Food Science and Technology Department


First Advisor

Ozan N. Ciftci

Date of this Version



Gudeman, J. (2019). Formation of Low Density and Free-Flowing Hollow Microparticles from Non-Hydrogenated Oils and Preparation of Pastries with Shortening Fat Composed of the Microparticles. Digital Commons.


A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Food Science and Technology, Under the Supervision of Professor Ozan N. Ciftci. Lincoln, Nebraska: October 2019.

Copyright (c) 2019 Joshua R. Grudeman


Solid fats provide critical functionality in the structuring, shortening, and stabilizing of many foods. However, their use as an ingredient is foods can present a number of challenges. The physical properties of solid fat can make them difficult to apply to or incorporate into foods consistently. On an industrial food production scale, handling of solid fats can difficult because they are often packed in heavy cubes or totes, and production delays and inefficiencies may be caused by the need to remelt the oils before use. Oils as a macronutrient also contribute a relatively high number of calories at 9 calories per gram.

The overall objective of this thesis is to create micron size hollow solid fat particles using supercritical CO2 that are free-flowing, easy to handle, quick to remelt, and simple to incorporate into foods. Specific objectives include forming free-flowing hollow solid lipid microparticles from fractionated palm oil and low moisture butter using CO2, to characterize these novel lipid particles, and to test the performance of these particles as a shortening in pastry products.

The solid fat particles produced were composed using 50:50, 25:75, and 0:100 ratios of butter and fractionated palm oil respectively. In presence of 120 bar pressurized CO2, the melting point of the fractionated palm oil decreased from 66.2 to 47.3 °C. The density of the particles decreased 5 folds compared to that of the original oils. With increasing fractionated palm oil 3 content, the particle size decreased. Ten percent (d10%) and fifty percent (d50%) of the 100% palm oil particles were smaller than 4.49 μm and 23.0 μm, respectively, whereas they were 14.5 μm and 58.3 μm when mixed with butter at 50% butter concentration, respectively. The hollow structure was more pronounced for the particles obtained from higher melting oils/oil blends, as well as with more spherical uniformity.

When used as the shortening fat in pastries, the microparticles increased firmness and thickness. Their high ratio of surface area to mass does hold potential for other applications, and the small size and free-flowing nature did make the particles easy to mix into the pastry flour.

The micron size hollow particle format for solid fats has the potential to provide a number of important benefits. It could allow for reduced calorie contributions from fat, better finished product quality, improved solid fat handling, and easier fat incorporation into formulas.

Advisor: Ozan N. Ciftci