Recipient Organization
UNIVERSITY OF NEBRASKA
(N/A)
LINCOLN,NE 68583
Performing Department
(N/A)
Non Technical Summary
Physical properties are important characteristics of fats that determine their use in various food applications from baking and confections to plant-based foods. Physical properties are driven by the crystallization kinetics of fats, and it is therefore essential to understand the factors that influence crystallization kinetics to obtain desired physical properties.The hypothesis of this research is that intrinsic properties of fats such as chemical composition, viscosity, surface tension, heat capacity, and density, in addition to thermodynamic factors such as supercooling, driving force, and activation free energy of nucleation play important roles in fat crystallization and therefore in tailoring physical properties. Two objectives will be pursued to test this hypothesis. In Objective 1 custom-made samples with different types (lauric, palmitic, and stearic fatty acids) and content (30, 50, and 70%) of saturated fatty acids will be produced via enzymatic interesterification to allow for the use of samples with controlled and systematic changes in chemical composition. In Objective 2, the effect of thermodynamic factors and intrinsic properties of these fats on their crystallization kinetics and physical properties will be evaluated.This project addresses the program Novel Foods and Innovative Manufacturing Technologies (A1364) because it aims to improve the knowledge and understanding of the chemical and physical properties of fats to increase productivity and use in food systems.Results from this study will benefit lipid producers by providing knowledge to efficiently optimize processing conditions to tailor the physical properties of fats for specific food applications: from baking and confectionery to plant-based foods.
Animal Health Component
(N/A)
Research Effort Categories
Basic
100%
Applied
(N/A)
Developmental
(N/A)
Goals / Objectives
Physical properties are important characteristics of fats that determine their use in various food applications from baking and confections to plant-based foods. Physical properties are driven by the crystallization kinetics of fats, and it is therefore essential to understand the factors that influence crystallization kinetics to obtain desired physical properties.The hypothesis of this research is that intrinsic properties of fats such as chemical composition, viscosity, surface tension, heat capacity, and density, in addition to thermodynamic factors such as supercooling, driving force, and activation free energy of nucleation play important roles in fat crystallization and therefore in tailoring physical properties. Two objectives will be pursued to test this hypothesis. In Objective 1 custom-made samples with different types (lauric, palmitic, and stearic fatty acids) and content (30, 50, and 70%) of saturated fatty acids will be produced via enzymatic interesterification to allow for the use of samples with controlled and systematic changes in chemical composition. In Objective 2, the effect of thermodynamic factors and intrinsic properties of these fats on their crystallization kinetics and physical properties will be evaluated.This project addresses the program Novel Foods and Innovative Manufacturing Technologies (A1364) because it aims to improve the knowledge and understanding of the chemical and physical properties of fats to increase productivity and use in food systems.Results from this study will benefit lipid producers by providing knowledge to efficiently optimize processing conditions to tailor the physical properties of fats for specific food applications: from baking and confectionery to plant-based foods.
Project Methods
Objective 1 will synthesize fats with differing chemical composition that will be used in Objective 2 for crystallization experiments. The chemical composition of the fats in terms of content of SFA and TAG will be quantified. Fats synthesized in this objective will allow us to evaluate in a systematic manner how the type and content of SFA affect crystallization behavior in objective 2 when the fats are crystallized using various thermodynamic parameters. Fats will be custom-made using enzymatic interesterification or acidolysis to obtain lauric-, palmitic-, and stearic-based fats with different types (lauric, palmitic, and stearic fatty acids) and contents of total SFA (30%, 50%, 70%). Lauric-, palmitic-, and stearic-based fats will be used to represent fats with intermediate and long carbon chain lengths that show differing crystallization behavior that are commonly used in food systems, such as palm kernel-, palm-, and soybean-based fats, respectively. The content of SFA will be changed to represent contents commonly found in edible fats. An approximate 30, 50, and 70% SFA will be used to represent fats with low, intermediate, and high levels of SFA, respectively. Fats with these levels of SFA include palm kernel oil (~50% SFA), palm oil (~40% SFA), milk fat (~40% SFA), cocoa butter (~60% SFA), and commercially available shortenings with low levels of SFA (~32% SFA). This experimental design therefore utilizes 9 different fats.The FA and TAG composition of the fats will be quantified and the type and content of SFA will be calculated.Objective 2 will evaluate the crystallization kinetics and physical properties of fats with differing SFA and TAG composition crystallized using various thermodynamic conditions to explore how these factors (chemical composition and thermodynamic factors) together with other intrinsic properties of the materials affect fat crystallization. Fats will be crystallized using 10 crystallization temperatures (Tc) to achieve various levels of supercooling (low, intermediate, and high values of supercooling and driving forces) and to calculate thermodynamic parameters such as driving force of crystallization and activation free energies of nucleation, associated with fat crystallization as will be later described. Fats with different types and amounts of TAGs and SFAs will be crystallized using similar supercooling and driving forces. This will allow us to evaluate if the same supercooling and/or driving force will produce different crystallization behavior in fats with different chemical compositions (different activation free energies of nucleation). Intrinsic properties of the samples beyond chemical composition such as viscosity, heat capacity, density, and surface tension will also be measured at Tc. For a specific fat we expect to see changes in some of the intrinsic properties (viscosity, heat capacity, density) with Tc. Therefore, if fats crystallized using similar thermodynamic conditions result in different crystallization behavior, intrinsic properties can be used to explain the results. This experimental design will allow us to evaluate if differences in crystallization behavior of fats crystallized under the same thermodynamic conditions (supercooling and/or driving force) are due to intrinsic properties. For example, if a stearic-based fat is crystallized under similar thermodynamic conditions than a palm-based fat, but the palm-based fat crystallizes slowly and has a higher viscosity, the delay in crystallization can be explained by slow molecular diffusion caused by high viscosity.