catalogue
abstract
Functional performance
manufacturing technique
raw material
Classify according to the types of raw materials.
Classification by manufacturing method
According to the different classification of additives used
Classification by performance
Classification by characteristics
According to the physical form of products.
Functional use classification
Plasticity of processing characteristics
pure and fresh
Tyrosine property
emulsibility
Oxidation stability
Raw materials and accessories, raw materials, oil and fat
condiments
Production status and technology of plastic shortening
Production of liquid shortening
Production of powdered shortening
abstract
Functional performance
manufacturing technique
raw material
Classify according to the types of raw materials.
Classification by manufacturing method
According to the different classification of additives used
Classification by performance
Classification by characteristics
According to the physical form of products.
Functional use classification
Plasticity of processing characteristics
pure and fresh
Tyrosine property
emulsibility
Oxidation stability
Raw materials and accessories, raw materials, oil and fat
condiments
Production status and technology of plastic shortening
Production of liquid shortening
Production of powdered shortening
Expand and edit this paragraph overview.
shorten
Shortened oil, the scientific name is white oil, because it looks white, like lard. Butter is one of the special oils in food industry. It has certain plasticity or consistency, and can be used as ingredients for pastry, surface spraying or demoulding. It can be used to crisp or soften baked goods, prevent protein and carbohydrates from hardening and caking during processing, and improve the taste. At first, shortening refers to good lard. Later, the consumption of shortening made of hydrogenated vegetable oil or a few other animal and vegetable oils greatly exceeded that of lard. According to the source of oil, it can be divided into animal or vegetable shortening; Partially hydrogenated or fully hydrogenated shortening; Emulsified or non-emulsified shortening. According to the use and functionality, it can be divided into bread, cakes, icing and fried ghee. According to the physical form, it can be divided into plastic, fluid and powdery shortening (so-called "powdery grease"). Shortened butter and margarine are similar in appearance, but they cannot be regarded as the same category. Margarine generally contains about 20% water, which is edible oil, that is, it is eaten directly and contains more additives (pigments, flavors, etc.). ). And ghee is generally not eaten directly. There are many kinds of shortening in foreign markets. Serialized according to the above classification. Such as hydrogenation degree of oil, plasticity, expansion rate, consistency or viscosity, oil content of powder and so on. However, there are not many domestic varieties in the domestic market, and the food industry has not put forward many or special requirements for this, so this aspect is still in the primary stage. Powdered shortening has been produced in China, all of which are microcapsules with an oil content of 20-80%.
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Shortened oil is the raw material oil for food processing, so its functional characteristics are particularly important, including plasticity, tyrosine and shortened oil.
Sex, emulsification, water absorption, etc. 1, plasticity is for solid shortening. Plasticity means that it can change shape under the action of external force and even flow like a liquid. Theoretically, if the solid oil is plastic, its composition must include a certain amount of solid oil and liquid oil. Shortened oil products basically have this fat component. Due to the plasticity of shortening, a thin striped film can be formed when it is mixed with dough in food processing. Under the same conditions, liquid oil can only be dispersed into particles or spheres. When the dough is processed with shortening with good plasticity, the dough has good ductility and can absorb or maintain a considerable amount of air, which is very beneficial to the production of baked goods. 2. When butter-like shortening bubbles in the air through high-speed stirring, tiny bubbles in the air are sucked by shortening, and this gas-containing property of oil is called butter. The magnitude of tyrosinase activity is expressed by tyrosinase activity value, that is, 100 times 1 ml of air contained in the sample. Cash is an important feature of food processing. Adding shortening to the batter can increase the volume of the batter and make the food soft. 3. Crispy refers to the crispness of food, which is especially important for baked goods such as biscuits, shortcakes and cakes. When shortening is used to make food, oil covers the periphery of flour because of its film-forming property, which blocks the combination between flour and prevents the fixation of gluten and starch. In addition, shortening plays a lubricating role in the baked food tissue layer, making the food tissue fragile and fragile. 4. It is the raw material of French fries. Shortening oil is also added when making popcorn seeds, which can improve the expansion rate and increase the crispness.
