Chemistry and technology of oils and fats pdf
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- Grasas y Aceites
- Fats and Oils Industry Overview
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- Recent Advances in Chemistry and Technology of Fats and Oils
It seems that you're in Germany. We have a dedicated site for Germany. Since we produced Fats and Oils: Chemistry and Technology in , the trend we anticipated to up-date the classical texts of oils and fats has manifested itself.
Grasas y Aceites
Fat and oil processing , method by which animal and plant substances are prepared for eating by humans. The oil and fat products used for edible purposes can be divided into two distinct classes: liquid oils, such as olive oil , peanut oil, soybean oil, or sunflower oil; and plastic fats , such as lard , shortening , butter , and margarine.
The physical nature of the fatty material is unimportant for some uses, but the consistency is a matter of consequence for other products. As a dressing on green salads, for example, a liquid oil is used to provide a coating on the ingredients; a plastic fat such as lard or butter would be unsuitable. Spreads for bread, foods that require a highly developed dough structure, or icings and fillings with a plastic structure require plastic fats rather than liquid oils.
For reasons related to both history and climate, there are pronounced geographic patterns of consumption of fats and oils. The ancestors of the present inhabitants of central and northern Europe obtained their edible fats almost exclusively from domestic animals. The food habits and the cuisine depended on the availability of plastic fats; and butter, lard, margarine, and shortening continue to be their primary fatty food materials. In contrast, population pressures in the older civilizations of the Orient and the Mediterranean countries of southern Europe, northern Africa, and the Middle East have long since made extensive raising of livestock impractical, necessitating that the edible oils of these regions be derived primarily from intensively cultivated vegetable crops.
In the tropics, conditions are relatively unfavourable for livestock but are well suited to culture of a variety of oil-bearing plants, many of which flourish in the wild state.
In contrast to most high-population-density tropical areas, cattle abound in India. Clarified butter or ghee is an important item of Indian cookery, and a hydrogenated shortening called vanaspati is designed to reproduce the coarsely crystalline plastic texture of ghee.
More than 90 percent of the world production of fats and oils is used in edible products, and the objective of most processing steps is to convert crude fats of low palatability or undesirable physical form into refined products that meet the regional requirements for food fats.
The annual consumption of visible fats—such as lard, butter, shortening, or salad oils that have been separated from the original animal or plant source—ranges from 18 to 25 kilograms 40 to 55 pounds per person in various highly industrialized European countries to 23 kilograms per person in the United States.
For the world as a whole, the average available supply is 10 kilograms per person; and in many areas of South America , Africa, and Southeast Asia , the annual consumption is 5 kilograms or less per person. About 40 percent of the dietary fat in the developed countries comes from isolated fats and oils, with 60 percent obtained from basic foods, whereas in the less developed countries most of the dietary fat is obtained from fruits, cereals, vegetables, dairy products, and meats, and relatively little is consumed in the form of isolated fat products.
The quantities of fats and oils in conventional food supplies vary over wide ranges. Most fruits and vegetables have from 0. Cereals range from 1 to 7 percent, and nuts may contain as much as 70 percent fat. The raw materials for the fat and oil industry are animal by-products from the slaughter of cattle, hogs, and sheep; fatty fish and marine mammals; a few fleshy fruits palm and olive ; and various oilseeds. Most oilseeds are grown specifically for processing to oils and protein meals, but several important vegetable oils are obtained from by-product raw materials.
Cottonseed is a by-product of cotton grown for fibre, and corn oil is obtained from the corn germ that accumulates from the corn-milling industry, whose primary products are corn grits, starch, and syrup. Fats may be recovered from oil-bearing tissues by three general methods, with varying degrees of mechanical simplicity: 1 rendering, 2 pressing with mechanical presses, and 3 extracting with volatile solvents. See Figure 1. The crudest method of rendering oil from oleaginous fruits, still practiced in some countries, consists of heaping them in piles, exposing them to the sun, and collecting the oil that exudes.
In a somewhat improved form, this process is used in the preparation of palm oil; the fresh palm fruits are boiled in water, and the oil is skimmed from the surface.
Such processes can be used only with seeds or fruits such as olive and palm that contain large quantities of easily released fatty matter. The rendering process is applied on a large scale to the production of animal fats such as tallow, lard, bone fat, and whale oil. It consists of cutting or chopping the fatty tissue into small pieces that are boiled in open vats or cooked in steam digesters.
