Strong-flavor rapeseed oil and preparation method thereof

Abstract

The invention belongs to the technical field of food processing, and particularly relates to strong-flavor rapeseed oil and a preparation method thereof. The preparation method comprises the following steps: (1) taking rapeseeds, removing impurities, and soaking the rapeseeds in an aqueous solution of sodium phytate for a period of time; (2) drying the rapeseeds soaked in the step (1), frying the rapeseeds, squeezing, and filtering to obtain crude oil; and (3) adding montmorillonite into the crude oil obtained in the step (2), stirring for a period of time at room temperature, adding tamarind polysaccharide, stirring for a period of time at room temperature, and filtering to obtain the rapeseed oil. The strong-flavor rapeseed oil obtained by the preparation method can improve the content of pyrazines, aldehydes and furans in the strong-flavor rapeseed oil, improves the flavor of the rapeseed oil, improves the quality of the rapeseed oil, and has a wide market prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and particularly relates to a strong-flavor rapeseed oil and a preparation method thereof. Background Art

[0002] my country is a major consumer of edible oils, with a rich variety of products, including soybean oil, peanut oil, rapeseed oil, corn oil, and other common oils. In recent years, with improved living standards and growing health awareness, consumer demand for edible oils has expanded beyond basic cooking functions to focus more on health and flavor. This consumption trend has accelerated the edible oil market's shift toward high-end products. Strong-flavor rapeseed oil, with its unique rich aroma and high nutritional value, is highly sought after by consumers and is gradually gaining market share. Consequently, manufacturers are continuously optimizing the production process for strong-flavor rapeseed oil, further improving its taste and quality through raw material screening, processing technology, and quality control, to meet the growing demand for healthy and delicious edible oils.

[0003] Strong-flavor rapeseed oil is made from rapeseed seeds through a process of drying, roasting, and pressing, resulting in a finished product with a rich, fragrant aroma. The characteristic flavor of strong-flavor rapeseed oil is closely related to the raw material source, pretreatment, roasting, and subsequent refining processes. Different processing techniques and methods can lead to different flavors. Traditional strong-flavor rapeseed oil production processes typically involve simply soaking the seeds in water or directly roasting them. While this process can produce a certain aroma, it often cannot precisely control the flavor of the rapeseed oil, and the pungent flavor is relatively weak. Furthermore, a significant issue in the production of strong-flavor rapeseed oil is the risk of aflatoxin contamination. Aflatoxin is a toxic metabolite produced by Aspergillus flavus and Aspergillus parasiticus. It is highly toxic and carcinogenic and is primarily found in grain and oil crops such as peanuts, rapeseed, corn, and soybeans, as well as their products. Aflatoxin is highly heat-resistant and difficult to completely remove through typical cooking processes. Therefore, aflatoxin levels must be strictly controlled during the production of edible oils. While traditional methods for removing aflatoxins from crude oil, such as activated carbon adsorption, are somewhat effective, they generally suffer from limitations such as limited removal efficiency and the absorption of beneficial flavor compounds. This makes it difficult to meet increasingly stringent food safety standards and consumer demand for high-quality edible oils. Therefore, how to quickly and effectively remove aflatoxins from crude oil while preserving the unique flavor and nutritional value of rich-flavor rapeseed oil has become a pressing challenge in the edible oil processing industry.

[0004] To achieve the above objectives, the present invention provides a strong-flavor rapeseed oil and a preparation method thereof. This method aims to produce safe and delicious strong-flavor rapeseed oil by optimizing the production process and introducing innovative aflatoxin removal technology, thereby meeting the demand for high-quality edible oil and promoting the development of the edible oil industry towards higher standards. Summary of the Invention

[0005] The first object of the present invention is to provide a method for preparing rich-flavor rapeseed oil.

[0006] The second object of the present invention is to provide a strong-flavor rapeseed oil.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for preparing rich-flavor rapeseed oil comprises the following steps:

[0009] (1) After removing impurities from rapeseed, soak it in an aqueous solution of sodium phytate for a period of time;

[0010] (2) drying the rapeseed after soaking in step (1), frying the seeds, pressing, and filtering to obtain crude oil;

[0011] (3) adding montmorillonite to the crude oil obtained in step (2) and stirring at room temperature for a period of time, then adding tamarind polysaccharide and stirring at room temperature for a period of time, and filtering to obtain rapeseed oil.

