Views:5 Author:Hebei Shipu Tech Publish Time: 2020-05-11 Origin:Site
Margarine can be made from a variety of animal fats and was once predominantly manufactured from beef fat and called oleo-margarine. Unlike butter, it can be packaged into a variety of consistencies, including liquid. No matter what the form, however, margarine must meet strict government content standards because it is a food item which government analysts and nutritionists consider to be easily confused with butter. These guidelines dictate that margarine be at least 80% fat, derived from animal or vegetable oils, or sometimes a blend of the two. Around 17-18.5% of the margarine is liquid, derived from either pasteurized skim milk, water, or soybean protein fluid. A slight percentage (1-3%) is salt added for flavor, but in the interest of dietary health some margarine is made and labeled saltfree. It must contain at least 15,000 units (from the U.S. Pharmacopeia standards) of vitamin A per pound. Other ingredients may be added to preserve shelf life.
1 When the ingredients arrive at the margarine manufacturing facility, they must first undergo a series of preparatory measures. The oil—safflower, corn, or soybean, among other types—is treated with a caustic soda solution to remove unnecessary components known as free fatty acids. The oil is then washed by mixing it with hot water, separating it, and leaving it to dry under a vacuum. Next, the oil is sometimes bleached with a mixture of bleaching earth and charcoal in another vacuum chamber. The bleaching earth and charcoal absorb any unwanted colorants, and are then filtered out from the oil. Whatever liquid is used in the manufacturing process—milk, water, or a soy-based substance—it too must undergo preparatory measures. It also undergoes pasteurization to remove impurities, and if dry milk powder is used, it must be checked for bacteria and other contaminants.
2 The oil is then hydrogenated to ensure the correct consistency for margarine production, a state referred to as "plastic" or semi-solid. In this process, hydrogen gas is added to the oil under pressurized conditions. The hydrogen particles stay with the oil, helping to increase the temperature point at which it will melt and to make the oil less susceptible to contamination through oxidation.
Combining the ingredients
The continuous-flow process is the most commonly used method in the manufacture of margarine. If milk is used as the liquid base, it is joined with salt and an emulsifying agent in a chamber. The emulsifying agent ensures that the emulsification process—chemically defined as a suspension of small globules of one liquid in a second liquid—takes place. An emulsifier works by decreasing the surface tension between the oil globules and the liquid mixture, thereby helping them form chemical bonds more easily. The result is a substance that is neither wholly liquid nor wholly solid but rather a combination of the two called semi-solid. Lecithin, a natural fat derived from egg yolk, soybean, or corn, is one typical emulsification agent used in margarine manufacturing.
3 In the initial step, the liquid, salt, and lecithin are mixed together into one tank opposite another vat holding the oils and oil-soluble ingredients. In the continuous-flow process, the contents of the two vats are fed on a timed basis into a third tank, typically called the emulsification chamber. While the blending process is taking place, the equipment's sensors and regulating devices keep the mixture's temperature near 100°F (38°C).
4 Next, the margarine mixture is sent to a device called a Votator, the brand name for the most commonly used apparatus in U.S. margarine manufacturing. It has been standard equipment to the industry since the 1930s. In the Votator, the margarine emulsion is cooled in what is referred to as Chamber A. Chamber A is divided into a trio of tubes that successively decrease its temperature. Within two minutes the mixture has reached 45-50°F (7-10°C). It is then pumped into a second vat called Chamber B. There it is occasionally agitated but generally left to sit still and form its semi-solid state. If it needs to be whipped or otherwise prepared for special consistency, the agitation is done in Chamber B.
Quality control is an obvious concern at modern food-processing facilities. Unclean equipment and shoddy methodology can lead to a mass bacterial contamination that could disrupt the stomachs and even lives of thousands of consumers within a matter of days. The U.S. government, under the auspices of the Department of Agriculture, maintain specific industrial hygiene codes for modern creameries and margarine manufacturing plants. Inspections and fines for poorly maintained equipment or unclean conditions help keep companies in compliance.
Butter is graded by USDA inspectors at the creamery. They inspect each batch, test it, taste it, and assign a score to it. They give a maximum of 45 points for flavor, 25 for body and texture, 15 points for color, 10 for salt content, and 5 for packaging. Thus, a perfect batch of butter can receive a score of 100 points, but usually the highest number assigned to a package is 93. At 93, butter is classified and labeled Grade AA; a batch that receives a score below 90 is considered inferior.
Guidelines for margarine production dictate that margarine contain at least 80% fat. The oils used in the production can be derived from a variety of animal and vegetable sources but all must be fit for human consumption. Its aqueous content may be milk, water, or a soy-based protein fluid. It must be pasteurized and contain at least 15,000 units of vitamin A. It may also contain a salt substitute, sweeteners, fatty emulsifiers, preservatives, vitamin D, and coloring agents.