CN111650338B - Method for measuring transesterification degree - Google Patents
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Abstract
The invention discloses a method for measuring the degree of ester exchange reaction. The method comprises the steps of analyzing fatty acid components of a grease sample before and after esterification, calculating an acyl transfer rate according to the change degree of the ratio content of the types of the fatty acids at the sn-2 position to the molar weight of S and U, and judging the transesterification degree by using the change of the sn-2 fatty acid components. This is due to the transesterification reaction under the action of 1,3 specific lipase, and if the sn-2 fatty acid composition ratio is changed, it indicates that there is acyl migration during the catalytic transesterification. The fatty acid composition at the sn-2 position is simplified to saturated fatty acids (S) and unsaturated fatty acids (U). The evaluation model of the invention can be used to form a key technology for processing and controlling the functional structure lipid of the food and the special lipid of the food.
Description
Technical Field
The invention belongs to the field of food, and particularly relates to a method for measuring the degree of transesterification.
Background
The ester exchange is an important technical means for modifying edible oil, fatty acid in triglyceride molecules can be rearranged through the ester exchange, so that the physical property and the nutritional function of the oil can be changed, and the application range of the oil in the field of food can be expanded. The ester exchange catalyzed by the sn-1,3 specific immobilized lipase is more and more emphasized due to mild reaction conditions and strong specificity. We have previously found that when sn-1,3 specific lipases catalyse transesterification of triglycerides, the fatty acid composition at the sn-2 position is also altered due to acyl migration during the transesterification process.
Distribution of fatty acyl in oil on a glycerin skeleton is an important influence factor for oil handling characteristics and fat nutrition, more and more oil has higher and higher requirements for fatty acid arrangement on a triglyceride skeleton, for example, animal oil and fat comprise human milk fat, more saturated fatty acid is on sn-2 position, and the oil has special nutritional value, for example, the sn-2 position palmitic acid (sn-OPO, sn-OPL) structure of milk powder special oil and fat, and infants are not easy to form calcium soap during digestion, relieve constipation and are easier for digestion and absorption of fatty acid and calcium. Researches also suggest that the content of sn-2 saturated fatty acid in animal feed grease improves the feed energy value, thereby improving the survival rate of piglets; studies on edible baked fats also suggest that the crispness of a lard pastry is also related to its higher content of saturated fatty acids in the sn-2 position. Different from animal fat, the sn-2 site fatty acid of the traditional palm oil is mainly unsaturated fatty acid, and the other great advantage of the enzymatic modification compared with the chemical method is catalytic specificity, in order to improve the operating characteristics and nutritional characteristics of bulk vegetable oil represented by the palm oil, the lipid with better plasticity and consistency is combined by using acyl exchange, and the side reaction 'acyl migration' in the ester exchange process can be researched and utilized to improve the content of the sn-2 site palmitic acid, so that the modified palm oil has higher nutritional value, the natural deficiency of the vegetable oil is further compensated, a substitution scheme is provided for animal fat with insufficient sources, and data support and guidance can be provided for the enzymatic industrial modification production.
The vegetable oil represented by palm oil is subjected to sn-1, 3-site enzyme catalyzed transesterification modification, so that the crystallization and physicochemical properties of the vegetable oil as special oil can be improved not only by changing the distribution of sn-1, 3-site fatty acid, but also the natural deficiency of low content of sn-2-site saturated fat of the vegetable oil can be improved by utilizing the acyl migration, and the nutritional application potential of the vegetable oil is improved (taking sn-POO type triglyceride rich in palm oil as an example, the transesterification process is shown in figure 1). The acyl migration rule (namely the change rate of sn-2-site fatty acid) of sn-1,3 specific lipase in the ester exchange process is detected, the ester exchange result can be more easily evaluated, whether the enzyme catalysis reaction reaches balance or not can be known, the product performance can be better predicted by combining the physical and chemical properties of triglyceride and the nutritional properties of special triglyceride, a controllable directional ester exchange technology is established, and the purpose of diversified modification is realized.
The transesterification directly influences the melting point of the fat and its SFC properties at different temperatures. Therefore, the detection of the melting point and SFC of the transesterification product is an effective evaluation method in industry. However, the physical and chemical characteristics of the reaction product cannot be completely and fundamentally reflected in the progress of the transesterification reaction.
