A high-quality seabuckthorn fruit oil and a method for obtaining seabuckthorn fruit oil from seabuckthorn cream

Abstract

The present invention provides a high-quality seabuckthorn fruit oil and a method for obtaining seabuckthorn fruit oil from seabuckthorn cream. Using seabuckthorn cream as the raw material, process water is added and stirred evenly. Alkali is used to adjust the three-dimensional conformation of proteins in the cream, and then the material is placed in a refrigerator to freeze and crystallize the oil. The crystallized material is melted under temperature control, and finally, high-speed centrifugation is used to separate the seabuckthorn fruit oil. The present invention prepares seabuckthorn fruit oil by non-enzymatic processing and non-thermal treatment technology. The process is advanced and reasonable, and the whole production process is green, environmentally friendly and low-carbon. Not only is the oil yield high, but the obtained seabuckthorn fruit oil has a strong fruity fragrance, good product quality, and is suitable for industrial production. The prepared seabuckthorn fruit oil can be applied in the fields of pharmaceuticals, health foods and cosmetics.

Description

Technical Field

[0001] The present invention belongs to the technical field of fine processing of sea buckthorn, and particularly relates to a high-quality sea buckthorn fruit oil and a method for obtaining sea buckthorn fruit oil from sea buckthorn cream. Background Art

[0002] Sea buckthorn (Hippophae rhamnoides) is a perennial deciduous small tree or shrub, which is a small berry plant that loves light, is drought-resistant, resistant to severe cold and heat, and has extremely strong adaptability to the soil. Its fruits are mostly red or orange-red. It is mainly distributed in the northwest, north and northeast regions of China, and is used for sand prevention and forest protection, improving the soil environment and preventing soil erosion. Sea buckthorn is rich in a variety of bioactive substances and has a variety of pharmacological effects. China is the country with the earliest record of the medicinal use of sea buckthorn in the world. As early as the 8th century AD, sea buckthorn has been used by Tibetan and Mongolian medicine to treat digestive system diseases, cardiovascular diseases, burns, frostbite, etc. In 1977, sea buckthorn was included in the "Chinese Pharmacopoeia".

[0003] Sea buckthorn fruit oil is a precious natural oil separated from natural sea buckthorn fruits. Sea buckthorn fruit oil contains more than a hundred bioactive substances such as flavonoids, fat-soluble vitamins, carotenoids and phytosterols. Sea buckthorn fruit oil is rich in fatty acids, among which the content of palmitoleic acid is relatively high, and its content in sea buckthorn fruit oil can reach more than 30%, which is the highest among all plant and animal oils. Current research shows that the main health care functions of sea buckthorn fruit oil include protecting the cardiovascular system, repairing skin damage and skin diseases, protecting chemical liver damage and immune regulation, etc. Sea buckthorn fruit oil has been applied in the fields of food, health food, cosmetics and pharmaceuticals, and its nutritional and health care effects have been recognized and accepted by the majority of consumers.

[0004] The existing methods for preparing sea buckthorn fruit oil mainly include centrifugation, hydraulic pressing, supercritical carbon dioxide extraction and enzymatic preparation processes. Among them, centrifugation separates oil and water in a centrifuge by means of the specific gravity difference between oil and water. Since the sea buckthorn fruit oil in sea buckthorn cream is wrapped by proteins, phospholipids, etc., direct centrifugal separation cannot fully break the emulsion layer, resulting in a low oil yield; hydraulic pressing is applicable to dried sea buckthorn fruits, and with the help of a hydraulic oil press, the yield of sea buckthorn fruit oil can reach about 50%. Another method is supercritical carbon dioxide extraction, which is also applicable to dried sea buckthorn fruits. The main disadvantage is the large equipment investment and high operating cost. Finally, the most commonly used method at present is enzymatic preparation of sea buckthorn fruit oil. By using biological enzymes for enzymatic hydrolysis and then combining with centrifugal separation, sea buckthorn fruit oil can be obtained. However, this method generally requires controlling the enzymatic hydrolysis time within 4-6 hours and the temperature within 50-70°C. The heating time of sea buckthorn raw pulp and cream is long, resulting in browning and a large loss of the fruity fragrance of sea buckthorn fruit oil, which affects the product quality of sea buckthorn fruit oil. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problems of low oil extraction rate, high cost, thermal browning, low quality and the like of sea buckthorn fruit oil in the prior art, and to provide a high-quality sea buckthorn fruit oil and a method for obtaining sea buckthorn fruit oil from sea buckthorn cream.

