Preparation method of aromatic rapeseed oil capable of improving cooking effects of different cuisines through regional flavor customized aroma production

Abstract

The invention relates to the field of edible oil processing, and discloses a preparation method of aromatic rapeseed oil capable of improving cooking effects of different cuisines through regional flavor customized aroma production. The method comprises the following steps: (1) obtaining the contents of carbohydrate, isoleucine, leucine, methionine, 3-butenyl glucosinolate, 2-hydroxy-3-butenyl glucosinolate and 5-methylsulfoxide glucosinolate in the rapeseeds; (2) according to the content of carbohydrate, 3-butenyl glucosinolate, isoleucine and leucine, determining the baking rate; and (3) according to the content of the 2-hydroxy-3-butenyl glucosinolate, the content of the 5-methylsulfoxide glucosinolate, the content of the 3-butenyl glucosinolate and the content of the methionine, determining the content of the fried water. According to the method, aroma-producing process conditions for preparing strong-flavor rapeseed oil (such as roasted flavor type rapeseed oil and spicy flavor type rapeseed oil) with the most appropriate flavor can be quickly formulated, so that customized production of specific flavor type rapeseed oil is realized.

Description

Technical Field

[0001] The invention relates to the field of edible oil processing, and relates to a method for preparing fragrant rapeseed oil which can enhance the cooking effects of different cuisines through customized aroma production of regional flavors, and specifically relates to a method for determining conditions for directional aroma production of rapeseed and a method for preparing fragrant rapeseed oil suitable for cooking of different cuisines. Background Art

[0002] Rapeseed oil is one of the most common flavored edible vegetable oils on the market. It is deeply loved by consumers for its unique and rich flavor. In recent years, fragrant rapeseed oil products have been launched one after another, becoming an oil product that is deeply loved by local consumers. In 2019, the output of fragrant rapeseed oil accounted for nearly 30% of the national rapeseed oil market share, becoming one of the leading products of rapeseed oil.

[0003] Strong aroma rapeseed oil is a finished product with strong aroma obtained by frying and pressing rapeseed as raw material. As the world's largest consumer of rapeseed oil, strong aroma rapeseed oil has a good market development prospect in my country.

[0004] The main raw material for producing strong-flavored rapeseed oil in my country is domestic rapeseed. At present, common rapeseed is mainly divided into two types: one is traditional rapeseed (also known as "double-high" rapeseed), which has high erucic acid and glucosinolate content, with an erucic acid content of 20%-60%; the other is low-erucic acid rapeseed (also known as "double-low" rapeseed). According to my country's low-erucic acid and low-glucosinolate rapeseed agricultural industry standard NY / T415-2000, the erucic acid content in double-low rapeseed does not exceed 3.00% of the total fatty acids, and the glucosinolate content in the cake does not exceed 35.00μmol / g. Due to the large differences in the types and components of rapeseed raw materials, the flavor types of rapeseed oil prepared under the same process conditions are quite different. Some rapeseeds are prepared through the aroma and fragrance retention processes to obtain roasted fragrant rapeseed oil, while others are prepared to obtain traditional flavor fragrant rapeseed oil (hereinafter referred to as "spicy fragrant rapeseed oil").

[0005] Flavor is an important criterion for evaluating rapeseed oil. The difference in flavor types of products will directly affect consumers' choice and preference of products. If the production process cannot well control the flavor type of rapeseed oil, it will also increase the instability of product flavor and affect consumers' trust in the flavor of the product. Existing research can only achieve the effect of affecting the flavor intensity of rapeseed oil by controlling process technology, but cannot control the aroma type of rapeseed oil in a targeted manner, thus failing to achieve customized production of rapeseed oil with a specific aroma. Summary of the invention

[0006] The purpose of the present invention is to overcome the problem in the prior art that it is impossible to formulate suitable rapeseed aroma production process conditions according to the differences in raw material components, resulting in the inability to directionally control the aroma type of rapeseed oil, and to provide a method for preparing strong-flavor rapeseed oil that improves the cooking effects of different cuisines through customized aroma production of regional flavors. The method can quickly formulate aroma production process conditions for preparing strong-flavor rapeseed oil (such as roasted-flavor rapeseed oil and spicy-flavor rapeseed oil) with the most suitable flavor according to the differences in the content of different raw material components, thereby realizing customized production of specific-flavor rapeseed oil.

[0007] In order to achieve the above object, the first aspect of the present invention provides a method for determining the conditions for directional aroma production of rapeseed, the method comprising the following steps:

[0008] (1) Obtaining the contents of carbohydrates, isoleucine, leucine, methionine, 3-butenyl glucosinolate, 2-hydroxy-3-butenyl glucosinolate and 5-methylsulfoxide glucosinolate in rapeseed;

[0009] (2) determining the roasting rate according to the contents of carbohydrates, 3-butenyl glucosinolate, isoleucine and leucine;

[0010] (3) Determine the moisture content before frying based on the content of 2-hydroxy-3-butenyl glucosinolate, 5-methylsulfoxide glucosinolate, 3-butenyl glucosinolate and methionine.

[0011] A second aspect of the present invention provides a method for preparing a fragrant rapeseed oil suitable for cooking different cuisines, the method comprising the following steps:

[0012] (1) determining the frying rate and the moisture content of rapeseed oil according to the method of the first aspect of the present invention;

[0013] (2) roasting the rapeseed according to the roasting rate and the moisture content before roasting, and pressing to obtain rapeseed oil.

[0014] Through the above technical solution, the present invention achieves at least the following beneficial technical effects:

[0015] (1) The present invention relates the differences in the contents of different rapeseed raw materials to the most suitable process conditions for aroma production, and constructs a calculation formula for the aroma production conditions and the contents of key components in the rapeseed raw materials. According to the differences in the contents of different raw materials, the aroma production process conditions for preparing the most suitable strong-flavored traditional flavor rapeseed oil (such as roasted-flavored rapeseed oil and spicy-flavored rapeseed oil) can be quickly formulated, thereby realizing the customized production of rapeseed oil with a specific aroma.

