The Crystal Structure of a Diacid Triglyceride

Advances in our understanding of the structure and functionality of edible fats and fat mimetics

The reasons for the increased world-wide incidence of obesity, type-2 diabetes, and cardiovascular disease include sedentary lifestyles and poor food choices. Regulatory agencies in several countries now require companies to add unattractive front of package labels to their products where salt, sugar and fat (or saturated fat) levels are prominently displayed. After the demise of partially hydrogenated fats, saturated fat has become the new target. Consumption of saturated fat over polyunsaturated oil has been clearly shown to increase cholesterol levels in humans. However, saturated fats provide the functionality required in many food products. To complicate matters, concerns over sustainability, veganism, genetically modified organisms, animal welfare, as well as religious beliefs, severely limit our sources of saturated fat. In this review we will discuss recent advances in our understanding of the nano and mesoscale structure of fats, responsible for their physical functionality and contrast it to that of fat mimetics. Fat mimetics include polymeric networks of ethylcellulose, emulsion-templated networks of proteins and polysaccharides, colloidal and self-assembled fibrillar networks of polar lipid crystals, as well as solid o/w emulsions of oil trapped within crystallized lamellar mesophases. Clean label and economic considerations will also be touched upon.

Electron crystallography on polymorphic organics

Organic materials, such as non-linear optical active compounds (1-(2-furyl)-3-(4-aminophenyl)-2-propene-1-one (FBAPPO) and 1-(2-furyl)-3-(4-benzamidophenyl)-2-propene-1-one (FAPPO)), polymeric materials like the metal coordinated polyelectrolyte (Fe(II) [ditopic bis-terpyridin] (MEPE)) or polymorphic materials (e.g. Cu-phthalocyanine), which do not crystallize big enough for single crystal x-ray structure analysis have been investigated by electron diffraction (ED) at 100 and 300 kV acceleration voltage. Sample preparation (direct crystallization, ultra sonication, ultra microtomy), diffraction strategies (selected area diffraction, nano diffraction, use of double-tilt rotation holder), data collection and data processing as well as structure solution strategies have been chosen dependent on the different requirements of the compounds under investigation. Structure analysis was carried out by simulation using ab initio quantum-mechanical methods like density functional theory (DFT), semi-empirical approach (MNDO/AM1/PM3) and force field packing energy calculations (DREIDING). The structure models resulting from simulation were refined kinematically as rigid bodies. Subsequently, refinements by multi-slice least squares (MSLS) procedures taking dynamical scattering into account were performed. The described combination of different methods which was used successfully on crystallizable materials is also adaptable to insoluble organic materials (e.g. pigments) and polymorphic systems.