High-stability edible blend oil rich in natural antioxidant and preparation method thereof

Abstract

The invention provides high-stability edible blend oil rich in natural antioxidants and a preparation method thereof, and belongs to the technical field of edible oil, the blend oil comprises camellia oil, sunflower seed oil, linseed oil, rice bran oil, rosmarinic acid, lychee seed extract, vitamin E microcapsules and lecithin; the linseed oil is distilled and purified linseed oil; the rice bran oil is rice bran oil subjected to low-temperature dewaxing; shell layers of the vitamin E microcapsules are Arabic gum and carboxymethyl chitosan; the rosmarinic acid is a product obtained by performing carbon dioxide supercritical extraction on rosemary and then adsorbing and purifying the rosemary through an AB-8 type macroporous adsorption resin column. The lychee seed extract is a product obtained by performing carbon dioxide supercritical extraction on lychee seeds and then adsorbing and purifying the lychee seeds through a D101 type macroporous adsorption resin column. The four kinds of oil are blended, balanced nutrition is provided, the rosmarinic acid, the lychee seed extract and the vitamin E microcapsules are added, the good anti-oxidation and stability-promoting effects are provided, and safety and health are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of edible oils, and in particular relates to a high-stability edible blended oil rich in natural antioxidants and a preparation method thereof. Background Art

[0002] Edible oils and fats are necessities in people's daily lives. They provide energy and a variety of nutrients for the human body and occupy an important position in the dietary structure. In the past, people mainly consumed single vegetable oils, such as soybean oil, rapeseed oil, sesame oil, peanut oil, olive oil, etc. However, the fatty acid composition of a single vegetable oil is relatively fixed, which makes it difficult to meet the body's demand for a balanced intake of various fatty acids. Studies have shown that fatty acid imbalance is an important factor in causing chronic diseases such as obesity, diabetes, cardiovascular and cerebrovascular diseases. A balanced intake of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids is essential for maintaining human health. For example, soybean oil has a high content of linoleic acid, but a relatively low content of monounsaturated fatty acids; while peanut oil has a high content of monounsaturated fatty acids, but the ratio of linoleic acid to linolenic acid is not ideal.

[0003] However, blended edible oil still has the following shortcomings: (1) Easy to oxidize and become rancid: Blended oil usually contains more unsaturated fatty acids, such as linoleic acid and linolenic acid. These unsaturated fatty acids are chemically active and are prone to oxidation under conditions of light, oxygen, high temperature, etc., producing harmful substances such as peroxides, aldehydes, and ketones, which not only change the flavor of the oil, but also reduce the nutritional value of the oil. Long-term consumption may have adverse effects on health.

[0004] (2) Poor storage stability: If the blended oil contains a large number of easily oxidizable components, it is easy to oxidize and deteriorate during storage. In addition, different vegetable oils have different freezing points. In a low temperature environment, the blended oil may become stratified, turbid or solidified, affecting its appearance and use.

[0005] (3) May contain additives: In order to improve the taste and color of blended oil or extend its shelf life, some products may contain chemical antioxidants, pigments, flavors and other additives. Long-term consumption of blended oil containing these additives may pose a potential risk to human health. Summary of the invention

[0006] In view of the problems existing in the existing blended edible oils, such as easy oxidation and rancidity, poor storage stability, and the presence of harmful additives, the present invention provides a highly stable blended edible oil rich in natural antioxidants and a preparation method thereof. The blended edible oil is prepared by blending sunflower oil, linseed oil, rice bran oil, and camellia oil in a certain proportion to provide balanced nutrition, and adding rosmarinic acid, litchi seed extract extracted by a special method, and vitamin E microcapsules to provide good antioxidant and stability-promoting effects, effectively improving the quality of the blended edible oil, and being safe and healthy. The specific technical solution is as follows: A highly stable blended edible oil rich in natural antioxidants, the blended edible oil comprising the following raw materials in parts by mass: 10 to 15 parts of camellia oil, 40 to 45 parts of sunflower oil, 10 to 15 parts of linseed oil, 20 to 25 parts of rice bran oil, 0.05 to 0.08 parts of rosmarinic acid, 0.03 to 0.05 parts of litchi seed extract, 0.10 to 0.15 parts of vitamin E microcapsules, and 0.01 to 0.02 parts of lecithin; the linseed oil is distilled and purified linseed oil; the rice bran oil is (low-temperature) dewaxed rice bran oil; the shell layer of the vitamin E microcapsules is arabic gum and carboxymethyl chitosan; the litchi seed extract is a product obtained by subjecting litchi seeds to supercritical carbon dioxide extraction and then adsorbing and purifying through a D101 macroporous adsorption resin column.

[0007] In the above blended edible oil, the linseed oil is distilled and purified by adding crude linseed oil to a distillation device and distilling it under the conditions of 175°C to 185°C and a pressure of 0.2 Pa to 0.4 Pa to remove free fatty acids and obtain purified linseed oil.

[0008] In the above blended edible oil, the rice bran oil is dewaxed at low temperature by preheating the rice bran oil to 60°C to 70°C to make the wax in a crystallizable state; transferring the preheated rice bran oil to a low-temperature crystallization device, maintaining the temperature at 3°C to 5°C, and the crystallization time at 20 h to 30 h; allowing the wax to crystallize and precipitate, and filtering and separating the wax from the oil to obtain dewaxed rice bran oil.

[0009] In the above blended edible oil, the preparation method of the vitamin E microcapsules comprises the following steps: preparing a wall material solution, which is an aqueous solution containing 2 wt% to 4 wt% of arabic gum and 1 wt% to 3 wt% of carboxymethyl chitosan; dissolving vitamin E in soybean oil 3 to 5 times the mass of vitamin E to obtain a core material oil solution, and then adding the core material oil solution to the wall material solution according to a volume ratio of 1: (4 to 5), homogenizing to form an oil-in-water emulsion, and spray drying to form a microcapsule structure of the wall material around vitamin E to obtain vitamin E microcapsules with a particle size range below 200 nm.