[0012] Furthermore, the concentration of the sodium phytate aqueous solution in step (1) is 0.3-0.5 w / v%, and the amount of the sodium phytate aqueous solution is 2-3 times the mass of the rapeseed after impurities are removed.

[0013] Furthermore, in terms of mass percentage, the amount of montmorillonite added in step (3) is 0.9-1.1% of the mass of the crude oil; and the amount of tamarind polysaccharide added is 1.5-2.1% of the mass of the crude oil.

[0014] Furthermore, the soaking temperature in step (1) is 40-50° C., the soaking time is 3-5 hours, and the moisture content of the rapeseed after impurities removal is 7-14 wt %.

[0015] Furthermore, the frying temperature of the seeds in step (2) is 120-140° C., the frying time is 20-40 min, and the moisture content of the rapeseed after frying is 1-4 wt %; and the oil residue is separated by filtration.

[0016] Furthermore, in step (3), the time for stirring the montmorillonite at room temperature is 60-80 minutes; the time for stirring the tamarind polysaccharide at room temperature is 20-30 minutes.

[0017] A strong-flavor rapeseed oil is prepared according to the above-mentioned method for preparing the strong-flavor rapeseed oil.

[0018] The beneficial technical effects of the present invention are:

[0019] The present invention provides a preparation method of strong-flavor rapeseed oil. The method comprises the following steps: removing impurities from rapeseed and then soaking the rapeseed in an aqueous solution of sodium phytate, thereby increasing the content of aromatic substances (pyrazines, aldehydes, and furans) in the strong-flavor rapeseed oil, thereby improving the aroma of the rapeseed oil and further improving the satisfaction of different consumers with the rapeseed oil. Furthermore, by first adding montmorillonite and then adding tamarind polysaccharide to the crude oil, the aflatoxin B1 content can be effectively adsorbed, thereby further improving the quality of the rapeseed oil. The method has broad market prospects. DETAILED DESCRIPTION

[0020] The following is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it is not intended that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art of the present invention, without departing from the inventive concept, several simple deductions or replacements can also be made, all of which should be considered to belong to the scope of protection of the present invention. The specific conditions not indicated in the examples are carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, unless otherwise specified, are conventional products obtained through commercial channels.

[0021] Example 1

[0022] A method for preparing rich-flavor rapeseed oil comprises the following steps:

[0023] (1) Rapeseed is cleaned to a moisture content of 10 wt %. The cleaned rapeseed is soaked in a 0.4 w / v % sodium phytate aqueous solution at 45° C. for 4 h, wherein the amount of the sodium phytate aqueous solution is twice the mass of the rapeseed after the cleaning.

[0024] (2) drying the rapeseed after soaking in step (1), frying the rapeseed at 130° C. for 30 minutes, wherein the moisture content of the rapeseed after frying is 2 wt %; and then pressing and filtering to obtain crude oil.

[0025] (3) adding 1.0% of montmorillonite by mass based on the mass of the crude oil to the crude oil obtained in step (2) and stirring at room temperature for 70 min, then adding 1.8% of tamarind polysaccharide by mass based on the mass of the crude oil and stirring at room temperature for 25 min, and filtering to obtain rapeseed oil.

[0026] This embodiment also provides a strong-flavor rapeseed oil obtained by the above preparation method.

[0027] Example 2

[0028] A method for preparing rich-flavor rapeseed oil comprises the following steps:

[0029] (1) Rapeseed is cleaned to a moisture content of 7 wt %. The cleaned rapeseed is soaked in a 0.3 w / v % sodium phytate aqueous solution at 40° C. for 3 h, wherein the amount of the sodium phytate aqueous solution is twice the mass of the rapeseed after the cleansing.

[0030] (2) drying the rapeseed after soaking in step (1), frying the rapeseed at 120° C. for 20 min, wherein the moisture content of the rapeseed after frying is 1 wt %; and then pressing and filtering to obtain crude oil.

[0031] (3) adding 0.9% of montmorillonite by mass based on the mass of the crude oil to the crude oil obtained in step (2) and stirring at room temperature for 60 min, then adding 1.5% of tamarind polysaccharide by mass based on the mass of the crude oil and stirring at room temperature for 20 min, and filtering to obtain rapeseed oil.

[0032] This embodiment also provides a strong-flavor rapeseed oil obtained by the above preparation method.

[0033] Example 3

[0034] A method for preparing rich-flavor rapeseed oil comprises the following steps:

[0035] (1) Rapeseed is cleaned to a moisture content of 14 wt %. The cleaned rapeseed is soaked in a 0.5 w / v % sodium phytate aqueous solution at 50° C. for 5 h, wherein the amount of the sodium phytate aqueous solution is 3 times the mass of the rapeseed after the cleansing.

