Vegetable oil-based diglyceride mixture, lipid composition capable of reducing oil content of fried food as well as preparation method and application of lipid composition

Abstract

The invention discloses a vegetable oil-based diglyceride mixture, a lipid composition capable of reducing the oil content of fried food and a preparation method and application of the lipid composition, and relates to the field of food. According to the lipid composition, the vegetable oil-based diglyceride mixture and the vegetable oil are blended to enable the content of diglyceride to reach 70-90 wt%, the vegetable oil-based diglyceride mixture is synthesized by catalyzing decomposition of the vegetable oil through the immobilized lipase Lipozyme RM IM and then reacting with glycerol added in three times, the synthesis rate of the diglyceride reaches 85 wt%, the addition amount of the immobilized lipase is low, and the lipid composition is suitable for industrial production. The catalytic reaction time is short, the production efficiency is effectively improved, the production cost is saved, when the lipid composition is applied to preparation of fried food, the oil content of the fried food can be reduced due to the high diglyceride content, the oil intake is reduced, and the healthy diet requirement is met.

Description

Technical Field

[0001] The invention relates to the field of food, and in particular to a vegetable oil-based diglyceride mixture and a lipid composition capable of reducing the oil content of fried food, as well as a preparation method and application thereof. Background Art

[0002] Fried foods are loved by people because of their crispness and special aroma, and have become an indispensable part of the family diet. During the frying process, due to the interaction of heat transfer and mass transfer, frying oil can quickly transfer heat to the food, causing its surface to quickly dehydrate and solidify, thus forming a crispy shell. In addition, the oil can dissolve and carry the flavor components in the food, improving the taste and flavor. However, fried foods have a high oil content, and excessive consumption can easily lead to excessive oil intake, which can cause a series of cardiovascular diseases such as obesity, hyperglycemia, hyperlipidemia, and diabetes. Therefore, the ideal frying oil should minimize the amount of oil absorbed by the food, reduce the oil content of the finished product, and reduce oil intake.

[0003] At present, the method of reducing the oil content of fried food is mainly achieved by increasing the interfacial tension between frying oil and food, thereby increasing the resistance of oil to enter food, such as applying modified starch and cellulose and gelatin and pectin on the surface of food. However, these coatings may increase the calories of food and affect the texture and taste of food. In addition, the physical and chemical properties of oils and fats, such as viscosity, surface tension, stability of polar compounds, etc., can also be used to reduce the oil content of food, but considering food safety, there are few reports on the above-mentioned edible oils for frying that meet relevant regulations and standards. At present, the technology discloses that by adding modified starch or polyoleyl fatty acid esters to oils and fats, the surface tension of oils and fats is changed to achieve the effect of reducing the oil content of fried foods, but this kind of coating and emulsification technology often leads to important changes in the taste of fried foods and oils. There is also a way of using vegetable oil and animal oil compounding to reduce the oil absorption rate of fried foods by changing the composition of oils and fats themselves, but this method is relatively limited to relatively simple deployment between different oils, and does not essentially change the structure of oils and fats, thereby achieving the purpose of reducing the oil content of food.

[0004] Diacylglycerol is a naturally occurring component in vegetable oils. It exists in two types, namely 1,2-(or 2,3)-diacyl-sn-glycerol (1,2-diacylglycerol) and 1,3-diacyl-sn-glycerol (1,3-diacylglycerol), both of which are present in various vegetable oils with a maximum content of 10%. Although 1,3-diacylglycerol and triglycerides are digested by the same gastrointestinal enzymes, compared with triglycerides, 1,3-diacylglycerol does not go through the 2-monoacylglycerol (2-MAG) pathway and glycerol-3-phosphate pathway of triglycerides after digestion, thereby preventing the resynthesis of new triglycerides. This unique digestive property has led to diacylglycerol showing benefits higher than triglycerides in clinical studies. For example, diacylglycerol can promote fat oxidation, inhibit weight gain, reduce visceral fat, improve cardiovascular and cerebrovascular health, etc., so it has great application prospects in frying oils. Summary of the invention

[0005] The present invention provides a vegetable oil-based diglyceride mixture and a lipid composition capable of reducing the oil content of fried foods, as well as a preparation method and application thereof. The lipid composition is used as frying oil to increase the proportion of diglycerides in the lipid composition, effectively reduce the oil content of fried foods, and reduce fat intake.