[0010] In the above-mentioned blended oil, the preparation method of the litchi seed extract comprises the following steps: loading litchi seed powder into an extraction kettle, using carbon dioxide as an extractant for extraction, so that the active ingredients in the litchi seeds are fully dissolved in the supercritical carbon dioxide fluid; introducing the supercritical fluid containing the active ingredients into a separation kettle, reducing the pressure to 5 MPa - 10 MPa and lowering the temperature to 35°C - 45°C to separate and precipitate the active ingredients from the carbon dioxide, and collecting to obtain the crude litchi seed extract; dissolving the crude litchi seed extract with methanol having a mass 8 - 10 times that of the crude litchi seed extract, loading it onto a resin column, first washing with deionized water for 3 - 5 column volumes to remove impurities, then eluting with a methanol aqueous solution having a volume concentration of 40% - 80% for 3 - 5 column volumes, collecting the eluate, concentrating under reduced pressure, and freeze-drying to obtain the litchi seed extract.

[0011] In the preparation method of the above-mentioned litchi seed extract, the extraction is carried out at a pressure of 45 MPa - 50 MPa and a temperature of 60°C - 65°C for 2 h - 3 h; the carbon dioxide flow rate is 25 L / h - 35 L / h.

[0012] In the preparation method of the above-mentioned litchi seed extract, the loading flow rate is 1 BV / h - 2 BV / h; the temperature for concentration under reduced pressure is 40°C - 60°C.

[0013] In the preparation method of the above-mentioned litchi seed extract, the resin column is filled with D101 macroporous adsorption resin, and the D101 macroporous adsorption resin is soaked in an embedding solution and then drained and loaded into the column; the embedding solution is an aqueous solution containing 0.5 wt% - 1 wt% carboxymethyl chitosan; the liquid level of the embedding solution during soaking is 1 cm - 2 cm higher than the upper surface of the D101 macroporous adsorption resin.

[0014] The preparation method of the above-mentioned high-stability edible blended oil rich in natural antioxidants comprises the following steps: mixing sunflower oil, linseed oil, rice bran oil and camellia oil evenly at a temperature below 30°C by mass parts to obtain a mixed oil; then adding rosmarinic acid, litchi seed extract, vitamin E microcapsules and lecithin and mixing evenly at a decreasing speed, standing, and filtering to obtain the blended oil.

[0015] In the above-mentioned preparation method, the mixing rotation speed of the mixed oil is 50 r / min - 100 r / min, and the mixing time of the mixed oil is 10 min - 20 min; the rotation speed for mixing at a decreasing speed is 30 r / min - 50 r / min, and the mixing time at a decreasing speed is 20 min - 30 min; the standing time is 1 h - 2 h, and the pore size of the filtration is 1.25 μm - 2.5 μm.

[0016] A high-stability edible blended oil rich in natural antioxidants and its preparation method according to the present invention have the following beneficial effects: I. The present invention uses a combination of various vegetable oils: sunflower oil, linseed oil, rice bran oil and camellia oil are mixed in a certain proportion, making the fatty acid composition of the blended oil more balanced, which can meet the body's balanced intake requirements of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids, and helps to maintain human health. Rosmarinic acid and litchi seed extract: They are rich in natural antioxidant components, which can effectively inhibit the oxidation reaction of unsaturated fatty acids in the blended oil, prevent oil rancidity, extend the shelf life of the blended oil, and avoid the health risks brought by the use of chemical antioxidants. Vitamin E microcapsules: Vitamin E is a strong antioxidant. After being made into microcapsules, it can better protect its activity, prevent it from being oxidized and damaged in the blended oil, can be slowly released in the oil, continuously play an antioxidant role, and improve the stability of the blended oil. Lecithin: It has an emulsifying effect, can make various components in the blended oil mix more evenly, and improve the stability and quality of the blended oil.

[0017] II. The distillation and purification of linseed oil can remove free fatty acids in crude linseed oil. Free fatty acids will reduce the quality of the oil and are prone to cause oxidation reactions. Through distillation, under specific temperature and pressure conditions, the free fatty acids are separated from the linseed oil to obtain purified linseed oil, thereby improving the stability and quality of the blended oil.

[0018] III. The low-temperature dewaxing of rice bran oil can remove the wax in rice bran oil. Wax will affect the appearance and fluidity of rice bran oil, and will also cause the oil to become turbid or solidify at low temperatures. Through steps such as preheating, low-temperature crystallization and filtration, the wax crystallizes and precipitates and is separated to obtain dewaxed rice bran oil, improving the storage stability and appearance of the blended oil at low temperatures.

[0019] IV. Vitamin E is encapsulated in microcapsules. The microcapsule structure formed by the wall material solution can protect vitamin E from the influence of external environmental factors (such as light, oxygen, moisture, etc.), improving its stability. Spray drying makes the wall material form uniform microcapsules around vitamin E. A small particle size (below 200 nm) is beneficial to its better dispersion in the blended oil, so as to more effectively play an antioxidant role.

[0020] V. Preparation of litchi seed extract: Supercritical carbon dioxide extraction can fully extract the effective components in litchi seeds. After separation in the separation kettle, a crude extract is obtained. Using macroporous adsorption resin and methanol aqueous solutions with different concentrations for elution and purification to remove impurities, a high-purity litchi seed extract is obtained. Its antioxidant components can effectively protect the unsaturated fatty acids in the blended oil, improve the stability of the blended oil, and further improve the antioxidant and stability-promoting effects.

[0021] VI. In the preparation method of the present invention, vegetable oil is first mixed evenly at a certain temperature and rotation speed to make the fatty acid composition balanced. Then rosmarinic acid, litchi seed extract, vitamin E microcapsules and lecithin are added, and the speed is reduced for mixing to make these components evenly dispersed in the blended oil. Small particles are allowed to settle by standing, and then possible impurities are removed by filtration to obtain a blended oil with stable quality and uniformity, having good antioxidant properties and storage stability. Detailed implementation manners

[0022] The present invention will be further described below in conjunction with specific implementation cases, but the present invention is not limited to these embodiments.