[0036] (2) drying the rapeseed after soaking in step (1), frying the rapeseed at 140° C. for 40 minutes, wherein the moisture content of the rapeseed after frying is 4 wt %; and then pressing and filtering to obtain crude oil.

[0037] (3) adding 1.1% of montmorillonite by mass based on the mass of the crude oil to the crude oil obtained in step (2) and stirring at room temperature for 80 min, then adding 2.1% of tamarind polysaccharide by mass based on the mass of the crude oil and stirring at room temperature for 30 min, and filtering to obtain rapeseed oil.

[0038] This embodiment also provides a strong-flavor rapeseed oil obtained by the above preparation method.

[0039] Comparative Example 1

[0040] The difference between Comparative Example 1 and Example 1 is that the aqueous solution of sodium phytate in step (1) is replaced by water, and the rest is the same as Example 1.

[0041] Comparative Example 2

[0042] The difference between Comparative Example 2 and Example 1 is that the tamarind polysaccharide in step (3) is omitted, and the rest is the same as Example 1.

[0043] Comparative Example 3

[0044] The difference between Comparative Example 3 and Example 1 is that the tamarind polysaccharide and montmorillonite in step (3) are added together to the crude oil and stirred at room temperature for 95 minutes. The other steps are the same as those in Example 1.

[0045] Test Example 1

[0046] Evaluation of the aroma of Luzhou-flavor rapeseed oil:

[0047] Ten professionally trained sensory evaluators were invited to score the aroma of the rich-flavor rapeseed oil prepared in Examples 1-3 of the present invention and Comparative Example 1. 25 g of the rapeseed oil products prepared in Examples 1-3 and Comparative Example 1 were placed in a beaker. The test was conducted based solely on the aroma quality. The sensory evaluation criteria for the aroma of the rich-flavor rapeseed oil are shown in Table 1, and the sensory evaluation results of the obtained rich-flavor rapeseed oil are shown in Table 2. SPME / GC-MS was also used to determine the content of its aromatic substances (pyrazines, aldehydes, and furans), and the results are shown in Table 3. Among them, pyrazines include: pyrazine, methylpyrazine, ethylpyrazine, 2.5-dimethylpyrazine, 2.3-dimethylpyrazine, 2.6-dimethylpyrazine, 3-ethyl-2,5-dimethylpyrazine; aldehydes include: acetaldehyde, 2-methylpropanal, butyraldehyde, 3-methylbutyraldehyde, 2-methylbutyraldehyde, 3-methylpentanal, hexaldehyde, heptaldehyde, octanal, nonanal, furfural, 5-methyl-2-furaldehyde, 2-methyl-2-butenal, 2-hexenal; furans include: furan, 2-methyl-furan, 2-ethyl-furan, 2-pentyl-furan, 2-vinyl-furan.

[0048] Table 1 Sensory evaluation criteria for aroma of Luzhou-flavor rapeseed oil

[0049]

[0050] Table 2 Sensory evaluation results of aroma of Luzhou-flavor rapeseed oil

[0051]

[0052] The results are shown in Table 2, which shows the sensory evaluation results of the aroma of strong-flavor rapeseed oil. As can be seen from the table, the sensory evaluation results of the aroma of the strong-flavor rapeseed oil prepared in Examples 1-3 of the present invention were higher than those in Comparative Example 1. This shows that soaking rapeseed in an aqueous solution of sodium phytate promotes the formation of rapeseed oil aroma.

[0053] Table 3 Contents of pyrazines, aldehydes and furans in rich-flavor rapeseed oil

[0054]

[0055] Result is as shown in Table 3, is the content of pyrazines, aldehydes, furans in strong fragrant rapeseed oil.As shown in Table 3, the strong fragrant rapeseed oil prepared by embodiment 1-3, its pyrazines, aldehydes, furans content do not have significant difference.Compared with comparative example 1 group, the strong fragrant rapeseed oil that embodiment 1-3 group prepares is higher in the content of fragrant substance (pyrazines, aldehydes, furans), and this shows that the present invention soaks with the aqueous solution of sodium phytate after rapeseed impurities removal, can improve the content of fragrant substance (pyrazines, aldehydes, furans) in strong fragrant rapeseed oil, improves the fragrance of rapeseed oil.May be because sodium phytate is a kind of antioxidant, this antioxidation action not only helps to keep the stability of grease, but also can prevent the oxidative decomposition of flavor substances, makes fragrant substance be better retained.