[0006] The main form of vegetable oil in plant cells is in the form of lipid bodies, and the oil is mainly wrapped by surface-active proteins and phospholipids. To improve the extraction rate of sea buckthorn fruit oil, it is necessary to consider how to destroy the emulsified structure of lipid bodies, especially the structure of proteins. The enzymatic hydrolysis method of the prior art is used to destroy the outer layer of lipid bodies of oil and extract sea buckthorn fruit oil. The sea buckthorn puree and cream are kept under 50-70°C heating conditions for a long time, resulting in serious browning of sea buckthorn fruit oil and a large loss of fruity flavor. Therefore, the inventor has conducted research on this. In order to avoid the influence of thermal processing on the quality of sea buckthorn fruit oil, a physical demulsification method combined with a chemical demulsification technology is used to destroy the water-in-oil lipid body structure in the sea buckthorn cream, and then the sea buckthorn fruit oil is gradually crystallized under low temperature conditions to form a needle-like structure, which can pierce the emulsified layer wrapped on the surface of the sea buckthorn fruit oil, so that the sea buckthorn fruit oil droplets overflow from the cream, thereby obtaining high-quality sea buckthorn fruit oil. In view of this, the inventor provides the following scheme of the present invention.

[0007] In order to achieve the purpose of the present invention, the first aspect of the present invention provides a method for preparing high-quality seabuckthorn fruit oil from seabuckthorn cream, comprising the following steps:

[0008] a) Mixing: Take seabuckthorn cream, add process water according to the mass ratio of water to seabuckthorn cream of 1:1 to 10:1, the conductivity of the process water is 30 to 100 μs / cm, stir and mix evenly, and the mixed material is set aside;

[0009] b) protein conformation adjustment: adding alkali to the above mixed material to adjust the pH value of the material to 4.0-5.5;

[0010] c) Oil crystallization: freeze the material at low temperature and crystallize it. The crystallization temperature is controlled at -15 to -30°C and the freezing time is 12 to 48 hours.

[0011] d) Crystal melting: Place the crystallized material in a water bath at 25-45°C for 20-120 minutes;

[0012] e) High-speed separation: The melted material is separated at high speed, and the centrifugal speed is controlled at 8000-16000 r / min and the centrifugal time is 10-30 min. After centrifugation, a high-quality sea buckthorn fruit oil with a bright and clear upper layer, dark red color and rich fruity aroma is obtained.

[0013] Further, the seabuckthorn cream described in step a) refers to the cream obtained by pulping seabuckthorn fruits to prepare seabuckthorn raw pulp and then separating it by low-speed centrifugation. The centrifugation conditions are 3000 - 5000 r / min for 5 - 30 min.

[0014] Further, the mass ratio of water to seabuckthorn cream in step a) is 1:1 - 3:1.

[0015] Further, the alkali used in step b) is sodium hydroxide or potassium hydroxide, and the pH value of the material is adjusted to 4.5 - 5.0.

[0016] Further, the optimum oil crystallization temperature in step c) is -18 - -25 °C, and the crystallization time is 24 - 36 h.

[0017] Further, the crystal melting temperature in step d) is controlled at 30 - 40 °C for 30 - 60 min.

[0018] Further, the centrifugation speed in step e) is controlled at 9000 - 10000 r / min, and the centrifugation time is controlled at 10 - 20 min.

