Morphology and Networks of Sunflower Wax Crystals in Soybean Oil Organogel

Publication date: Available online 23 April 2015 Source:Food Structure Author(s): Hong-Sik Hwang , Sanghoon Kim , Kervin O. Evans , Clarissa Koga , Youngsoo Lee Sunflower wax has been recognized as an excellent organogelator for edible oil. The detailed morphology and networks of sunflower wax crystals formed in an edible oil organogel has been studied. In this work, we found that phase contrast microscopy is an excellent, convenient tool to investigate wax crystals in organogel. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) further confirmed plate-like crystals of sunflower wax determined by phase contrast microscopy. AFM showed that the thickness of these crystals typically range from 100 to 250nm. Wax esters also were found to produce the thin plate-like crystals in soybean oil, which indicates that the major ingredients in sunflower wax, wax esters, are responsible for the crystal morphology. Effect of the medium on crystal morphology was also investigated. For the first time, this study reports from SEM pictures of cross-section samples that were prepared by our newly developed sample preparation method that plate-like crystals are well connected to each other to form dense networks. In this method, soybean oil in the organogel was replaced with a UV-curable resin and the resin was cured with light. The previously reported strong gelation ability of sunflower wax can be explained by the effectiveness of immobilization of oil with the netwo...

Source: Food Structure - April 24, 2015 Category: Food Science Source Type: research