At present, the study of the degree of ester exchange reaction catalyzed by sn-1,3 site specific lipase by scholars at home and abroad mainly focuses on the change of the composition and the content of triglyceride. The transesterification rates under different reaction conditions were compared by roughly characterizing and quantifying triglycerides based on the total triglyceride carbon number or Equivalent carbon number (ECN, ECN ═ 2 times the total triglyceride carbon number) by gas chromatography or high performance liquid chromatography, and comparing the content changes before and after transesterification of certain characteristic triglycerides. However, the fatty acid composition of natural oils and fats is complicated, and thus the combination of triglycerides is diversified, and most of triglyceride isomers except individual triglycerides cannot be separated efficiently by gas or liquid chromatography, and positional isomers of triglycerides remain a difficulty in oil and fat analysis. Therefore, in the case of the sn-1, 3-position specific lipase-catalyzed transesterification, the actual degree of acyl group exchange on the glycerol backbone cannot be comprehensively reflected by simple analysis of triglycerides with undistinguished positional isomerism.
Disclosure of Invention
In order to solve the disadvantages and shortcomings of the prior art, the present invention aims to provide a method for measuring the degree of transesterification, which uses the degree of acyl migration (the degree of change in sn-2 fatty acid) to accurately determine the degree of transesterification.
The purpose of the invention is realized by the following technical scheme:
a method for determining the degree of transesterification, comprising the steps of:
after the transesterification reaction is completed, centrifuging and layering the reaction liquid, carrying out sn-2 fatty acid composition analysis on a grease sample before and after the transesterification reaction (namely an initial substrate and an oil sample after the centrifugation and layering), simplifying the fatty acid composition at the sn-2 position into saturated fatty acid and unsaturated fatty acid in the analysis, then calculating acyl mobility (namely the change rate of the fatty acid at the sn-2 position) according to the change degree of the molar mass proportion content of the saturated fatty acid and the unsaturated fatty acid at the sn-2 position, thereby judging the transesterification reaction degree, wherein S is used as the saturated fatty acid and U is used as the unsaturated fatty acid in a calculation formula, and the calculation formula is as follows:
wherein, U2And S2Is the mole percentage proportion of initial U and S at the sn-2 position of an initial substrate; u shape2tAnd S2tIs the mol percentage ratio of the U at the sn-2 position to the S after reacting for a certain time t; u shape0And S0Is the molar percentage of U and S in the total fatty acids of the initial substrate.
In the method for measuring the degree of transesterification as described above, the sn-2 fatty acid composition analysis is measured by referring to one of the following methods: AOCS official method: Ch 3-91,1997, GB/T24894-2010, ISO 6800: 1997.
The method of measuring the degree of transesterification as described above is a method of determining the degree of transesterification by using a change in sn-2 fatty acid composition, which is caused by the transesterification reaction by the action of 1, 3-specific lipase, and a change in the sn-2 fatty acid composition ratio indicates that there is acyl group migration during the catalytic transesterification. The fatty acid composition at the sn-2 position is simplified to saturated fatty acids (S) and unsaturated fatty acids (U). The change rate of the sn-2 position fatty acid is calculated from the degree of change in the content of the sn-2 position fatty acid species in proportion to the molar amounts of S and U.
The method for measuring the degree of transesterification as described above, wherein the transesterification is an enzymatic transesterification or a chemical transesterification.
The steps of the enzymatic transesterification reaction are as follows: putting palm oil into a reaction container, adding a certain amount of immobilized lipase lipozyme TL IM after the reaction temperature is reached, controlling the reaction temperature, uniformly stirring, and carrying out ester exchange reaction under the vacuum condition;
the transesterification reaction is carried out under vacuum conditions with an absolute pressure of 5000 Pa;
the addition amount of the enzyme is 0-11% of the palm oil, preferably 3%, 5%, 7%, 9% or 11%, and most preferably 7%;
the transesterification reaction temperature is 60-90 ℃, preferably 60 ℃, 70 ℃, 80 ℃ or 90 ℃;
the ester exchange reaction time is 0-8 h;
the ester exchange reaction is carried out under the stirring condition, and the stirring rotating speed is 400 r/min.
Compared with the prior art, the invention has the following advantages and beneficial effects:
(1) the sn-1,3 specific lipase catalyzes an ester exchange process, and an acyl mobility evaluation model is established by analyzing the species and the content growth and decay change of sn-2 site fatty acid, so that the acyl migration rule of the palm oil ester exchange process is clarified.
(2) The evaluation model of the invention can be used to form key technology for processing and controlling the lipid with the food functional structure and the special oil for food (for example, the reaction equipment is selected from the traditional stirred tank reactor, the acyl migration is easy to occur due to higher enzyme adding amount and longer reaction time, but the acyl migration (sn-2 saturated fat content) can be controlled by controlling the reaction condition), and the fixed bed reactor can reduce the acyl migration generation due to shorter catalytic reaction time although the enzyme adding amount is excessive), thereby laying a solid theoretical foundation for finally obtaining the controllable oriented transesterification technology.
Drawings
FIG. 1 is a diagram of sn-1,3 specific lipase catalyzed transesterification (attached acyl group transfer).
FIG. 2 is a model of calculation of migration intensity of acyl group at sn-2 position (calculated from the ratio of U and S changes in fatty acid at sn-2 position).