[0023] Example 1 A highly stable edible blended oil rich in natural antioxidants, the blended oil comprises the following raw materials in parts by mass: 13 parts of camellia oil, 42 parts of sunflower seed oil, 13 parts of linseed oil, 22 parts of rice bran oil, 0.06 part of rosmarinic acid, 0.04 part of litchi seed extract, 0.12 part of vitamin E microcapsules and 0.015 part of lecithin.

[0024] Among them, the linseed oil is purified by distillation. The crude linseed oil is added to a distillation device and distilled under the conditions of 180 °C and 0.3 Pa pressure to remove free fatty acids (under these conditions, low-boiling substances such as free fatty acids will preferentially volatilize from the material) to obtain purified linseed oil.

[0025] Among them, the rice bran oil is dewaxed at low temperature. The rice bran oil is preheated to 65 °C to make the wax in a crystallizable state; the preheated rice bran oil is transferred to a low-temperature crystallization device (crystallization tank), and the temperature is maintained at 4 °C, and the crystallization time is 24 h; the wax crystallizes out, and the wax and oil are separated by filtration to obtain dewaxed rice bran oil.

[0026] Among them, the preparation method of the vitamin E microcapsules comprises the following steps: preparing a wall material solution, the wall material solution being an aqueous solution containing 3 wt% of arabic gum and 2 wt% of carboxymethyl chitosan; dissolving vitamin E in soybean oil 4 times the mass of vitamin E to obtain a core material oil solution, and then adding the core material oil solution to the wall material solution according to a volume ratio of 1:4.5 of the core material oil solution to the wall material solution, and performing homogenization treatment to form an oil-in-water emulsion, and spray drying to form a microcapsule structure of the wall material around vitamin E to obtain vitamin E microcapsules with a particle size range below 200 nm.

[0027] Among them, the preparation method of the litchi seed extract includes the following steps: loading litchi seed powder into an extraction kettle, using carbon dioxide as the extraction agent, extracting at a pressure of 48 MPa and a temperature of 62 °C for 2.5 h, controlling the carbon dioxide flow rate at 30 L / h, so that the active ingredients in the litchi seeds are fully dissolved in the supercritical carbon dioxide fluid; allowing the supercritical fluid containing the active ingredients to enter a separation kettle, reducing the pressure to 8 MPa and lowering the temperature to 40 °C, so that the active ingredients are separated and precipitated from the carbon dioxide, and collecting to obtain the crude litchi seed extract; preparing an embedding solution, which is an aqueous solution containing 0.8 wt% carboxymethyl chitosan; soaking the D101 macroporous adsorption resin in the embedding solution, with the liquid level of the embedding solution being 1.5 cm higher than the upper surface of the D101 macroporous adsorption resin, draining after soaking for 50 min and loading into a column; dissolving the crude litchi seed extract with methanol at 9 times the mass of the crude litchi seed extract, loading the sample onto the resin column at a flow rate of 1.5 BV / h, first washing with deionized water for 4 column volumes to remove impurities, then eluting with a 60% volume concentration methanol aqueous solution for 4 column volumes, collecting the eluate, concentrating under reduced pressure at 50 °C, and freeze-drying to obtain the litchi seed extract.

[0028] The above preparation method of a highly stable edible blended oil rich in natural antioxidants includes the following steps: by mass fraction, mixing sunflower oil, linseed oil, rice bran oil and camellia oil at 25 °C and 80 r / min for 15 min until uniform to obtain a blended oil; then adding rosmarinic acid, litchi seed extract, vitamin E microcapsules and lecithin, reducing the speed to 40 r / min and mixing for 25 min until uniform, standing for 1.5 h to precipitate possible small particles, and filtering with a 1.25 μm pore size to obtain the blended oil.

[0029] Example 2 A highly stable edible blended oil rich in natural antioxidants, the blended oil comprising the following raw materials by mass fraction: 10 parts of camellia oil, 40 parts of sunflower oil, 10 parts of linseed oil, 20 parts of rice bran oil, 0.05 part of rosmarinic acid, 0.03 part of litchi seed extract, 0.10 part of vitamin E microcapsules and 0.01 part of lecithin.

[0030] Among them, the linseed oil is purified by distillation. The crude linseed oil is added to a distillation device and distilled under the conditions of 175 °C and 0.2 Pa pressure to remove free fatty acids (under these conditions, low-boiling substances such as free fatty acids will preferentially volatilize from the material) to obtain purified linseed oil.

[0031] Among them, the rice bran oil is dewaxed at low temperature. The rice bran oil is preheated to 60 °C to make the wax in a crystallizable state; the preheated rice bran oil is transferred to a low-temperature crystallization device (crystallization tank), the temperature is maintained at 3 °C, and the crystallization time is 20 h; the wax crystallizes and precipitates, and the wax and oil are filtered and separated to obtain the dewaxed rice bran oil.

[0032] Among them, the preparation method of vitamin E microcapsules includes the following steps: Prepare a wall material solution, which is an aqueous solution containing 2 wt% of gum arabic and 1 wt% of carboxymethyl chitosan; dissolve vitamin E in soybean oil with a mass three times that of vitamin E to obtain a core material oil solution, and then add the core material oil solution to the wall material solution according to a volume ratio of 1:4 of the core material oil solution to the wall material solution, and perform homogenization treatment to form an oil-in-water emulsion, and then spray dry to form a microcapsule structure of the wall material around vitamin E to obtain vitamin E microcapsules with a particle size range of less than 200 nm.