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The preparation method of solid shortening is the same as margarine, except that there is no preparation of water phase and emulsification of oil and water. The production technology of plastic shortening generally includes oil blending, cooling and plasticizing, packaging and curing. I won't talk about it here. Plastic solid shortening is a kind of early developed and widely used at present. In addition, there are flowing shortening and powdered shortening. Flowing shortening is a kind of liquid oil. Emulsifier and high melting point oil are added to make it milky white, with processing characteristics and fluidity. Mobile shortening is suitable for bulk transportation and pipeline transportation at room temperature. The appearance of powdery shortening is powdery solid, but in fact, the particles of oil are wrapped by colloidal substances such as protein. During production, protein or starch such as oil, emulsifier, gelatin, casein, etc. are emulsified in water, and then spray-dried into powder. Because the oil is wrapped by colloidal substances, the oil is isolated from the outside air, so it has good preservation. In addition, powdered shortening is oil-impermeable, can be kept dry, and can be easily mixed with other foods. The oil content of powdered shortening is 50-82%.
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Shortening is not a universal name in the world. Some European countries call shortening compound cooking fat. shortening
Initially, it refers to a plastic solid fat used to make baked goods brittle or soft. Because the newly developed liquid shortening, powder shortening and margarine with water content less than 20% all have the functional characteristics endowed by plastic fat, today's shortening contains a wide range of products. So it is difficult to define it accurately. Generally speaking, shortening refers to refined animal and vegetable oil, hydrogenated oil or the mixture of the above oils with or without quenching, and is a solid or liquid oil with plasticity, emulsification and other functional characteristics. All grease products that give some baked goods a shiny appearance and surface and are used for emulsification, layering and lubrication are shortening. The main difference between shortening and margarine is that shortening contains no water phase and cannot be eaten directly. It is often used to bake food, make cheese or fry food. Shortened oil is a kind of plastic fat, and its triglyceride composition contains a considerable amount of saturated acid esters. At room temperature, these saturated acid esters contain liquid oil in fine solid crystals, forming a plastic state against fine external stress. Butter and pig fat are natural plastic fats, which have been paid attention to and widely used for a long time because they can prevent protein from combining with starch to make baked goods brittle or soft. However, the lack of resources can not meet the growing consumer demand, which urges scientists to constantly seek to develop alternative petroleum products. /kloc-at the end of 0/9, with the advent of the first generation of margarine products, people replaced pig fat with bovine soft fat for the first time. 1860- 1865, Americans mixed refined cotton oil with bovine stearin to produce the first generation of plastic fat. 19 10, the United States applied to Europe to introduce hydrogenation technology to process highly unsaturated vegetable oil and marine animal oil into. Shortening petroleum processing time has entered a new era. According to the application in food processing, shortening is divided into ordinary type, stable type and high emulsification type. Its functional characteristics are mainly obtained by hydrogenation or transesterification oil modification technology and processing. Nowadays, the food industry has higher and higher technical requirements for the functional characteristics of shortening. With the progress of hydrogenation and transesterification technology, scientists are making unremitting efforts to study shortening. The newly developed shortening has flowing and powdery products, all of which have the same uses and properties as plastic products. Therefore, the scope of shortening is very wide, and it is difficult to make an exact definition. Different countries and regions have different definitions of shortening. The definition of shortening in JAS is: shortening refers to refined animal and vegetable oil, hydrogenated oil or the mixture of the above oils, solid oil made by quenching kneading, or solid or liquid oil products made without quenching kneading. Shortened oil has processing characteristics such as plasticity, brittleness and emulsification. Shortened oil is generally not suitable for direct consumption, and it is used to process cakes, bread or fried foods, which requires good processing performance.