[0006] In order to solve the above technical problems, one of the purposes of the present invention is to provide a method for preparing a vegetable oil-based diglyceride mixture, comprising the following steps:

[0007] (1) After the vegetable oil and water are evenly mixed, immobilized lipase Lipozyme RM IM is added, heated and stirred for reaction, and the upper oil phase of the reactant is molecularly distilled to obtain fatty acids;

[0008] The mass ratio of vegetable oil to water is 1:(0.5-1.5), and the immobilized lipase Lipozyme RMIM accounts for 2wt%-10wt% of the mass of the vegetable oil;

[0009] (2) mixing fatty acids, glycerol A and immobilized lipase Lipozyme RM IM uniformly, heating the mixture for reaction for 3-6 hours, adding glycerol B and glycerol C to the mixture at intervals during the reaction, and the intervals between adding glycerol A, glycerol B and glycerol C are 1-2 hours to obtain a final reaction product, removing fatty acids and monoglycerides through molecular distillation to obtain a vegetable oil-based diglyceride mixture containing diglycerides and triglycerides;

[0010] Among them, the mass ratio of glycerol A, glycerol B and glycerol C is (40-50): (30-35): (20-25), the immobilized lipase Lipozyme RM IM accounts for 5wt%-15wt% of the mass of fatty acids, the mass ratio of the fatty acids and the total amount of glycerol is 100: (5-15), and the total amount of glycerol is the sum of glycerol A, glycerol B and glycerol C.

[0011] By adopting the above scheme, more than 90% of the vegetable oil is triglyceride. The present application adopts a specific immobilized lipase Lipozyme RM IM to catalyze the decomposition of vegetable oil and react with glycerol to synthesize diglyceride. The addition of glycerol in three times can effectively improve the synthesis efficiency. The addition amount of immobilized lipase is low, and the catalytic reaction time is short, which effectively improves the production efficiency and saves production costs. The diglyceride content in the finally synthesized vegetable oil-based diglyceride mixture reaches a relatively high level, reaching as high as more than 85wt%. The high diglyceride content has the advantages of promoting fat oxidation, inhibiting weight gain, reducing visceral fat, and improving cardiovascular and cerebrovascular health. It can be used in the preparation of fried foods to reduce the oil content of fried foods and meet healthy dietary requirements.

[0012] As a preferred embodiment, in step (1), the temperature of the heating and stirring reaction is 40-50°C, and the reaction time is 24-36h. After many experiments by the inventors, within the temperature and time range of the above-mentioned catalytic reaction, the efficiency of synthesizing fatty acids from vegetable oil is relatively high, which helps to improve production efficiency.

[0013] As a preferred embodiment, in step (2), the temperature of the heating reaction is 40-50°C. The inventors have found through multiple experiments that within the above-mentioned catalytic reaction temperature range, the catalytic reaction synthesis efficiency of immobilized lipase on fatty acids and glycerol is roughly the same, and the diglyceride synthesis efficiency is high within this temperature range. The catalytic reaction time is controlled within this temperature range to avoid a decrease in the diglyceride synthesis efficiency as the catalytic reaction time increases.

[0014] As a preferred embodiment, the vegetable oil is at least one of soybean oil, rapeseed oil, peanut oil, corn oil, sunflower seed oil, sesame oil, camellia oil, linseed oil, olive oil, coconut oil, palm oil, palm kernel oil, olive pomace oil, walnut oil, rice bran oil, rice oil, cottonseed oil, perilla oil, safflower seed oil, grape seed oil, pumpkin seed oil, peony seed oil, tea seed oil, eucommia seed oil, algae oil, krill oil, Acer truncatum seed oil, shea butter, milk thistle seed oil, triacyl arachidonate, conjugated linoleic acid glyceride, samarassima oil, sachalinensis oil, tomato seed oil, almond oil, senna nut oil, sedge seed oil, and royal rice oil.

[0015] The present application uses vegetable oil to generate fatty acids through the catalysis of immobilized lipase, and then the fatty acids and glycerol are catalyzed to synthesize diglyceride. The raw material cost is low and the diglyceride yield is high. The vegetable oil of the present application preferably contains flaxseed oil and tea seed oil components with high content of ω-3 or ω-9 unsaturated fatty acids. When the product prepared from the raw oil is used as frying oil, the oil content of fried food is lower than that of other raw oils, thereby meeting people's requirements for healthy diet.

[0016] As a preferred embodiment, in steps (1) and (2), the temperature of molecular distillation is 150-200°C and the vacuum degree is less than 10Pa.

[0017] As a preferred embodiment, in step (1), the vegetable oil and water are mixed evenly, and then preheated at 40-50° C. for 1-2 h, and then the immobilized lipase Lipozyme RM IM is added to heat and stir for reaction.

[0018] In order to solve the above technical problems, the second object of the present invention is to provide a vegetable oil-based diglyceride mixture.

[0019] In order to solve the above technical problems, the third purpose of the present invention provides a lipid composition that can reduce the oil content of fried foods, the lipid composition comprises vegetable oil, a vegetable oil-based diglyceride mixture and an antioxidant, the diglyceride content in the vegetable oil-based diglyceride mixture is 75wt%-90wt%, the diglyceride content in the vegetable oil is less than 5wt%, the diglyceride content in the lipid composition is 70wt%-90wt%, and the concentration of the antioxidant in the lipid composition is 0.1-0.2g / kg.