[0033] Among them, the preparation method of litchi seed extract includes the following steps: Load litchi seed powder into an extraction kettle, use carbon dioxide as the extractant, extract at a pressure of 45 MPa and a temperature of 60 °C for 2 h, control the carbon dioxide flow rate at 25 L / h, so that the active ingredients in litchi seeds are fully dissolved in the supercritical carbon dioxide fluid; let the supercritical fluid containing the active ingredients enter the separation kettle, reduce the pressure to 5 MPa and lower the temperature to 35 °C to separate and precipitate the active ingredients from carbon dioxide, and collect to obtain the crude litchi seed extract; prepare an embedding solution, which is an aqueous solution containing 0.5 wt% of carboxymethyl chitosan; soak the D101 macroporous adsorption resin in the embedding solution, and the liquid level of the embedding solution is 1 cm higher than the upper surface of the D101 macroporous adsorption resin, drain it after soaking for 30 min and load it into a column; dissolve the crude litchi seed extract with methanol with a mass eight times that of the crude litchi seed extract, load it onto the resin column at a flow rate of 1 BV / h, first wash with deionized water for 3 column volumes to remove impurities, and then elute with a 40% (v / v) methanol aqueous solution for 3 column volumes, collect the eluate, concentrate it under reduced pressure at 40 °C, and freeze-dry to obtain the litchi seed extract.

[0034] The preparation method of the above-mentioned highly stable edible blended oil rich in natural antioxidants includes the following steps: By mass, mix sunflower oil, linseed oil, rice bran oil and camellia oil at 20 °C and 50 r / min for 10 min until uniform to obtain a blended oil; then add rosmarinic acid, litchi seed extract, vitamin E microcapsules and lecithin, reduce the speed to 30 r / min and mix for 20 min until uniform, let it stand for 1 h, precipitate the possible small particles, and filter with a 2-μm pore size to obtain the blended oil.

[0035] Example 3 A highly stable edible blended oil rich in natural antioxidants, the blended oil includes the following raw materials in parts by mass: 15 parts of camellia oil, 45 parts of sunflower oil, 15 parts of linseed oil, 25 parts of rice bran oil, 0.08 part of rosmarinic acid, 0.05 part of litchi seed extract, 0.15 part of vitamin E microcapsules and 0.02 part of lecithin.

[0036] Among them, the flaxseed oil is purified by distillation. The crude flaxseed oil is added to a distillation device and distilled under the conditions of 185°C and a pressure of 0.4 Pa to remove free fatty acids (under these conditions, low-boiling substances such as free fatty acids will preferentially volatilize from the material), and purified flaxseed oil is obtained.

[0037] Among them, the rice bran oil is dewaxed at low temperature. The rice bran oil is preheated to 70°C to make the wax in a crystallizable state; the preheated rice bran oil is transferred to a low-temperature crystallization device (crystallization tank), and the temperature is maintained at 5°C for a crystallization time of 30 h; the wax crystallizes out, and the wax and oil are filtered and separated to obtain dewaxed rice bran oil.

[0038] Among them, the preparation method of vitamin E microcapsules includes the following steps: preparing a wall material solution, which is an aqueous solution containing 4 wt% arabic gum and 3 wt% carboxymethyl chitosan; dissolving vitamin E in soybean oil 5 times the mass of vitamin E to obtain a core material oil solution, and then adding the core material oil solution to the wall material solution according to a volume ratio of 1:5, and performing homogenization treatment to form an oil-in-water emulsion, followed by spray drying to form a microcapsule structure of the wall material around vitamin E, and obtaining vitamin E microcapsules with a particle size range of less than 200 nm.

[0039] Among them, the preparation method of the litchi seed extract includes the following steps: loading litchi seed powder into an extraction kettle, using carbon dioxide as an extractant, extracting at a pressure of 50 MPa and a temperature of 65°C for 3 h, controlling the carbon dioxide flow rate at 35 L / h to make the active ingredients in the litchi seeds fully dissolve in the supercritical carbon dioxide fluid; the supercritical fluid containing the active ingredients enters a separation kettle, the pressure is reduced to 10 MPa and the temperature is reduced to 45°C to separate and precipitate the active ingredients from carbon dioxide, and the crude litchi seed extract is collected; preparing an embedding solution, which is an aqueous solution containing 1 wt% carboxymethyl chitosan; soaking the D101 macroporous adsorption resin in the embedding solution, with the liquid level of the embedding solution 2 cm higher than the upper surface of the D101 macroporous adsorption resin, draining after soaking for 60 min and loading into a column; dissolving the crude litchi seed extract in methanol 10 times the mass of the crude litchi seed extract and loading it onto the resin column at a flow rate of 2 BV / h, first washing with deionized water for 5 column volumes to remove impurities, and then eluting with an 80% volume concentration methanol aqueous solution for 5 column volumes, collecting the eluate, concentrating under reduced pressure at 60°C, and freeze-drying to obtain the litchi seed extract.

[0040] The preparation method of the above high-stability edible blended oil rich in natural antioxidants includes the following steps: By mass fraction, sunflower oil, linseed oil, rice bran oil and camellia oil are mixed at 28 °C and 100 r / min for 20 min until uniform to obtain a blended oil; then rosmarinic acid, litchi seed extract, vitamin E microcapsules and lecithin are added, and the speed is reduced to 50 r / min and mixed for 30 min until uniform, then left standing for 2 h to precipitate possible small particles, and filtered through a filter with a pore size of 2.5 μm to obtain the blended oil.

[0041] Example 4 A high-stability edible blended oil rich in natural antioxidants, the blended oil comprising the following raw materials by mass fraction: 15 parts of camellia oil, 40 parts of sunflower oil, 15 parts of linseed oil, 20 parts of rice bran oil, 0.05 part of rosmarinic acid, 0.05 part of litchi seed extract, 0.10 part of vitamin E microcapsules and 0.02 part of lecithin.

[0042] Among them, the linseed oil is purified by distillation. The crude linseed oil is added to a distillation device and distilled under the conditions of 175 °C and 0.4 Pa pressure to remove free fatty acids (under these conditions, low-boiling substances such as free fatty acids will preferentially volatilize from the material) to obtain purified linseed oil.

