JPS626558B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for isolating polar cereal lipids from a mixture of polar and non-polar cereal lipids. The polar and non-polar lipid mixture used in the present invention is a lipid mixture that can be recovered from cereals using known methods. That is, wheat contains about 2% lipids, about half of which are polar lipids such as phospholipids and galactolipids;
The other half is nonpolar and primarily triglycerides. These lipids can be recovered, for example, by extracting the flour with an organic solvent or by centrifuging the flour-water mixture. An effective extractant is water-saturated butanol, which is capable of releasing up to about 80% of lipids from flour. Other useful extractants are chloroform, benzene-chloroform mixtures in a 1:1 ratio, ethanol, ethanol-water mixtures with a water content up to 90% and ethanol-diethyl ether-water mixtures in a 2:2:1 ratio. be.
When producing wheat starch, the remainder of water-soluble protein,
Gluten and lipids are obtained. Lipids can be isolated from this residue by extraction. Other grains that may provide lipid mixtures useful as starting materials for the present invention include rye, triticale,
(a hybrid of wheat and rye), barley, oats and corn. The polar lipid products obtained according to the invention are primarily intended for use as food additives. Furthermore, the products can advantageously be used as a substitute for the emulsifiers currently used in baking, such as stearyl-lactyl-lactate salts, tartaric acid esters and monoglycerides. They impart improved grain aroma and increased volume to bread as well as improved texture and shelf life. The excellent effects of polar cereal lipids in bread baking have already been demonstrated, for example by Mac
Ritchie, J.Sci.Fd Agric., Vol. 28 (1977), pp. 53-58. use as an additive for the food, in which case the product is used as an additive for the food;
Gives a more crumbly texture. The present invention relates to the removal of non-polar lipids from total extracts. This is because non-polar lipids act counter to the desired effects of the products according to the invention mentioned above.
Therefore, isolation of polar lipids is possible when the polar lipids are up to 25
It is desirable to be effective to the extent that it contains % by weight of non-polar lipids. The method according to the invention comprises mixing the aforementioned lipid mixture with water in an amount such that the lipid-water mixture contains at least 50% by weight of water, and then subjecting the mixture to gravity separation, which contains the main proportion of polar lipids. The heaviest oily phase obtained by said gravity separation is separated last. According to the invention, water, preferably distilled water, is added to said lipid mixture so that at least 50% of the lipid-water mixture is added to said lipid mixture.
It is added in such an amount that it contains % water by weight. According to the present invention, 70% water by weight has been found to be a suitable water content. If the water content exceeds 80% by weight, the volume of the resulting mixture will be large enough to make gravity separation difficult. Preferably, the temperature of the mixture is maintained above 25°C so that the desired phase has a suitable consistency for handling. However, it is preferred that the temperature is below 50°C to prevent oxidation of the fat. Phase equilibrium is achieved after 3-6 hours. The mixture is then subjected to gravity separation, preferably in a centrifuge. Centrifugation is continued until two oily phases are formed separated by an aqueous phase. Centrifugation is preferably carried out at at least 5000 g, in which case it takes about 1 to 2 hours to completely separate the phases. If the speed of the separator is increased to 10,000 g, complete phase separation can be achieved in about 20-30 minutes. The topmost, lightest phase is an oil consisting almost entirely of nonpolar lipids, primarily triglycerides, but also containing small amounts of fatty acids, diglycerides, and sterol esters. Beneath this phase is a pure water phase. The lowest, heaviest phase is a light yellow colored oily phase containing the desired polar lipids. According to the invention, it was found by thin layer chromatography that this phase consists primarily of galactolipids (mainly digalactodiglyceride and small amounts of monogalactodiglyceride) and phospholipids such as lecithin and lysolacitin. Surprisingly, it was found that this phase contains a high water content, ie about 50-70% by weight of water, depending on the amount of water added. Despite this fact, said phases are immiscible with water. The heavy oily phase mentioned above consists of a dispersion of lamellar liquid crystal phases in the so-called L2-phase. The L2-phase has already been extensively studied in simple systems such as sodium caprylate/decanol/water and is often described as an inverted micellar state with aggregates of water molecules in a continuous hydrocarbon environment. The content of non-polar lipids in the oily phase containing polar lipids can be reduced slightly (e.g. 25-10% by weight) if the salt added in the lipid extract is added to the water. . The appropriate salt content of water as mentioned above is 0.4 to 4% by weight,
The salt is suitably an alkali metal halide salt. EXAMPLE This example relates to the preparation of a lipid mixture from flour, the isolation of polar lipids and the use of polar lipids in bread baking. A. Preparation of lipids from wheat flour 10Kg of flour was mixed with 40Kg of butanol saturated with water in a mixer. The mixer was run for 2 hours. The temperature of the mixture was 20-25°C. The mixture was transferred to a centrifuge and centrifuged at 1800g for 1 hour. Approximately 35 g of liquid was obtained after this time. This liquid was evaporated by heating at 50° C., yielding a dry residue weighing approximately 160 g. In food applications, it is important that evaporation is complete so that no organic solvent remains in the liquid mixture. B. Isolation of polar lipids 300 g of a lipid mixture of the type prepared according to step A above were mixed with 700 g of distilled water and stirred until an apparently homogeneous mixture was obtained. The mixture was left at 30° C. for 4 hours without stirring. It was then transferred to a centrifuge and centrifuged at 5000g for 1 hour. Two extracted phases were obtained, separated from each other by an aqueous layer. The heaviest oily phase was separated. This oily phase was found to have a volume of 750 ml and a water content of 70%. C. Bread Baking Bread baking experiments are done using Swedish Date Seeds.
It was carried out according to the standard method specified by the Association (Sweden). The flour was a so-called bread mix produced by the Swedish flour milling company Kungso¨rnen. The fermentation and baking oven used was manufactured by Simmons, UK. The polar wheat lipids produced in step B were added to 0.83% by weight of the amount of flour mentioned above.
amount was added. For comparison, pens were baked (1) with the same amount of sodium stearyl-lactyl-lactate added and (2) without any other additional emulsifier additions. The following results were obtained. In the table, porosity is expressed on a scale of 1 to 8, with the highest value indicating microporosity. The elasticity of the inside of the bread, that is, the soft inner part of the bread, is expressed on a scale of 1 to 6, with 6 indicating extremely good elasticity. The appearance of bread is expressed on a scale of 1 to 4, with 1 being the best value and indicating perfect appearance.

[Table] Furthermore, it was found that the texture of the bread filling and the taste of the finished bread were better in the baking batches containing polar wheat lipids. It is well known that the addition of conventional emulsifiers reduces the elasticity of the bread filling, and this was very clearly demonstrated by the above comparative experiments of the present invention. Polar wheat lipids do not have any of the negative effects mentioned above,
It gave better elasticity to the bread filling.

Claims (1)

[Claims] 1 Polar and non-polar cereal lipid mixture with water;
mixed in such an amount that the lipid-water mixture contains at least 50 wt. A method for isolating polar lipids from a mixture of polar and non-polar cereal lipids, comprising separating the oily phase.