Addition of olein from milk fat positively affects the firmness of butter

Abstract

Butter is highly valued for its characteristic flavor and aroma; however, it has the disadvantage of unsatisfactory spreadability at low temperatures. The functional characteristics of butter can be modified by changing its composition or physical structure. The objective of this study was to evaluate the effect of olein on structure and composition of butter. Olein was obtained by two stage dry fractionation process of the anhydrous milk fat (AMF) and added to commercial cream prior to butter manufacture. The fractions were characterized for triacylglycerols composition, solid fat content, crystallization isotherm, and thermal behavior. Butter was manufactured using commercial cream or cream containing 50% olein. Butter samples were characterized for physicochemical composition, instrumental color, crystallization parameters, and firmness after 1 and 7days of storage at 10°C. The firmness of butter subjected to room temperature was also evaluated. Butter containing olein differed significantly from the control and had darker yellow color, higher crystallization time, and lower solid fat content after 120min at 15°C, and hence lower firmness after 1 and 7days of refrigerated storage. Although lower firmness was observed over time for all samples at room temperature, butter containing olein exhibited lower firmness after both 1 and 7days, thus suggesting changes in organization of solid fat crystal network in the liquid fat. The addition of olein to butter allowed obtaining a softer product, with more intense color and possible nutritional benefits due to the medium chain triglycerides and higher carotene levels.