一.Basic situation of palm oil stock
Palm oil is extracted from palm fruits of oil palm trees. Palm trees are native to West Africa. They were introduced to Malaysia in the late 18th century and gradually planted in Southeast Asia. At present, many countries in Southeast Asia, South America and Africa have planted palm trees. Palm oil was obtained by boiling, crushing and pressing of palm fruits. After refining, free fatty acids, natural colors and odors were removed, refined palm oil (RBD PO) and palm salad oil (RBD PKO) were obtained. According to different needs, the palm oil with different melting points of 24 degrees, 33 degrees, and 44 degrees can be obtained by fractionation. Palm oil is rich in nutrients and antioxidants, and has been widely used in food industry and chemical industry. The hydrolysis of lipase or fatty acid catalase in palm fruit makes the quality of palm oil unstable, so it is necessary to fill the tank with nitrogen to ensure the quality of palm oil.
(一) the history of palm oil development
Palm oil is extracted from the palm fruit of the oil palm tree (Elaeis Guineensis), which has been used as a natural food for more than 5,000 years. Oil palm is a kind of crop that blossoms and blossoms in the four seasons and has harvest all the year round. The commercial production of oil palm can be maintained for 25 years. Oil palm is the most productive oil plant in the world. Palm trees usually begin to bear fruit in two to three years, reach a peak in eight to fifteen years, and begin to age and yield decline after eighteen to twenty years. Palm fruit grows on the big fruit string of palm trees, and each fruit string has about more than 2000 palm fruits. The origin of palm oil is in West Africa. Palm trees were introduced to Malaysia in 1870 when they were only ornamental plants. It was not until 1917 that the first commercial plantation was made. In the 1960s, Malaysia began to increase palm oil production on a large scale to reduce its dependence on rubber and coffee. Improved palm products are now widely grown in tropical Africa, Latin America and Southeast Asia. Palm oil production is highly concentrated in Malaysia and Indonesia.
（二） palm oil production technology
Palm oil (CPO) and palm meal (PE) can be obtained from palm pulp by boiling, crushing and extracting, and palm seeds (i.e. palm kernels) are separated during crushing, crushed and shelled, and the remaining kernels are pressed to obtain CPKO and PE. Palm kernel meal (PKE). Oil palm fruit contains two different kinds of oils, from the pulp to get palm oil; from palm seeds (kernels) to get palm kernel oil, the former two oils are more important. All of these products are effectively applied to food, chemical, agricultural and other fields. It can be said that palm is a good economic plant.
After the above primary stage of extraction, the crude palm oil and the crude palm kernel oil are sent to the refinery for refining. After removing free fatty acids, natural colors and odors, the crude palm oil (RBD PO) and the crude palm oil salad oil (RBD PKO) become salad grade oils. The refined palm oil is close to colorless and transparent in liquid and nearly white in solid state. In addition, palm oil can be further fractionated and treated to form palm oleic acid (PFAD), palm liquid oil (OLEAN) and palm stearin (STEARINE or ST). Oil palm fruit contains more lipase, so the harvested fruit must be processed or killed in time, palm crude oil is easy to hydrolyze and produce more free fatty acids, acid value increases rapidly, so it must be refined or fractionated in time.
（三） nutritional components of palm oil
Palm oil is also known as saturated fat because it contains 50% saturated fat. Oil is composed of three components: saturated fat, monounsaturated fat and polyunsaturated fat. The digestion and absorption rate of palm oil is over 97%. Like all other vegetable oils, palm oil itself contains no cholesterol.
As a highly saturated oil, palm oil has been speculated to increase cholesterol levels in human serum. However, many experts have further demonstrated that palm oil does not increase serum cholesterol, but has a tendency to reduce cholesterol, because a large number of research data show that different saturated fatty acids have different effects on blood lipids, palm oil is rich in neutral fatty acids, promote cholesterol increase. The palm oil is rich in natural vitamin E and triene tocopherol (600-1000 mg/kg), carotenoids (500-700 mg/kg) and linoleic acid (10%) which are very beneficial to human health. Some researchers have studied different species (Europe, the Americas, Asia) and found that palm oil is a kind of edible vegetable oil which fully meets the needs of human health.
