Crystalline stability of self-assembled fibrillar networks of 12-hydroxystearic acid in edible oils

The stability of organogels differs based on the organogelator concentration, storage temperature, and solvent type. Organogel post-crystallization annealing was monitored at 5 degrees C, 15 degrees C, 20 degrees C or 30 degrees C for up to 1 month. Gels, stored at 5 degrees C, had highly immobilized oil, as judged from large T-2 relaxation peaks at 50-70 ms determined by pulsed nuclear magnetic resonance (pNMR) and visual observations. When the gels were stored at 30 degrees C, the 50-70 ms T-2 relaxation peak shifted to longer relaxation times, indicating that the oil was more mobile than at 5 degrees C. Along with the increase in syneresis at 30 degrees C, the 12HSA network's crystallinity was also greater, having fewer inclusions of liquid oil, as determined by pNMR. The highly branched network observed at 5 degrees C changed more in time with regards to crystallinity although it entrained the oil to a much greater extent than the gels stored at 30 degrees C. (C) 2008 Elsevier Ltd. All rights reserved.