FIG. 3 is a graph showing the effect of reaction temperature and reaction time on acyl mobility during transesterification.
FIG. 4 shows the melting characteristics of the starting material and the product, A being the POL starting material and B, C being the product under different reaction conditions.
FIG. 5 shows the crystallization characteristics of the starting material and the product, where A is POL starting material and B, C are the products under different reaction conditions.
FIG. 6 shows SFC curves for feedstock versus product, where A is POL feedstock and B, C is the product under different reaction conditions.
FIG. 7 is a PLM (times.100, 200, 500) of the starting material and the product, A is POL starting material, B, C is the product under different reaction conditions, wherein 7% of the reference indicates the amount of enzyme added.
FIG. 8 shows XRD spectra of raw material and product, where A is POL raw material, B, C is products under different reaction conditions, and the enzyme addition amounts of B and C are both 7%.
Detailed Description
The present invention will be described in further detail with reference to examples and drawings, but the embodiments of the present invention are not limited thereto. The raw materials related to the invention can be directly purchased from the market. For process parameters not specifically noted, reference may be made to conventional techniques.
The invention provides a method for measuring the degree of ester exchange reaction, which comprises the following steps:
after the transesterification reaction is completed, centrifuging and layering the reaction liquid, carrying out sn-2 fatty acid composition analysis on an oil sample, simplifying the fatty acid composition of the sn-2 position into saturated fatty acid and unsaturated fatty acid in the analysis, then calculating the acyl transfer rate according to the change degree of the molar weight proportion content of the saturated fatty acid and the unsaturated fatty acid of the sn-2 position, thereby judging the transesterification reaction degree, wherein S refers to the saturated fatty acid and U refers to the unsaturated fatty acid in a calculation formula, and the calculation formula is as follows:
wherein, U2And S2Is the mole percentage proportion of initial U and S at the sn-2 position of an initial substrate; u shape2tAnd S2tIs the mol percentage ratio of the U at the sn-2 position to the S after reacting for a certain time t; u shape0And S0Is the molar percentage of U and S in the total fatty acids of the initial substrate.
In the method for measuring the degree of transesterification as described above, the sn-2 fatty acid composition analysis is measured by referring to one of the following methods: AOCS official method: Ch 3-91,1997, GB/T24894-2010, ISO 6800: 1997.
The method for measuring the degree of transesterification as described above, wherein the analysis of the glyceride composition is performed by HPLC (high performance liquid chromatography) and the type and content of the glyceride are calculated.
The method of measuring the degree of transesterification as described above is a method of determining the degree of transesterification by using a change in sn-2 fatty acid composition, which is caused by the transesterification reaction by the action of 1, 3-specific lipase, and a change in the sn-2 fatty acid composition ratio indicates that there is acyl group migration during the catalytic transesterification. The fatty acid composition at the sn-2 position is simplified to saturated fatty acids (S) and unsaturated fatty acids (U). The degree of acyl transfer was calculated from the degree of change in the content of the sn-2 position fatty acid species in proportion to the molar amounts of S and U.
The method for measuring the degree of transesterification as described above, wherein the transesterification is an enzymatic transesterification or a chemical transesterification.
The steps of the enzymatic transesterification reaction are as follows: putting palm oil into a reaction container, adding a certain amount of immobilized lipase lipozyme TL IM after the reaction temperature is reached, controlling the reaction temperature, uniformly stirring, and carrying out ester exchange reaction under the vacuum condition;
the transesterification reaction is carried out under vacuum conditions with an absolute pressure of 5000 Pa;
the addition amount of the enzyme is 0-11% of the palm oil, preferably 3%, 5%, 7%, 9% or 11%, and most preferably 7%;
the transesterification reaction temperature is 60-90 ℃, preferably 60 ℃, 70 ℃, 80 ℃ or 90 ℃;
the ester exchange reaction time is 0-8 h;
the ester exchange reaction is carried out under the stirring condition, and the stirring rotating speed is 400 r/min.
The invention establishes a sn-2 acyl migration intensity calculation model, as shown in figure 2. Wherein, when the sn-1,3 specific lipase catalyses transesterification with acyl migration, the ratio of S to U at the sn-2 position will change towards the final ratio of S to U in the feedstock. Therefore, the degree of acyl migration can be quantified by measuring the molar weight ratio of S and U in the palm oil original fatty acid, the molar weight ratio of the initial S and U at the sn-2 position of the palm oil and combining the change of the molar weight ratio of S and U at the sn-2 position of the product in the actual reaction process, and the calculation formula is as follows:
wherein, U2And S2Is the mole percentage proportion of initial U and S at the sn-2 position of an initial substrate; u shape2tAnd S2tIs the mol percentage ratio of the U at the sn-2 position to the S after reacting for a certain time t; u shape0And S0Is the molar percentage of U and S in the total fatty acids of the initial substrate. DtThe distance from the point sn-2t to the point sn-o after reacting for a certain time t; d0The distance from point sn-2 to point sn-o is the start of the reaction.
