CN112841313A

CN112841313A - Preparation method of oil rich in OPL and OPO and product thereof

Info

Publication number: CN112841313A
Application number: CN202110067687.0A
Authority: CN
Inventors: 郑明明; 黄凤洪; 张羽飞; 王晶
Original assignee: Oil Crops Research Institute of Chinese Academy of Agriculture Sciences
Current assignee: Oil Crops Research Institute of Chinese Academy of Agriculture Sciences
Priority date: 2021-01-19
Filing date: 2021-01-19
Publication date: 2021-05-28

Abstract

The invention discloses a preparation method of grease rich in OPL and OPO, which comprises the following steps: (1) preparation of OPO or LPL: mixing PPP and oleic acid/linoleic acid =1:3-1:5, adding lipase and solvent, stirring or carrying out continuous flow at a certain temperature for a certain time to carry out enzymatic transesterification, and purifying to remove fatty acid to obtain grease rich in OPO/LPL; (2) preparing oil rich in OPO and OPL: mixing the oil rich in OPO/LPL with linoleic acid/oleic acid according to a certain proportion, adding lipase and solvent, stirring or carrying out continuous flow at a certain temperature for enzymatic transesterification, and purifying to remove fatty acid to obtain the oil rich in OPO and OPL. The invention takes the cheap and easily obtained glycerol, palmitic acid, oleic acid and linoleic acid as raw materials, can obtain the grease rich in OPO and OPL by preparing the intermediate product OPO/LPL, and has the advantages of relatively simple components of the synthesized product, controllable content of the target product and the like.

Description

Preparation method of oil rich in OPL and OPO and product thereof

Technical Field

The invention relates to a preparation method of grease rich in OPL and OPO and a product thereof, belonging to the field of preparation of structural ester and food additives.

Background

1, 3-dioleoyl-2-palmitic acid triglyceride (OPO) is used as a nutrition enhancer mainly for infant formula food. For infants, breast milk is the most desirable food source for growth and development. However, infant formula is an ideal choice when breast feeding is not possible for some special reasons. Although the milk fat is about 3-5% of the milk components, the milk fat provides 50-60% of energy for infants, and is a main source of energy required by the growth of the infants. More than 98% of breast milk fat is triglyceride, 70% of palmitic acid in breast milk is located at sn-2 position of triglyceride, and glyceride of palmitic acid located at sn-2 position can be absorbed in form of monoglyceride. The palmitic acid of common vegetable oil is distributed on sn-1 and 3 positions of a glycerol skeleton, and can generate free palmitic acid after being hydrolyzed by human pancreatic esterase and be combined with calcium and magnesium ions in vivo to be discharged out of a body, so that the palmitic acid and the calcium are lost. However, the content of 1-oleic acid-2-palmitic acid-3-linoleic acid (OPL) in natural breast milk is found to be higher than that of OPO in areas such as Beijing, Hubei, Sichuan and the like. Therefore, the method for artificially synthesizing the OPL is provided, and has important significance for simulating human milk fat. According to the different diets of pregnant women or lactating mothers, the milk fat structure and composition of the lactating mothers are greatly different, but the lactating mothers are mainly rich in two structural esters, namely OPO and OPL, and the proportion of the two structural esters is also greatly different. At present, a large number of documents exist for preparing 1, 3-dioleoyl-2-palmitic acid triglyceride (OPO), but the preparation of breast milk fat substitutes rich in both OPO and 1-oleic-2-palmitic-3-linoleic acid triglyceride (OPL) structural esters is only reported, and the invention patent applications CN 109468349A and CN109566769A respectively disclose methods for preparing OPL and OPO/OPL-rich oil compositions, wherein high-purity tripalmitin is used as a raw material, the raw material cannot be directly obtained, and the raw material can be obtained only by multi-step preparation and purification; the method is generally adopted by a one-pot method, namely tripalmitin (PPP) is added with oleic acid, linoleic acid and other raw materials at the same time for reaction, so that a large number of byproducts with different structures, such as LPL (1, 3-dilinoleic acid-2-palmitic acid triglyceride), OOO, LLL, LOL, OLO, PPO, PPL and the like, are easily generated; the grease rich in two active structure esters of OPO and OPL can not be accurately prepared, the higher content of OPL and OPO grease is difficult to obtain, and the proportion of OPO/OPL can not be regulated and controlled.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a preparation method of high-purity OPO and OPL aiming at the defects of the technology, and the preparation method has the advantages of relatively simple product, controllable content of target substances and the like.

