THE INFLUENCE OF TEMPERATURE ON INTERACTIONS AND STRUCTURES IN SEMISOLID FATS

The strength of fat crystal networks in oil increases at elevated temp eratures due to increased adhesion between partially melted crystal su rfaces. This strong adhesion, in combination with low oil viscosity (w eak hydrodynamic force), is the reason for extensive fat crystal flocc ulation at elevated temperatures. The crystal flocs likely sinter, dra matically increasing the thickness of semisolid fats. Crystal growth a lso occurs. The described temperature-induced crystal changes may be s uppressed by a controlled sintering process at low tempera tute. Emuls ifiers, such as sorbitan esters of tristearate, also suppress the temp erature-induced changes, Fat crystals can be used as thickeners or gel ling agents for triglyceride oils in various applications; It is possi ble to direct the thickening to a specific temperature, and to control the degree of thickening, by choice of fat phase composition, additiv es, tempering conditions, and crystallization technique.