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Due to the continuous improvement of modern oil processing technology, shortening products can meet various requirements of food industry and life, and products can be classified from various angles.
Classification by raw material type
There are vegetable shortening, animal shortening and mixed shortening. (1) Vegetable shortening-It is composed of hydrogenated vegetable oil in different degrees. (2) animal shortening-such as pig fat. (3) Animal and vegetable mixed shortening-composed of animal fat and vegetable oil or lightly hydrogenated vegetable oil.
Classification by manufacturing method
The raw oils of (1) and fully hydrogenated shortening are composed of oils with different hydrogenation degrees, and their oxidation stability is particularly good. However, due to natural unsaturated shortening
Low fatty acid content has a certain impact on nutritional value, and the price is also high. (2) A certain proportion of liquid oil is added into hydrogenated oil mixed with shortening (or animal fat with high saturation) as raw oil. This shortening has a wide range of plasticity, can be adjusted at will according to requirements, and is cheap. (3) Ester exchange shortening is made of ester exchange oil. This shortening retains the nutritional value of unsaturated fatty acids in crude oil.
According to the different classification of additives used
(1) Non-emulsified shortening (2) emulsified shortening.
Classification by performance
(1), universal shortening is widely used, mainly for processing bread, biscuits and so on. (2) Emulsified shortening contains more emulsifiers, usually 10% ~ 20% monoglyceride and other emulsifiers. Its processing performance is good, and it is often used to process western-style cakes and heavy sugar cakes with large sugar content. The cakes processed with this shortening are large, soft, delicious and not easy to age. (3) High-stability shortening can be stored for a long time and is not easy to be oxidized and deteriorated. Fully hydrogenated shortening mostly belongs to this type.
Classification by characteristics
(1), plastic shortening, (2), liquid shortening refers to edible oil which can be processed and transported by pump at room temperature, has fluidity and processing characteristics, and does not precipitate solid components during storage. It can be divided into three categories: ① flowing shortening: the oil is milky white with suspended solids of solid fat; ② liquid shortening: the grease is a transparent liquid; ③O/w emulsified shortening: water-containing emulsified oil. (3) Powder shortening, also known as powder oil, is produced in the process of convenience food development, and its oil content is generally 50% ~ 80%, and some are as high as 92%. Can be added into convenience food such as cake, instant soup and curry.
According to the physical form of products.
(l) Solid (plastic) shortening-Shortening is a plastic solid at room temperature and has the best functional characteristics. (2) Fluid shortening refers to the fluid oil with the functional characteristics of shortening, which is in a fluid state at room temperature and can be directly used in the continuous production line of bread and cakes, without precipitation and separation during storage.
Functional use classification
(1) Common shortening-has extensive plasticity and many functional characteristics of shortening, and is used in bread processing industry. (2) Stable shortening-high oxidation stability, used for processing biscuits, salt and pepper biscuits and fried foods. (3) High emulsified shortening-adding a large amount of emulsifier, when used in pastry processing, can make the product large in size, good in taste and not easy to age. Its functional characteristics are also good.
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Processing characteristics of shortening Because shortening is the raw material oil for food processing, its functional characteristics are particularly important, including plasticity, crispness, casein, milk shortening and so on.
Chemical properties, water absorption, oxidation stability and frying performance. Different uses require different processing characteristics. Plasticity is the most basic feature.