In order to solve the technical problems, the invention provides the following technical scheme:

a preparation method of OPO and OPL rich in comprises the following steps:

(1) preparation of PPP structural ester: glycerin and palmitic acid are subjected to esterification reaction under the catalysis of acid to obtain a high-purity PPP raw material (> 70%); or palm oil stearate is adopted for chemical random rearrangement to obtain PPP raw material;

(2) preparation of OPO or LPL: mixing PPP raw material and oleic acid according to the ratio of PPP to oleic acid being 1:3-1:8, adding lipase and solvent, stirring at a certain temperature for a certain time to carry out transesterification reaction, and purifying to remove fatty acid to obtain grease rich in OPO (the content of OPO is more than 60%);

or mixing the PPP raw material and the linoleic acid according to the ratio of the PPP to the linoleic acid being 1:3-1:8, adding lipase and a solvent, stirring at a certain temperature for a certain time to perform transesterification reaction, and purifying to remove the fatty acid to obtain the oil rich in LPL (the content of the LPL is more than 60%);

(3) preparation of structural ester rich in OPL: mixing the oil rich in OPO with linoleic acid according to a certain proportion, adding lipase and a solvent, stirring and reacting for a certain time at a certain temperature, and purifying to remove fatty acid to obtain the oil rich in OPO and OPL;

or mixing the oil rich in LPL with oleic acid according to a certain proportion, adding lipase and solvent, stirring and reacting for a certain time at a certain temperature, and purifying to remove fatty acid to obtain the oil rich in OPO and OPL.

According to the scheme, the oleic acid is from high oleic rapeseed oil, peanut oil, sunflower oil hydrolysate and the like; linoleic acid is derived from sunflower oil, hydrolysate of soybean oil, etc.

According to the scheme, the glycerol and the palmitic acid in the step (1) react, the catalyst is acid catalyst such as sulfuric acid, p-toluenesulfonic acid and the like, the reaction temperature is 90-110 ℃, and the reaction time is 1-2 hours.

According to the scheme, the content of fatty acid in the palmitic acid hard ester in the step (1) is more than 70%, the alkali catalyst is sodium ethoxide, sodium methoxide and the like, the reaction temperature is 60-80 ℃, and the reaction time is 1-2 hours.

According to the scheme, the addition amount of the lipase in the step (2) is 3-8% of the total mass of the substrate, the reaction temperature is 50-70 ℃, and the stirring speed is 100-300 r/m.

According to the scheme, the lipase sources in the steps (2) and (3) comprise one or more of candida antarctica, candida lipolytica, burkholderia cepacia, porcine pancreatic enzyme and the like.

According to the scheme, the adding amount of the lipase in the step (3) is 3-8% of the total mass.

According to the scheme, the adopted reaction method comprises stirring reaction or continuous flow reaction, the reaction temperature is 50-70 ℃, the stirring speed is 100-300rpm, and the reaction time is 3-10 h; wherein the flow rate of the continuous flow reaction is 10-100 mL/min. Wherein, the continuous flow reaction is to immobilize lipase, fill the immobilized lipase into a stainless steel column tube with the inner diameter of 10-40cm and a jacket, arrange a coil pipe in the column tube, adopt a circulating water bath to ensure the constant temperature in the column tube, flow the raw material liquid through the enzyme reactor at the flow rate of 10-150mL/min under the drive of a peristaltic pump or a gear pump, and the temperature of a reaction column is 50-65 ℃.

According to the scheme, the purification method in the step (2) is to remove the free fatty acid in the reaction system by molecular distillation, wherein the vacuum degree is less than 20Pa, the temperature is 180 ℃ and 240 ℃, and the film scraping speed is 200 ℃ and 400 rpm.