[0019] The second aspect of the present invention provides a high-quality seabuckthorn fruit oil, which is prepared by the above method.

[0020] The beneficial effects of the present invention compared with the prior art are as follows:

[0021] 1. The present invention uses seabuckthorn cream as the raw material to prepare seabuckthorn fruit oil. One of the advantages is that while obtaining the upper-layer cream by centrifuging seabuckthorn raw pulp, the defatted seabuckthorn raw pulp obtained in the middle layer can be directly sterilized and filled to obtain seabuckthorn raw pulp products. In this way, during the process of preparing seabuckthorn fruit oil, the production of seabuckthorn raw pulp is not affected. Moreover, the mass of the obtained seabuckthorn cream is only 1 / 6 - 1 / 7 of that of seabuckthorn raw pulp, greatly reducing the later operation burden.

[0022] 2. In the preparation method of obtaining high-quality seabuckthorn fruit oil from seabuckthorn cream according to the present invention, first, it is considered to adjust the pH value of the material to change the three-dimensional spatial structure conformation of the protein on the cream surface, reduce its surface activity, and lower its emulsifying performance, thereby to a certain extent destroying the inherent emulsifying layer structure, which is beneficial to the diffusion of seabuckthorn fruit oil from the internal phase of the water-in-oil emulsion; then, the technology of oil crystallization demulsification is selected. The cream is placed at an appropriate low temperature. At this temperature, seabuckthorn fruit oil will form crystal nuclei, and with the extension of time, it will gradually crystallize and grow larger. During the crystallization process, needle-like structures are formed, which can pierce the external emulsifying layer structure of the liposome, resulting in the fruit oil inside the liposome flowing out through the pores. Since the fatty acids in seabuckthorn fruit oil are mainly hexadecanoic acid, and its degree of unsaturation is only 60-70%, with more saturated fatty acids such as palmitic acid, this leads to a relatively high crystallization temperature of seabuckthorn fruit oil, between -18°C and -30°C. While the degree of unsaturation of ordinary vegetable oils is above 80%, and the crystallization temperature is generally between -40°C and -50°C, and even can reach -60°C. Therefore, the energy consumption required for seabuckthorn fruit oil to adopt the oil crystallization technology is relatively low, and the requirements for industrial production are relatively easy to achieve. During the gradual heating and melting process of the oil, the oils in different liposomes will overflow from the original crystallization pores of the cream, collide and combine with each other to form large oil droplets, which are easy to float to the upper layer of the water phase, realizing the oil-water separation process.

[0023] 3. In the present invention, the material after crystal melting is separated by centrifugation. Through high-speed centrifugation, the seabuckthorn fruit oil droplets are collected to the upper layer of the water phase through the density difference, so as to efficiently obtain seabuckthorn fruit oil.

[0024] 4. The main advantage of the preparation method adopted in the present invention is that it is a non-enzymatic and non-thermal processing technology during the preparation process, no organic solvents are used, the temperature of the whole process of the material is controlled below 40°C, and the obtained seabuckthorn fruit oil has a strong fruit fragrance, is clear and transparent, and is dark red in color, with good product quality.

[0025] 5. The preparation method of obtaining seabuckthorn fruit oil from seabuckthorn cream according to the present invention combines composite demulsification technologies such as adjusting the protein spatial conformation, seabuckthorn fruit oil crystallization, melting, and high-speed centrifugation demulsification, and has very good effects in the separation and purification of seabuckthorn fruit oil, is suitable for industrial production, and the product yield of seabuckthorn fruit oil can reach more than 90%. Description of the Drawings

[0026] The present invention will be further described below in conjunction with the drawings and embodiments:

[0027] Figure 1 It is a physical photo of the seabuckthorn fruit oil product prepared in Example 1. Detailed Embodiments

[0028] In the following embodiments, unless otherwise specified, the equipment and raw materials involved are commercially available products.

[0029] Raw materials are shown in Table 1.