When D is presentt＝D0When the lipase is used, the catalytic specificity of the sn-1,3 site specific lipase is strongest, and the lipase does not generateAcyl migration, transesterification occurs only at the sn-1 position and the sn-3 position; when D istAt 0, the sn-1,3 position specific lipase is catalyzed with the weakest specificity, the acyl group migration is the strongest, and the reaction achieves almost complete random transesterification at sn-1, sn-2, sn-3 position. Therefore, the degree of acyl migration can be quantified by taking the molar percentage ratio of U and S in the total fatty acids of the initial substrate (also in a completely random interesterification state) as the equilibrium point of acyl migration, in combination with the change in molar percentage ratio of U and S at the sn-2 position of the interesterified sample during the actual reaction.
Aiming at the technical scheme, the invention also takes an enzyme method ester exchange reaction as an example, and researches the following experimental examples:
1. single factor test
1.1 Effect of enzyme addition on the degree of transesterification
The reaction was carried out at a temperature of 80 ℃ for 2 hours, and the influence of the amounts of the enzymes on the degree of transesterification was examined, and the results are shown in tables 1.1 and 1.2. As is clear from Table 1.2, the acyl group mobility increased as the amount of enzyme added increased from 0 wt% to 11 wt%. After the enzyme addition increased to 7 wt%, the acyl mobility still increased slowly. The maximum amount of enzyme added reached 63.41% at 11 wt%. This occurs because as the amount of enzyme added increases, the time required for the reaction to reach equilibrium is correspondingly longer and the acyl group migrates more. Furthermore, studies have shown that an excess of enzyme leads to an increased degree of acyl migration of the intermediate product. Since the degree of acyl group migration was little changed at the enzyme addition amounts of 7%, 9% and 11%, and the acyl group migration was observed to the maximum extent in view of cost saving, the enzyme addition amount of 7 wt% was selected in the subsequent experiments.
TABLE 1.1 fatty acid composition of palm oil feedstock
TABLE 1.2 Effect of different enzyme additions on acyl mobility during transesterification
1.2 Effect of reaction temperature and reaction time on the extent of transesterification
The results of examining the change in the degree of transesterification reaction with the lapse of the reaction time at the reaction temperature of 60 ℃, 70 ℃, 80 ℃ and 90 ℃ under the condition that the enzyme addition amount is 7% are shown in FIG. 3. As is clear from FIG. 3, the acyl group mobility gradually increased with the increase in the reaction temperature. This is because the lower temperature during the catalytic transesterification reaction of the enzyme increases the viscosity of the system, prevents the heat and mass transfer of the substrate, and reduces the reaction efficiency while reducing the acyl group migration. In addition, the enzyme is used as a biological preparation with an optimal temperature, and the higher temperature can change the conformation of the enzyme to a certain extent, so that the specificity of the enzyme is changed, and the acyl migration condition is aggravated. And the time required for the acyl group to reach equilibrium is also reduced as the temperature is increased. The acyl mobility was 92.23% for 8h at 60 ℃ and up to 99.07% for 4h at 90 ℃. It can be seen that the two thermodynamic parameters, temperature and time, affect the equilibrium of acyl migration. This is in line with the general rule of the Arrhenius equation, and less time is required to reach equilibrium when high temperatures are used. Therefore, it is an advantageous means to control the acyl group migration by controlling the reaction temperature and time.