（四） main uses of palm oil
Palm oil has two characteristics. One is that it contains more saturated fatty acids and has good stability, so it is not easy to oxidize. Two, palm oil is rich in vitamin A (500-700ppm) and vitamin E (500-800ppm). The palm oil is separated from the liquid oil by separating the solid fat from the liquid oil, in which the solid fat can be used as a substitute for expensive cocoa butter for chocolate, and the liquid oil can be used as a cold, cooking or frying oil with a light and refreshing taste. A large number of unfractionated palm oils are used in the soap industry. Soaps made from palm oil have durable foams and strong detergency. Palm oil can also be used for tinning of tinplate and rolling of aluminum foil. Therefore, palm oil is widely used in the catering industry, food manufacturing and oil and fat industry in the world.
Application of 1. palm oil in catering industry
History shows that human beings have used palm oil for catering for more than 5000 years. Compared with other edible oils, palm oil products have more advantages in frying and barbecuing food, which are mainly due to the following three reasons:
(1) Excellent antioxidant (explosive resistance): This is mainly because palm oil is moderately unsaturated, does not contain linolenic acid, rich in natural vitamin E and triene tocopherol is a natural antioxidant, which makes palm oil more suitable for fried, barbecue food than other oils.
(2) Composed of nutritive fatty acids: Palm oil has 50% unsaturated fatty acids, no trans-acid, difficult to polymerize with acids.
(3) Economy: The cost of oil has always been an important consideration in the choice of frying and barbecue oil for the catering industry. Oil palm is a high-yielding perennial oil plant, which can be harvested for about 20 years in a single planting, and the annual oil yield per unit area is much higher than other vegetable oils, and the yield is relatively stable, which makes palm oil the most expensive vegetable oil in the world. Oil palm is the most prolific oil crop. On average, an hectare of land produces 3.5 tons of palm oil and 0.4 tons of palm kernel oil annually. Its production efficiency is much higher than that of similar vegetable oils, which also means that the yield of palm oil per hectare is 9-10 times that of soybean.
In our country, the main index of edible refined palm oil is melting point not more than 24 33 C. It is used for food (bread, biscuits, etc.) boiling and frying, and the annual demand accounts for the vast majority of imported.
2. palm oil for food industry
In the food industry, palm oil is generally processed into shortening, margarine, hydrogenated palm oil, fried oil and special oils. Like other edible oils, palm oil is easy to digest, absorb and promote health. Palm oil is an important ingredient in fat. It has mild properties and is a good material for making food. From the palm oil composition, its high solid glycerol content keeps food stable from hydrogenation and effectively resists oxidation. It is also suitable for hot climates as a good seasoning for pastries and bakery products. Because palm oil has these characteristics, it is loved by food manufacturers.
(1) Shortening: Unlike margarine, margarine is 80% fat and 20% water, while shortening is 100% pure fat. There are many kinds of shortening. Strictly speaking, each kind of food needs special shortening, but there are also general-purpose shortening which is suitable for many kinds of food. It is usually used to fry and bake food, such as chips, cakes, biscuits, sandwiches and bread. Usually, shortening needs to be mixed with different ingredients in the process of production and use, so as to be suitable for different products, such as ice cream, biscuits with different flavors and so on.
(2) margarine: margarine is an emulsifier composed of water and fat. Originally margarine was developed to imitate butter, but now a variety of products have been formed. Among them, palm oil is suitable for making liquid margarine, and palm stearin is more suitable for making solid margarine.
(3) Hydrogenated palm oil: Hydrogenated palm oil has a wide range of markets in India, Pakistan and the Middle East, where it is commonly used as a cheese product.
(4) Fried oil: This is one of the most widely used palm oil in the food industry, the main reason is that it has good antioxidant properties (its rich tocopherol is a natural antioxidant), is not easy to polymerize with acids, has a healthy fatty acid composition (50% unsaturated fatty acids, trans-acid-free). Most of the instant noodles produced in most countries, including China, are fried with palm products. In the Chinese market, some local fried foods (such as fried breakfast, fried snacks, etc.) also use palm products to make instant noodles.
(5) Special oils: Palm oil and palm kernel oil are ideal raw materials for producing special oils and oils, which are mainly used in the production of candies, especially chocolate foods. The palm kernel stearin is also known as cocoa butter because its physical properties are very close to cocoa butter.
Palm oil is widely used in food industry, mainly because of its good natural antioxidant, unique physical properties, suitable for human health nutritional composition and obvious economy. With the continuous efforts of oil research institutes, palm oil will be more widely used in various fields of food industry.
