SUMMARYThe fat spreads market shows considerable regional variations on a global basis. In Northern Europe, America and Australasia in particular, the market is strongly brands oriented; there has, however, been a changing emphasis from butter and packet margarine to products containing 'health' blends and reduced fat driven by increasing consumer awareness of the relationship between diet and health.Within Europe the first low fat spread was launched in 1968 and many different types of yellow spreads are now commercially available incll'ding products with fat levels ranging from 80°;() to less than 5%, blends of milkfat with vegetable fat, and water continuous emulsions.Until recently the microstructure of volume market spreads has been that of emulsions mainly of a fat continuous nature with dispersed aqueous drops. The structure of the product is dominated by the crystallisation characteristics of the fat (crystal size, shape and intercrystalline bonding). The stability of the product emulsion is significant during manufacture and spreading and also influences the perceived performance of the products especially those of the reduced fat type, which should predominantly invert to an oil in water emulsion on the palate. Bicontinuous phase spreads have also been reported.Various methods for processing spreads are now available including traditional churning techniques as used for butter, controlled inversion of water continuous emulsions, crystallisation offat continuous emulsions, and cold mixing of plastic products. Unlike the situation for traditional high fat products, control of the aqueous phase rheology of reduced fat spreads is a significant factor in successful processing and optimised palate response.Methods for identifying key characteristics in spreads include the measurement of fat solids index in both fat blend and product and this last approach offers improved process control. Measurements of the hardness, spreadability, electrical conductivity, emulsion stability, size of dispersion, appearance, and a range of consumer detectable sensory properties are also employed.Water continuous spreads are presently a relatively small section of the overall market and comprise soft and processed cheeses, spreading mayonnaise, peanut butter and the like.
D. P. J. Moran et al. (eds.), Fats in Food Products