Microscopic and rheological studies of fat crystal networks

This talk discusses the quantification of microstructure in fat crystal net works by using the relationship of the elastic moduli (G') to the solid fat content (SFC) via the fractal dimension (D) of the network. Results from a pplication of a scaling theory developed for colloidal gels [W.H. Shih et a l., Phys. Rev. A 42 (1990) 4772] to chemically and enzymatically interester ified and non-interesterified butterfat/canola oil mixtures and to cocoa bu tter and Salatrim(TM) are presented and discussed. In situ images from conf ocal laser microscopy and polarized light microscopy of the crystal network of butterfat and butterfat-canola oil blends yielded fractal dimensions of D = 1.88 and D = 2.02 +/- 2% respectively, which are in good agreement. Th e use of rheological measurements to calculate a fractal dimension of the c rystal network of butterfat-canola oil blends yielded D = 1.99, in good agr eement with D calculated from the confocal laser microscopy and the polariz ed light microscopy images. (C) 1999 Elsevier Science B.V. All rights reser ved.