The fat, gradually liberated from the cells, floats to the surface of the water, where it is collected by skimming. The membranous matter greaves is separated from the aqueous gluey phase by pressing in hydraulic or screw presses; additional fat is thereby obtained.
The residue is used for animal feed or fertilizer. Several centrifugal separation processes were developed in the s. Cells of the fatty tissues are ruptured in special disintegrators under close temperature control. The protein tissue is separated from the liquid phase in a desludging type of centrifuge, following which a second centrifuge separates the fat from the aqueous protein layer. Compared with conventional rendering, the centrifugal methods provide a higher yield of better-quality fat, and the separated protein has potential as an edible meat product.
Fat and oil processing Article Media Additional Info. Article Contents. Print print Print. Table Of Contents. While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions. Facebook Twitter. Give Feedback. Let us know if you have suggestions to improve this article requires login. External Websites. See Article History. Britannica Quiz.
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Fats and Oils Industry Overview
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Fats and oils are the most abundant lipids in nature. They provide energy for living organisms, insulate body organs, and transport fat-soluble vitamins through the blood. Fats and oils are called triglycerides or triacylcylgerols because they are esters composed of three fatty acid units joined to glycerol , a trihydroxy alcohol:. If all three OH groups on the glycerol molecule are esterified with the same fatty acid, the resulting ester is called a simple triglyceride. Although simple triglycerides have been synthesized in the laboratory, they rarely occur in nature.
The papers explore the chemistry and technology of edible oils and fats, with emphasis on analytical procedures, the methods of industrial processing, and the pattern of dietary fat consumption seen from the viewpoint of the economist. This book is comprised of seven chapters and opens with a discussion on the physical and chemical properties of the constituents of edible oils and fats, with particular reference to the fatty acids, the glycerides, and those closely related compounds which are fatty in a general sense. The final chapter deals with the use of spectroscopic and X-ray techniques in the analysis of oils and fats. This monograph will be a useful resource for chemists and food technologists.
Grasas y Aceites is a scientific journal published by CSIC and edited by the Instituto de la Grasa , peer-reviewed and devoted to the publication of original articles concerning the broad field of lipids, especially edible fats and oils from different origins, including non acyl lipids from microbial origin relevant to the food industry. It publishes full research articles, research notes, reviews as well as information on references, patents, and books. The journal publishes original articles on basic or practical research, as well as review articles on lipid related topics in food science and technology, biology, bio chemistry, medical science, nutrition, bio technology, processing and engineering. Topics at the interface of basic research and applications are encouraged. Manuscripts related to by-products from the oil industry and the handling and treatment of the wastewaters are also welcomed.
Recent Advances in Chemistry and Technology of Fats and Oils
The Chemistry and Technology of Edible Oils and Fats and their High Fat Products covers the theoretical and practical aspects associated with the chemistry and technology of oils and fats. The book discusses the chemistry of edible fats; vegetable-oil separation technology; and water- and heat-promoted fat separation from animal and plant "fatty tissues". The text also describes the refining process; the fat-modification processes; and the production of edible-fat products of high fat content. The technologies applied to speciality fats; the storage and transport of oils and fats; and energy demands of the oil-milling and edible-fat processing operations. People involved in the processing of edible oils and fats will find the book useful. We are always looking for ways to improve customer experience on Elsevier. We would like to ask you for a moment of your time to fill in a short questionnaire, at the end of your visit.
Fat and oil processing , method by which animal and plant substances are prepared for eating by humans. The oil and fat products used for edible purposes can be divided into two distinct classes: liquid oils, such as olive oil , peanut oil, soybean oil, or sunflower oil; and plastic fats , such as lard , shortening , butter , and margarine. The physical nature of the fatty material is unimportant for some uses, but the consistency is a matter of consequence for other products. As a dressing on green salads, for example, a liquid oil is used to provide a coating on the ingredients; a plastic fat such as lard or butter would be unsuitable. Spreads for bread, foods that require a highly developed dough structure, or icings and fillings with a plastic structure require plastic fats rather than liquid oils. For reasons related to both history and climate, there are pronounced geographic patterns of consumption of fats and oils.
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