Physical compatibility between wax esters and triglycerides in hybrid shortenings and margarines prepared in rice bran oil.

Abstract

Wax esters contribute to the transformation of liquid oils into solid-like oleogel systems, which can act as alternatives for trans- and/or saturated fats in food products. The use of solely waxes reduces the solid content, consistency and sensory quality in the final products. Therefore, a combination of sunflower wax and palm fat in rice bran oil was created to accomplish the hybrid low-saturated shortenings and margarines with a compatible structure and lower amounts of saturated fats. During cooling of the hybrid shortenings, sunflower wax crystallized first and acted as nucleation sites for the crystallisation of palm fat. At 5 °C, a mixture of different crystal morphologies (α, β', and β crystals) existed in the hybrid shortening. In margarine processing, the hybrid samples were subjected to a simultaneous cooling-emulsification, in which sunflower wax crystallised first at the interface and adsorbed onto the water droplets. Based on the hardness measurements, the maximum amount of palm fat replaceable by 1.0%wt sunflower wax was up to 40% in shortenings and 25% in margarines. A higher amount of sunflower wax (2.5%wt) reduced up to 40% of saturated fats in the hybrid emulsions. The addition of 1.0%wt sunflower wax enhanced the solid content and network strength of hybrid palm-based shortenings. Sunflower wax helped to stabilise the water droplets inside the wax-based crystalline network without flocculation during shear-cooling. This research provides fundamental insight into the structuring of hybrid systems containing waxes, which could be interesting for the production of low-saturated fat products in the food industry. © 2017 Society of Chemical Industry.