According to the scheme, the reaction system comprises nonaqueous systems such as n-hexane, isooctane, n-butane and the like; adding a buffer solution into the raw materials to form an emulsion reaction system; or using no solvent, namely using oleic acid or linoleic acid as solvent;

compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, by synthesizing an intermediate product OPO/LPL, the generation of other byproducts in the preparation of OPL by a one-pot method is avoided, the contents of target products OPL and OPO are improved, the obtained product mainly contains two main components of OPO and OPL in breast milk structural ester, the total content of OPO and OPL is between 30% and 60%, the content of PPP is less than 5%, and the mass ratio of OPO to OPL is within the range of 3:1-1: 3;

2. according to the invention, parameters such as the addition amount of oleic acid/linoleic acid, reaction time, temperature and the like are controlled, so that the proportion of OPO and OPL in the product can be simply and accurately controlled, and a reliable method is provided for the development of breast milk fat substitutes composed of different structural esters;

3. the invention mainly adopts enzyme method for preparation, and the reaction condition is mild; the method can adopt continuous flow enzyme reaction, has simple operation procedure, is easy for scale and automation, and can ensure the quality and the quality stability of products.

Drawings

FIG. 1 is a chromatogram of OPO and OPL in the oil and fat products prepared in examples 3 and 5, wherein a represents example 3 and b represents example 5.

Detailed Description

For a better understanding of the present invention, the following examples are given to further illustrate the present invention, but the present invention is not limited to the following examples.

Example 1

A preparation method of grease rich in OPO and OPL specifically comprises the following steps:

(1) preparation of PPP structural ester: adding catalyst p-toluenesulfonic acid (accounting for 0.5 percent of the total weight of reaction substrates) into a flask with the molar ratio of glycerol to palmitic acid being 1:5, stirring at the speed of 200rpm, at the reaction temperature of 90 ℃, reacting for 2 hours, continuously introducing nitrogen as protective gas during the reaction, and separating and purifying to obtain a high-purity PPP raw material after the reaction is finished;

through liquid phase detection, the PPP content in the reaction product is 85% (by mass percent);

(2) preparation of structural esters of OPO: mixing a PPP raw material and oleic acid according to the molar ratio of 1:3 of PPP to oleic acid, adding Candida antarctica lipase with the mass of 3% of that of a substrate and n-hexane with the mass of 10 times that of the substrate, carrying out transesterification reaction for 10 hours at 50 ℃ and at the stirring speed of 100rpm, and removing fatty acid and fatty acid ester through molecular distillation purification to obtain grease rich in OPO;

through liquid phase detection, the content of OPO in the reaction product obtained in the step is 51 percent;

(3) preparation of structural esters rich in OPO and OPL: mixing the obtained OPO and linoleic acid according to a molar ratio of 1:3, adding 3% of candida lipolytica lipase (the amount of the lipase is calculated by percentage of the substrate) and n-hexane (the amount of the solvent is generally 8-12 times of the mass of the substrate), carrying out transesterification reaction for 10h at 50 ℃, stirring at a speed of 100rpm, and removing fatty acid through molecular distillation to obtain the oil rich in OPO and OPL.

Through liquid phase detection, the content of OPO in the reaction product is 23%, the content of OPL is 22%, the content of PPP is 3%, and other main components are OOO, LLL, LPL and the like.

Example 2

(1) preparation of PPP structural ester: taking palm stearin with the palmitic acid content of more than 70 percent as a raw material, adding a chemical catalyst sodium methoxide, carrying out intramolecular rearrangement reaction, and after the reaction is finished, separating and purifying to obtain a triglyceride raw material rich in palmitic acid;

(2) preparation of OPO structural ester: mixing PPP raw material and oleic acid according to the molar ratio of 1:5 of PPP to oleic acid, adding 5% of Candida lipolytica lipase and isooctane, carrying out transesterification reaction for 8h at the temperature of 60 ℃ and the stirring speed of 200rpm, carrying out molecular distillation purification, and removing fatty acid to obtain grease rich in OPO; liquid phase detection shows that the content of OPO in the reaction product is 48%;

(3) preparation of structural esters rich in OPO and OPL: mixing the obtained OPO and linoleic acid according to a molar ratio of 1:5, adding 5% Burkholderia cepacia lipase and isooctane, performing transesterification reaction for 8h at 60 ℃, stirring at a speed of 200rpm, and removing fatty acid by molecular distillation to obtain oil rich in OPO and OPL. Through liquid phase detection, the content of OPO in the reaction product is 28 percent, and the content of OPL in the reaction product is 14 percent.

