Assessment of chemical and sensory quality of unsalted and salted sweet cream butter during storage at different temperatures and time

Abstract

Quality of butter depends on many factors such as quality of raw material, production method, ingredients used, type of packaging. Chemical changes taking place during storage of final product are also important. Extent of oxidation and the amount of free fatty acids in Estonian butter have not been investigated recently in experimental studies and have been evaluated at national level only with regard to intervention buying-in. The purpose of this work was to evaluate the quality of salted and unsalted sweet cream butter produced in continuous butter machine and stored at different storage temperatures and time periods. Three batches of salted and unsalted sweet cream butter were prepared and were stored at three different temperatures: at –20 °C for 24 weeks, at +5 °C for 12 weeks, at +20 °C for 8 weeks. Dry matter and salt content, peroxide value, acid value and organoleptic properties were evaluated. No major differences were found when comparing acid values and peroxide values at different storage temperatures. There were no significant differences between salted and unsalted butter samples and no age trends for the values. At all storage temperatures, the level of acid value (maximum value 0.81 mmol 100 g-1 fat) was lower than the upper limit established for high-quality butter (1.2 mmol 100 g-1 fat). The peroxide value (maximum value 0.050 meq per kg fat) was also lower than the upper limit established for high-quality butter (0.3 meq kg-1 fat) at all storage temperatures. After eight weeks of storage the sensory characteristics of butter – appearance, taste and flavour – scored at least 4 points or higher on 5 point scale that corresponds to high-quality butter.

Keywords

• sweet cream butter
• salted butter
• free fatty acids
• peroxide value
• sensory analysis