[0016] (2) The rapeseed oil prepared by the method of the present invention has a high content of characteristic flavor substances (such as pyrazines and isothiocyanates), authentic flavor and good quality; the acid value and peroxide value are low, and the characteristic aroma of rapeseed is more intense and longer-lasting, and is suitable for cooking dishes of different cuisines. DETAILED DESCRIPTION

[0017] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0018] The first aspect of the present invention provides a method for determining the conditions for directional aroma production of rapeseed, the method comprising the following steps:

[0019] (1) Obtaining the contents of carbohydrates, isoleucine, leucine, methionine, 3-butenyl glucosinolate, 2-hydroxy-3-butenyl glucosinolate and 5-methylsulfoxide glucosinolate in rapeseed;

[0020] (2) determining the roasting rate according to the contents of carbohydrates, 3-butenyl glucosinolate, isoleucine and leucine;

[0021] (3) Determine the moisture content before frying based on the content of 2-hydroxy-3-butenyl glucosinolate, 5-methylsulfoxide glucosinolate, 3-butenyl glucosinolate and methionine.

[0022] According to some embodiments of the present invention, the frying rate is calculated according to the formula shown in formula (I):

[0023]

[0024] In formula (I), V 烘焙 is the baking rate, in °C / min;

[0025] C 碳水化合物 is the carbohydrate content, in g / 100g;

[0026] C GNA is the 3-butenyl glucosinolate content, in μmol / g;

[0027] C Ile is the isoleucine content, in mg / 100mg;

[0028] C Leu is the leucine content, the unit is mg / 100mg.

[0029] In the present invention, the formula of the roasting rate is obtained according to the following method: rapeseeds from different regions and with different glucosinolate contents are collected, and all physical and chemical indicators in the rapeseeds are measured; the optimal roasting rates of different raw materials are optimized one by one; the main raw material composition influencing factors affecting the roasting rate conditions are clarified as the contents of carbohydrates, 3-butenyl glucosinolate, isoleucine and leucine; a regression model is established by using methods such as linear regression, logistic regression, polynomial regression, stepwise regression, ridge regression, lasso regression, partial least squares method, neural network, etc., the model with the highest prediction value is selected, and the roasting rate formula is formed.

[0030] According to some embodiments of the present invention, the moisture content of the stir-fry is calculated according to the formula shown in formula (II):

[0031] C 入炒水分 =9.2-0.19*(0.34*C PRO +0.22*C GNL +0.41C GNA )+11.4*

[0032] C Met Formula (II);

[0033] In formula (II), C 入炒水分 is the moisture content of rapeseed during roasting, in %;

[0034] C PRO is the 2-hydroxy-3-butenyl glucosinolate content, in μmol / g;

[0035] C GNL is the 5-methylsulfoxide glucosinolate content, in μmol / g;

[0036] C GNA is the 3-butenyl glucosinolate content, in μmol / g;

[0037] C Met It is the methionine content, the unit is mg / 100mg.

[0038] In the present invention, the formula for the moisture content before frying is obtained according to the following method: rapeseeds from different regions and with different glucosinolate contents are collected, and all physical and chemical indicators in the rapeseeds are measured; the optimal frying rates of different raw materials are optimized one by one; the main raw material composition influencing factors affecting the moisture conditions before frying are clarified as the contents of 2-hydroxy-3-butenyl glucosinolate, 5-methylsulfoxide glucosinolate, 3-butenyl glucosinolate and methionine; a regression model is established by using methods such as linear regression, logistic regression, polynomial regression, stepwise regression, ridge regression, lasso regression, partial least squares method, neural network, etc., the model with the highest prediction value is preferably selected, and the formula for the moisture content before frying is formed.

[0039] In the present invention, the content of carbohydrates in rapeseed is determined according to the method of "GB / Z 21922-2008 Basic Terminology of Food Nutrients"; the content of 3-butenyl thioglucoside, 2-hydroxy-3-butenyl thioglucoside and 5-methyl sulfoxide thioglucoside is determined according to the method of "NY / T 3296-2018 Determination of thioglucosides in rapeseed by liquid chromatography-tandem mass spectrometry"; the content of isoleucine, leucine and methionine is determined according to the method of "GB / T 5009.124-2016 National Food Safety Standard Determination of Amino Acids in Food".

[0040] In the present invention, rapeseed is also called Brassica seed or rapeseed, which is the seed of the cruciferous crop rapeseed.

[0041] According to some embodiments of the present invention, the content of glucosinolates in the oil seeds is 10-150 μmol / g.

[0042] In order to further increase the content of characteristic aroma substances of "roasted aroma", a roasted aroma type rapeseed oil suitable for cooking Huaiyang cuisine and enhancing the umami taste of dishes is prepared. Preferably, the content of glucosinolates in the oil seeds is 10-45 μmol / g; in order to further increase the total content of characteristic aroma substances, a spicy aroma type rapeseed oil suitable for cooking Northwestern cuisine and spicy dishes that are fragrant but not spicy is prepared. Preferably, the content of glucosinolates in the oil seeds is 90-110 μmol / g; in order to further increase the content of characteristic aroma substances of "spicy aroma", a spicy aroma type rapeseed oil suitable for cooking Sichuan cuisine and enhancing the saltiness of dishes is prepared. Preferably, based on the weight of the oil seeds, the content of glucosinolates in the oil seeds is 130-150 μmol / g.

[0043] In the present invention, the content of glucosinolates in oilseeds refers to the sum of glucosinolate substances, which is determined by "NY / T 3296-2018 Determination of glucosinolates in rapeseed by liquid chromatography-tandem mass spectrometry".

[0044] A second aspect of the present invention provides a method for preparing a fragrant rapeseed oil suitable for cooking different cuisines, the method comprising the following steps:

[0045] (1) determining the frying rate and the moisture content of rapeseed oil according to the method of the first aspect of the present invention;

[0046] (2) roasting the rapeseed according to the roasting rate and the moisture content before roasting, and pressing to obtain rapeseed oil.

