Butter spreadability

The addition of surfactants to milk fat may also improve butter texture (Gupta and deMan, 1985). Butter spreadability was improved in some cases, depending on the nature of the surfactant (Kapsalis et al., 1963). Some surfactants resulted in a brittle and sticky product. Also, the effect of the surfactants was found to be temporary. Setting was delayed, but ultimately there was no effect of the surfactants on the SFC of butter (Kapsalis et al., 1963). For this reason, surfactants have little practical significance for butter rheology (Hayakawa et al., 1986). 

Rohm, H. 1990. Magnitude estimation of butter spreadability by untrained panelists. J. Food Sci. Technol. 23, 550-552. 

Single fractionation of butter oil produces stearin and olein which by blending with the original fat can be used to enhance baking properties or produce a soft butter spreadable from the refrigerator. 

Schaap, J. E., Hagedoorn, H. G. and Rutten, G. A. M. 1981. Effect of storage time, temperature and working on the firmness and spreadability of butter. Zuivelzicht 73, 38-40. (Dutch)... 

Puncture probes are commonly used for fruits and vegetables, and allow for the determination of force at rupture of the cellular structure. The procedure outlined below is adapted from the method of Bourne (1979). Cone penetrometers are commonly employed for determining firmness and yield value for foods such as margarine and butter, which may be a reflection of the product s spreadability. Quite often it is desirable to use a testing system that provides a constant deformation rate. Additionally, a mechanical testing machine allows for production of a force/deformation curve to further analyze the data. 

Butter has a limited plastic range. At refrigerator temperature ( 1-0°C), butter behaves essentially as a solid and lacks spreadability, whereas at room temperature (21-25°C), it oils off and exhibits moisture exudation. 

A study carried out on the effects of grind size on peanut butter texture demonstrated that an increase of that variable decreased sensory smoothness, spreadability, and adhesiveness (Crippen et al, 1989). 

Spreadability is another important parameter of butter texture. A spreadability index (S) can be calculated from the yield stress value obtained for butter before and after working using a constant-weight penetrometer, as shown in Equation (5), where fu and /w are the yield stress values before and after working respectively (Haighton, 1965). 

Several rheological characteristics of milk fat and butter have practical significance. Setting, spreadability, hardness, work softening and thixotropy are affected by the rheology of milk fat. Setting refers to the continued increase in the firmness of newly manufactured butter. Increases in firmness... 

To be spreadable, butter should possess an SFC between 20 and 40% (deMan, 1962) and have an apparent yield value (determined according to IDF, 1980) of 30-60 kPa (Rohm and Raaber, 1991). According to Figure 7.1, milk fat has an SFC between 20 and 40% at a temperature between 11 and 20°C. More homogeneous butter structures, as visualized by electron microscopy, have also been correlated with a firmer consistency (Precht and Buchheim, 1979, 1980). 

Milk fat and butter can be tailored to have desired properties and functionalities. Treatments are often aimed at improving cold spreadability without compromising room temperature stability. To modify the texture and rheological properties of butter, composition and processing conditions can be manipulated... 

Banks, W. and Christie, W.W. 1990. Feeding cows for the production of butter with good spreadability at refrigeration temperatures outlook on Agriculture 19(1), 43 17. 

Davey, K.R., Jones, P.N. 1985. Evaluation of a sliding pin consistometer for measurement of the hardness and spreadability of butter and margarine. J. Text. Stud. 16, 75-84. 

Deffense, E. 1987. Multi-step butteroil fractionation and spreadable butter. Fat Sci. Technol. 89, 502 107. 

Dixon, B.D. 1974. Spreadability of butter-determination. 1. Description and comparison of 5 methods of testing. Aust. J. Dairy Technol. 29, 15-22. 

Kaylegian, K.E., Lindsay, R.C. 1992. Performance of selected milk fat fractions in cold-spreadable butter. J. Dairy Sci. 75, 3307-3317. 

Precht, D., Buchheim, W. 1979. Electron microscopic studies on the physical structure of spreadable fats. 1. The microstructure of fat globules in butter. Milchwissenschaft. 34, 745-749. 

---