[0020] By adopting the above scheme, the content of diglyceride in the lipid composition of the present application is controlled between 75wt% and 90wt%, and the remainder is diglyceride or other trace impurities. When used for frying food, a high diglyceride content can effectively reduce the oil content of the fried food, and as the diglyceride content increases, the oil content gradually decreases, and the higher the content of ω-3 or ω-9 unsaturated fatty acids in the raw oil used in the lipid composition, the further the oil content of the fried food can be reduced, effectively reducing the intake of fats and oils, and meeting people's needs for healthy diet.

[0021] As a preferred embodiment, the antioxidant is at least one of tertiary butylhydroquinone, vitamin E, ascorbyl palmitate, tea polyphenols, sodium phytate, and butylated hydroxyanisole, and the vegetable oil is at least one of soybean oil, rapeseed oil, peanut oil, corn oil, sunflower seed oil, sesame oil, camellia oil, linseed oil, olive oil, coconut oil, palm oil, palm kernel oil, olive pomace oil, walnut oil, rice bran oil, rice oil, cottonseed oil, perilla oil, safflower seed oil, grape seed oil, pumpkin seed oil, peony seed oil, tea seed oil, eucommia seed oil, algae oil, krill oil, Acer truncatum seed oil, shea butter, silybum seed oil, triacyl arachidonate, conjugated linoleic acid glyceride, samarassima oil, sachalinensis oil, tomato seed oil, almond oil, smilax glabra fruit oil, salsa salsa seed oil, and royal rice oil.

[0022] In order to solve the above technical problems, the fourth purpose of the present invention provides a method for preparing a lipid composition that can reduce the oil content of fried foods, comprising the following steps: mixing and compounding vegetable oil, a vegetable oil-based diglyceride mixture and an antioxidant according to specific contents, adding the vegetable oil-based diglyceride mixture and vegetable oil according to the content of diglyceride in the lipid composition, to obtain the lipid composition.

[0023] In order to solve the above technical problems, the fifth purpose of the present invention provides a lipid composition that can reduce the oil content of fried foods for use in preparing fried foods, shortening, margarine, convenience foods, biscuits, cakes, pies, candies, and ice cream.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present application adopts a specific immobilized lipase Lipozyme RM IM to catalyze the decomposition of vegetable oil. Adding glycerol three times can effectively improve the synthesis efficiency. The amount of immobilized lipase added is low, and the catalytic reaction time is short, which effectively improves the production efficiency and saves production costs. The content of synthesized diglyceride is as high as 85wt% or more, which can be used in the preparation of fried foods to reduce the oil content of fried foods, reduce the intake of fats and oils, and meet the requirements of a healthy diet.

[0026] 2. The diglyceride content in the lipid composition of the present application reaches more than 70wt%. When used for fried foods, the diglyceride content is positively correlated with the oil content of the fried foods. Compared with the raw oil with a higher triglyceride content, the increase in the diglyceride content in the present application helps to reduce the oil content of fried foods, and the higher content of ω-3 or ω-9 unsaturated fatty acids in vegetable oils can further reduce the oil content, which can significantly reduce the oil absorption rate by more than 20%, thereby reducing the intake of fat. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1: is a chart showing the oil content of food fried with the lipid compositions of Example 1 and Comparative Examples 1 and 5 of the present invention as a function of frying time;

[0028] Figure 2 : A chart showing the oil content of food fried with the lipid compositions of Example 2 and Comparative Examples 2 and 6 of the present invention as a function of frying time;

[0029] Figure 3 : A chart showing the oil content of food fried with the lipid compositions of Example 3 and Comparative Examples 3 and 7 of the present invention as a function of frying time;

[0030] Figure 4 : is a chart showing the oil content of food fried with the lipid composition of Example 4 of the present invention and Comparative Examples 4 and 8 as the frying time changes. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0033] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0034] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0035] As used herein:

[0036] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0037] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0038] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically inventing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is invented separately. For example, when a range of "1 to 5" is invented, the described range should be interpreted as including the range "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0039] In these examples, parts and percentages are by mass unless otherwise indicated.

[0040] "Parts by mass" refers to the basic unit of measurement that represents the proportional relationship between the masses of multiple components. 1 part can represent any unit mass. If we say that the mass of component A is a parts and the mass of component B is b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Or, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass parts of all components is not limited to 100 parts.

[0041] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0042] In the description of the present invention, it is necessary to understand that the terms "up", "down", "left", "right", "top", "bottom", etc., indicating directions or positional relationships, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0043] To further illustrate the present invention, a lipid composition for reducing the oil content of fried food provided by the present invention, as well as a preparation method and application thereof are described in detail below in conjunction with examples, but they should not be construed as limiting the scope of protection of the present invention.

