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Date of manufacture

Figure 1. Effect of Alnarp-type treatment on firmness of winter butter. —•— Control 5°C; - -•- - Alnarp; control 15°C; - • • • - Alnarp;-----upper limit of spreadability. Source: Ref. 49.

Date of manufacture

Figure 1. Effect of Alnarp-type treatment on firmness of winter butter. —•— Control 5°C; - -•- - Alnarp; control 15°C; - • • • - Alnarp;-----upper limit of spreadability. Source: Ref. 49.

butter is held (50). The European butter market demands that butter be softer and more spreadable in winter and harder in summer. With information on the changes in fat composition from gas-liquid chromatography analysis and the use of nuclear magnetic resonance to estimate solid fat, suitable tempering procedures can be selected to modify the fat composition and produce the most acceptable product for the consumer. A spreadable consistency of butter can be achieved by either varying the fatty acid composition or varying heat-step cream-ripening times and temperatures (51).

In efforts to improve the spreading properties of butter in relation to hard butter fat, one alternative put forward is the use of soft fat fractions obtained in the fractionation of anhydrous milk fat. Although several practical methods of fractionation have been presented, the use of soft fat fractions in butter making has not become general practice. This is evidently because fractionation in all cases significantly raises the cost of the butter produced. In addition, a common problem has been to find suitable uses for the hard fat fractions. Furthermore, in fractionation methods that use solvents or additives, fractionation should be linked to fat refining; and in this process butter also loses its natural food classification. In studies that have used soft butter fat fractions, a substantial softening of the butter has been obtained; however, this butter, like normal butter, hardens as the temperature increases and again decreases. One of the new ways to improve butter spread-ability is to add vegetable oil during manufacturing. The best known of these preparations, which cannot be called butter, is the Swedish Bregott, in which 20% of the fat used is vegetable oil. A similar product is made in many other countries, Finland among them, where it has been well received, possibly just because of its better spreadability compared with normal butter.

Two industrial processes in practice for the fractionation of milk fat are the Tirtiaux system, and the DeSmet, which is a semicontinuous bulk crystallization process. They are dry fractionation processes enabling one- or two-step fractionation of butter oil at any temperature from 50 to 2°C. The milk fat fractions thus obtained can be used as such or they can be blended in different proportions for use as ingredients in various food fat formulations or in preparing spreadable butter (52).

Figure 2 depicts the solid fat content profiles of the control and anhydrous milk fat: the low melting, high melting, and 20% very high melting milk fat; the milk fat fractions used in the low melting, high melting, and 20% very high melting butter: the 30S fraction; the 13L fraction; and the 15S fraction. The fraction number includes the fractionation temperature (°C) and its physical form (solid or liquid) (53).

The major shortcoming inherent in this system is the long residence time (8-12 h) for nucleation and crystal growth.

Butter samples made from low melting liquid fractions and from a combination of primarily low melting liquid fractions and a small amount of high melting solid fractions exhibited good spreadability at refrigerator temperature (4°C) but were almost melted at room temperature (21°C). Butters made with a high proportion of low melting liquid fraction, a small proportion of high melting solid, and a small proportion of very high melting solid fractions were spreadable at refrigerator temperature and maintained their physical form at room temperature (53).

Some newer modifications and improvements to processes for the enhancement of spreadability have recently been patented (54,55). They include the use of a hydropho-

Figure 2. The fraction number includes the fractionation temperature (°C) and its physical form (solid or liquid).-15S Fraction (top line);----and the milk fat fractions used in the low melting, high melting, and 20% very high melting butter: 30S fraction; • • • • the low melting, high melting, and 20% very high melting milk fat;-----solid fat content profiles of the control and anhydrous milk fat;-13L fraction (bottom line).

Figure 2. The fraction number includes the fractionation temperature (°C) and its physical form (solid or liquid).-15S Fraction (top line);----and the milk fat fractions used in the low melting, high melting, and 20% very high melting butter: 30S fraction; • • • • the low melting, high melting, and 20% very high melting milk fat;-----solid fat content profiles of the control and anhydrous milk fat;-13L fraction (bottom line).

bic membrane to separate high and low melting point fractions and improved blending techniques.

Homemade Pet Food Secrets

Homemade Pet Food Secrets

It is a well known fact that homemade food is always a healthier option for pets when compared to the market packed food. The increasing hazards to the health of the pets have made pet owners stick to containment of commercial pet food. The basic fundamentals of health for human beings are applicable for pets also.

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