'A16' kernels sourced from two geographically-distant plantations at Bundaberg and Clunes, Australia. We also purchased macadamia kernels of unknown cultivar and origin from a retail outlet. The samples were incubated at 45 degrees C for 24 days. Headspace gas (40 mL) was collected at 1, 10 and 24 days following incubation and analysed for hexanal content using e-nose (OdourScan (R)) as an indicator of oxidative stability. Hexanal content increased significantly throughout the incubation period in kernels of all different origins. However, hexanal content did not differ significantly between the different kernel origins. Our results suggest that kernel origin does not affect the shelf life of kernels that commence storage at similar levels of oxidative activity.