Cooking oils defined

Matter can also be categorized into three distinct phases solid, liquid, and gas. An object that is solid has a definite shape and volume that cannot be changed easily. Trees, automobiles, ice, and coffee mugs are all in the solid phase. Matter that is liquid has a definite volume but changes shape quite easily. A liquid flows to take on the shape of its container. Gasoline, water, and cooking oil are examples of common liquids. Solids and liquids are termed condensed phases because of their well-defined volumes. A gas has neither specific shape nor constant volume. A gas expands or contracts as its container expands or contracts. Helium balloons are filled with helium gas, and the Earth s atmosphere is made up of gas that flows continually from place to place. Molecular pictures that illustrate the three phases of matter appear in Figure 1-12. 

Bio-diesel differs from the term bio-fuel in that bio-diesel is conventionally defined as a bio-fiiel that is produced through frani -esterification of the oil or fat with methyl alcohol resulting in the formation of methyl esters (bio-diesel feedstock) and the byproduct glycerine. Bio-diesel can be made from animal fats, recycled cooking oils, restaurant greases, vegetable oils, marine oils, and others. The product has been produced in Europe for many years, and European development is more advanced than in the United States. Table 10 shows the relative production of bio-diesel in five European countries compared with the United States for three different years, 1997, 2000, and 2003 (29). 

Deep-fat frying can be defined as a process of cooking food by immersing them in edible oil at a temperature above the boiling point of water, and therefore, may be classified as a dehydration process (Farkas, 1994). Frying temperatures usually range between 130 and 190 °C, but most... 

If that does occur, then the present system of classification of oils may be impossible to police, and a modified system may become necessary. Perhaps the sale and perceived value of oils will necessarily become dependent on the performance, not the source of the oil. With bulk oils such as palm, peanut, sunflower, safflower, sesame, soya, rapeseed, com, fish, and animal fats and oils, the fatty acid composition will obviously be important for health reasons. If the oil is to be used for frying then the frying properties will be important. In the case of palm products the physical properties and minor components such as carotenoids will be defined. Similarly animal fats will be judged mainly on physical behaviour and effect on the product in which they are used. In all cases the oxidative and stability of the oil will have to be defined. Sesame is a very stable oil, and thus its stability, together with its low level of linolenic acid, would be its major attribute, except for toasted sesame, which would probably be classed as a specialist oil. Already most baking fats sold to the public are blends developed to give the best performance, with no mention on the pack as to the source. If a bulk oil of this type had the desired chemical composition, stability and cooking behaviour, then perhaps the source would not be a matter of concern. 

Frying is defined as a process of cooking and drying through contact with hot oil. It is intended to make food more palatable and tasteful, but at the same time makes food safer and provides a preservative effect that results from thermal destruction of microorganisms and enzymes, and a reduction in water activity at the surface or throughout the food. The shelf life of fried products is mostly determined by the moisture content after frying. Products that retain a moist... 

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