Lipid shortenings: a review

Relating structure of fat crystal networks to mechanical properties: a review.

This review deals, with waxes of members of two quite different groups of insects, the bees and the scale insects, which secrete large amounts of wax. The former use was as a structural material and the latter as a protective material. The compositions of waxes from some of these insects are described and particular attention is paid to the compositions of the unhydrolyzed waxes and to the presence of hydroxy acids. New analyses of beeswax and of wax of a species of bumble bee are reported. The structures of the diesters, hydroxyesters and diols of beeswax are elucidated. The bumble bee wax contains major proportions of saturated and unsaturated hydrocarbons, and of long chain saturated, mono- and diunsaturated esters. The relationship between structure and function of the waxes is discussed.

The composition of beeswax and other waxes secreted by insects

In order to give a unified picture of recent findings on glyceride polymorphism a review is presented which covers in some detail the saturated single fatty acid triglycerides, the mixed C16−C18 saturated triglycerides, saturated diglycerides, and saturated monoglycerides. Mention is made, merely by way of comparison, of unsaturated and saturated-unsaturated triglycerides and unsaturated diglycerides. The value of a knowledge of glyceride polymorphism in the identification of naturally occurring glycerides is indicated by a number of examples.

Review of the polymorphism of saturated even glycerides

Crystallography AG Marangoni Crystallization Kinetics AG Marangoni Lipid Phase Behavior K L Humphrey and SS Narine Rheology Fundamentals and Structural Theory of Elasticity AG Marangoni and SS Narine Viscoelasticity AG Marangoni Dynamic Methods AG Marangoni Microstructure SS Narine and AG Marangoni The Yield Stress and Elastic Modulus of a Fat Crystal Network AG Marangoni Experimental Methodology R Campos Scaling Behavior of the Elastic Modulus in Colloidal Networks of Fat Crystals TS Awad, MA Rogers and AG Marangoni Comparison Between Image Analyses Methods for the Determination of the Fractal Dimension of Fat Crystal Networks TS Awad and AG Marangoni The Nature of Fractility in Fat Crystal Networks AG Marangoni Identifying Key Indicators of Mechanical Strength in Mixtures of Milk Fat Fractions and Cocoa Butter AG Marangoni and SS Narine The Functionality of Milk Fat Fractions in Confectionery and Plastic Fats AG Marangoni Liquid-Multiple Solid Phase Equilibria in Fats: Theory and Experiments LH Wesdorp, JA van Meeteren, S de Jong, R Giessen, P Overbosch, PAM Grootscholten, M Struik, E Royers, A Don, T de Loos, C Peters, and I Gandasasmita Imaging of a Model Plastic Fat System by 3-Dimensional Wide-Field Transmitted Polarized Light Microscopy and Image Deconvolution JW Litwinenko Index

Fat Crystal Networks

139. Alternation in long-chain compounds. Part II. An X-ray and thermal investigation of the triglycerides

The normal fatty acids may unquestionably be regarded as one of the most interesting and important groups of chemical compounds. Many of them occur commonly in nature, and form the basis of valuable industrial products. The part which they and their derivatives play in life processes gives them a particular interest to the biologist. As compounds, which appear to be readily obtainable pure, and which form regular series including a comparatively large number of individuals, they furnish the chemist and physicist with material peculiarly adapted for the study of the relationship between constitution and properties. For these reasons they have been the subject of an almost endless number of investigations, in which the preparation and properties both of individual members or groups of individuals have been studied. At this stage, it might well have been assumed that every member of the series had long since been obtained pure, and its properties determined with so high a degree of accuracy, that only the exacting requirements of some new investigation would have demanded further study of the subject. Reference to the literature of the subject, however, showed that the real position was by no means satisfactory. While, on the one hand, the results of the determination of such a property as the melting point of certain members of the series, for instance, arachidic acid, obtained from various natural sources by chemists of established reputation, gave a constant value, and while the criteria of purity of the various samples were quite satisfactory, the material was certainly not identical with samples of the corresponding acid prepared synthetically. The difference was in some cases such as to justify the assumption that the natural and synthetic acids were differently constituted, but no theory could be found to account for the observed differences.

Thomas Malkin

Papers

139. Alternation in long-chain compounds. Part II. An X-ray and thermal investigation of the triglycerides

The n-Fatty Acids

360. An X-ray and thermal examination of the glycerides. Part II. The α-monoglycerides

CCCVI.—An X-ray study of some structural modifications of long-chain compounds

290. An X-ray and thermal examination of the glycerides. Part III. The αα′-diglycerides