Novel high energy media mill produced macadamia butter: Effect on the physicochemical properties, rheology, nutrient retention and application

A novel high energy media mill (HEMM) was used to prepare macadamia butter (MB). The effect of grinding time on the properties of MB was investigated. Results showed that with the grinding time increased from 0 min to 65 min, the D[3,2], D[4,3], D50 and D90 value of the MB samples were gradually decreased from 24.03, 68.48, 59.50, and 124.67 μm to 4.37, 14.25, 8.82, and 34.07 μm, respectively, and the release of volatile flavor compounds gradually increased. Moreover, it did not adversely impact the color and chemical composition. Rheological analysis showed that the viscosity and yield stress of MB gradually decreased with the increasing of grinding time and the non-Newtonian shear thinning fluid behavior (flow behavior index, n < 1) was observed. In addition, HEMM treatment result in more oil separation and poor spreadability of MB. The maximum oil separation rate reached 49.46 g/100 g after 65 min of grinding. However, the addition of 1–3 g rice bran wax/100 g can significantly improve its oil separation and spreadability in toast. The results can provide a support for the application of HEMM in MB processing, and new insights for the development of multi-purpose MB.