[0044] The sources and types of raw materials used in the following examples and comparative examples of the present application are all commercially available unless otherwise specified, and the same raw materials are used in parallel experiments.

[0045] Preparation Examples 1-8 and Comparative Preparation Examples 1-3

[0046] A method for preparing a soybean oil-based diglyceride mixture, the reaction conditions and product components are shown in Table 1 below, and the method comprises the following steps:

[0047] (1) taking 250 g of soybean oil and adding 250 g of distilled water, mixing well and preheating at 40-50° C. for 1 hour, then adding 5-12.5 g of immobilized lipase, stirring and reacting for 20 hours, taking the upper oil phase of the reactant and molecularly distilling to obtain fatty acids, wherein the solid lipase is at least one of Novozymes' Lipozyme 435, Lipozyme RM IM, and Lipozyme TL IM;

[0048] (2) taking 100 g of fatty acid, adding 4 g of glycerol and 5-12.5 g of immobilized lipase, mixing evenly and reacting at 40-50° C. for 3-6 hours, adding 3 g of glycerol and 2 g of glycerol to the reactant during the reaction, and adding 4 g of glycerol, 3 g of glycerol and 2 g of glycerol at intervals of 1-2 hours to obtain a final reactant;

[0049] (3) The final reactant is subjected to molecular distillation to remove fatty acids and monoglycerides. The evaporation temperature of the molecular distillation is 180° C. and the vacuum degree is 8 Pa, thereby obtaining a soybean oil-based diglyceride mixture containing diglyceride oil and triglyceride.

[0050] The contents of diglyceride and triglyceride in the products of the preparation example and the comparative preparation example were tested according to GB / T 26636-2011 standard. The test results are shown in Table 1 below.

[0051] Table 1 - Reaction conditions and product compositions in Preparation Examples 1-8 and Comparative Preparation Examples 1-3 of the present application

[0052]

[0053]

[0054] As shown in Table 1, by comparing the solutions of Preparation Example 1 and Comparative Preparation Examples 1-2, it can be seen that the present application utilizes immobilized lipase for catalysis in a solvent-free system. Under the same enzyme content and process conditions, when Lipozyme RMIM is selected as the solid lipase, it has higher catalytic efficiency and high diacylglycerol synthesis rate compared with Lipozyme 435 and Lipozyme TL IM solid lipases. The diacylglycerol content in the obtained product is relatively high, which can reach up to 85wt%. When used for frying food, the higher diacylglycerol content effectively reduces the oil content of the food.

[0055] As shown in Table 1, from the comparison of Preparation Examples 1-6, it can be seen that when soybean oil is used as the raw material, as the amount of immobilized lipase added increases, the content of diglyceride synthesized in the lipid composition shows a slight upward trend, indicating that the increase in the content of immobilized lipase can improve the synthesis efficiency of diglyceride, but the degree of improvement is limited; and when the temperature of the immobilized lipase catalyzing the reaction of fatty acids and glycerol is in the range of 40-50°C, the synthesis efficiency of diglyceride is basically the same, and the synthesis efficiency is higher within this temperature range.

[0056] As shown in Table 1, by comparing Preparation Examples 1, 7-8 and Comparative Preparation Example 3, it can be seen that when soybean oil is used as raw material and immobilized lipase is used to catalyze the synthesis of diglyceride from fatty acids and glycerol, the reaction time is 3-8 hours. As the reaction time increases, the content of synthesized diglyceride shows a downward trend, and when the reaction time is 8 hours, the diglyceride content is reduced to 72%, indicating that too long a reaction time will lead to a decrease in the diglyceride content in the product.

[0057] Preparation Example 9

[0058] A method for preparing a rapeseed oil-based diglyceride mixture comprises the following steps:

[0059] (1) Take 250 g rapeseed oil, add 200 g distilled water, mix well and preheat at 45° C. for 1 hour, then add 7.5 g immobilized lipase Lipozyme RM IM, stir and react for 24 hours, and take the upper oil phase of the reactant for molecular distillation to obtain fatty acids;

[0060] (2) Take 100 g fatty acid, add 4 g glycerol and 7.5 g immobilized lipase Lipozyme RM IM, mix well and react at 45°C for 1 hour, then add 3 g glycerol to the reactant, after an interval of 1 hour, add 2 g glycerol to the reactant, and after 1 hour, obtain the final reactant;

[0061] (3) The final reactant is subjected to molecular distillation to remove fatty acids and monoglycerides. The evaporation temperature of the molecular distillation is 190° C. and the vacuum degree is 8 Pa, thereby obtaining a rapeseed oil-based diglyceride mixture with a diglyceride oil mass percentage of 83.6% and a triglyceride mass percentage of 16.4%.