[0043] Among them, the rice bran oil is dewaxed at low temperature. The rice bran oil is preheated to 60 °C to make the wax in a crystallizable state; the preheated rice bran oil is transferred to a low-temperature crystallization device (crystallization tank), and the temperature is maintained at 5 °C for a crystallization time of 20 h; the wax crystallizes out, and the wax and oil are filtered and separated to obtain dewaxed rice bran oil.

[0044] Among them, the preparation method of the vitamin E microcapsules includes the following steps: Prepare a wall material solution, which is an aqueous solution containing 4 wt% of arabic gum and 1 wt% of carboxymethyl chitosan; dissolve vitamin E in soybean oil 5 times the mass of vitamin E to obtain a core material oil solution, and then add the core material oil solution to the wall material solution according to a volume ratio of 1:4 of the core material oil solution to the wall material solution, and perform homogenization treatment to form an oil-in-water emulsion, and spray dry to form a microcapsule structure of the wall material around vitamin E to obtain vitamin E microcapsules with a particle size range of less than 200 nm.

[0045] Among them, the preparation method of the litchi seed extract includes the following steps: loading the litchi seed powder into an extraction kettle, using carbon dioxide as the extractant, extracting at a pressure of 50 MPa and a temperature of 60 °C for 3 h, controlling the carbon dioxide flow rate at 25 L / h, so that the active ingredients in the litchi seeds are fully dissolved in the supercritical carbon dioxide fluid; allowing the supercritical fluid containing the active ingredients to enter a separation kettle, reducing the pressure to 10 MPa and lowering the temperature to 35 °C, so that the active ingredients are separated and precipitated from the carbon dioxide, and collecting to obtain the crude litchi seed extract; preparing an embedding solution, which is an aqueous solution containing 1 wt% carboxymethyl chitosan; soaking the D101 macroporous adsorption resin in the embedding solution, with the liquid level of the embedding solution being 1 cm higher than the upper surface of the D101 macroporous adsorption resin, draining after soaking for 60 min and loading into a column; dissolving the crude litchi seed extract with methanol at 8 times the mass of the crude litchi seed extract, loading the sample onto the resin column at a flow rate of 2 BV / h, first washing with deionized water for 3 column volumes to remove impurities, then eluting with an 80% volume concentration methanol aqueous solution for 3 column volumes, collecting the eluate, concentrating under reduced pressure at 60 °C, and freeze-drying to obtain the litchi seed extract.

[0046] The preparation method of the above-mentioned high-stability edible blended oil rich in natural antioxidants includes the following steps: by mass, mixing sunflower oil, linseed oil, rice bran oil and camellia oil at 20 °C and 100 r / min for 10 min until uniform to obtain a blended oil; then adding rosmarinic acid, litchi seed extract, vitamin E microcapsules and lecithin, reducing the speed to 50 r / min and mixing for 20 min until uniform, standing for 2 h to precipitate possible small particles, and filtering with a 1.25 μm pore size to obtain the blended oil.

[0047] Example 5 A high-stability edible blended oil rich in natural antioxidants, the blended oil comprises the following raw materials in parts by mass: 10 parts of camellia oil, 45 parts of sunflower oil, 10 parts of linseed oil, 25 parts of rice bran oil, 0.08 part of rosmarinic acid, 0.03 part of litchi seed extract, 0.15 part of vitamin E microcapsules and 0.01 part of lecithin.

[0048] Among them, the linseed oil is purified by distillation. The crude linseed oil is added to a distillation device and distilled under the conditions of 185 °C and 0.2 Pa pressure to remove free fatty acids (under these conditions, low-boiling substances such as free fatty acids will preferentially volatilize from the material) to obtain purified linseed oil.

[0049] Among them, the rice bran oil is dewaxed at low temperature. The rice bran oil is preheated to 70 °C to make the wax in a crystallizable state; the preheated rice bran oil is transferred to a low-temperature crystallization device (crystallization tank), maintaining the temperature at 3 °C and the crystallization time at 30 h; allowing the wax to crystallize and precipitate, filtering to separate the wax and the oil to obtain the dewaxed rice bran oil.

[0050] Among them, the preparation method of vitamin E microcapsules includes the following steps: Prepare a wall material solution, which is an aqueous solution containing 2 wt% of arabic gum and 3 wt% of carboxymethyl chitosan; dissolve vitamin E in soybean oil with a mass three times that of vitamin E to obtain a core material oil solution, and then add the core material oil solution to the wall material solution according to a volume ratio of 1:5 of the core material oil solution to the wall material solution, and perform homogenization treatment to form an oil-in-water emulsion, and spray dry it to form a microcapsule structure around vitamin E to obtain vitamin E microcapsules with a particle size range below 200 nm.

[0051] Among them, the preparation method of the litchi seed extract includes the following steps: Load the litchi seed powder into the extraction kettle, use carbon dioxide as the extractant, extract at a pressure of 45 MPa and a temperature of 65 °C for 2 h, control the carbon dioxide flow rate at 35 L / h, so that the active ingredients in the litchi seeds are fully dissolved in the supercritical carbon dioxide fluid; let the supercritical fluid containing the active ingredients enter the separation kettle, reduce the pressure to 5 MPa and lower the temperature to 45 °C, so that the active ingredients are separated and precipitated from the carbon dioxide, and collect to obtain the crude litchi seed extract; prepare an embedding solution, which is an aqueous solution containing 0.5 wt% of carboxymethyl chitosan; soak the D101 macroporous adsorption resin in the embedding solution, and the liquid level of the embedding solution is 2 cm higher than the upper surface of the D101 macroporous adsorption resin, drain it after soaking for 30 min and load it into the column; dissolve the crude litchi seed extract with methanol with a mass 10 times that of the crude litchi seed extract, load it onto the resin column at a flow rate of 1 BV / h, first wash it with deionized water for 5 column volumes to remove impurities, and then elute it with a 40% volume concentration methanol aqueous solution for 5 column volumes, collect the eluate, concentrate it under reduced pressure at 40 °C, and freeze-dry it to obtain the litchi seed extract.