2. Analysis of physicochemical Properties
2.1 fatty acid and glyceride composition
And (3) analyzing the fatty acid component, referring to a method for determining the sn-2 site fatty acid component of the TAG molecule of the animal and vegetable oil and fat GB/T24894-2010/ISO 6800: 1997. Neutralizing free fatty acid in a sample, purifying by column chromatography, hydrolyzing TAG into 2-MAG by using enzyme, separating by thin layer chromatography, and determining the content of the fatty acid component by using gas chromatography. The fatty acid methyl esterification is carried out according to national standard GB/T17376-2008, and a sample is processed by BF3The methanol is subjected to rapid methyl esterification and then subjected to gas phase analysis, wherein the gas chromatograph is GC-7820A of Agilent, provided with a flame ionization detector, and the chromatographic column is CP-sil88 capillary column (100m × 0.25mm × 0.2mm) using N2As a carrier gas, columnThe pressure is 30.8psi, the sample injection amount is 0.5 mu L, the split ratio is 40:1, the initial temperature of the oven is kept at 120 ℃ for 3min, and then the temperature is raised to 175 ℃ at 8 ℃/min and kept for 18 min. The detector and injection port temperatures were both 260 ℃. This method is referred to Zhang et al (Zhang Z, Wang Y, Ma X, et al, characterization and oxidation stability of monoacylglycerols from partially hydrogenated corn oil [ J]Food Chem,2015,173:70-79.) gas chromatography conditions to analyze the fatty acid composition of the starting material. (same as table 1.1 above)
Glyceride composition analysis was performed with reference to the liquid chromatography conditions of hong ying (hong ying. triglyceride composition characteristics of edible fat and oil and HPLC determination method research [ D ]. south of the river university, 2015.). The analysis was performed using a Diamondsil Plus C18 column (250.0 mm. times.4.6 mm. times.5.0 μm; Dick. in China). The amount of sample was 1. mu.L. The mobile phases used were as follows: solvent A-isopropanol (0.1% formic acid), solvent B-acetonitrile methanol (15:1, v/v, 0.1% formic acid). The mobile phase gradient was as follows: solvent B decreased from 70% to 60% within the first 30min, then decreased to 55% within 40min and held for 10min, then increased to 60% within 2min, then increased to 65% within 2min, then increased to 70% within 2min and held for 14 min. The flow rate of the mobile phase was 0.8mL/min and the column temperature was set at 30 ℃.
TABLE 2 analysis of the glyceride composition by HPLC
The glyceride composition before and after the transesterification reaction is shown in the data in Table 2. Wherein the sample A is a palm oil raw material, and the measured data is the glyceride composition before the reaction of the palm oil; the sample B is composed of glyceride which is added with 7 percent of enzyme and is measured when the reaction is carried out for 2 hours at 70 ℃; sample C was a glyceride composition measured at 80 ℃ for 3 hours with 7% enzyme added. As can be seen from Table 2, the glyceride composition varied before and after the transesterification, and as the transesterification proceeded, the S/S and U/U/U contents increased, while the S/U/S content decreased. In addition, the glyceride compositions of samples B and C changed very little, indicating that the glyceride compositions did not change significantly with little change in reaction time and temperature.
2.2 determination of the thermodynamic Properties
The melting and crystallization properties of the samples were analyzed by thermogravimetric analysis (DSC-1, mettler-toledo, switzerland). Accurately weighing 8.0-12.0 mg of the sample, sealing the sample in an aluminum crucible by covering, and taking an empty crucible as a reference. The temperature control program is as follows: the initial temperature is 25 ℃, the temperature is increased to 80 ℃ at 40 ℃/min and is kept for 10 min; cooling to-80 deg.C at a rate of 10 deg.C/min and maintaining for 10min, heating to 80 deg.C at a rate of 10 deg.C/min, and purifying with high purity N2The flow rate was 45 mL/min. And obtaining the melting and crystallization curves of the sample through a dynamic temperature rising process. Fig. 4 and 5 are melt crystallization characteristics (fig. 4 is a melt curve, and fig. 5 is a crystallization curve) of the reaction raw material (a) and the reaction product (B, C), respectively. As can be seen, both the melting and crystallization temperatures increased after transesterification.
2.3 Solid Fat Content (SFC)
The solid fat content was measured by means of NM-2 type nuclear magnetic resonance analyzer (New Youmei, Shanghai, Ltd.). Dry thermostats (model: DC10, hang state ruichen instruments ltd) are used to rapidly cool down and provide accurate temperature control. Each temperature was corrected using triolein as a standard. Weighing about 1.5g of oil sample in a nuclear magnetic resonance test tube, maintaining the temperature at 60 ℃ for 30min to melt the sample and eliminate crystal memory, then maintaining the temperature at 0 ℃ for 30min, and finally maintaining the temperature at constant temperature from low temperature to high temperature (10, 20, 30, 40 and 50 ℃) for 30 min. All samples were assayed in duplicate. The SFC values were measured in turn and SFC curves were plotted. As can be seen in FIG. 6, the SFC curves changed significantly before and after the transesterification. The overall increase of the SFC value after ester exchange is particularly obvious in the range of 10-40 ℃. This is related to the transesterification reaction changing the glyceride composition of the system, and the change trend is consistent with the change of the S/S/S concentration in TAG.
2.4 Crystal micro-morphology
The crystal form of the oil was observed by a polarization microscope (SMART-POL polarization microscope, Chongqing Otto optical instruments Co., Ltd.). The oil sample is firstly melted to eliminate the crystal memory, then a drop of glass slide is dropped and then preheated, and then the glass slide is pressed well to generate a proper thickness and avoid the generation of bubbles. Then left to stand for 24 hours and observed at 25 ℃. It can be seen from FIG. 7 that POL (A) is hardly detectable in the form of a crystal at ordinary temperature because it is liquid or semi-solid at ordinary temperature. And the crystal form of the sample after the ester exchange reaction is obvious by observing the three groups of samples, which also indicates that the glyceride composition is changed after the reaction. In addition, the comparison shows that the crystal forms change under different reaction conditions, and the crystal forms are more closely and uniformly arranged under the condition C.