[0062] Preparation Example 10

[0063] A method for preparing a tea seed oil-based diglyceride mixture comprises the following steps:

[0064] (1) Take 250 g of tea seed oil, add 145 g of distilled water, mix well and preheat at 45° C. for 1 hour, then add 10 g of immobilized lipase Lipozyme RM IM, stir and react for 26 hours, and take the upper oil phase of the reactant for molecular distillation to obtain fatty acids;

[0065] (2) Take 100 g fatty acid, add 4 g glycerol and 10 g immobilized lipase Lipozyme RM IM, mix well and react at 45°C for 1 hour, then add 3 g glycerol to the reactant, after an interval of 1 hour, add 2 g glycerol to the reactant, and after 1 hour, obtain the final reactant;

[0066] (3) The final reactant is subjected to molecular distillation to remove fatty acids and monoglycerides. The evaporation temperature of the molecular distillation is 190° C. and the vacuum degree is 8 Pa, thereby obtaining a tea seed oil-based diglyceride mixture with a diglyceride oil mass percentage of 83.9% and a triglyceride mass percentage of 16.1%.

[0067] Preparation Example 11

[0068] A method for preparing a linseed oil-based diglyceride mixture comprises the following steps:

[0069] (1) Take 250 g of linseed oil, add 125 g of distilled water, mix well and preheat at 50° C. for 1 hour, then add 12.5 g of immobilized lipase Lipozyme RM IM, stir and react for 30 hours, and take the upper oil phase of the reactant for molecular distillation to obtain fatty acids;

[0070] (2) Take 100 g fatty acid, add 4 g glycerol and 12.5 g immobilized lipase Lipozyme TL IM, mix well and react at 50°C for 1 hour, then add 3 g glycerol to the reactant, after an interval of 1 hour, add 2 g glycerol to the reactant, and after 1 hour, obtain the final reactant;

[0071] (3) The final reactant is subjected to molecular distillation to remove fatty acids and monoglycerides. The evaporation temperature of the molecular distillation is 200° C. and the vacuum degree is 8 Pa, thereby obtaining a linseed oil-based diglyceride mixture with a diglyceride oil mass percentage of 85.78% and a triglyceride mass percentage of 14.22%.

[0072] By comparing the schemes of Preparation Examples 1 and 9-11, it can be seen that when soybean oil, rapeseed oil, tea seed oil and linseed oil are used as raw materials to synthesize diglyceride, respectively, under the premise of using the same enzyme type and process conditions, there is no obvious difference in the content of diglyceride in the diglyceride mixture prepared from different raw oils, indicating that the type of raw oil does not have a significant effect on the synthesis rate of diglyceride.

[0073] Comparative Preparation Example 4

[0074] A method for preparing a soybean oil-based diglyceride mixture, the reaction conditions and product components are shown in Table 1 below, and the method comprises the following steps:

[0075] (1) 250 g of soybean oil was added with 250 g of distilled water, the mixture was mixed well and preheated at 40° C. for 1 hour, and then 5 g of immobilized lipase was added. The mixture was stirred and reacted for 20 hours. The upper oil phase of the reactant was molecularly distilled to obtain fatty acids. The solid lipase was Lipozyme RM IM.

[0076] (2) Take 100 g fatty acid, add 9 g glycerol and 5 g immobilized lipase, mix well and react at 40° C. for 3 hours. After the reaction is completed, the final reaction product is obtained;

[0077] (3) The final reactant was subjected to molecular distillation to remove fatty acids and monoglycerides. The evaporation temperature of the molecular distillation was 180° C. and the vacuum degree was 8 Pa, thereby obtaining a soybean oil-based diglyceride mixture containing 60.3 wt % of diglycerides and 39.7 wt % of triglycerides.

[0078] The addition methods of fatty oil and glycerol in the schemes of Preparation Example 1 and Comparative Preparation Example 4 are different. In Preparation Example 1, glycerol is added three times at intervals, while in Comparative Preparation Example 4, glycerol and fatty acids are added simultaneously. The result table shows that, compared with Comparative Preparation Example 4, the addition of glycerol in Preparation Example 1 in three times can significantly improve the reaction efficiency, make the synthesis rate of diglycerol higher in a short time, and reduce the production cost.

[0079] Example 1

[0080] A lipid composition capable of reducing the oil content of fried food comprises 70wt% diglyceride, 0.1g / kg vitamin E and the remainder of diglyceride and other impurities. The preparation method comprises the following steps: ordinary soybean oil, the soybean oil-based diglyceride mixture of Preparation Example 1 and vitamin E are mixed and compounded according to specific contents, and the soybean oil-based diglyceride mixture is added according to the content of diglyceride in the lipid composition, so that the ordinary soybean oil comprises 99wt% triglyceride and 1wt% diglyceride.

[0081] Example 2

[0082] A lipid composition capable of reducing the oil content of fried food comprises 70wt% of diglyceride, 0.1g / kg of vitamin E and the remainder of diglyceride and other impurities. The preparation method comprises the following steps: ordinary rapeseed oil, the rapeseed oil-based diglyceride mixture of Preparation Example 9 and vitamin E are mixed and compounded according to specific contents, and the rapeseed oil-based diglyceride mixture is added according to the content of diglyceride in the lipid composition, so that the ordinary rapeseed oil comprises 99.2wt% of triglyceride and 0.8wt% of diglyceride.