Example 3

(1) preparation of PPP structural ester: same as example 1

(2) Preparing OPO: mixing PPP raw material and oleic acid according to the molar ratio of 1:8 of PPP to oleic acid, adding 8 percent of Candida lipolytica lipase and buffer emulsion (pH 7.0, total mass of substrate is 2 percent), carrying out ester exchange reaction for 3h at 70 ℃, stirring at the speed of 300rpm, purifying by molecular distillation, and removing fatty acid to obtain grease rich in OPO; through liquid phase detection, the content of OPO in the reaction product is 65 percent;

(3) preparation of structural esters rich in OPO and OPL: mixing the OPO and linoleic acid according to the molar ratio of 1:8, adding 8% Burkholderia cepacia lipase and buffer emulsion (pH 7.0, total substrate mass 2%), performing ester exchange reaction at 70 deg.C and stirring rate of 300rpm for 3h, and removing fatty acid by molecular distillation to obtain oil rich in OPO and OPL. The content of OPO in the reaction product was 25% and the content of OPL was 28% by liquid phase detection (a in FIG. 1).

Example 4

(1) preparation of PPP structural ester: same as example 1

(2) Preparation of LPL structural ester: mixing PPP raw material and linoleic acid according to the molar ratio of 1:3 of PPP to linoleic acid, adding Candida lipolytica lipase, carrying out transesterification reaction for 10h at the temperature of 50 ℃ and the stirring speed of 100rpm under the condition of no solvent, carrying out molecular distillation and purification, and removing fatty acid to obtain oil rich in LPL; through liquid phase detection, the content of LPL in the reaction product is 62%;

(3) preparation of structural esters rich in OPL and OPO: mixing the obtained LPL and oleic acid at a molar ratio of 1:3, adding Burkholderia cepacia lipase, stirring at 50 deg.C and no solvent at 100rpm for 10 hr, and purifying by molecular distillation to remove fatty acid to obtain oil rich in OPL and OPO. Through liquid phase detection, the content of OPO in the reaction product is 22 percent, and the content of OPL in the reaction product is 30 percent.

Example 5

(1) preparation of PPP structural ester: same as example 1

(2) Preparation of LPL structural ester: mixing PPP raw material and linoleic acid according to the molar ratio of 1:5 of PPP to linoleic acid, adding candida lipase and buffer emulsion, carrying out transesterification reaction for 6h at the temperature of 60 ℃ and the stirring speed of 200rpm, purifying by molecular distillation, and removing fatty acid to obtain oil rich in LPL; through liquid phase detection, the content of LPL in the reaction product is 52%;

(3) preparation of structural esters rich in OPL and OPO: mixing the obtained LPL and oleic acid according to a molar ratio of 1:5, adding Burkholderia cepacia lipase and isooctane, carrying out transesterification reaction for 6h at 60 ℃, stirring at a speed of 200rpm, and carrying out molecular distillation purification to remove fatty acid to obtain the oil rich in OPL and OPO. The content of OPO in the reaction product was 12% and the content of OPL was 36% by liquid phase detection (b in FIG. 1).

Example 6

(1) preparation of PPP structural ester: same as example 1

(2) Preparation of LPL structural ester: mixing PPP raw material and linoleic acid according to the molar ratio of 1:8 of PPP to linoleic acid, adding Candida lipolytica lipase and buffer emulsion (pH 7.0, total mass of substrate is 5%), carrying out ester exchange reaction for 3h at 70 ℃, stirring at the speed of 300rpm, purifying by molecular distillation, and removing fatty acid to obtain grease rich in LPL; through liquid phase detection, the content of LPL in the reaction product is 62%;

(3) preparation of structural esters rich in OPL and OPO: mixing the LPL and oleic acid at a molar ratio of 1:8, adding Burkholderia cepacia lipase and a buffer emulsion (pH 7.0, substrate total mass 5%), performing transesterification reaction at 70 deg.C and stirring rate of 300rpm for 3h, and removing fatty acid by molecular distillation to obtain oil rich in OPL and OPO. Through liquid phase detection, the content of OPO in the reaction product is 12 percent, and the content of OPL in the reaction product is 36 percent.

Example 7

The main steps are the same as example 3, a continuous flow reaction is adopted to replace a stirring reaction, immobilized candida lipolytica lipase is filled into a stainless steel column with the inner diameter of 10cm, a jacket and a coil, the reaction temperature is 50 ℃, and the reaction flow rate is 10 mL/min.