[0030] Table 1

[0031] Raw material name Source Seabuckthorn fruit Wild Chinese seabuckthorn purchased from farmers Sodium hydroxide Binzhou Chemical Industry Group Co., Ltd. Potassium hydroxide Binzhou Chemical Industry Group Co., Ltd.

[0032] In the following examples, the test methods for the involved properties are as follows:

[0033] 1. Calculation of the yield of seabuckthorn fruit oil

[0034] Yield of seabuckthorn fruit oil = Seabuckthorn fruit oil obtained by centrifugal separation / Total amount of seabuckthorn fruit oil in seabuckthorn cream * 100%

[0035] 2. Detection of oil content

[0036] The detection method for the oil content in seabuckthorn cream refers to the second method in "GB5009.6 Determination of Fat in Foods".

[0037] Example 1

[0038] This example provides a high-quality seabuckthorn fruit oil, and the preparation method is as follows:

[0039] Take 1000 g of thawed seabuckthorn fruits, beat them into pulp with a pulper, and the obtained seabuckthorn pulp is centrifugally separated at 5000 r / min. 120 g of seabuckthorn cream is obtained from the top layer. Add 120 g of process water to the seabuckthorn cream and mix evenly. The conductivity of the process water is 48 μs / cm. After measurement, the pH value of the material at this time is between 3.0 and 3.2. Adjust the pH value of the mixed material system to 4.5 - 4.6 with 10% sodium hydroxide; then place the material in a -21°C refrigerator for 24 h for oil crystallization treatment, and then take it out and place it in a 35°C constant temperature water bath for 30 min to melt the crystals. Centrifuge the melted material at a high speed of 10000 r / min for 15 min, and the top layer separated is 30.9 g of seabuckthorn fruit oil.

[0040] It is determined that the content of seabuckthorn fruit oil in the raw material seabuckthorn cream before extracting seabuckthorn fruit oil is 28%. After calculation, the final yield of seabuckthorn fruit oil is 92.0%, and as Figure 1 shown, the prepared seabuckthorn fruit oil is clear, transparent, dark red in color, and has a strong fruity aroma.

[0041] Example 2

[0042] This example provides a high-quality seabuckthorn fruit oil, and the preparation method is as follows:

[0043] Take 1000 g of thawed seabuckthorn fruits, beat them into pulp using a pulper, and then centrifuge the obtained seabuckthorn puree at 4000 r / min. 116 g of seabuckthorn cream is obtained from the top layer. Add 232 g of process water to the seabuckthorn cream and mix evenly. The conductivity of the process water is 44 μs / cm. Adjust the pH value of the mixed material system to 4.7 - 4.8 using 10% potassium hydroxide; then place the material in a -25°C refrigerator for 36 h for oil crystallization treatment, and then take it out and place it in a 30°C constant temperature water bath to melt the crystals for 60 min. Centrifuge the melted material at a high speed of 8000 r / min for 20 min, and the top layer separated is 30.3 g of seabuckthorn fruit oil.

[0044] It was determined that the content of seabuckthorn fruit oil in the raw material seabuckthorn cream before extracting seabuckthorn fruit oil was 28%. After calculation, the final yield of seabuckthorn fruit oil was 93.3%, and as Figure 1 shown, the prepared seabuckthorn fruit oil is clear and bright, dark red in color, and has a strong fruity aroma.

[0045] Comparative Example 1

[0046] Seabuckthorn fruit oil was prepared in this comparative example according to a method similar to that of Example 1. The difference is that no alkali was added for protein conformation regulation. The specific steps are as follows:

[0047] Take 1000 g of thawed seabuckthorn fruits, beat them into pulp using a pulper, and then centrifuge the obtained seabuckthorn puree at 5000 r / min. 121 g of seabuckthorn cream is obtained from the top layer. Add 121 g of process water to the seabuckthorn cream and mix evenly. The conductivity of the process water is 48 μs / cm. Place the mixed material in a -21°C refrigerator for 24 h for oil crystallization treatment, and then take it out and place it in a 35°C constant temperature water bath to heat and melt the crystals for 30 min. Centrifuge the melted material at a high speed of 10000 r / min for 15 min, and the top layer separated is 26.7 g of seabuckthorn fruit oil.