[0083] Example 3

[0084] A lipid composition capable of reducing the oil content of fried food comprises 70wt% diglyceride, 0.1g / kg vitamin E and the remainder of diglyceride and other impurities. The preparation method comprises the following steps: ordinary tea seed oil, the tea seed oil-based diglyceride mixture of Preparation Example 10 and vitamin E are mixed and compounded according to specific contents, and the tea seed oil-based diglyceride mixture is added according to the content of diglyceride in the lipid composition, so that the ordinary tea seed oil comprises 97.7wt% triglyceride and 2.3wt% diglyceride.

[0085] Example 4

[0086] A lipid composition capable of reducing the oil content of fried food comprises 70wt% of diglyceride, 0.1g / kg of vitamin E and the remainder of diglyceride. The preparation method comprises the following steps: ordinary linseed oil, the linseed oil-based diglyceride mixture of Preparation Example 11 and vitamin E are mixed and compounded according to specific contents, and the linseed oil-based diglyceride mixture is added according to the content of diglyceride in the lipid composition, so that the ordinary linseed oil comprises 98.2wt% of triglyceride and 1.8wt% of diglyceride.

[0087] Example 5

[0088] A lipid composition capable of reducing the oil content of fried food comprises 80wt% of diglyceride, 0.15g / kg of vitamin E and the remainder of diglyceride and other impurities. The preparation method comprises the following steps: ordinary linseed oil, the linseed oil-based diglyceride mixture of Preparation Example 11 and vitamin E are mixed and compounded according to specific contents, and the linseed oil-based diglyceride mixture is added according to the content of diglyceride in the lipid composition, so that the ordinary linseed oil comprises 98.2wt% of triglyceride and 1.8wt% of diglyceride.

[0089] Comparative Example 1

[0090] A lipid composition includes common soybean oil, wherein the common soybean oil includes 99 wt % of triglyceride and 1 wt % of diglyceride.

[0091] Comparative Example 2

[0092] A lipid composition comprises common rapeseed oil, wherein the common rapeseed oil comprises 99.2 wt % of triglyceride and 0.8 wt % of diglyceride.

[0093] Comparative Example 3

[0094] A lipid composition comprises common tea seed oil, wherein the common tea seed oil comprises 97.7 wt % of triglyceride and 2.3 wt % of diglyceride.

[0095] Comparative Example 4

[0096] A lipid composition comprises common linseed oil, wherein the common linseed oil comprises 98.2 wt % of triglyceride and 1.8 wt % of diglyceride.

[0097] Comparative Example 5

[0098] A lipid composition capable of reducing the oil content of fried food comprises 50wt% diglyceride, 0.1g / kg vitamin E and the remainder of diglyceride and other impurities. The preparation method comprises the following steps: ordinary soybean oil, the soybean oil-based diglyceride mixture of Preparation Example 1 and vitamin E are mixed and compounded according to specific contents, so as to obtain the soybean oil-based diglyceride mixture, wherein the soybean oil-based diglyceride mixture is added according to the content of diglyceride in the lipid composition, and the ordinary soybean oil comprises 99wt% triglyceride and 1wt% diglyceride.

[0099] Comparative Example 6

[0100] A lipid composition capable of reducing the oil content of fried food comprises 50wt% of diglyceride, 0.1g / kg of vitamin E and the remainder of diglyceride and other impurities. The preparation method comprises the following steps: ordinary rapeseed oil, the rapeseed oil-based diglyceride mixture of Preparation Example 9 and vitamin E are mixed and compounded according to specific contents, so as to obtain the rapeseed oil-based diglyceride mixture, wherein the rapeseed oil-based diglyceride mixture is added according to the content of diglyceride in the lipid composition, and the ordinary rapeseed oil comprises 99.2wt% of triglyceride and 0.8wt% of diglyceride.

[0101] Comparative Example 7

[0102] A lipid composition capable of reducing the oil content of fried food comprises 50wt% diglyceride, 0.1g / kg vitamin E and the remainder of diglyceride and other impurities. The preparation method comprises the following steps: ordinary tea seed oil, the tea seed oil-based diglyceride mixture of Preparation Example 10 and vitamin E are mixed and compounded according to specific contents, so as to obtain the tea seed oil-based diglyceride mixture, wherein the tea seed oil-based diglyceride mixture is added according to the content of diglyceride in the lipid composition, and the ordinary tea seed oil comprises 97.7wt% triglyceride and 2.3wt% diglyceride.