2.5 Crystal forms
Crystal polymorphisms were observed using an MSAL-XD-II X-ray diffractometer (Bruker AXS, karlsrue, germany) equipped with Cu-ka radiation (λ ═ 1.54) and Ni filters. The sample was scanned from 5 to 40 deg. at 36kV and 20mA at a speed of 2 deg./min with divergence, scattering and receiving slits of 1.0, 1.0 and 0.3mm, respectively. The results are shown in FIG. 8, where three groups of samples were 4.6 and
and strong diffraction peaks appear nearby, namely, the polymorphism of the coexistence of beta and beta' is presented.
In the experimental example, the influence rule of the reaction conditions on the transesterification degree of the palm oil catalyzed by the Lipozyme TL IM enzyme method is obtained by researching the change of the different enzyme addition amounts, the reaction time and the temperature on the components of glyceride and sn-2 fatty acid after the enzymatic transesterification reaction; and the physical and chemical properties of the product are analyzed by a liquid chromatograph (HPLC), a Gas Chromatograph (GC), a Differential Scanning Calorimeter (DSC), a pulse nuclear magnetic resonance instrument (p-NMR), an X-diffractometer (XRD), a Polarized Light Microscope (PLM) and the like, so that a corresponding theoretical basis is provided for the application of the product in the field of food.
The experimental examples study the influence rule of single factors of enzyme addition amount, reaction time and temperature on the acyl migration degree, and characterize the acyl migration rate by the model established by the invention. The research of the experimental examples shows that the calculation model of the invention is established on a theoretical basis and has a factual basis. This can be used in practical experiments as a means of characterizing the degree of acyl migration.
The palm oil in the following examples is 24-degree fractionated palm olein supplied by jahai camari, and the immobilized lipase lipozyme tl IM used is produced by danish novicel.
Example 1
50g of palm oil is taken in a 250mL flat-bottomed flask, heated to 60 ℃, added with 7 wt% lipozyme TL IM, the reaction temperature is controlled to be kept at 60 ℃, and the mixture is uniformly stirred on a magnetic stirrer at the rotating speed of 400r/min, and the reaction is carried out for 8h under the condition of water ring pump vacuum pumping (the absolute pressure is 5000 Pa). And after the reaction is finished, centrifuging and layering the reaction solution immediately to finish the ester exchange.
Sn-2 fatty acid composition analysis was performed under the gas chromatography conditions described in the experimental examples (physicochemical characteristic analysis), and the total fatty acid composition and content of sn-2 fatty acid, sn-2 fatty acid of POL raw material (palm oil) at normal temperature, and POL raw material at normal temperature measured by GC under the reaction conditions in example 1 are shown in table 3 below:
TABLE 3
1. The sn-2 acyl mobility is calculated by the method of Bin Pen (Trace water activity co-produced acyl migration of 1,3-oleic-2-medium chain-rich triacylglycerol by promoting acyl migration in the lipase RM IM catalyzed interaction [ J ]. Elsevier Ltd,2020,313.). The calculation formula is as follows:
(wherein A is0、A1Respectively representing the content of sn-2 certain fatty acid before and after reaction)
The acyl mobility is calculated as follows:
taking C16:0 as an example,
taking C18:0 as an example,
taking the C18:1 as an example,
taking the C18:2 as an example,
2. the experimental data are substituted into the sn-2 acyl migration intensity calculation model in the invention, and the acyl migration rate in the enzymatic transesterification process is 92.23%. The acyl mobility is calculated as follows:
wherein C16:0, C18:0 are saturated fatty acids (SFA, abbreviated as S), C16:0 molar mass is 256, C18:0 molar mass is 284; c18:1 and C18:2 are unsaturated fatty acids (UFA, abbreviated as U), the molar mass of C18:1 is 282, and the molar mass of C18:2 is 280.
The above results are substituted into a formula to obtain,
example 2
50g of palm oil was taken in a 250mL flat-bottomed flask, heated to 70 ℃ and then 7 wt% lipozyme TL IM was added, the reaction temperature was controlled to be 70 ℃ and stirred uniformly on a magnetic stirrer at a rotation speed of 400r/min, and the reaction was carried out for 2h under the condition of water ring pump vacuum (absolute pressure: 5000 Pa). And after the reaction is finished, centrifuging and layering the reaction solution immediately to finish the ester exchange.
