Title: High intensity ultrasound: A new way to replace partially hydrogenated oil

Name: Zachary Cooper
Mentor: Silvana Martini

College: College of Agriculture and Applied Sciences

Department: Nutrition, Dietetics, and Food

Hometown: Erda UT

Abstract: 
Interesterified soybean oil was crystallized at 32, 30, 28, and 26 °C with and without high intensity ultrasound (20 kHz). Samples were placed in 1 cm diameter tubes and stored at 5 °C for 48 h. After storage, a 1.3 cm height cylinder was cut from the cylinder and placed in a filter paper (diameter 12.5 cm) at 5 and 25 °C for 24 h. Oil migration was measured as the diameter of the oil diffusing out of the crystalline matrix into the filter paper. Oil migration in samples stored at 25 °C occurred very fast and the diameter of diffused oil exceeded the diameter of the filter paper after 24 h. Oil migration occurred more slowly in samples stored at 5 °C. Results show that samples crystallized in the presence of sonication and stored at 5 °C for oil migration measurements had a significantly lower oil migration compared to the non-sonicated ones. For example, samples crystallized at 32 and 30 °C had diameters of 6.6 ± 0.2 and 8.9 ± 0.6 for samples crystallized without sonication compared to 1.9 ± 0.1 and 1.8 ± 0.1 for samples crystallized in the presence of sonication. The solid fat content of these samples was measured as a function of time and no significance difference was found between sonicated and non-sonicated samples except for in the sample crystallized at 32 °C, which SFC was 2.972 ± 0.3 and 6.584 ± 0.665 % for the non-sonicated and sonicated sample, respectively. This delay in oil migration can be attributed to differences in the characteristics of the crystalline network formed. Harder and more elastic crystalline networks are obtained in the presence of sonication with significantly smaller crystals.