plastic
Plasticity means that it can change shape under the action of external force and even flow like a liquid. For example, edible margarine can be coated on bread for eating, and this coating performance is an example of its plastic flow. Theoretically speaking, if solid oil has certain plasticity, its composition must contain certain solid oil and liquid oil, and solid oil is dispersed in liquid oil with extremely fine particles. Because of cohesion, all oils and fats are combined together, and because the gap between solid particles is very small, liquid can not seep out of solid oils and fats. The finer and more solid particles, the less plasticity; The coarser and less solid particles, the greater the plasticity. Therefore, the solid-liquid ratio must be appropriate to obtain the required plasticity. Plasticity is also related to temperature. With the increase of temperature, part of solid fat melts, plastic fat softens, plasticity increases, temperature decreases, part of liquid oil solidifies, viscosity of uncured liquid oil increases, plastic fat hardens and plasticity decreases. It can be seen that the solid fat content in plastic fat and the size of crystal particles determine its plasticity. Plasticity is the basic characteristic of shortening, from which some other characteristics are derived. For example, shortening can form thin strips and films when mixed with dough in food processing, which is determined by the plasticity of shortening; Under the same conditions, liquid oil can only be dispersed into particles or spheres. Therefore, the fat film can lubricate a larger area in the dough than the same amount of granular liquid oil. When the dough is processed with plastic shortening, the dough has good ductility, so the texture, volume and taste of the product are ideal. In addition, when shortening is mixed with dough, a considerable amount of air can be inhaled or maintained, which is very important for making baked goods or other foods with high sugar content.
pure and fresh
Crispy refers to the crispness of baked cakes. All kinds of biscuits are representative of crispy snacks. When shortening is used to make food, oil is distributed on the surface of wheat flour particles in the form of film to prevent gluten from sticking to each other and make baked snacks crisp and delicious. Generally speaking, shortening with moderate plasticity has good brittleness. Oil is too hard and lumpy in dough, so the crispness of the product is poor, while the liquid oil in dough makes the product porous and rough. The brittleness of oil is expressed by brittleness value, and the smaller the brittleness value, the better the brittleness.
Tyrosine property
When shortening is added to the mixed batter, fine bubbles in the air are sucked away by shortening when it is whipped at high speed. This gas-containing property of oil is called casein. The size of casein can be expressed by casein value (CV). 100 times the number of milliliters of air contained in 1g oil represents casein value. Short oil is much better than butter and margarine in tyrosinase. If you don't use caseinated oil when processing cakes, it won't have a large volume. The volume of the cake is directly proportional to the air content in the dough.
emulsibility
Oil and water are immiscible with each other, but in food processing, oil phase and water phase are often mixed together, and it is hoped that the mixture will be uniform and stable. Usually shortening contains a certain amount of emulsifier, so it can be emulsified with eggs, milk, sugar, water and so on. And can be evenly dispersed in dough to promote volume expansion, and bread and snacks with good flavor can also be processed.
Oxidation stability
Compared with ordinary grease, shortening has good oxidation stability. This is because selectively hydrogenated oil is used in raw materials. Among them, fully hydrogenated vegetable shortening has the best effect, while animal oil must use antioxidants, such as BHA or tocopherol.
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crude oil
There are two kinds of raw oil for shortening: soybean oil, cottonseed oil, rapeseed oil, coconut oil, palm oil, rice bran oil and other vegetable oils and their hydrogen shortening.
Chemical oil; Animal fats and oils, such as lard, tallow, fish oil and hydrogenated oil. Oils and fats are well refined, and hydrogenated oil must be selectively hydrogenated oil.
condiments
The additives of shortening are emulsifier, defoamer, colorant and perfume. (1), emulsifier ① fatty acid glyceride: the addition amount is 0.2% ~ 1.0%. It can improve the emulsification, casein and water absorption of shortening. Evenly disperse with flour, eggs, water, etc. Increase the volume of food. In addition, monoglyceride and starch form a complex, which is beneficial to keep moisture and prevent food from aging. ② Fatty acid sucrose ester: similar to monoglyceride. ③ Soybean phospholipids: generally not used alone, but often used together with other emulsifiers such as monoglyceride. In general shortening, the addition of soybean phospholipids and fatty glycerides is 0. 1% ~ 0.3%. ④ Fatty acid propylene glycol ester: Usually, propylene glycol and monoglyceride have synergistic effect when used together, and the addition amount is 5% ~ 10%. ⑤ Fatty acid sorbose ester: It is an ester formed by combining the hydroxyl group of sorbose with fatty acid, which has strong emulsifying ability. The addition of high emulsified shortening is 5% ~ 10%. (2) Tocopherol, tert-butyl hydroxyanisole (BHA), di-tert-butyl hydroxytoluene (BHT) and propyl gallate (PG) are used as antioxidants in the antioxidant shortening, and the addition amount must be within the range specified by the Food Hygiene Law. (3) When defoaming agent is used for frying shortening, it is necessary to eliminate bubbles. Generally, the addition of polymethylsiloxane is 2 ~ 5 mg/kg, and defoamer is not used to process shortening for bread and cake. (4) Nitrogen per 100 g of quick-cooling kneaded shortening should contain no more than 20 mL of nitrogen. The frying oil used after melting does not need to be injected with nitrogen.
