Background: Individual factors, which interfere in the continuous churning, were manipulated to enhance the rheological properties and chemical composition of butter. This process leads to achieve softer; more spreadable, and ultimately healthier product for consumers. In addition it could prevent hardening of texture especially in winter.Methods: Firstly, Pasteurized cream with different fat contents (40 & 45% fat) was passed through heat treatments, and then it was injected to a continuous churn. Textural and melting behavior and fatty acid composition of butter were analyzed. Results: Increasing the fat content of cream (from 40 to 45 %) and holding time (from 3h to 5h) in mid-temperature (18 ºC) and reducing the churning temperature (from 12 ºC to 10 ºC), resulted in soft butter texture and improved butter spreadability. Loss Tangent (tan δ) was increased from 0.11 to 0.74 (T=15 ºC;f=1Hz). The melting temperature of butter was decreased from 36ºC to 32ºC and total trans fatty acid content was decreased from 3.2 % to 1.87 %. Conclusion: It was concluded that such heating process (which has been studied and reported in patents) absorbs the low- SFC fats of the cream, integrates them into the butter texture a softer and more spreadable product.
Keywords: Butter, heat treatment, rheology, spreadability.