Date of Award:

8-2020

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Nutrition, Dietetics, and Food Sciences

Committee

Silvana Martini

Committee

Robert Ward

Committee

Luis Bastarrachea

Abstract

Lecithin is an ingredient commonly used in foods composed of high concentration of phospholipids. Phospholipids are a type of fat that can mix with both water and oil. In the current food industry, most lecithins come from sunflower, egg, and soybean sources. An additional source of phospholipids can be the waste streams from the dairy industry, such as the whey protein and butter making processes, since these contain a high concentration of phospholipids. Dairy phospholipids have been isolated in the past, but their traits as a functional ingredient are still unknown. In addition, most isolated dairy phospholipids still contain protein, lactose, minerals, or other types of non-fat soluble molecules. In the food, cosmetic, and pharmaceutical industry the crystallization of fats and functionality of phospholipids is very important. Crystallization gives structure to food, cosmetic products, and some pharmaceutical products as well. The ways in which the molecules align and organize themselves into structures is referred to as crystallization. In this thesis it will be discussed how to isolate dairy phospholipids from a commercially available phospholipid concentrate into an oil soluble isolate and how the phospholipids influence the crystallization of anhydrous milk fat (concentrated butter containing less than 0.01% water) and the structuring of soybean oil. For the anhydrous milk fat, low concentrations of phospholipid was added (0%, 0.01%, and 0.1%) and crystallized at 24, 26, and 28 °C in anhydrous milk fat where the amount of solids (solid fat content), type of crystals (polymorphism), viscoelastic properties (the way crystals react under shear stress), hardness, melting behavior (the way in which the samples melt as temperature increases), and crystal shapes (crystal morphology) were measured. Results showed that PL can be used to tailor the crystals in anhydrous milk fat. In addition, three different mixtures were made using soybean oil and various concentration of PL (15%, 30%, and 45%). The amount of solids, oil binding capacity (ability to entrap liquid oil), viscosity (ability for samples to flow), melting behavior (the way in which the samples melt as temperature increases), and crystal shapes (crystalmorphology) were measured. It was observed that PL could be used to form a semi-solid structure and tailor the crystal formations that are formed due to the fatty acid composition of the lipid components of the PLI.

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Food Science Commons

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