Structure and physical properties of oleogels containing peanut oil and saturated fatty alcohols

This study examined the capability of fatty alcohols with chain lengths from C14OH to C22OH to gel peanut oil. The gelation was achieved by crystallizing the samples at 5 degrees C/min or 40 degrees C/min. Results showed that minimum gelling concentration decreased as fatty alcohol chain length increased and it was higher for fast cooled samples than for the corresponding slow cooled ones. More than 7% of C14OH was necessary to obtain a self-standing material highlighting its low capacity as oleogelator. Other oleogels were compared at 5% fatty alcohol concentration in peanut oil and oleogels containing C16OH yielded the weakest system, with the lowest ability to retain oil. This was attributed to its higher solubility in oil as compared to other fatty alcohols as well as to the formation of larger crystal aggregates. As the fatty alcohol chain length increased, systems became stronger, displaying smaller crystal aggregates. For all cases, an increase in cooling rate lead to the formation of weaker gels with reduced capacity to entrap oil. Practical applications: A novel strategy to reduce saturated/trans fats in food products involves the use of oleogels. Here we report on the use of even saturated fatty alcohols to gel peanut oil, thus preventing oil separation during storage and handling of products such as nut butters. The structure and physical properties of fatty alcohol oleogels greatly depend on fatty alcohols chain length as well as cooling rate applied during crystallization. Fatty alcohols proved to be a very efficient peanut oil stabilizer. Fatty alcohol chain length and cooling rate greatly affected organogel structure and physical properties.