Sn-2 fatty acid composition analysis was performed under the gas chromatography conditions described in the experimental examples (physicochemical characteristic analysis), and GC measurements showed that the total fatty acid composition and content of sn-2 fatty acid, sn-2 fatty acid of POL raw material at normal temperature, and POL raw material at normal temperature in the reaction conditions in example 2 are shown in table 4 below:
TABLE 4
1. The sn-2 acyl mobility is calculated by the method of Bin Pen (Trace water activity co-produced acyl migration of 1,3-oleic-2-medium chain-rich triacylglycerol by promoting acyl migration in the lipase RM IM catalyzed interaction [ J ]. Elsevier Ltd,2020,313.). The calculation formula is as follows:
(wherein A is0、A1Respectively representing the content of sn-2 certain fatty acid before and after reaction)
The acyl mobility is calculated as follows:
taking C16:0 as an example,
taking C18:0 as an example,
taking the C18:1 as an example,
taking the C18:2 as an example,
2. the experimental data are substituted into the sn-2 acyl migration intensity calculation model in the invention, and the acyl migration rate in the enzymatic transesterification process is 54.43%. The acyl mobility is calculated as follows:
wherein C16:0 and C18:0 are Saturated Fatty Acids (SFA), the molar mass of C16:0 is 256, and the molar mass of C18:0 is 284; c18:1 and C18:2 are Unsaturated Fatty Acids (UFA), the molar mass of C18:1 is 282, and the molar mass of C18:2 is 280.
The above results are substituted into a formula to obtain,
example 3
50g of palm oil is taken in a 250mL flat-bottomed flask, heated to 80 ℃, added with 7 wt% lipozyme TL IM, the reaction temperature is controlled to be 80 ℃, and the mixture is uniformly stirred on a magnetic stirrer at the rotating speed of 400r/min, and the reaction is carried out for 3h under the condition of water ring pump vacuum pumping (the absolute pressure is 5000 Pa). And after the reaction is finished, centrifuging and layering the reaction solution immediately to finish the ester exchange.
The sn-2 fatty acid composition analysis was performed under the gas chromatography conditions described in the experimental examples (physicochemical property analysis), and the total fatty acid composition and content of the sn-2 fatty acid, the sn-2 fatty acid of the POL raw material at normal temperature, and the POL raw material at normal temperature measured by GC under the reaction conditions in example 3 are shown in table 5 below
TABLE 5
1. The sn-2 acyl mobility is calculated by the method of Bin Pen (Trace water activity co-produced acyl migration of 1,3-oleic-2-medium chain-rich triacylglycerol by promoting acyl migration in the lipase RM IM catalyzed interaction [ J ]. Elsevier Ltd,2020,313.). The calculation formula is as follows:
(wherein A is0、A1Respectively representing the content of sn-2 certain fatty acid before and after reaction)
The acyl mobility is calculated as follows:
taking C16:0 as an example,
taking C18:0 as an example,
taking the C18:1 as an example,
taking the C18:2 as an example,
2. the experimental data are substituted into the sn-2 acyl migration intensity calculation model in the invention, and the acyl migration rate of the embodiment is 76.03%. The acyl mobility is calculated as follows:
wherein C16:0 and C18:0 are Saturated Fatty Acids (SFA), the molar mass of C16:0 is 256, and the molar mass of C18:0 is 284; c18:1 and C18:2 are Unsaturated Fatty Acids (UFA), the molar mass of C18:1 is 282, and the molar mass of C18:2 is 280.
The above results are substituted into a formula to obtain,
in summary, comparing the calculation methods disclosed in the prior art and the calculation models of the present invention in examples 1, 2, and 3, it is found that the methods disclosed in the prior art for calculating acyl mobility have the following disadvantages: (1) the acyl mobility was calculated by considering only a specific fatty acid (C18:0) at the sn-2 position as the acyl mobility. However, when considering the variation of other fatty acids (C16:0, C18:1, C18:2) at the sn-2 position, the acyl mobilities obtained under the same conditions are not equal; (2) when the acyl group mobility is calculated by this method, the value is more than 100%, which is not ideal. In the acyl mobility calculation method adopted by the invention, the two-position fatty acid is divided into SFA and UFA for comprehensive consideration, and the design of a calculation model is reasonable, so that the unrealistic situation that the mobility exceeds 100% is avoided. In summary, the method of the present invention completely avoids the above-mentioned disadvantages.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.
Claims (7)
1. A method for measuring the degree of transesterification, comprising the steps of:
after the transesterification reaction is completed, centrifuging and layering reaction liquid, carrying out sn-2 fatty acid composition analysis on a grease sample before and after the transesterification reaction, simplifying the fatty acid composition of the sn-2 position into saturated fatty acid and unsaturated fatty acid in the analysis, and then calculating acyl mobility according to the change degree of the molar mass proportional content of the saturated fatty acid and the unsaturated fatty acid of the sn-2 position so as to judge the transesterification reaction degree, wherein S refers to the saturated fatty acid and U refers to the unsaturated fatty acid in a calculation formula, and the calculation formula is as follows:
wherein, U2And S2Is the mole percentage proportion of initial U and S at the sn-2 position of an initial substrate; u shape2tAnd S2tIs the mol percentage ratio of the U at the sn-2 position to the S after reacting for a certain time t; u shape0And S0Is the molar percentage of U and S in the total fatty acids of the initial substrate.
