Sandy margarines

Kathy boasted that she kept her cholesterol down and kept slim with a diet that included a special margarine. It never has that effect for me , said Sandy. Mind you, she did have a full cooked breakfast and five pieces of toast and marmalade. The polyunsaturated fat got lost in the crowd of harmful fats. Generally speaking fats are mostly saturated hydrocarbon compounds. Oils , on the other hand, do contain many C=C bonds and are said to be unsaturated . Natural vegetable oils contain many C=C bonds they are polyunsaturated. Poly means many. 

Figure 2. Crystallization of sunflower oil margarine, (a) Normal p form, (b) sandy p form. (Courtesy of Grindsted Products, Inc., Industrial Airport, Kansas.).

Storage conditions play quite an important role for the overall quality of margarine products. Insufficient or improper storage conditions can lead to several product failures such as sandiness or graininess, oiling out, lack of plasticity, brittleness, or microbiological spoilage for sensitive product types (86). 

The most important functional properties of margarines and spreads are spreadability , oiliness and melting property. These properties relate to fat level and type and stability of the emulsion. Spreadability can be predicted by SFI and penetration measurement. Oil-off refers to the phenomenon when fine fat crystals no longer form a stable network to trap the liquid oil. Consistency and emulsion stability depend on the amount and type of crystallized fat. During rapid cooling, the most unstable a crystals form but they quickly transform to the ( / form, which is relatively stable and consists of a very fine crystal network capable of immobilizing a large quantity of oil. These ( / crystals may also transform into the most stable (> form, which has a coarse and sandy texture and... 

Sorbitan esters like sorbitan tristearate are very effective crystal modifiers in chocolate and confectionery coatings (anti-bloom agent) or in margarines formulated with fats with a tendency to form large /8-crystals which cause textural problems (sandiness). 

Margarine, which is produced worldwide in amounts exceeding 7 million t/a, is a water in oil emulsion. Its stability is achieved by an increase in viscosity of the continuous fat phase due to partial crystallization and through emulsifiers. The fat crystals form a three dimensional network. They should be present in the P -modification a conversion P —> P is undesirable because the P-modification causes a sandy texture defect. Hydrogenated fats, which are frequently used as... 

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