[0048] It was determined that the content of seabuckthorn fruit oil in the raw material seabuckthorn cream before extracting seabuckthorn fruit oil was 28%. After calculation, the final yield of seabuckthorn fruit oil was 78.8%.

[0049] The yield of seabuckthorn fruit oil is significantly lower than that of Example 1. This may be because the seabuckthorn fruit oil in the seabuckthorn cream mainly exists in the form of lipid bodies, and the surface is mainly wrapped by proteins with strong surface activity. In this comparative example, during the preparation process, no alkali treatment was carried out, and the protein layer on the surface of the cream was relatively stable. In Example 1, by adjusting the pH value of the system near the charge neutrality of the protein, it is easy to cause changes in the three-dimensional structure of the protein, affecting the firmness of its wrapping of the oil, thus facilitating the overflow of seabuckthorn fruit oil and increasing the product yield. If the pH value is not adjusted, it is difficult for the fruit oil to overflow and the yield decreases.

[0050] Comparative Example 2

[0051] This comparative example prepared seabuckthorn fruit oil according to a method similar to that of Example 1. The difference is that no pre-treatment operations of oil crystallization and heating and melting were performed on the cream. The specific steps are as follows:

[0052] Take 1000 g of thawed seabuckthorn fruit, beat it into pulp with a pulper, and then centrifuge the obtained seabuckthorn pulp at 5000 r / min to obtain 118 g of seabuckthorn cream. Add 118 g of process water to the seabuckthorn cream and mix evenly. The conductivity of the process water is 48 μs / cm. Adjust the pH value of the mixed material system to 4.5 - 4.6 with 10% sodium hydroxide; then centrifuge the mixed material at a high speed of 10000 r / min for 15 min, and separate and take the upper layer to obtain 10.3 g of seabuckthorn fruit oil.

[0053] The content of seabuckthorn fruit oil in the raw material seabuckthorn cream before extracting seabuckthorn fruit oil was measured to be 28%, and after calculation, the final yield of seabuckthorn fruit oil was 31.2%.

[0054] In the operation of this comparative example, no pre-treatment operations of oil crystallization and crystal melting were carried out, and the yield of the seabuckthorn fruit oil product was very low. The main reason is that without oil crystallization, the integrity of the lipid body emulsion layer containing seabuckthorn fruit oil is relatively good, and the oil exists inside the lipid body emulsion layer, and it is not easy for the oil to overflow during the post-treatment process.

[0055] Comparative Example 3

[0056] To further explore the effect of pH value on the extraction of seabuckthorn fruit oil during protein conformation regulation, this comparative example prepared seabuckthorn fruit oil according to a method similar to that of Example 1. The difference is that the pH value conditions for protein conformation regulation are different, as shown in Table 2 specifically.

[0057] Table 2

[0058] Example 1 Comparative example 3-1 Comparative example 3-2 pH value of the mixed material 4.5～4.6 3.5-3.6 5.9-6.0 Yield of seabuckthorn oil (%) 92.0 74.5 78.4

[0059] As can be seen from the above data, when the pH value for protein conformation regulation is 4.5 - 4.6, the yield of seabuckthorn fruit oil is the highest. The main reason is that the surface-active protein in the lipid body emulsion layer of the seabuckthorn cream has a surface charge close to neutral near this pH value, and its three-dimensional spatial structure changes greatly, resulting in a decrease in its surface activity, a weakening of the film-forming property, and a weakening of the oil encapsulation degree in the lipid body, which is conducive to the destruction of the emulsion layer and the overflow of oil. From Table 2, when the pH is around 6.0, the yield of seabuckthorn fruit oil is slightly higher than when it is around 3.5. The possible reason is that at pH = 6.0, it can slightly reduce the surface activity of the protein in the emulsion layer and weaken the firmness of the emulsion layer wrapping. However, from the results, neither is as effective as when the pH value is between 4.5 - 4.6.