2. The method according to claim 1, wherein the sn-2 fatty acid composition analysis is determined by reference to one of the following methods: AOCS official method: Ch 3-91,1997, GB/T24894-2010, ISO 6800: 1997.
3. The method according to claim 1, wherein the transesterification reaction is an enzymatic transesterification reaction or a chemical transesterification reaction.
4. The method of claim 3, wherein the step of the enzymatic transesterification reaction is as follows: placing the grease into a reaction container, adding a certain amount of immobilized lipase lipozyme TL IM after the reaction temperature is reached, controlling the reaction temperature, uniformly stirring, and carrying out ester exchange reaction under the vacuum condition.
5. The method for determining the degree of transesterification according to claim 4, wherein the immobilized lipase lipozyme TL IM is added in an amount of 0-11% by mass of the fat and oil, and the temperature of the enzymatic transesterification is 60-90 ℃; the enzymatic transesterification reaction time is 0-8 h.
6. The method of claim 4, wherein the immobilized lipase lipozyme TLIM is added in an amount of 3%, 5%, 7%, 9% or 11% by mass of the fat or oil, and the enzymatic transesterification reaction temperature is 60 ℃, 70 ℃, 80 ℃ or 90 ℃.
7. The method of claim 4, wherein the enzymatic transesterification reaction is carried out under a vacuum condition at an absolute pressure of 5000 Pa;
the enzymatic transesterification is carried out under the condition of stirring, and the rotating speed of the stirring is 400 r/min.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001040388A (en) * | 1999-05-26 | 2001-02-13 | Asahi Denka Kogyo Kk | Preparation of composition containing vegetable sterol fatty acid ester |
| CN1300322A (en) * | 1998-05-11 | 2001-06-20 | 纳幕尔杜邦公司 | Novel gene combinations that alter the quality and functionality of soybean oil |
| CN102757988A (en) * | 2012-07-25 | 2012-10-31 | 浙江大学 | Preparation method of 1,3-dioleoyl-2-palmitoyl triglyceride |
| CN102776077A (en) * | 2012-08-07 | 2012-11-14 | 浙江大学 | Preparation method of grease with humanized structure |
| CN105936922A (en) * | 2016-06-02 | 2016-09-14 | 北京化工大学 | Method for enzymatic transesterfication preparation of cocoa butter equiralent by using 33-DEG C palm oil |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130053442A1 (en) * | 2010-02-25 | 2013-02-28 | Brandeis University | Balanced myristate- and laurate-containing edible oil |
-
2020
- 2020-06-11 CN CN202010528437.8A patent/CN111650338B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1300322A (en) * | 1998-05-11 | 2001-06-20 | 纳幕尔杜邦公司 | Novel gene combinations that alter the quality and functionality of soybean oil |
| JP2001040388A (en) * | 1999-05-26 | 2001-02-13 | Asahi Denka Kogyo Kk | Preparation of composition containing vegetable sterol fatty acid ester |
| CN102757988A (en) * | 2012-07-25 | 2012-10-31 | 浙江大学 | Preparation method of 1,3-dioleoyl-2-palmitoyl triglyceride |
| CN102776077A (en) * | 2012-08-07 | 2012-11-14 | 浙江大学 | Preparation method of grease with humanized structure |
| CN105936922A (en) * | 2016-06-02 | 2016-09-14 | 北京化工大学 | Method for enzymatic transesterfication preparation of cocoa butter equiralent by using 33-DEG C palm oil |
Non-Patent Citations (4)
| Title |
|---|
| Evaluation of enzymatic interesterification in structured triacylglycerols preparation: a concise review and prospect;Zhen Zhang et al.;《Critical Reviews in Food Science and Nutrition》;20200722;第1-15页 * |
| Rate of acyl migration in lysophosphatidylcholine (LPC) is dependent upon the nature of the acyl group. Greater stability of sn-2 docosahexaenoyl LPC compared to the more saturated LPC species;Dhavamani Sugasini et al.;《PLOS ONE》;20171108;第1-13页 * |
| Trace water activity could improve the formation of 1,3-oleic-2-medium chain-rich triacylglycerols by promoting acyl migration in the lipase RM IM catalyzed interesterification;Bin Peng et al.;《Food Chemistry》;20191226;第1-9页 * |
| 猪油化学随机酯交换催化剂的研究;张谦益等;《粮油食品科技》;20101031(第05期);第26-30页 * |
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