[0052] The preparation method of the above-mentioned high-stability edible blended oil rich in natural antioxidants includes the following steps: By mass, mix sunflower oil, linseed oil, rice bran oil and camellia oil at 28 °C and 50 r / min for 20 min until uniform to obtain a blended oil; then add rosmarinic acid, litchi seed extract, vitamin E microcapsules, and lecithin, reduce the speed to 30 r / min and mix for 30 min until uniform, let it stand for 1 h, precipitate the possible small particles, and filter with a 2.5 μm pore size to obtain the blended oil.

[0053] In the above-mentioned examples, the sunflower oil, linseed oil, rice bran oil and camellia oil are self-made pressed oils. The arabic gum is sourced from Anhui Weimao Biotechnology Co., Ltd., food grade. The lecithin is sourced from Henan Fengwei Biotechnology Co., Ltd., soy lecithin, food grade. The sodium alginate is sourced from Henan Anrui Biotechnology Co., Ltd., food grade. The carboxymethyl chitosan is sourced from Tianben Biotechnology (Shanxi) Co., Ltd., food grade. The rosmarinic acid is sourced from Gelubo Bioproducts (Shaanxi) Co., Ltd., with a content of 98 wt%.

[0054] Comparative Example 1 The litchi seed extract was extracted by ethanol percolation, and the ethanol percolate was concentrated and dried to obtain the litchi seed extract; other parameters and methods were the same as those in Example 1.

[0055] Comparative Example 2 In the preparation method of the litchi seed extract, the D101 macroporous adsorption resin was replaced with the AB-8 macroporous adsorption resin; other parameters and methods were the same as those in Example 1.

[0056] Comparative Example 3 The vitamin E microcapsules were replaced with vitamin E; other parameters and methods were the same as those in Example 1.

[0057] Comparative Example 4 The distillation and purification temperature of the linseed oil was 120 °C; other parameters and methods were the same as those in Example 1.

[0058] Comparative Example 5 The rice bran oil was not dewaxed at low temperature; other parameters and methods were the same as those in Example 1.

[0059] Comparative Example 6 In the preparation method of the vitamin E microcapsules, the wall material solution was an aqueous solution containing 1 wt% arabic gum and 5 wt% carboxymethyl chitosan; other parameters and methods were the same as those in Example 1.

[0060] Comparative Example 7 In the preparation method of the litchi seed extract, the D101 macroporous adsorption resin was not soaked in the embedding solution; other parameters and methods were the same as those in Example 1.

[0061] Comparative Example 8 In the preparation method of the litchi seed extract, the D101 macroporous adsorption resin was replaced with the AB-8 macroporous adsorption resin and not soaked in the embedding solution; other parameters and methods were the same as those in Example 1.

[0062] The safety of the litchi seed extract prepared in Example 1 was detected.

[0063] Acute toxicity test: Fifty healthy Kunming mice weighing 18 - 22 g, with an equal number of males and females, were selected. Before the experiment, the mice were housed in an environment with a temperature of 22℃ ± 2℃ and a relative humidity of 50% ± 10% for 1 week to adapt to the environment, during which they were given sufficient food and water. The mice were randomly divided into 5 groups of 10 each, and the extract was formulated into 5 different dose groups with distilled water: 5000 mg / kg, 2500 mg / kg, 1250 mg / kg, 625 mg / kg, and 312.5 mg / kg. Administration was by oral gavage, with a gavage volume of 0.2 mL / 10 g body weight. After administration, the mice were returned to the breeding cages and observed continuously for 7 days. The mental state, diet, activity ability, hair color, feces, and other poisoning symptoms of the mice were observed regularly every day, and the death of the mice was recorded. Results: None of the mice in each dose group died or showed obvious poisoning symptoms during the observation period. According to the acute toxicity classification standard, LD50 > 5000 mg / kg, belonging to the actual non-toxic level.

[0064] Sub-chronic toxicity test: Forty healthy SD rats weighing 180 - 220 g, with an equal number of males and females, were selected. Before the experiment, they were adaptively bred in an environment with a temperature of (22 ± 2)℃, a relative humidity of (50 ± 10)%, and a 12 h light / 12 h dark cycle for 1 week, with free access to food and water. They were randomly divided into 4 groups of 10 each. A low-dose group (50 mg / kg), a medium-dose group (150 mg / kg), a high-dose group (500 mg / kg), and a control group (given an equal volume of distilled water) were set up. Administration was by oral gavage at a fixed time every day, and the gavage volume was adjusted according to the rat body weight, being 2 mL / 100 g body weight. After the experiment, the rats were subjected to physical and chemical tests. Results: There were no abnormalities in each dose group of rats, and there was no significant difference in the weekly weight gain; there was also no obvious difference in food intake during the entire test period. The results of hematological and blood biochemical index tests were normal. No obvious abnormalities were found in the histopathological examination of the main organs. It shows that the extract has no obvious sub-chronic toxicity at the test doses.

[0065] The above-mentioned blended oils were subjected to oxidative rancidity detection and storage stability detection.

[0066] I. Oxidative rancidity detection: 1. Peroxide value determination: Take 2 g of blended oil and determine it by the titration method in GB 5009.227-2016 "National Food Safety Standard - Determination of Peroxide Value in Foods", and calculate the peroxide value (mmol / kg). The detection results are shown in Table 1 below.

[0067] 2. Acid value determination: Take 3 g of blended oil and determine it by the cold solvent indicator titration method in GB 5009.229-2016 "National Food Safety Standard - Determination of Acid Value in Foods". Calculate the acid value (mgKOH / g). The detection results are shown in Table 1 below.

