Dr. Robert Lencki's Research Project

1) Fat crystallization

Triacylglycerol (TAG) polymorphism influences the functionality of many products. Yet, this key aspect of TAG crystallization is not well-understood. While most studies of TAG polymorphism have focused on the relative position of methylene units in the acyl chains (unit subcell), we are the first research group to explore differences in the stereochemistry of molecules within the unit cell, and how this important parameter influences the β or β′ polymorph tendencies of TAG. We have shown that the unit cell for TAG in the β′ polymorph contains only one conformer or enantiomer, whereas the unit cell for TAG in the β polymorph contains both conformers or enantiomers. This perspective improves upon the current mechanism by considering the stereochemical orientation of the constituent TAG molecules. Furthermore, this simple distinction between the stereochemical arrangement of TAG molecules in β and β′ forms explains the β′-stability of enantiopure TAG. This discovery is of very significant industrial importance because the control of crystal polymorphism is essential for the production of a wide range of fat-containing food products. 

2)  1,3-Diacylglycerol (1, 3-DAG) for hard fat applications
 
This project has focusedon the development of a functional 1, 3 diacylglycerol (DAG) fat. Conventional fats and oils composed of triacylglycerols (TAG) containing saturated or trans fatty acids have been shown to have a deleterious effect on human health. However, by replacing dietary TAG with 1, 3 diacylglycerols (DAG), weight loss is promoted and blood lipids are improved (thereby reducing the risk of cardiovascular disease and mitigating symptoms of type 2 diabetes). In Japan, DAG oil (marketed as EconaTM) is now the best selling premium oil, but a similar product has had only limited success on this continent because it is less suited to many North American food applications. This project involves designing DAG molecules so that they provide the same functionality as commercial fats such as butter or margarine.
 
3) Casein micelle structure
 
This research addresses an important yet unresolved question in Food Science: what is the underlying structure that stabilizes casein micelles? In this work, we have demonstrated that αS- and κ-casein are both capable of forming fibril-like structures. Congo red and thioflavin T dye binding experiments showed that fibril-like structures are also present in fresh raw skim milk casein micelles. Protofibrils were also confirmed by TEM analysis. This finding is of particular interest because fibril structures are rare in vivo because of their very high stability, but could be present in milk to ensure that caseins do not denature in the cow’s utter.