Example 8

The main steps are the same as example 3, a continuous flow reaction is adopted to replace a stirring reaction, immobilized candida antarctica lipase is filled into a stainless steel column with the inner diameter of 40cm and a jacket and a coil, the reaction temperature is 60 ℃, and the reaction flow rate is 150 mL/min.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, many modifications and changes can be made without departing from the inventive concept of the present invention, and these modifications and changes are within the protection scope of the present invention.

Claims

1. A preparation method of grease rich in OPL and OPO is characterized by mainly comprising the following two steps:

firstly, oleic acid and PPP react under the catalysis of immobilized lipase, excessive fatty acid is removed through molecular distillation, and OPO with the purity of more than 60 percent is prepared;

and step two, mixing OPO and linoleic acid according to a certain proportion, carrying out reaction under the catalysis of immobilized enzyme, converting a part of OPO into OPL, and removing excessive fatty acid through molecular distillation to prepare the grease rich in both OPO and OPL.

2. A preparation method of grease rich in OPL and OPO is characterized by mainly comprising the following two steps:

firstly, reacting linoleic acid and PPP under the catalysis of immobilized lipase, and removing excessive fatty acid through molecular distillation to prepare LPL with the purity of more than 60%;

and step two, mixing LPL and oleic acid according to a certain proportion, reacting under the catalysis of immobilized enzyme, converting a part of LPL into OPL and OPO, and removing excessive fatty acid through molecular distillation to prepare grease rich in OPO and OPL simultaneously.

3. The method for preparing oil rich in OPL and OPO as claimed in claim 1, wherein in step two, the molar ratio of PPP to oleic acid is 1:3-1:8, the addition amount of lipase is 3% -8% of the total mass of PPP and oleic acid, and the reaction temperature is 50-70 ℃^oC, stirring speed is 100-300rpm, and reaction lasts for 3-10 h.

4. The method for preparing grease rich in OPL and OPO according to claim 2, characterized in that in the second step, the molar ratio of the PPP to the linoleic acid is 1:3-1:8, the addition amount of the lipase is 3% -8% of the total mass of the PPP and the linoleic acid, and the reaction temperature is 50-70 ℃^oC, stirring speed is 100-300rpm, and reaction lasts for 3-10 h.

5. The method for preparing oil rich in OPL and OPO according to claim 1 or 2, wherein the conditions of molecular distillation are as follows: the vacuum degree is less than 20Pa, the temperature is 160-220 ℃, the film scraping speed is 200-400rpm, and the free fatty acid in the reaction system is removed.

6. The method for preparing oil rich in OPL and OPO according to claim 1 or 2, wherein a non-aqueous reaction system, an emulsion reaction system or a solvent-free reaction system can be adopted in the first and second steps; wherein, the non-aqueous system can adopt one or more of n-hexane, isooctane or n-butane as a reaction solvent; the emulsion reaction system is formed by adding a buffer solution with 5-10% of the total mass of the substrate into the raw materials; the solvent-free reaction system adopts the oleic acid or linoleic acid as a solvent.

7. The method as claimed in claim 6, wherein the emulsion reaction system is a homogeneous emulsion reaction system formed by adding 2% -5% buffer solution into substrate and homogenizing at 5000-.

8. The method according to claim 1 or 2, wherein the reaction in the first and second steps is a continuous flow reaction, the lipase is immobilized and filled into a stainless steel column tube with an inner diameter of 10-40cm and a jacket, a coil is arranged in the column tube, a circulating water bath is used to ensure the temperature in the column tube is constant, the raw material liquid flows through the enzyme reactor at a flow rate of 10-150mL/min under the drive of a peristaltic pump or a gear pump, and the temperature of the reaction column is 50-65%^oC。

9. The method for preparing oil and fat rich in OPL and OPO according to claim 1 or 2, wherein the lipase source comprises one or more of Candida antarctica, Candida lipolytica, Burkholderia cepacia, and porcine pancreatic enzyme.

10. The oil rich in OPL and OPO prepared by the method of claim 1 or 2, wherein the total content of OPO and OPL in the oil is between 30% and 60%, the content of PPP is less than 5%, and the mass ratio of OPO to OPL is in the range of 3:1 to 1: 3.