[0047] According to some embodiments of the present invention, the end point temperature of the roasting is 150-165°C.

[0048] According to some embodiments of the present invention, the pressing method includes: pressing the roasted rapeseed in a screw oil press to obtain crude oil.

[0049] In the present invention, the screw oil press is purchased from Nanyang Lefa Machinery Equipment Co., Ltd., and the instrument model is a 95-type screw oil press.

[0050] According to some embodiments of the present invention, the method further comprises solid-liquid separation, hydration, sedimentation, dewaxing and fine filtration.

[0051] In the present invention, the crude oil obtained after the rapeseed is squeezed contains a lot of oil residues, which makes the rapeseed oil of poor quality, and the oil residues are further removed by solid-liquid separation. The method of solid-liquid separation is not particularly limited, such as filtration and / or centrifugal separation, and the oil residues can be removed by filtration with a filter membrane, or the crude oil after squeezing can be removed by a horizontal spiral sedimentation centrifuge to obtain crude oil.

[0052] In the present invention, the horizontal spiral sedimentation centrifuge was purchased from Zhejiang Sanlian Environmental Protection Technology Co., Ltd., and the instrument model is LW450 horizontal spiral sedimentation centrifuge.

[0053] According to some embodiments of the present invention, the hydration method includes: mixing the crude oil obtained after solid-liquid separation with a hydrating agent to carry out a hydration reaction to obtain semi-clear oil.

[0054] Preferably, the hydrating agent is selected from water and / or sodium chloride solution.

[0055] Preferably, based on the mass of the crude oil obtained after the solid-liquid separation, the amount of the hydrating agent is 0.1wt%-5wt%.

[0056] Preferably, the temperature of the hydration reaction is 23-35°C.

[0057] More preferably, the mass concentration of the sodium chloride solution is 0.5wt%-10wt%.

[0058] According to some embodiments of the present invention, the sedimentation method includes allowing the semi-clear oil obtained after the hydration treatment to stand in a temporary storage tank for 36-48 hours, draining the oil residue, and obtaining the semi-finished oil.

[0059] According to some embodiments of the present invention, the dewaxing method includes mixing and stirring the semi-finished oil obtained after sedimentation treatment with a filter aid, cooling the temperature to 5-10° C., and then crystallizing and growing the crystals.

[0060] Preferably, the filter aid is selected from at least one of diatomaceous earth, activated clay, attapulgite, activated carbon, silica gel and perlite.

[0061] Preferably, based on the mass of the semi-finished oil obtained after the sedimentation treatment, the amount of the filter aid is 0.1wt%-2wt%.

[0062] Preferably, the stirring time is 0.5-1h.

[0063] Preferably, the crystallization time is not less than 8 hours, and the crystal growing time is not less than 16 hours.

[0064] According to some embodiments of the present invention, the fine filtration method includes subjecting the semi-finished oil obtained after dewaxing to a first filtration and a second filtration in sequence through a paperboard filter and a bag filter.

[0065] Preferably, the pore size of the paperboard filter is 0.2 μm-20 μm; and the pore size of the bag filter is ≤15 μm.

[0066] Preferably, the filtration pressures of the first filtration and the second filtration are independently 0.1 MPa-2 MPa.

[0067] According to a particularly preferred embodiment of the present invention, a method for preparing a fragrant rapeseed oil suitable for cooking different cuisines is provided, the method comprising the following steps:

[0068] (1) Selecting rapeseed raw materials with full grains and stable quality, and removing impurities through magnetic separation, screening and air separation, and temporarily storing them in a silo;

[0069] (2) Detection of the content of glucosinolates (including 2-hydroxy-3-butenyl glucosinolate, 5-methylsulfoxide glucosinolate and 3-butenyl glucosinolate), amino acids (including isoleucine, leucine and methionine), and carbohydrates in rapeseed;

[0070] Wherein, the content of glucosinolates in the oilseeds is 10-150 μmol / g;

[0071] (3) Calculating the roasting process parameters according to formulas (I) and (II), adjusting the moisture content of the rapeseed at the start of roasting and the roasting rate, controlling the final roasting temperature to be 156-160° C., and roasting;

[0072] The formula shown in formula (I) is used for calculation:

[0073]

[0074] In formula (I), V 烘焙 is the baking rate, in °C / min;

[0075] C 碳水化合物 is the carbohydrate content, in g / 100g;

[0076] C GNA is the 3-butenyl glucosinolate content, in μmol / g;

[0077] C Ile is the isoleucine content, in mg / 100mg;

[0078] C Leu is the leucine content, in mg / 100mg;

[0079] The formula shown in formula (II) is used for calculation:

[0080] C 入炒水分 =9.2-0.19*(0.34*C PRO +0.22*C GNL +0.41C GNA )+11.4*

[0081] C Met ;

[0082] In formula (II), C 入炒水分 is the moisture content of rapeseed during roasting, in %;

[0083] C PRO is the 2-hydroxy-3-butenyl glucosinolate content, in μmol / g;

[0084] C GNL is the 5-methylsulfoxide glucosinolate content, in μmol / g;

[0085] C GNA is the 3-butenyl glucosinolate content, in μmol / g;

[0086] C Met is the methionine content, in mg / 100mg;

[0087] The roasted rapeseed is pressed in a screw oil press to obtain crude oil, and the crude oil is removed from the oil residue in a horizontal screw sedimentation centrifuge to obtain crude oil;

[0088] (4) adding 2-5 wt% of water to the crude oil, hydrating the crude oil at 30-35° C. to obtain semi-clear oil; placing the semi-clear oil in a temporary storage tank and allowing it to settle for 38-48 hours, and after settling, placing it in a semi-finished oil tank to obtain semi-finished oil;

[0089] (5) adding 0.1-2 wt% of diatomaceous earth to the semi-finished oil, stirring for 0.5-1 h, cooling to 5-10° C., crystallizing for 8-10 h, growing the crystals for 16-20 h, and then fine filtering by combining a cardboard filter (pore size of 10-20 μm) with a bag filter (pore size ≤ 2 μm) at a filtration pressure of 0.1-2 MPa to obtain a rapeseed oil product.