[0103] Comparative Example 8

[0104] A lipid composition capable of reducing the oil content of fried food comprises 50wt% of diglyceride, 0.1g / kg of vitamin E and the remainder of diglyceride and other impurities. The preparation method comprises the following steps: ordinary linseed oil, the linseed oil-based diglyceride mixture of Preparation Example 11 and vitamin E are mixed and compounded according to specific contents, and the linseed oil-based diglyceride mixture is added according to the content of diglyceride in the lipid composition, so that the ordinary linseed oil comprises 98.2wt% of triglyceride and 1.8wt% of diglyceride.

[0105] Performance testing

[0106] The specific steps of the continuous frying French fries experiment are as follows: add 1L of the lipid composition of the embodiment or the comparative example into the fryer and preheat for 1 hour to stabilize the temperature at 180±5°C, then add 50g of French fries for frying, remove them after frying for 5 minutes, and then continue to fry new French fries after an interval of 15 minutes, and fry continuously for 8 hours. The fried French fries are collected at the first frying (0h), the 11th frying (4h), and the 23rd frying (8h), and are cooled to room temperature and stored in bags at -20°C. The collected French fries are tested for oil content according to GB / T14488.1-2008 standard. The test results are as follows Figure 1-4 And as shown in Table 2.

[0107] Table 2 - Oil content of French fries at different times after frying test of lipid compositions in the present application examples and comparative examples

[0108]

[0109] As shown in Table 2, by comparing Example 1 with Comparative Examples 1 and 5, it can be seen that when soybean oil is used as the raw material oil, Comparative Example 1 is the raw material soybean oil, the lipid composition of Example 1 contains 70wt% diglyceride, and Comparative Example 5 contains 50wt% diglyceride. After the frying experiment, the oil content of the food in Example 1 is the highest decrease rate compared with the raw material oil, and the oil content is the lowest. Although the oil content of Comparative Example 5 is 5%-21% lower than the raw material oil, and as the frying time increases, its decrease first increases and then decreases, the oil content still maintains a high level and cannot meet the product requirements of this application, indicating that as the content of diglyceride increases, the oil content of fried food shows a downward trend, and the diglyceride content is positively correlated with the oil content of fried food.

[0110] As shown in Table 2, by comparing Example 2 with Comparative Examples 2 and 6, it can be seen that when rapeseed oil is used as the raw material oil, Comparative Example 2 is the raw material rapeseed oil, the lipid composition of Example 2 contains 70wt% diglyceride, and Comparative Example 6 contains 50wt% diglyceride. After the frying experiment, the oil content of the food in Example 2 is the highest decrease rate compared with the raw material oil, and the oil content is the lowest. Although the oil content of Comparative Example 6 is 6%-11% lower than the raw material oil, the oil content still maintains a high level and cannot meet the product requirements of this application.

[0111] As shown in Table 2, by comparing Example 3 with Comparative Examples 3 and 7, it can be seen that when tea seed oil is used as the raw material oil, Comparative Example 3 is the raw material tea seed oil, the lipid composition of Example 3 contains 70wt% diglyceride, and Comparative Example 7 contains 50wt% diglyceride. After the frying experiment, the oil content of the food in Example 3 is the highest decrease rate compared with the raw material oil, and the oil content is the lowest. Although the oil content of Comparative Example 7 is 11%-21% lower than the raw material oil, the oil content still maintains a high level, and with the extension of time, the degree of decrease in the oil content gradually decreases, which cannot meet the product requirements of this application.

[0112] As shown in Table 2, by comparing Examples 4-5 with Comparative Examples 4 and 8, it can be seen that when tea seed oil is used as the raw material oil, Comparative Example 4 is raw material tea seed oil, the lipid composition of Examples 4-5 contains 70wt%-80wt% diglyceride, and Comparative Example 8 contains 50wt% diglyceride. After the frying experiment, the oil content of the food in Examples 4-5 is the highest decrease rate compared with the raw material oil, and the oil content is the lowest. Although the oil content of Comparative Example 8 is 2%-15% lower than the raw material oil, the oil content still maintains a high level and cannot meet the product requirements of this application.

[0113] As shown in Table 2, by comparing the schemes of Examples 1-4, it can be seen that during the continuous frying process, the oil content of the flaxseed oil lipid composition for fried French fries is not only lower than that of the flaxseed oil raw material oil, but also due to the high content of ω-3 or ω-9 unsaturated fatty acids in flaxseed oil, the oil content of the fried French fries is lower than that of the rapeseed oil, tea seed oil, and soybean oil lipid compositions with the same diglyceride content, further reducing the oil content of the fried food.

