EFFECT OF TEMPERING ON THE TEXTURE AND POLYMORPHIC BEHAVIOR OF MARGARINE FATS

Separated fats from commercial soft (soft fat) and stick (stick fat) m argarines and mixtures of hydrogenated super olein (H-olein) and canol a oil, were temperature cycled between 4 degrees C and 15, 20 and 25 d egrees C. The polymorphic form, SFC and texture of the fats were evalu ated. Temperature cycling of soft fats between 4 and 20 degrees C resu lted in the crystals being either in the beta polymorphic form or mixt ures of beta' and beta. When temperature cycled between 4 and 15 degre es C the presence of beta' crystals was improved, but there were soft fats that after the fourth cycle contained only beta crystals. When st ick fats were temperature cycled between 4 and 20 degrees C, the cryst als after the fourth cycle were either in the beta' form or contained mixtures of beta' and beta. Mixtures of H-olein-canola showed superior beta' stability throughout. A mixture of 20% H-olein/canola oil compa red well with the SFC and texture of soft margarines while a mixture o f 40% H-olein/canola oil with those of stick margarines. Texture was e valuated by constant speed penetration. Texture of fats is very depend ent on temperature history. DSC crystallization curves of the fats sho wed a variety of patterns.