[0090] The present invention will be described in detail below through examples.

[0091] In the examples, rapeseed No. 1 (the moisture content of rapeseed is 7.5%, and the content of glucosinolate is 10.5 μmol / g) was purchased from COFCO Corporation, and the origin is Hubei Province.

[0092] In the examples, rapeseed No. 2 (the moisture content of rapeseed is 6.5%, and the content of glucosinolate is 100.8 μmol / g) was purchased from COFCO Corporation, and the origin is Qinghai Province.

[0093] In the examples, rapeseed No. 3 (the moisture content of rapeseed is 6.0%, and the content of glucosinolate is 135.1 μmol / g) was purchased from COFCO Corporation, and the origin is Sichuan Province.

[0094] The carbohydrate content in rapeseed is determined according to the method of "GB / Z 21922-2008 Basic Terminology of Food Nutrition Components".

[0095] The contents of 3-butenyl glucosinolate, 2-hydroxy-3-butenyl glucosinolate and 5-methylsulfoxide glucosinolate in rapeseed were determined according to the method of "NY / T 3296-2018 Determination of glucosinolates in rapeseed by liquid chromatography-tandem mass spectrometry".

[0096] The content of isoleucine and leucine in rapeseed is determined according to the method of "GB 5009.124-2016 National Food Safety Standard Determination of Amino Acids in Food".

[0097] The roasting rate of rapeseed in the following examples is calculated according to the formula shown in formula (I):

[0098]

[0099] In formula (I), V 烘焙 is the baking rate, in °C / min;

[0100] C 碳水化合物 is the carbohydrate content, in g / 100g;

[0101] C GNA is the 3-butenyl glucosinolate content, in μmol / g;

[0102] C Ile is the isoleucine content, in mg / 100mg;

[0103] C Leu is the leucine content, the unit is mg / 100mg.

[0104] In the following examples, the moisture content of rapeseed before frying was calculated according to the formula shown in formula (II):

[0105] C 入炒水分 =9.2-0.19*(0.34*C PRO +0.22*C GML +0.41C GNA )+11.4*

[0106] C Met Formula (II);

[0107] In formula (II), C 入炒水分 is the moisture content of rapeseed during roasting, in %;

[0108] C PRO is the 2-hydroxy-3-butenyl glucosinolate content, in μmol / g;

[0109] C GNL is the 5-methylsulfoxide glucosinolate content, in μmol / g;

[0110] C GNA is the 3-butenyl glucosinolate content, in μmol / g;

[0111] C Met It is the methionine content, the unit is mg / 100mg.

[0112] The screw oil press was purchased from Nanyang Lefa Machinery Equipment Co., Ltd., and the instrument model is 95 type screw oil press.

[0113] The horizontal spiral sedimentation centrifuge was purchased from Zhejiang Sanlian Environmental Protection Technology Co., Ltd., and the instrument model is LW450 horizontal spiral sedimentation centrifuge.

[0114] Unless otherwise specified in the following examples, the materials are all commercially available products.

[0115] Example 1

[0116] (1) Selecting rapeseed raw materials (rapeseed No. 1) with full grains and stable quality, and removing impurities through magnetic separation, screening and air separation, and temporarily storing them in a silo;

[0117] (2) The contents of glucosinolates, amino acids and carbohydrates in rapeseed were detected, among which the content of 2-hydroxy-3-butenyl glucosinolate was 1.52 μmol / g, the content of 5-methylsulfoxide glucosinolate was 0.16 μmol / g, the content of 3-butenyl glucosinolate was 0.74 μmol / g, the content of methionine was 0.51 mg / 100 mg, the content of isoleucine was 0.63 mg / 100 mg, the content of leucine was 1.17 mg / 100 mg, and the content of carbohydrates was 10.33 g / 100 g;

[0118] (3) Calculating the roasting process parameters according to the above formulas (I) and (II), adjusting the moisture content of the rapeseed to 14.9%, the roasting rate to 3.7° C. / min, and controlling the final roasting temperature to 160° C. for roasting;

[0119] The roasted rapeseed is pressed in a screw oil press to obtain crude oil, and the crude oil is removed from the oil residue in a horizontal screw sedimentation centrifuge to obtain crude oil;

[0120] (4) adding 2 wt% of water to the crude oil, hydrating the crude oil at 30° C. to obtain semi-clear oil; placing the semi-clear oil in a temporary storage tank and allowing it to settle for 38 hours, and after settling, placing it in a semi-finished oil tank to obtain semi-finished oil;

[0121] Add 2 wt% diatomaceous earth to the semi-finished oil, stir for 1 hour, cool to 10°C, crystallize for 10 hours, and grow the crystal for 20 hours. Then, use a cardboard filter (pore size of 10 μm) combined with a bag filter (pore size of 2 μm) for fine filtration at a filtration pressure of 2 MPa to obtain a rapeseed oil product.

[0122] Example 2

[0123] (1) Selecting rapeseed raw materials (rapeseed No. 2) with full grains and stable quality, and removing impurities through magnetic separation, screening and air separation, and temporarily storing them in a silo;

[0124] (2) The contents of glucosinolates, amino acids and carbohydrates in rapeseed were detected, among which the content of 2-hydroxy-3-butenyl glucosinolate was 36.32 μmol / g, the content of 5-methylsulfoxide glucosinolate was 2.04 μmol / g, the content of 3-butenyl glucosinolate was 19.48 μmol / g, the content of methionine was 0.23 mg / 100 mg, the content of isoleucine was 0.64 mg / 100 mg, the content of leucine was 1.11 mg / 100 mg, and the content of carbohydrates was 14.6 g / 100 g;

[0125] (3) Calculating the roasting process parameters according to the above formulas (I) and (II), adjusting the moisture content of the rapeseed to 9%, the roasting rate to 7.9° C. / min, and controlling the final roasting temperature to 160° C. for roasting;

[0126] The roasted rapeseed is pressed in a screw oil press to obtain crude oil, and the crude oil is removed from the oil residue in a horizontal screw sedimentation centrifuge to obtain crude oil;

[0127] (4) adding 2 wt% of water to the crude oil, hydrating the crude oil at 30° C. to obtain semi-clear oil; placing the semi-clear oil in a temporary storage tank and allowing it to settle for 38 hours, and after settling, placing it in a semi-finished oil tank to obtain semi-finished oil;

[0128] Add 2 wt% diatomaceous earth to the semi-finished oil, stir for 1 hour, cool to 10°C, crystallize for 10 hours, and grow the crystal for 20 hours. Then, use a cardboard filter (pore size of 10 μm) combined with a bag filter (pore size of 2 μm) for fine filtration at a filtration pressure of 2 MPa to obtain a rapeseed oil product.

