阅读说明：本技术 一种通过非定位酶合成1,3-二油酸-2-棕榈酸甘油三酯组合物的方法 (Method for synthesizing 1, 3-dioleoyl-2-palmitic acid triglyceride composition by using non-localized enzyme ) 是由 翁志坚 叶长青 黄镇平 徐胜荣 于 2019-07-03 设计创作，主要内容包括：本发明公开了一种通过非定位酶合成1,3-二油酸-2-棕榈酸甘油三酯组合物的方法,包括：将碘值为8～35的棕榈油硬酯精进行随机酯交换后,与油酸或其非甘油酯进行非特异性酶促酯交换,所述酶促反应体系的水含量小于0.1％；分离去除棕榈酸或棕榈酸非甘油酯的酯,得到含1,3-二油酸-2-棕榈酸甘油三酯的组合物。以本发明提供的方法制备的含有OPO甘油三酯组合物,其组成按重量计,OPO为40～52％,Sn-2为52～65％,PPP％<8％；符合国标规定的OPO产品中二位棕榈酸占所有棕榈酸含量要大于52％,1,3-二油酸-2-棕榈酸甘油三酯含量(以C52计)要高于40％的要求。(The invention discloses a method for synthesizing a 1, 3-dioleoyl-2-palmitic acid triglyceride composition by using a non-localized enzyme, which comprises the following steps: carrying out random ester exchange on palm oil stearin with an iodine value of 8-35, and then carrying out non-specific enzymatic ester exchange on the palm oil stearin and oleic acid or non-glyceride thereof, wherein the water content of an enzymatic reaction system is less than 0.1%; separating to remove palmitic acid or palmitic non-glyceride esters to obtain a composition containing 1, 3-dioleoyl-2-palmitic triglyceride. The composition containing OPO triglyceride prepared by the method comprises, by weight, 40-52% of OPO, 52-65% of Sn-2 and less than 8% of PPP; the OPO product meeting the national standard has the requirements that the content of dipalmitic acid in all palmitic acid products is more than 52 percent, and the content of 1, 3-dioleic acid-2-palmitic acid triglyceride (calculated as C52) is more than 40 percent.)

1. A method for synthesizing a 1, 3-dioleoyl-2-palmitoyl triglyceride composition by a non-localized enzyme, comprising:

(1) carrying out random ester exchange on palm oil stearin with an iodine value of 8-35;

(2) performing enzymatic transesterification on the palm oil stearin and oleic acid or non-glyceride thereof subjected to random transesterification in the step (1), wherein the water content of an enzymatic reaction system is less than 0.1%; separating and removing palmitic acid or non-glyceride esters of palmitic acid to obtain a composition comprising 1, 3-dioleoyl-2-palmitoyl triglyceride;

wherein the enzyme used in the enzymatic transesterification reaction is a lipase which is not specific for 1, 3-position.

2. The method of synthesizing 1, 3-dioleoyl-2-palmitate triglyceride compositions using non-localized enzymes as claimed in claim 1, wherein the process step of controlling the water content of the enzymatic reaction system to less than 0.1% comprises:

vacuumizing and dehydrating palm oil stearin, non-1, 3-site specific lipase and oleic acid or non-glyceride thereof subjected to random ester exchange in the step (1) at the temperature of 60-70 ℃, controlling the vacuum degree to be less than 1000Pa, and vacuumizing for 1-3 hours; or the like, or, alternatively,

vacuumizing the palm oil stearin and oleic acid or non-glyceride thereof subjected to random ester exchange in the step (1) at the temperature of 150-160 ℃, controlling the vacuum degree to be 2-20 kPa, and vacuumizing for 0.5-1 hour; then cooling the system to below 70 ℃, and adding non-1, 3-site specific lipase; or the like, or, alternatively,

carrying out random ester exchange on palm oil stearin and oleic acid or non-glyceride thereof obtained in the step (1) at the temperature of 150-160 ℃, controlling the water content of a system to be less than 0.1% by inert gas partial pressure, cooling the system to below 70 ℃, and adding non-1, 3-site specific lipase; wherein the flow rate of the inert gas per 100 g of the material is controlled to be 10-100 ml/min.

3. The method for synthesizing 1, 3-dioleic acid-2-palmitic acid triglyceride composition by non-localized enzyme according to claim 1 or 2, characterized in that the enzymatic reaction is carried out in inert gas atmosphere, the water content of the reaction system is 0.01-0.05%, the temperature of the enzymatic reaction is 55-60 ℃, and the end point is that the content of palmitic acid triglyceride in total triglyceride is less than 8%.

4. The method for synthesizing 1, 3-dioleoyl-2-palmitate triglyceride compositions using non-localized enzymes according to claim 1, wherein the non-1, 3-specific lipase is Novozym 435 or Lipozyme TM IM, in an amount of 2-30% by weight of the total mass of the materials used in the enzymatic reaction.

5. The method for synthesizing 1, 3-dioleic acid-2-palmitic acid triglyceride composition by non-localized enzyme according to claim 1, wherein the weight ratio of palm oil stearin and oleic acid or its non-glyceride after random transesterification is 1: 1-10.

6. The method for synthesizing a 1, 3-dioleoyl-2-palmitoyl triglyceride composition by a non-localized enzyme according to claim 1 or 5, wherein the non-glyceride of oleic acid is methyl oleate or ethyl oleate.

7. The process for the synthesis of 1, 3-dioleoyl-2-palmitate triglyceride compositions by non-localized enzymes according to claim 1, characterised in that the enzymatic transesterification reaction is carried out in a batchwise or continuous manner, optionally in an organic solvent system or in a solvent-free system.

