Tuesday, September 2, 2008

Butter


Butter is a dairy product made by churning fresh or fermented cream or milk. It is used as a spread and a condiment, as well as in cooking applications such as baking, sauce making, and frying. Butter consists of butterfat, water and milk proteins.

Most usually made from cows' milk, butter can also be manufactured from that of other mammals, including sheep, goats, buffalo, and yaks. Salt, flavorings and preservatives are sometimes added to butter. Rendering butter produces clarified butter or ghee, which is almost entirely butterfat. Butter remains a solid when refrigerated, but softens to a spreadable consistency at room temperature, and melts to a thin liquid consistency at 32–35 °C (90–95 °F).

The density of butter is 911 kg/m3 (1535.5 lb/yd3).[1] It generally has a pale yellow color, but varies from deep yellow to nearly white. Its color is dependent on the animal's feed and is commonly manipulated with food colorings in the commercial manufacturing process, most commonly annatto or carotene.




The characteristic butter flavor comes partly from the high proportion of short-chain fatty acids milk fat contains, especially butyric acid. Ripening gives a "lactic" flavor derived principally from a substance called diacetyl, produced by the bacterial species involved





Here is the process for making butter




Magarine


Margarine, originally known as oleomargarine, is produced from vegetable – and sometimes animal - fats that have undergone hydrogenation to create a solid. Most “regular” margarines contain trans-fatty acids and/or saturated fats, which is no healthier than butter, but many brands have little or no cholesterol.

Margarine is convenient because it is spreadable even when cold.


Varieties

Tubs, bottles, sprays, and sticks are produced by a variety of manufacturers.

Products include low- or no-fat, whipped, and liquid. These may contain higher percentages of water and air and should not be used for sautéing or baking.

Salted and unsalted versions are available, along with gluten-free, dairy-free, vegetarian, and organic.

“Soft” margarine contains less trans-fats.

Buying Tips

“Regular” or “hard” margarine can replace butter in most baking. By law, an 80% oil content is required, which means it can be substituted in any recipe that uses butter. These may contain some animal fats. The oil content is listed only on reduced fat products.

For the healthiest alternatives, look for labeling that states pure vegetable oil as well as monounsaturated and polyunsaturated fats.

Storage Tips

Refrigerate for two months or longer after opening and freeze for as long as a year. Unopened, it can remain in the refrigerator for several months.

Keep tubs and bottles tightly closed to avoid absorbing odors from other foods.

Usage Tips

Make flavored spreads by adding seasoning and herbs to small amounts of margarine.

Many recipes – especially those found on product labels – have been adapted to the use of margarines that have as little as 60% oil content.

Mayonniase

Mayonnaise is a thick, creamy sauce or dressing that is made of oil, egg yolks, lemon juice or vinegar, and seasonings. It's not the same as salad dressing, which doesn't contain egg yolks and is generally sweeter than mayonnaise.




Mayonnaise is an emulsion, which is a mixture of two liquids that normally can't be combined. Combining oil and water is the classic example. Emulsifying is done by slowly adding one ingredient to another while simultaneously mixing rapidly. This disperses and suspends tiny droplets of one liquid through another.

However, the two liquids would quickly separate again if an emulsifier were not added. Emulsifiers are liaisons between the two liquids and serve to stabilize the mixture. Eggs and gelatin are among the foods that contain emulsifiers. In mayonnaise, the emulsifier is egg yolk, which contains lecithin, a fat emulsifier.

Chemically, emulsions are colloids, heterogeneous mixtures composed of tiny particles suspended in another immiscible (unmixable) material. These particles are larger than molecules, but less than one one-thousandth of a millimeter (.001mm). Small particles like this do not settle out and will pass right through filter paper. The particles in a colloid can be solid, liquid or bubbles of gas. The medium that they are suspended in can be a solid, liquid or gas (although gas colloids cannot be suspended in gas).

Emulsions are liquid-liquid colloids, tiny liquid droplets suspended in another liquid. Emulsions are usually thick in texture and satiny in appearance.

Emulsions are used in many different ways:

  • by pharmacists, as a vehicle for medication
  • in photography, to coat plates, film and paper
  • in explosives, paints, coatings, make-up and detergents
  • in food, including baked goods and confectionery products
Mayonnaise is made by combining lemon juice or vinegar with egg yolks. Eggs (containing the emulsifier lecithin) bind the ingredients together and prevent separation. Then, oil is added drop by drop as the mixture is rapidly whisked. Adding oil too quickly (or insufficient, rapid whisking) will keep the two liquids from combining (emulsifying). But, as the sauce begins to thicken, oil can be added more rapidly. Seasonings are whisked in after all of the oil has been added. Blenders, mixers and food processors make it easy to make homemade mayonnaise, which many gourmets feel is far superior in taste and consistency to commercial mayonnaise.

Since homemade mayonnaise is uncooked, be sure to use the freshest eggs possible, and ones that you are reasonably sure are free from salmonella. Homemade mayonnaise will last three to four days in the refrigerator.

Commercial mayonnaise, which will last up to six months in the refrigerator, contain (by U.S. law) at least 65-percent oil by weight (except reduced-fat and fat-free mayonnaises). The standard of identity law also requires that all commercial "real mayonnaise" use only egg as an emulsifier. Reduced fat mayonnaise, which isn't considered real mayonnaise, usually contains modified food starch, cellulose gel and other thickeners and emulsifiers.

Mayonnaise is used as the base for other sauces, such as tartar sauce and thousand-island salad dressing. Aioli is garlic-flavored mayonnaise. Another classic emulsion sauce is hollandaise, which is a cooked mixture of butter, egg yolks and lemon juice.