[0068] 2. Storage stability test: 1. Low temperature stability test: Take 50mL of blended oil sample and put it into a colorimetric tube. Put the colorimetric tube with the sample into a refrigerator at 4℃. Take out the colorimetric tube every 24 hours and observe vertically under natural light to see if there is any change (at least one change of stratification, turbidity and coagulation); observe continuously for 30 days. If the above phenomenon occurs, record the time of occurrence to measure the low temperature stability of the blended oil. The test results are shown in Table 1 below.

[0069] 2. Long-term storage stability test: Place the blended oil sample in a brown glass bottle, which effectively blocks ultraviolet rays and reduces the impact of photooxidation on oil. Store the glass bottle in a constant temperature and humidity chamber at 25°C and 60% relative humidity. Take samples after 3 months, and determine the peroxide value and acid value according to the method in the above-mentioned oxidation rancidity test. The test results are shown in Table 1 below.

[0070] Table 1 Test data results From the above results, it can be seen that the blended oils of Examples 1 to 5 use natural antioxidants, which achieve the effects of being not easy to oxidize and become rancid, having good storage stability, and being safe and healthy.

[0071] Comparative Example 1: The litchi kernel extract was extracted by ethanol percolation. The extraction method was different, and the product composition obtained was different. After being added to the blended oil, the impurities had reacted, the stability became poor, and the various indicators were not as good as those in the embodiment.

[0072] Comparative Example 2 does not add lychee kernel extract. The lychee kernel extract slows down the oxidation rate by removing free radicals generated by oil oxidation. In the absence of lychee kernel extract, the free radical scavenging ability of the blended oil is weakened, the oxidation reaction is accelerated, and the peroxide value and acid value increase. At the same time, the accumulation of oxidation products changes the physical properties of the oil, affects its stability at low temperatures, and the time of stratification, turbidity or coagulation is advanced. During long-term storage, as the degree of oxidation deepens, the peroxide value and acid value continue to increase.

[0073] Comparative Example 3 does not add vitamin E microcapsules. Vitamin E is a natural antioxidant that can capture peroxide free radicals generated during oil oxidation, terminate chain reactions, and thus delay oil oxidation. Microcapsule technology encapsulates vitamin E, which can protect it from external environmental factors (such as oxygen, moisture, light, etc.), allowing it to play an antioxidant role more stably. Without vitamin E microcapsules, vitamin E is directly exposed to oil and fat, easily oxidized and loses its activity, and cannot continuously and effectively inhibit oil oxidation, resulting in a significant increase in peroxide value and acid value. In a low temperature environment, due to the high degree of oil oxidation, instability is more likely to occur, and the peroxide value and acid value will further deteriorate after long-term storage.

[0074] In Comparative Example 4, the linseed oil was not subjected to distillation purification, and the crude linseed oil contained a relatively large amount of free fatty acids and impurities. Free fatty acids have high activity and are prone to oxidation reactions with oxygen during storage, producing peroxides and small-molecule aldehydes, ketones and other substances, resulting in an increase in peroxide value and acid value. The presence of impurities also affects the stability of the oil. Some impurities can act as catalysts or initiators for oxidation reactions, accelerating the oxidative rancidity of the oil. At low temperatures, the presence of impurities and free fatty acids will change the freezing point and intermolecular forces of the oil, making the blended oil more likely to show stratification, turbidity or solidification, and the low-temperature stability becomes worse. After long-term storage, the oxidation reaction continues, and the peroxide value and acid value further increase.

[0075] In Comparative Example 5, the rice bran oil was not dewaxed at low temperature, and the rice bran oil contained a certain amount of wax. The wax will gradually crystallize and precipitate at low temperatures, resulting in poor fluidity of the oil product, stratification, turbidity or solidification, seriously affecting the low-temperature stability. Moreover, the presence of wax affects the oxidation process of the oil. On the one hand, some components in the wax will interact with the oil, changing the physical and chemical properties of the oil and making the oil more easily oxidized; on the other hand, the process of wax crystallization and precipitation will destroy the homogeneity of the oil and promote the occurrence of oxidation reactions. Therefore, for the blended oil made from non-dewaxed rice bran oil, the peroxide value and acid value will also increase to some extent, and the degree of oxidation will intensify after long-term storage.

[0076] In Comparative Example 6, the vitamin E microcapsules were replaced with vitamin E. The microcapsule structure can provide a protective barrier for vitamin E, delaying its oxidation rate and enabling it to continuously play an antioxidant role for a long time. When directly using vitamin E, since it is directly exposed to the oil environment, it is easily oxidized and inactivated by factors such as oxygen, moisture, and light. The inactivated vitamin E cannot effectively inhibit the oxidation of the oil, resulting in an accelerated oxidation rate of the blended oil, an increase in peroxide value and acid value. In terms of low-temperature stability and long-term storage stability, it is similar to the case without adding vitamin E microcapsules. Due to the high degree of oil oxidation, unstable phenomena are more likely to occur, and the peroxide value and acid value further increase after long-term storage.

[0077] In the preparation method of the litchi seed extract of Comparative Example 7, the D101 macroporous adsorption resin is not soaked in the embedding solution. The embedding solution treatment can improve the adsorption performance and selectivity of the macroporous adsorption resin, enabling it to more effectively adsorb the active ingredients in the litchi seed extract while removing impurities. Without soaking in the embedding solution, the adsorption and separation effects of the macroporous adsorption resin on the litchi seed extract are affected, and the purity of the obtained extract is not high. The content of antioxidant components in the extract with insufficient purity is relatively low, and the antioxidant effect cannot be fully exerted, resulting in the easy oxidation of the blended oil during storage, with an increase in peroxide value and acid value. In terms of low-temperature stability, due to the increased degree of oxidation, layering, turbidity or solidification is more likely to occur, and the peroxide value and acid value further increase after long-term storage.