[0129] Example 3

[0130] (1) Selecting rapeseed raw materials (rapeseed No. 3) with full grains and stable quality, and removing impurities through magnetic separation, screening and air separation, and temporarily storing them in a silo;

[0131] (2) The contents of glucosinolates, amino acids and carbohydrates in rapeseed were detected, among which the content of 2-hydroxy-3-butenyl glucosinolate was 44.5 μmol / g, the content of 5-methylsulfoxide glucosinolate was 1.88 μmol / g, the content of 3-butenyl glucosinolate was 22.19 μmol / g, the content of methionine was 0.27 mg / 100 mg, the content of isoleucine was 0.65 mg / 100 mg, the content of leucine was 1.17 mg / 100 mg, and the content of carbohydrates was 13.63 g / 100 g;

[0132] (3) Calculating the roasting process parameters according to the above formulas (I) and (II), adjusting the moisture content of the rapeseed to 7.6%, the roasting rate to 8.4° C. / min, and controlling the final roasting temperature to 160° C. for roasting;

[0133] The roasted rapeseed is pressed in a screw oil press to obtain crude oil, and the crude oil is removed from the oil residue in a horizontal screw sedimentation centrifuge to obtain crude oil;

[0134] (4) adding 2 wt% of water to the crude oil, hydrating the crude oil at 30° C. to obtain semi-clear oil; placing the semi-clear oil in a temporary storage tank and allowing it to settle for 38 hours, and after settling, placing it in a semi-finished oil tank to obtain semi-finished oil;

[0135] Add 2 wt% diatomaceous earth to the semi-finished oil, stir for 1 hour, cool to 10°C, crystallize for 10 hours, and grow the crystal for 20 hours. Then, use a cardboard filter (pore size of 10 μm) combined with a bag filter (pore size of 2 μm) for fine filtration at a filtration pressure of 2 MPa to obtain a rapeseed oil product.

[0136] Example 4

[0137] (1) Selecting rapeseed raw materials with full grains and stable quality, and removing impurities through magnetic separation, screening and air separation, and temporarily storing them in a silo;

[0138] (2) The contents of glucosinolates, amino acids and carbohydrates in rapeseed were detected, among which the content of 2-hydroxy-3-butenyl glucosinolate was 44.5 μmol / g, the content of 5-methylsulfoxide glucosinolate was 1.88 μmol / g, the content of 3-butenyl glucosinolate was 22.19 μmol / g, the content of methionine was 0.27 mg / 100 mg, the content of isoleucine was 0.65 mg / 100 mg, the content of leucine was 1.17 mg / 100 mg, and the content of carbohydrates was 13.63 g / 100 g;

[0139] (3) Calculating the roasting process parameters according to the above formulas (I) and (II), adjusting the moisture content of the rapeseed to 7.6%, the roasting rate to 8.4° C. / min, and controlling the final roasting temperature to 155° C. for roasting;

[0140] The roasted rapeseed is pressed in a screw oil press to obtain crude oil, and the crude oil is removed from the oil residue in a horizontal screw sedimentation centrifuge to obtain crude oil;

[0141] (4) adding 2 wt% of water to the crude oil, hydrating the crude oil at 30° C. to obtain semi-clear oil; placing the semi-clear oil in a temporary storage tank and allowing it to settle for 38 hours, and after settling, placing it in a semi-finished oil tank to obtain semi-finished oil;

[0142] Add 2 wt% diatomaceous earth to the semi-finished oil, stir for 1 hour, cool to 10°C, crystallize for 10 hours, and grow the crystal for 20 hours. Then, use a cardboard filter (pore size of 10 μm) combined with a bag filter (pore size of 2 μm) for fine filtration at a filtration pressure of 2 MPa to obtain a rapeseed oil product.

[0143] Example 5

[0144] (1) Selecting rapeseed raw materials with full grains and stable quality, and removing impurities through magnetic separation, screening and air separation, and temporarily storing them in a silo;

[0145] (2) The contents of glucosinolates, amino acids and carbohydrates in rapeseed were detected, among which the content of 2-hydroxy-3-butenyl glucosinolate was 44.5 μmol / g, the content of 5-methylsulfoxide glucosinolate was 1.88 μmol / g, the content of 3-butenyl glucosinolate was 22.19 μmol / g, the content of methionine was 0.27 mg / 100 mg, the content of isoleucine was 0.65 mg / 100 mg, the content of leucine was 1.17 mg / 100 mg, and the content of carbohydrates was 13.63 g / 100 g;

[0146] (3) Calculating the roasting process parameters according to the above formulas (I) and (II), adjusting the moisture content of the rapeseed to 7.6%, the roasting rate to 8.4° C. / min, and controlling the final roasting temperature to 165° C. for roasting;

[0147] The roasted rapeseed is pressed in a screw oil press to obtain crude oil, and the crude oil is removed from the oil residue in a horizontal screw sedimentation centrifuge to obtain crude oil;

[0148] (4) adding 2 wt% of water to the crude oil, hydrating the crude oil at 30° C. to obtain semi-clear oil; placing the semi-clear oil in a temporary storage tank and allowing it to settle for 38 hours, and after settling, placing it in a semi-finished oil tank to obtain semi-finished oil;

[0149] Add 2 wt% diatomaceous earth to the semi-finished oil, stir for 1 hour, cool to 10°C, crystallize for 10 hours, and grow the crystal for 20 hours. Then, use a cardboard filter (pore size of 10 μm) combined with a bag filter (pore size of 2 μm) for fine filtration at a filtration pressure of 2 MPa to obtain a rapeseed oil product.

