Physicochemical and Rheological Properties of Red Palm Olein Oleogels Made With Beeswax as the Oleogelator

Abstract

Red palm olein (RPO) is a source of carotenoids that can act as provitamin A and pigment. RPO is liquid at room temperature and heating degrades carotenoids easily. Modifying RPO into a solid by oleogelation is essential to expand its application in food products. This study aimed to identify the physicochemical and rheological properties of RPO oleogels, using beeswax as the oleogelator, including crystal morphology and formation, solid fat content, total carotenoid content, and colour analysis. This study consisted of three stages: characterisation of the raw materials, preparation of RPO oleogels (0%-10% beeswax), and characterisation of the RPO oleogels. RPO starts to form as a solid at 3% beeswax with a melting point of 40.61 ± 1.73°C (solid at room temperature) and 557.73 ± 10.28 ppm of total carotenoid. Furthermore, increasing the beeswax concentration increased the compacity of the needle-shaped crystal structure, which has an impact on the rheological properties of the oleogels, including the higher linear viscoelastic region, yield stress, melting point, and stability against frequency and temperature. RPO oleogel viscoelasticity showed a positive relationship with solid fat content. However, increasing beeswax concentration significantly decreases the total carotenoids of RPO oleogels, while increasing the lightness and yellowish colour of the oleogels.