[0056] Test Example 2

[0057] Detection of aflatoxin B1 content in Luzhou-flavor rapeseed oil:

[0058] The fragrant rapeseed oils prepared in Examples 1-3 and Comparative Examples 1-3 were tested for aflatoxin B1 content. According to the latest national standard "National Food Safety Standard Limit of Mycotoxins in Food", the limit of aflatoxin B1 in rapeseed oil is less than 10 ppb. The detection of aflatoxin B1 content was performed using high-performance liquid chromatography. The specific detection method was as follows: a standard solution of aflatoxin B1 was prepared with a standard solution of a series of concentrations, a standard curve was drawn, and the aflatoxin B1 content in the sample was calculated by comparing the peak area of ​​the sample with the peak area of ​​the standard according to the standard curve method. The specific test results are shown in Table 4:

[0059] Table 4 Aflatoxin B1 content in Luzhou-flavor rapeseed oil

[0060]

[0061] The results are shown in Table 4, which shows the aflatoxin B1 content in Luzhou-flavor rapeseed oil. As can be seen from the table, compared with Comparative Examples 2 and 3, the aflatoxin B1 content in the Luzhou-flavor rapeseed oil prepared in Examples 1, 2, 3, and 1 of the present invention was significantly reduced. This demonstrates that the addition of montmorillonite and tamarind polysaccharide can adsorb aflatoxin B1, and that only by first adding montmorillonite to the crude oil and then adding tamarind polysaccharide can the aflatoxin B1 content in Luzhou-flavor rapeseed oil be effectively removed, further improving the quality of the rapeseed oil.

[0062] In summary, by removing impurities from rapeseed and then soaking it in a sodium phytate solution, the content of aromatic substances (pyrazines, aldehydes, and furans) in strong-flavor rapeseed oil can be increased, thereby enhancing the aroma of the rapeseed oil. Furthermore, by first adding montmorillonite to the crude oil and then adding tamarind polysaccharide, the aflatoxin B1 content in strong-flavor rapeseed oil can be effectively removed, further improving the quality of the rapeseed oil.

[0063] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the same. The basic principles and main features of the present invention have been described above using specific implementation schemes. Modifications or substitutions may be made based on the present invention, but such modifications or substitutions do not detract from the essence of the corresponding technical solutions from the scope of protection claimed by the present invention.

Claims

1. A method for preparing a fragrant rapeseed oil, characterized in that: The following steps are involved: (1) After removing impurities from rapeseed, soak it in an aqueous solution of sodium phytate for a period of time; (2) drying the rapeseed after soaking in step (1), frying the seeds, pressing, and filtering to obtain crude oil; (3) adding montmorillonite to the crude oil obtained in step (2) and stirring at room temperature for a period of time, then adding tamarind polysaccharide and stirring at room temperature for a period of time, and filtering to obtain rapeseed oil.

2. The preparation method of Luzhou-flavor rapeseed oil according to claim 1, wherein The concentration of the aqueous solution of sodium phytate in step (1) is 0.3-0.5 w / v%, and the amount of the aqueous solution of sodium phytate used is 2-3 times the mass of the rapeseed after impurities are removed.

3. The preparation method of Luzhou-flavor rapeseed oil according to claim 1, wherein In terms of mass percentage, the amount of montmorillonite added in step (3) is 0.9-1.1% of the mass of the crude oil; the amount of tamarind polysaccharide added is 1.5-2.1% of the mass of the crude oil.

4. The preparation method of Luzhou-flavor rapeseed oil according to claim 1, wherein The soaking temperature in step (1) is 40-50° C., the soaking time is 3-5 hours, and the moisture content of the rapeseed after impurities removal is 7-14 wt %.

5. The preparation method of Luzhou-flavor rapeseed oil according to claim 1, wherein The frying temperature of the rapeseed in step (2) is 120-140° C., the frying time is 20-40 min, and the moisture content of the rapeseed after frying is 1-4 wt %.

6. The preparation method of Luzhou-flavor rapeseed oil according to claim 1, wherein In the step (3), the time for adding montmorillonite and stirring at room temperature is 60-80 minutes; the time for adding tamarind polysaccharide and stirring at room temperature is 20-30 minutes.

7. A fragrant rapeseed oil, characterized in that The rapeseed oil is prepared according to the method for preparing the rich-flavor rapeseed oil according to any one of claims 1 to 6.

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