Date of Award:

5-2016

Document Type:

Dissertation

Degree Name:

Doctor of Philosophy (PhD)

Department:

Nutrition, Dietetics, and Food Sciences

Committee Chair(s)

Silvana Martini

Committee

Silvana Martini

Committee

Marie K. Walsh

Committee

Robert E. Ward

Committee

Cheng-Wei Tom Chang

Committee

Conly Hansen

Abstract

Partially hydrogenated oil (PHO) has no longer GRAS status. However, PHO is one of the important ingredients in bakery and confectionary industry and therefore the food industry is seeking for an alternative fat to replace PHO. Waxes have shown promise to fulfill that demand because of its easy availability and cheap in price. Waxes with high melting points (> 40 °C) help in the crystallization process when mixed with low melting point oils. A crystalline network is formed in this wax/oil crystallization process where liquid oil is entrapped in wax crystal network. A new material is formed which is neither completely solid nor completely liquid; it’s called semisolid material. This wax/oil semisolid material is formed physically; there are no chemical processes or treatments involved. This material has a potential use in the lipid industry due to its resemblance to the properties of commercial margarine or similar lipids. BW has shown softer crystalline network formation compared to SFW and RBW. It is understood that presence of higher wax ester in SFW and RBW leads to stronger crystalline material formation. Blending waxes of different chemical composition (e.g. BW: wax ester, hydrocarbon, fatty acids, di-esters, hydroxyl esters. RBW: 100% wax ester) shows differences in physical characteristics at different blending proportions. HIU technology helps in delaying phase separation of crystals in low concentration (0.5 and 1% wt. basis) of wax/oil system. Our overall wax crystallization study has shown that there are different physical characteristics of wax/oil semi-solid system based on different parameters and processing conditions such as wax concentration, wax and oil type, cooling rate, storage temperature, high intensity ultrasound. The hypothesis of this dissertation is that chemical composition of waxes and vegetable oils and also processing conditions affect wax crystallization and physical properties of wax/oil materials.

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