[0150] Example 6

[0151] (1) Selecting rapeseed raw materials with full grains and stable quality, and removing impurities through magnetic separation, screening and air separation, and temporarily storing them in a silo;

[0152] (2) The contents of glucosinolates, amino acids and carbohydrates in rapeseed were detected, among which the content of 2-hydroxy-3-butenyl glucosinolate was 44.5 μmol / g, the content of 5-methylsulfoxide glucosinolate was 1.88 μmol / g, the content of 3-butenyl glucosinolate was 22.19 μmol / g, the content of methionine was 0.27 mg / 100 mg, the content of isoleucine was 0.65 mg / 100 mg, the content of leucine was 1.17 mg / 100 mg, and the content of carbohydrates was 13.63 g / 100 g;

[0153] (3) Calculating the roasting process parameters according to the above formulas (I) and (II), adjusting the moisture content of the rapeseed to 7.6%, the roasting rate to 8.4° C. / min, and controlling the final roasting temperature to 160° C. for roasting;

[0154] The roasted rapeseed is pressed in a screw oil press to obtain crude oil, and the crude oil is removed from the oil residue in a horizontal screw sedimentation centrifuge to obtain crude oil;

[0155] (4) adding salt water (the mass concentration of the salt water is 10 wt%) in an amount of 1.8 wt% of the weight of the crude oil to the crude oil, and hydrating the crude oil at 30° C. to obtain semi-clear oil; placing the semi-clear oil in a temporary storage tank and allowing it to settle for 38 hours, and after settling, placing the semi-finished oil tank to obtain semi-finished oil;

[0156] Add 2 wt% diatomaceous earth to the semi-finished oil, stir for 1 hour, cool to 10°C, crystallize for 10 hours, and grow the crystal for 20 hours. Then, use a cardboard filter (pore size of 10 μm) combined with a bag filter (pore size of 2 μm) for fine filtration at a filtration pressure of 2 MPa to obtain a rapeseed oil product.

[0157] Example 7

[0158] The method of Example 3 is followed, except that in step (5), 0.5 wt% of activated carbon by weight of the semi-finished oil is added to the semi-finished oil, stirred for 1 hour, cooled to 10° C., crystallized for 10 hours, and grown for 20 hours to obtain a finished rapeseed oil.

[0159] Comparative Example 1

[0160] The method of Example 3 is different in that the skilled worker roasts the rapeseed at 145° C. for 25 minutes based on experience to obtain the finished rapeseed oil.

[0161] Comparative Example 2

[0162] The method of Example 3 is different in that the skilled worker roasts the rapeseed at 200° C. for 45 minutes based on experience to obtain the finished rapeseed oil.

[0163] Comparative Example 3

[0164] (1) selecting rapeseed raw materials (rapeseed No. 3) with full grains and stable quality, and temporarily storing them in a silo after impurity removal processes such as magnetic separation, screening and air separation; adjusting the moisture content of the rapeseed to 14.9%, the roasting rate to 3.7° C. / min, and the final roasting temperature to 160° C. for roasting;

[0165] (2) the roasted rapeseed is pressed in a screw oil press to obtain crude oil, and the crude oil is passed through a horizontal screw sedimentation centrifuge to remove oil residue to obtain crude oil;

[0166] (3) adding 2 wt% of water to the crude oil, hydrating the crude oil at 30° C. to obtain semi-clear oil, settling the semi-clear oil in a temporary storage tank for 38 hours, and then placing the semi-finished oil in a semi-finished oil tank to obtain semi-finished oil;

[0167] Add 2 wt% diatomaceous earth to the semi-finished oil, stir for 1 hour, cool to 10°C, crystallize for 10 hours, and grow the crystal for 20 hours. Then, use a cardboard filter (pore size of 10 μm) combined with a bag filter (2 μm) for fine filtration at a filtration pressure of 2 MPa to obtain a rapeseed oil product.

[0168] Comparative Example 4

[0169] According to the method of Example 3, the difference is that the skilled worker adds water to the rapeseed based on experience to adjust the moisture content of the rapeseed to 20%, controls the end point roasting temperature to 160° C., and roasts to obtain a rapeseed oil product;

[0170] According to the method of comparative example 4, workers moistened the oil by experience, which resulted in the rapeseed being too moist (excessive water content) during frying, and the resulting rapeseed oil had a serious green taste.

[0171] Comparative Example 5

[0172] According to the method of Example 3, the difference is that the skilled worker stir-fries the rapeseed based on experience, and judges the degree of stir-frying according to whether the color of the crushed rapeseed kernels after stir-frying turns golden yellow, and stops stir-frying. Specifically, the terminal roasting temperature is controlled to be 160° C., and the rapeseed is quickly stir-fried for 10 minutes (the roasting rate is calculated to be 16° C. / min), to obtain a rapeseed oil product;

[0173] According to the method of comparative example 5, workers perform frying based on experience and are unable to accurately determine the optimal frying conditions, resulting in an incomplete or too intense aroma reaction, and unable to prepare edible oil with a specific aroma.

[0174] Test Example 1

[0175] The contents of characteristic flavor substances in the finished rapeseed oils of the above-mentioned embodiments and comparative examples as well as the acid value and peroxide value of the rapeseed oils were measured respectively. The results are shown in Table 1.