[0060] From the data of the above examples and comparative examples, it can be seen that the yield of sea buckthorn fruit oil prepared by the method of adjusting the protein spatial conformation and centrifugal separation in Comparative Example 2 is the lowest, and the effect of the oil crystallization method on the preparation of sea buckthorn fruit oil in Comparative Example 1 under low-temperature conditions is very obvious. In Examples 1 and 2, by adjusting the conformation of the emulsifying layer protein, the emulsifying layer structure was initially disrupted, and then oil crystallization was adopted. The needle-shaped crystals formed during the crystallization process of the oil pierced the emulsifying layer, and the constant-temperature slow melting promoted the aggregation of the oil and high-speed centrifugation. By combining the three-phase separation technology based on the density difference between the oil, water phase, and protein, the product yield of sea buckthorn fruit oil can be increased by more than 90%. Moreover, the main feature of this process is not only the high product yield, but also that the preparation process is carried out under non-enzymatic and non-thermal processing (less than 40 °C throughout the process) conditions, avoiding the generation of peculiar smells caused by long-term heating and enzymatic hydrolysis during the preparation by the aqueous enzymatic method. The product prepared by this invention has a strong fruity aroma, good product quality, and does not affect the production and quality of sea buckthorn puree during the processing process.

[0061] Finally, it should be noted that the above is only used to illustrate the technical solution of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred arrangement, those of ordinary skill in the art should understand that the technical solution of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A preparation method for obtaining high-quality sea buckthorn fruit oil from sea buckthorn cream, characterized in that, The preparation method includes the following steps: a) Mixing: Take seabuckthorn cream, add process water according to the mass ratio of water to seabuckthorn cream being 1:1 to 3:

1. The conductivity of the process water is 30 to 100 μs / cm. Stir and mix evenly, and set aside the mixed material; The seabuckthorn cream refers to the uppermost cream obtained by low-speed centrifugal separation after the seabuckthorn fruit is pulped to prepare seabuckthorn puree. The centrifugation conditions are 3000 to 5000 r / min and the time is 5 to 30 min; b) Protein conformation regulation: Add alkali to the above-mentioned mixed material to adjust the pH value of the material to 4.0 to 5.5; c) Oil crystallization: Place the material in a low-temperature freezer for crystallization. The crystallization temperature is controlled at -15 to -30 °C, and the freezing time is 12 to 48 h, so that the oil forms needle-shaped crystals to pierce the emulsified layer wrapped on the surface of seabuckthorn fruit oil; d) Crystal melting: Place the crystallized material in a water bath at 25 to 45 °C for a constant temperature time of 20 to 120 min; e) High-speed separation: Centrifuge the melted material at a high speed, control the centrifugal speed at 8000 to 16000 r / min, and the centrifugation time at 10 to 30 min; After centrifugation, high-quality seabuckthorn fruit oil with a transparent, dark red and strong fruity aroma in the upper layer is obtained.

2. The preparation method according to claim 1, wherein The alkali used in step b) is sodium hydroxide or potassium hydroxide, and the pH value of the material is adjusted to 4.5 to 5.

0.

3. The preparation method according to claim 1, characterized in that, In step c), the most suitable oil crystallization temperature is -18 to -25 °C, and the crystallization time is 24 to 36 h.

4. The preparation method according to claim 1, wherein In step d), the crystal melting temperature is controlled at 30 to 40 °C, and the time is 30 to 60 min.

5. The preparation method according to claim 1, wherein In step e), the centrifugal speed is controlled at 9000 to 10000 r / min, and the centrifugation time is controlled at 10 to 20 min.

6. A high-quality seabuckthorn fruit oil, characterized in that, The seabuckthorn fruit oil is obtained by the preparation method described in any one of claims 1 to 5.

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