[0078] In the preparation method of the litchi seed extract of Comparative Example 8, the D101 macroporous adsorption resin is not used for adsorption and purification. There are many impurities in the crude litchi seed extract, and the relative content of the effective antioxidant components is low. The presence of impurities will not only dilute the concentration of antioxidant components but also interfere with the reaction between antioxidant components and lipid oxidation free radicals, reducing the antioxidant effect. In addition, some components in the impurities will promote the oxidation reaction of lipids and accelerate the rancidity of lipids. Therefore, the litchi seed extract without adsorption and purification cannot effectively delay the oxidation of lipids, resulting in poor storage stability of the blended oil, with an increase in peroxide value and acid value. At low temperatures, due to the high degree of lipid oxidation, unstable phenomena are more likely to occur, and the peroxide value and acid value continue to increase after long-term storage.

Claims

1. A high-stability edible blended oil rich in natural antioxidants, characterized in that: The invention comprises the following raw materials in parts by weight: 10-15 parts of camellia oil, 40-45 parts of sunflower oil, 10-15 parts of linseed oil, 20-25 parts of rice bran oil, 0.05-0.08 parts of rosmarinic acid, 0.03-0.05 parts of litchi kernel extract, 0.10-0.15 parts of vitamin E microcapsules and 0.01-0.02 parts of lecithin; the linseed oil is linseed oil purified by distillation; the rice bran oil is dewaxed rice bran oil; the shell layer of the vitamin E microcapsule is gum arabic and carboxymethyl chitosan; the litchi kernel extract is a product obtained by extracting litchi kernels with supercritical carbon dioxide and then adsorbing and purifying them with an adsorption resin column.

2. The high-stability edible blended oil rich in natural antioxidants according to claim 1, characterized in that: The linseed oil is purified by distillation. The crude linseed oil is added into a distillation device and distilled under the conditions of 175° C. to 185° C. and 0.2 Pa to 0.4 Pa pressure to remove free fatty acids and obtain purified linseed oil.

3. The high-stability edible blended oil rich in natural antioxidants according to claim 1, characterized in that: The rice bran oil is dewaxed at low temperature, the rice bran oil is preheated to 60°C-70°C, so that the wax is in a crystallizable state; the preheated rice bran oil is transferred to a low-temperature crystallization device, the temperature is maintained at 3°C-5°C, and the crystallization time is 20h-30h; the wax is crystallized and precipitated, and the wax and oil are separated by filtering to obtain the dewaxed rice bran oil.

4. The high-stability edible blended oil rich in natural antioxidants according to claim 1, characterized in that: The preparation method of the vitamin E microcapsule comprises the following steps: preparing a wall material solution, wherein the wall material solution is an aqueous solution containing 2wt% to 4wt% of gum arabic and 1wt% to 3wt% of carboxymethyl chitosan; dissolving vitamin E in soybean oil 3 to 5 times the mass of vitamin E to obtain a core material oil liquid; then adding the core material oil liquid to the wall material solution at a volume ratio of 1: (4 to 5) of the core material oil liquid to the wall material solution, homogenizing to form an oil-in-water emulsion, spray drying to allow the wall material to form a microcapsule structure around the vitamin E, and obtaining vitamin E microcapsules with a particle size range of less than 200nm.

5. The high-stability edible blended oil rich in natural antioxidants according to claim 1, characterized in that: The preparation method of the litchi kernel extract comprises the following steps: loading litchi kernel powder into an extraction kettle, using carbon dioxide as an extractant to perform extraction, so that the effective components in the litchi kernel are fully dissolved in a supercritical carbon dioxide fluid; passing the supercritical fluid containing the effective components into a separation kettle, reducing the pressure to 5MPa-10MPa, and reducing the temperature to 35°C-45°C, so that the effective components are separated and precipitated from the carbon dioxide, and collecting to obtain a crude litchi kernel extract; dissolving the crude litchi kernel extract in methanol with a mass of 8-10 times that of the crude litchi kernel extract, loading the sample onto a resin column, first washing with deionized water for 3-5 column volumes to remove impurities, and then eluting with a methanol aqueous solution with a volume concentration of 40%-80% for 3-5 column volumes, collecting the eluate, concentrating under reduced pressure, and freeze-drying to obtain the litchi kernel extract.

6. The high-stability edible blended oil rich in natural antioxidants according to claim 5, characterized in that: The extraction is carried out at a pressure of 45MPa to 50MPa and a temperature of 60°C to 65°C for 2h to 3h; the carbon dioxide flow rate is 25L / h to 35L / h.

7. The high-stability edible blended oil rich in natural antioxidants according to claim 5, characterized in that: The flow rate of the sample loading is 1 BV / h to 2 BV / h; the temperature of the reduced pressure concentration is 40° C. to 60° C.

8. The high-stability edible blended oil rich in natural antioxidants according to claim 5, characterized in that: The resin column is filled with D101 macroporous adsorption resin, which is soaked in embedding solution and then drained and loaded into the column; the embedding solution is an aqueous solution containing 0.5wt% to 1wt% carboxymethyl chitosan; the immersion liquid level of the embedding solution is 1cm to 2cm higher than the upper surface of the D101 macroporous adsorption resin.

9. The method for preparing a high-stability edible blended oil rich in natural antioxidants according to claim 1, characterized in that: The method comprises the following steps: mixing sunflower seed oil, linseed oil, rice bran oil and camellia oil at a temperature below 30 DEG C according to weight proportions to obtain mixed oil; then adding rosmarinic acid, litchi kernel extract, vitamin E microcapsule and lecithin to mix evenly at a reduced speed, standing and filtering to obtain blended oil.

10. The method for preparing a high-stability edible blended oil rich in natural antioxidants according to claim 9, characterized in that: The mixing speed of the mixed oil is 50r / min~100r / min, and the mixing time of the mixed oil is 10min~20min; the speed of the reduced speed mixing is 30r / min~50r / min, and the time of the reduced speed mixing is 20min~30min; the standing time is 1h~2h, and the pore size of the filter is 1.25μm~2.5μm.

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