Supercritical Fluid Processing of Milk Fat: Fractionation, Scale-Up, and Economics

摘要

INCREASING CONSUMER CON-cerns over the role of fat in fitness and health have made milk fat the dairy industry's problem child. Also, new fields of application for milk fat remain constrained because of its very limited functionality. As a result, thenational surplus of milk fat has grown steadily in recent years and in 1990 rose to 340 million 1b (USDA, 1991). The trend is projected to continue and reach 1.2 billion 1b/year by the year 2000 (Jesse, 1988). Quantitatively, the largest portion of thefatty acids in milk fat is comprised of even number, saturated and unsaturated C_4-C_(18) straight-chain fatty acids. Due to the complex fatty acid composition, milk fat contains a large variation of triglycerides so that, crystallization and melting occurs over a wide temperature range (-40 to 40°C). Thus in its native form milk fat does not lend itself to utilization in many food formulations. For example, the wide melting range of milk fat makes it difficult to produce butter of improved plasticityand spreadability at refrigeration temperatures, and makes it unattractive for other uses such as in bakery and confectionery products.