[0114] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a vegetable oil-based diglyceride mixture, characterized in that: The following steps are involved: (1) After the vegetable oil and water are evenly mixed, immobilized lipase Lipozyme RM IM is added, heated and stirred for reaction, and the upper oil phase of the reactant is molecularly distilled to obtain fatty acids; The mass ratio of vegetable oil to water is 1:(0.5-1.5), and the immobilized lipase Lipozyme RM IM accounts for 2wt%-10wt% of the mass of the vegetable oil; (2) mixing fatty acids, glycerol A and immobilized lipase Lipozyme RM IM uniformly, heating the mixture for reaction for 3-6 hours, adding glycerol B and glycerol C to the mixture at intervals during the reaction, and the intervals between adding glycerol A, glycerol B and glycerol C are 1-2 hours to obtain a final reaction product, removing fatty acids and monoglycerides through molecular distillation to obtain a vegetable oil-based diglyceride mixture containing diglycerides and triglycerides; Among them, the mass ratio of glycerol A, glycerol B and glycerol C is (40-50): (30-35): (20-25), the immobilized lipase Lipozyme RM IM accounts for 5wt%-15wt% of the mass of fatty acids, the mass ratio of the fatty acids and the total amount of glycerol is 100: (5-15), and the total amount of glycerol is the sum of glycerol A, glycerol B and glycerol C.

2. The method for preparing the vegetable oil-based diglyceride mixture according to claim 1, wherein In step (1), the temperature of the heating and stirring reaction is 40-50°C, and the reaction time is 24-36h; in step (2), the temperature of the heating reaction is 40-50°C.

3. The method for preparing the vegetable oil-based diglyceride mixture according to claim 1, wherein: The vegetable oil is at least one of soybean oil, rapeseed oil, peanut oil, corn oil, sunflower seed oil, sesame oil, camellia oil, linseed oil, olive oil, coconut oil, palm oil, palm kernel oil, olive pomace oil, walnut oil, rice bran oil, rice oil, cottonseed oil, perilla oil, safflower seed oil, grape seed oil, pumpkin seed oil, peony seed oil, tea seed oil, eucommia seed oil, algae oil, krill oil, Acer truncatum seed oil, shea butter, milk thistle seed oil, triacyl arachidonate, conjugated linoleic acid glyceride, samarassima oil, sachalinensis oil, tomato seed oil, almond oil, elm oil, salsa salsa seed oil, and royal rice oil.

4. The method for preparing the vegetable oil-based diglyceride mixture according to claim 1, wherein In steps (1) and (2), the temperature of molecular distillation is 150-200° C. and the vacuum degree is less than 10 Pa.

5. The method for preparing the vegetable oil-based diglyceride mixture according to claim 1, wherein In step (1), the vegetable oil and water are mixed evenly, and then preheated at 40-50° C. for 1-2 h, and then the immobilized lipase Lipozyme RM IM is added to heat and stir for reaction.

6. A vegetable oil-based diglyceride mixture prepared by the method for preparing a vegetable oil-based diglyceride mixture as claimed in any one of claims 1 to 5.

7. A lipid composition capable of reducing the oil content of fried food, characterized in that: Containing the vegetable oil-based diglyceride mixture as described in claim 6, the lipid composition comprises vegetable oil, the vegetable oil-based diglyceride mixture and an antioxidant, the diglyceride content in the vegetable oil-based diglyceride mixture is 75wt%-90wt%, the diglyceride content in the vegetable oil is less than 5wt%, the diglyceride content in the lipid composition is 70wt%-90wt%, and the concentration of the antioxidant in the lipid composition is 0.1-0.2g / kg.

8. The lipid composition for reducing the oil content of fried food according to claim 7, characterized in that: The antioxidant is at least one of tertiary butylhydroquinone, vitamin E, ascorbyl palmitate, tea polyphenols, sodium phytate, and butylated hydroxyanisole; and the vegetable oil is at least one of soybean oil, rapeseed oil, peanut oil, corn oil, sunflower seed oil, sesame oil, camellia oil, linseed oil, olive oil, coconut oil, palm oil, palm kernel oil, olive pomace oil, walnut oil, rice bran oil, rice oil, cottonseed oil, perilla oil, safflower seed oil, grape seed oil, pumpkin seed oil, peony seed oil, tea seed oil, eucommia seed oil, algae oil, krill oil, Acer truncatum seed oil, shea butter, silybum seed oil, triacyl arachidonate, conjugated linoleic acid glyceride, samarassima oil, sachalinensis oil, tomato seed oil, almond oil, elm oil, salsa salsa seed oil, and royal rice oil.

9. A method for preparing a lipid composition capable of reducing the oil content of fried food as claimed in claim 7 or 8, characterized in that: The method comprises the following steps: mixing and compounding vegetable oil, vegetable oil-based diglyceride mixture and antioxidant according to specific contents, and adding the vegetable oil-based diglyceride mixture and vegetable oil according to the content of diglyceride in the lipid composition to obtain the lipid composition.

10. Use of the lipid composition capable of reducing the oil content of fried food as claimed in claim 7 or 8 in the preparation of fried food, shortening, margarine, instant food, biscuits, cakes, pies, candies and ice cream.

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