Assessing Fatty Acid Profiles of Macadamia Nuts

The kernel of the macadamia nut (Macadamia integrifolia and M. tetraphylla) is very high in oil, accounting for about three -quarters of their mass. In the current investigation, oil extracts from 20 breeding accessions and 14 cultivars had a range of 12.3% to 17.0% saturated fat, averaging 14.2%. Although all samples were found to be very high in “healthy” monounsaturated fats, the level of saturated fat slightly exceeds that of many other nuts that are able to make qualified health claims. The lowest saturated fat content (12.3%) corresponded to 4.6 g saturated fat/50 g kernels, which was slightly greater than the 4.0 g maximum. Despite this, potential exists to develop a reduced-saturated fat macadamia by combining characteristics found in different lines. The current trial indicates that lower total saturated fat was associated with a stronger ability to partition C16 and C18 fats to their monounsaturated fatty acids, or to elongate C16:0 to C18:0 and subsequently desaturate C18:0 to C18:1. It was also observed that the pollinizer parent is likely to have an influence on saturated fat content, although this would need to be confirmed in controlled pollination trials. Macadamia varieties generally outcross, and because the edible kernel (embryo) is formed from a pollinated ovule, it is likely any future reduced-saturated fat line would also require a reduced-saturated fat pollinizer parent