[0176] Determination of the content of characteristic flavor substances in roasted rapeseed oil (calculated as the sum of pyrazine substances) and the content of characteristic flavor substances in spicy rapeseed oil (calculated as the sum of isothiocyanate substances):

[0177] (1) Pretreatment conditions: 5 g of rapeseed oil sample was added to a 20 ml headspace bottle, and 1 μL of 2-methyl-3-heptanone (concentration of 41 mg / mL) was added as an internal standard. After mixing, the sample was sealed and placed; the sample was placed in a constant temperature water bath for equilibration for 20 min, and the water bath temperature was set to 55 °C. Then, a solid phase microextraction fiber head (CAR / DVB / PDMS) was inserted for headspace adsorption for 40 min. After the adsorption was completed, the extraction head was inserted into the gas chromatography injection port and analyzed at a temperature of 250 °C for 5 min;

[0178] (2) GC conditions: The initial temperature of the temperature program was set at 40 °C, maintained at this temperature for 3 min, then raised to 200 °C at 5 °C / min, then raised to 230 °C at 15 °C / min, and maintained at this temperature for 3 min; the carrier gas was helium, the constant flow rate was set to 1.6 mL / min, the injection port temperature was set to 250 °C, and the split ratio was set to splitless;

[0179] (3) MS conditions: the ion source type was electron bombardment, the electron energy was 70 eV, the transfer line temperature was 280 °C, the ion source temperature was maintained at 230 °C, the quadrupole temperature was set to 150 °C, the mass scan range was m / z 40–250, and the solute delay was 3 min;

[0180] (4) Identification method: The relative content of each compound in rapeseed oil was quantitatively calculated by the internal standard method through GC-MS chemical workstation processing; 2-methyl-3-heptanone was used as the internal standard (there was no internal standard substance in the sample itself, and the internal standard and other substances had no effect on each other), and the concentration of the unknown compound was calculated through the relationship between peak area and concentration.

[0181] The acid value of rapeseed oil is determined according to the method of "GB / T 5009.229-2016 National Food Safety Standard Determination of Acid Value in Food".

[0182] The peroxide value of rapeseed oil is determined according to the method of "GB / T 5009.227-2023 National Food Safety Standard Determination of Peroxide Value in Food".

[0183] Test Example 2

[0184] The finished rapeseed oil products in the above embodiments and comparative examples were tested for sensory properties, aroma type and cooking effect. The results are shown in Table 2.

[0185] Rapeseed oil sensory and aroma type test: Refer to the standard "GB / T16291.1-2012 General Guidelines for Selection, Training and Management of Sensory Analysis Evaluators Part 1: Preferred Evaluators" to form a 10-person rapeseed oil evaluation team and determine the sensory descriptors, definitions and scoring scales for rapeseed oil. Under the standard sensory evaluation test environment, evaluators are required to describe and score randomly numbered samples, with a score range of 1-15 points, where 1-5 points represent weak flavor intensity, 6-10 points represent medium flavor intensity, and 11-15 points represent strong flavor intensity.

[0186] Preparation method of Mapo Tofu: Dice 300g tofu and soak it in boiling water with 10g salt for 10min; mince the beef, cut the garlic into 3cm segments, and mince the garlic. Add 40g rapeseed oil to the pot, heat it at 1000w for 40s on the induction cooker, turn to 1500w, add 50g minced meat, stir-fry it, add 2g salt and 5g cooking wine, stir-fry for 70s, and set aside; add 100g rapeseed oil, heat it at 2100w for 30s on the induction cooker, turn to 1500w, pour in 25g Pixian bean paste, 15g chili powder, 20g minced garlic, and 3g fermented black beans and stir-fry for 30s, pour in salty soup, soy sauce, tofu, and minced meat, cook it at 2100W for 90s on the induction cooker, add 15g water starch, 30g garlic, and 7g pepper powder, and cook it at 2100W for 30s before serving.

[0187] Preparation of shredded potatoes: Wash, peel, and shred potatoes, rinse with water three times and soak for 1 hour. Boil the shredded potatoes in boiling water for 60 seconds and remove them for later use; microwave the pan at 2100W for 20 seconds, add 20g of rapeseed oil and heat for 3 seconds, pour in 100g of shredded potatoes and stir-fry for 60 seconds, and pour the dish into a white plate.

[0188] Cooking effect test: A 10-member food evaluation team was formed to evaluate the odor intensity, flavor intensity, and spiciness persistence of the dish Mapo Tofu. Under the standard sensory evaluation test environment, the evaluators were required to score the odor and flavor intensity of the randomly numbered samples, with a score range of 1-15 points, where 1-5 points represent weak intensity, 6-10 points represent medium intensity, and 11-15 points represent strong intensity; the evaluators were required to score the saltiness and umami suitability of the randomly numbered samples, with a score range of 1-15 points, where 1-5 points represent too weak intensity, 6-10 points represent weak intensity, and 11-15 points represent suitable intensity; the spiciness persistence was calculated based on the residual time after the dish was ingested.

[0189] Dish appearance test: A 10-member dish evaluation team was formed to evaluate the color and brightness of the shredded potatoes. In a standard sensory evaluation test environment, the evaluators were required to score the color and brightness of the randomly numbered samples on a scale of 1-15, where 1-5 represented that the color of the dish was too dark or too light / the brightness was very dark, 6-10 represented that the color of the dish was darker or lighter / the brightness was darker, and 11-15 represented that the color of the dish was just right / the brightness was bright.

[0190] Table 1

[0191]

[0192] Table 2

[0193]

[0194] It can be seen from the results in Tables 1-2 that the method in Example 1 of the present invention is used to prepare roasted flavor rapeseed oil according to the customized process based on the characteristics of the raw materials, which significantly improves the flavor, physical and chemical quality and cooking effect of the rapeseed oil. The roasted flavor is strong, the aroma type of the roasted flavor rapeseed oil is prominent, and the color, aroma, taste and umami of the cooked dishes are significantly improved, and it is suitable for Huaiyang cuisine cooking.

[0195] It can be seen from the results in Tables 1-2 that the spicy flavor rapeseed oil prepared by the method in Example 2 of the present invention according to the customized process of raw material characteristics significantly improves the flavor, physical and chemical quality and cooking effect of the rapeseed oil, has a strong flavor, and the spicy rapeseed oil has a prominent aroma type. It has a significant effect on improving the color, fragrance and taste of cooked dishes. When cooking spicy dishes, the dishes are fragrant but not spicy, and are suitable for cooking Northwest flavor dishes.