3. industrial uses of palm products
In recent years, the industrial use of palm oil has been developed rapidly. In developed countries, a large number of palm oil has been used for industrial use. In China, the palm industrial products are called industrial monosodium glutamate, which shows its wide application. The refined palm oil used in industry requires a melting point of not less than 44 C. It is mainly used to make soap, stearic acid and glycerin. The annual demand is more than 100,000 tons. In recent years, with the rising price of crude oil, the subject of bio-fuel has been excavated again, palm oil as a bio-fuel has been discovered, and has become a new growth point for the future use of palm oil.
Palm oil can be obtained directly from palm products, such as soap, epoxy palm oil and its polyols, polyurethane and polyacrylate products. The other is oil chemical products, such as fatty acids, esters, fatty alcohols, nitrogenous compounds and glycerol. On the basis of these products, various derivatives can be produced by different chemical methods. The main raw material of oil chemical industry is rich in C12-C14 and C16-C18, in which palm kernel oil, palm stearic acid and palm stearic acid are the main raw materials.
(五) preservation of palm oil
In palm oil, acid formation is caused by hydrolysis of either lipase or fatty acid catalase in palm fruit. Free fatty acids are very low in undisturbed fruits, but once the cells are damaged and the lipase is activated, the free fatty acids will rise sharply in the early stage, then the rise of free fatty acids will be slowed down until the lipase inactivation stops. The level of free fatty acids in palm oil actually depends on three factors: the degree of immaturity of the fruit (which is too ripe to be damaged), the degree of ear pretreatment (inactivation), and the delay between harvest and lipase inactivation.
Iron is added to the process of oil production, which can indirectly control oxidation. At the same time, attention should be paid to all environmental conditions that promote the oxidation of oils and fats. The conveyor and hoist are cleaned regularly to prevent soil and crushed materials from polluting the oil. Do not use copper, brass and bronze fittings to prevent contact between copper and oil. The reason is that copper is a strong oxidant. Keep the lower temperature as far as possible without prejudice to oil extraction. At the same time, try to make the oil less exposed to the air.
During storage, refrigerators can be installed at the back of the vacuum drying section of the plant, so that the temperature of the oil can be reduced to 45-50 degrees Celsius before entering the tank. After the oil is packed into the tank, inert gases (carbon dioxide and nitrogen) are filled into the tank. Some antioxidants can also be added to the oil to passivate trace metals in order to eliminate the oxidation of oil during storage. In addition, when large containers are used for oil storage, the oxidation can also be controlled and the spatter of oil will be reduced.
The precautions in transportation and unloading: First, the paint used in the tank epoxy resin, before loading oil tank cleaning inspection. Second, spray cloth and cover with inert gas. Third, the loading of oil is not spatter. Fourth, oil temperature is maintained at 32-40 C during shipping. Heat up the oil before loading to increase its temperature. The rate does not exceed 5 degrees every 24 hours. Fifth, the loading temperature of the oil is not more than 55 C. Sixth, when the deodorized palm oil arrives at the terminal, it is filled in an epoxy-coated tank and filled with nitrogen.
Two. Production and trade of palm oil worldwide
The global oil market is dominated by four crops: soybeans, palm oil, sunflower seeds and rapeseed. In 2005, global oil production reached 139 million tons, an increase of 9 million tons compared with the previous year. At the end of the 1970s, global oil demand was about 51 million tons, which has nearly tripled. Vegetable oil accounted for 82% of the total oil, and the rest consisted of butter, lard, tallow and fish oil. Although oil production has been increasing in recent years, animal oil production has remained basically unchanged. The increase of oil production mainly comes from vegetable oil. Among all vegetable oils, palm oil has increased most significantly in the past decade.
(1) global palm oil production
Palm oil production has increased rapidly in recent years. The reason for the increase is the increase of arable land area and the increase of yield. Before 1989, palm oil production worldwide was less than 10 million tons, and before 1997, production had increased only slightly, from 10 million tons to 20 million tons. Since 1998, global palm oil production has grown by leaps and bounds with the rapid growth of palm oil production in Southeast Asia. By 2006, global palm oil production has exceeded 35 million tons, equivalent to seven times the production in the 1950s. The expansion of industrial uses of edible palm oil and palm oil has promoted the rapid increase of palm oil production. Low prices relative to other oil products and the rapid economic development of the world and parts of the region have set off one peak after another in palm oil consumption, thus promoting the vigorous development of palm planting in Southeast Asia. Since 1995, world palm oil production has increased substantially, and at the current rate of growth, it is expected to exceed soybean oil production.