Fats and Oils: Texture of Foods

The presence of crystals in solid fats accounts for the pleasant, crumbly texture of pastry. The crystals force the starch particles in the flour apart and retard the formation of elastic gluten (as in bread), so the pastry stays ‘short’. If the pastry becomes warm in making, the crystals melt, gluten forms, and the pastry becomes tough. Using too little fat also allows gluten to form. Fats with large crystals make good pastry. One such fat is lard, whose molecules tend to have a particularly large acid in the centre of each triglyceride trio, which helps large crystals to form. Small crystals, such as those in vegetable cooking fats, make better creamed cake mixes. The fat spreads evenly throughout the flour and lubricates the surfaces of starch and gluten particles, so that they slide together when eaten and the cake has a tender texture.