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Production technology of plastic shortening
The continuous production process of plastic shortening includes four stages: raw material mixing, quenching kneading, packaging and curing. Several raw oil according to shortening.
After being measured according to a certain proportion, it is added into the blending tank. The additive is dissolved in the oil and poured into the mixing tank. Pre-cooled to 49℃ in the blending tank, then pumped into the quenching machine, and quickly cooled to supercooled state (25℃) with liquid ammonia, and part of the oil began to crystallize. Then it is kneaded continuously with a kneader and crystallized here, and the outlet temperature is 30℃ ... The preparation method of solid shortening is the same as that of margarine, except that there is no preparation of water phase and emulsification of oil and water. The production technology of plastic shortening generally includes oil blending, cooling and plasticizing, packaging and curing. I won't talk about it here. Plastic solid shortening is a kind of early developed and widely used at present. In addition, there are flowing shortening and powdered shortening. Flowing shortening is a kind of liquid oil. Emulsifier and high melting point oil are added to make it milky white, with processing characteristics and fluidity. Mobile shortening is suitable for bulk transportation and pipeline transportation at room temperature. The appearance of powdery shortening is powdery solid, but in fact, the particles of oil are wrapped by colloidal substances such as protein. During production, protein or starch such as oil, emulsifier, gelatin, casein, etc. are emulsified in water, and then spray-dried into powder. Because the oil is wrapped by colloidal substances, the oil is isolated from the outside air, so it has good preservation. In addition, powdered shortening is oil-impermeable, can be kept dry, and can be easily mixed with other foods. The oil content of powdered shortening is 50-82%.
Production of liquid shortening
There are many kinds of liquid shortening, which are roughly as follows: mix raw oil and auxiliary materials, quench them with a quenching machine, then store them in a storage tank for more than 16 h, stir them to fluidize them, and put them into a container; Grinding stearin or emulsifier into fine powder, adding it into grease as base material, and stirring evenly with a blender; The prepared raw materials are heated to 65℃ for melting, slowly stirred, and slowly cooled to form B-type crystals until the temperature drops to the canning temperature (about 26℃).
Production of powdered shortening
There are many methods to produce powdered shortening, and most of them are produced by spray drying at present. The preparation process is as follows: the grease, coating substance, emulsifier and water are emulsified together, and then spray-dried into powder. The oil used is generally hydrogenated vegetable oil with melting point of 30 ~ 35℃, and animal oil and liquid oil such as lard are also used. The coating materials used include protein and carbohydrates. Protein contains casein, animal glue, whey and egg white. Carbohydrates are fresh starch such as corn and potatoes, some use colloidal starch, starch sugars and lactose, and some patents introduce the use of cellulose or microcrystalline cellulose. Emulsifiers include lecithin, monoglyceride, propylene glycol ester and sucrose ester. Examples of powder oil components are: fat 79.5% ~ 80.8%, protein 7.9% ~ 8. 1%, carbohydrate 4. 1% ~ 4.6%, inorganic 3.5% ~ 3.8% (K2HPO4, CaO, etc. ), while water 1.5% ~ 65.