[0196] It can be seen from the results in Tables 1-2 that the spicy flavor rapeseed oil prepared by the method of Examples 3-7 of the present invention according to the customized process based on the characteristics of the raw materials significantly improves the flavor, physical and chemical quality and cooking effect of the rapeseed oil. The spicy flavor is strong, the aroma type of the spicy rapeseed oil is prominent, and the color, fragrance, taste, saltiness and spiciness of the cooked dishes are significantly improved, which is suitable for Sichuan cuisine cooking.

[0197] Compared with the embodiment, Comparative Examples 1-4 respectively rely on the experience of technical workers to fry and moisten the rapeseed, and cannot accurately determine the optimal frying conditions, resulting in incomplete or too intense aroma production reaction, low content of characteristic flavor substances (such as pyrazines and isothiocyanates) in rapeseed oil, high acid value and peroxide value, and cannot prepare edible oil with a specific aroma in a targeted manner, resulting in poor oil quality.

[0198] In summary, the method of the present invention can be used to quickly formulate the aroma process conditions for preparing the most suitable strong-flavor rapeseed oil (such as roasted-flavor rapeseed oil and spicy-flavor rapeseed oil) according to the differences in the contents of different raw material components, thereby realizing the customized production of specific-flavor rapeseed oil, and the prepared rapeseed oil has a high content of characteristic flavor substances (such as pyrazines and isothiocyanates), authentic flavor and good quality; the acid value and peroxide value are low, and the characteristic aroma of rapeseed is richer and more lasting, which is suitable for cooking dishes of different cuisines.

[0199] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for determining the conditions for directional aroma production of rapeseed, characterized in that: The method comprises the following steps: (1) Obtaining the contents of carbohydrates, isoleucine, leucine, methionine, 3-butenyl glucosinolate, 2-hydroxy-3-butenyl glucosinolate and 5-methylsulfoxide glucosinolate in rapeseed; (2) determining the roasting rate according to the contents of carbohydrates, 3-butenyl glucosinolate, isoleucine and leucine; (3) Determine the moisture content before frying based on the content of 2-hydroxy-3-butenyl glucosinolate, 5-methylsulfoxide glucosinolate, 3-butenyl glucosinolate and methionine.

2. The method according to claim 1, wherein: The baking rate is calculated according to the formula shown in formula (I): In formula (I), V 烘焙 is the baking rate, in °C / min; C 碳水化合物 is the carbohydrate content, in g / 100g; C GNA is the 3-butenyl glucosinolate content, in μmol / g; C Ile is the isoleucine content, in mg / 100mg; C Leu is the leucine content, the unit is mg / 100mg.

3. The method according to claim 1 or 2, wherein: The moisture content of the stir-fry is calculated according to the formula shown in formula (II): C 入炒水分 =9.2-0.19*(0.34*C PRO +0.22*C GNL +0.41C GNA )+11.4* C Met Formula (II); In formula (II), C 入炒水分 is the moisture content of rapeseed during roasting, in %; C PRO is the 2-hydroxy-3-butenyl glucosinolate content, in μmol / g; C GNL is the 5-methylsulfoxide glucosinolate content, in μmol / g; C GNA is the 3-butenyl glucosinolate content, in μmol / g; C Met It is the methionine content, the unit is mg / 100mg.

4. The method according to any one of claims 1, wherein: The content of glucosinolate in the rapeseed is 10-150 μmol / g.

5. A method for preparing a fragrant rapeseed oil suitable for cooking different cuisines, characterized in that: The method comprises the following steps: (1) Determining the roasting rate and the moisture content of rapeseed oil according to the method described in any one of claims 1 to 4; (2) roasting the rapeseed according to the roasting rate and the moisture content before roasting, and pressing to obtain rapeseed oil.

6. The method according to claim 5, wherein: The end point temperature of the baking is 150-165°C; And / or, the pressing method includes: pressing the roasted rapeseed in a screw oil press to obtain crude oil; And / or, the method further comprises solid-liquid separation, hydration, sedimentation, dewaxing and fine filtration.

7. The method according to claim 6, wherein: The solid-liquid separation method includes: removing oil residue from the pressed crude oil through a horizontal spiral sedimentation centrifuge to obtain crude oil.

8. The method according to claim 6, wherein: The hydration method includes: mixing the crude oil obtained after solid-liquid separation with a hydrating agent to carry out a hydration reaction to obtain semi-clear oil; Preferably, the hydrating agent is selected from water and / or sodium chloride solution; Preferably, based on the mass of the crude oil obtained after the solid-liquid separation, the amount of the hydrating agent is 0.1wt%-5wt%; Preferably, the temperature of the hydration reaction is 23-35°C; More preferably, the mass concentration of the sodium chloride solution is 0.5wt%-10wt%.

9. The method according to claim 6, wherein: The sedimentation method includes placing the semi-clear oil obtained after the hydration treatment in a temporary storage tank for 36-48 hours, draining the oil residue, and obtaining the semi-finished oil; And / or, the dewaxing method includes mixing and stirring the semi-finished oil obtained after the sedimentation treatment with a filter aid, cooling to 5-10° C., and then crystallizing and growing the crystals; Preferably, the filter aid is selected from at least one of diatomaceous earth, activated clay, attapulgite, activated carbon, silica gel and perlite; Preferably, based on the mass of the semi-finished oil obtained after the sedimentation treatment, the amount of the filter aid is 0.1wt%-2wt%; Preferably, the stirring time is 0.5-1h; Preferably, the crystallization time is not less than 8 hours, and the crystal growing time is not less than 16 hours.

10. The method according to claim 6, wherein: The fine filtration method includes sequentially passing the semi-finished oil obtained after dewaxing through a paperboard filter and a bag filter for first filtration and second filtration; Preferably, the pore size of the paperboard filter is 0.2 μm-20 μm; the pore size of the bag filter is ≤15 μm; Preferably, the filtration pressures of the first filtration and the second filtration are independently 0.1 MPa-2 MPa.

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