Vegetable oil olive, coconut etc.), and it is preferred by most "health-food" customers in the United States and in Europe. There are several different types of mechanical extraction. Expeller-pressing extraction is common, though the screw press, ram press, and ghani (powered mortar and pestle) are also used. Oilseed presses are commonly used in developing countries, among people for whom other extraction methods would be prohibitively expensive; the ghani is primarily used in India. The amount of oil extracted using these methods varies widely, as shown in the following table for extracting mowrah butter in India: The processing of vegetable oil in commercial
Butter It is rare in Europe as well. Several "spreadable" butters have been developed. These remain softer at colder temperatures and are therefore easier to use directly out of refrigeration. Some methods modify the makeup of the butter's fat through chemical manipulation of the finished product, some manipulate the cattle's feed, and some incorporate vegetable oil into the butter. "Whipped" butter, another product designed to be more spreadable, is aerated by incorporating nitrogen gas—normal air is not used to avoid oxidation and rancidity. All categories of butter are sold in both salted and unsalted forms. Either granular salt or a strong