8. The method for the synthesis of 1, 3-dioleoyl-2-palmitoyl triglyceride compositions by non-localized enzymes according to claim 7, wherein the enzymatic transesterification is carried out in a batch mode, comprising in particular the steps of:

(i) carrying out enzymatic transesterification on palm olein and oleic acid or non-glyceride thereof subjected to random transesterification under the action of non-1, 3-site specific lipase 1 to prepare a composition containing 1, 3-dioleoyl-2-palmitic acid triglyceride;

(ii) (ii) after separating excess oleic acid and palmitic acid formed by the reaction, repeating step (i) with new oleic acid or a non-glyceride thereof under the action of a non-1, 3-specific lipase 2 to obtain a high 1, 3-dioleic acid-2-palmitic acid triglyceride composition;

wherein the non-1, 3-position specific lipase 1 and the non-1, 3-position specific lipase 2 are the same or different.

9. Application of the composition containing 1, 3-dioleoyl-2-palmitic acid triglyceride prepared by the preparation method according to any one of claims 1 to 8 in preparation of infant dairy products.

Technical Field

The invention relates to a product capable of replacing human milk fat oil, in particular to a method for synthesizing a 1, 3-dioleoyl-2-palmitic acid triglyceride composition by using non-localized enzyme.

Background

1, 3-dioleoyl-2-palmitoyl triglyceride (commonly known as OPO) is the main characteristic component of breast milk fat. At present, OPO is mostly added into infant formula milk powder, and the OPO content is close to breast milk as far as possible from the composition of total fatty acid, the composition of fatty acid at Sn-2 position and the OPO content.

At present, the more common method for producing a composition containing triglycerides of 1, 3-dioleoyl-2-palmitate is: (1) providing grease with rich palmitic acid at the Sn-2 position; (2) providing an oleic acid acyl donor which may be a fatty acid non-triglyceride ester of oleic acid such as oleic acid, methyl oleate or ethyl oleate; (3) and finally, completing the directional transesterification reaction under the catalysis of 1, 3-position selective enzyme (specific lipase) to synthesize the OPO triglyceride, wherein the essence of the directional transesterification reaction catalyzed by the specific lipase is the substitution reaction of unsaturated fatty acid on Sn-1/3-position fatty acid in the Sn-2-position palmitic acid-rich grease, and the composition of the Sn-2-position fatty acid is not influenced. And the redistribution of acyl groups between molecules or in molecules of the triglyceride under the action of non-1, 3-site specific lipase is randomly distributed according to probability, so that after random ester exchange reaction, the distribution probability of one fatty acid on any site of the triglyceride is the same, which is not favorable for preparing the high-content OPO triglyceride composition, therefore, the prior art mostly adopts grease rich in palmitic acid at Sn-2 site and acyl donor, and prepares the high-content OPO triglyceride composition through ester exchange under the catalysis of 1, 3-site selective enzyme.

For example, patent CN101679909A discloses a method for preparing a composition comprising OPO glycerides by subjecting one or more palm oil stearin fractions having an iodine value of 18 to 40 to a random transesterification reaction to obtain triglycerides rich in palmitic acid at the Sn-2 position, followed by a specific lipase-catalyzed trans-esterification reaction with oleic acid or non-triglycerides thereof. Patent CN102827885 discloses a method for preparing OPO, which adopts ester rich in saturated fatty acid residue and ester rich in unsaturated fatty acid residue to perform random ester exchange reaction, and then performs enzyme-oriented ester exchange reaction with unsaturated fatty acid or its ester. Patent CN102776077 discloses a method for preparing OPO, which comprises subjecting palm oil with palmitic acid content more than 50% to intramolecular rearrangement reaction under the action of catalyst, and subjecting to ester exchange reaction with mixed fatty acid or its non-glyceride ester under the action of 1, 3-position obligate lipase.

However, the 1, 3-specific lipase is expensive, high in cost and poor in economic benefit, but a method for preparing OPO by using nonspecific enzyme to catalyze grease with rich palmitic acid at Sn-2 position and an oleic acid acyl donor is not available in the prior art, because the OPO product prepared by using nonspecific enzyme is difficult to meet the requirements of national standard (GB30604-2015), the content of dipalmitic acid in the OPO product is more than 52% of all palmitic acid, and the content of 1, 3-dioleic acid-2-palmitic acid triglyceride (calculated by C52) is more than 40%.

Disclosure of Invention

The invention provides a method for synthesizing a 1, 3-dioleate-2-palmitic acid triglyceride composition by using non-localized enzyme, which breaks through the limitation that only 1, 3-bit specific lipase can be used for preparing an OPO product meeting the national standard in the traditional preparation of the OPO product, greatly reduces the industrial production cost and has remarkable economic benefit.

A method for synthesizing a 1, 3-dioleoyl-2-palmitoyl triglyceride composition by a non-localized enzyme, comprising:

(1) carrying out random ester exchange on palm oil stearin with an iodine value of 8-35;

(2) performing enzymatic transesterification on the palm oil stearin and oleic acid or non-glyceride thereof subjected to random transesterification in the step (1), wherein the water content of an enzymatic reaction system is less than 0.1%; separating and removing palmitic acid or non-glyceride esters of palmitic acid to obtain a composition comprising 1, 3-dioleoyl-2-palmitoyl triglyceride;

wherein the enzyme used in the enzymatic transesterification reaction is a lipase which is not specific for 1, 3-position.

The palm oil stearin is obtained by fractionating palm oil or a derivative thereof, the palm oil being selected from the group consisting of crude palm oil, refined palm oil, palm oil fractions (such as fractions obtained by Lanza fractionation), palm oil derivatives or mixtures thereof; the purpose of the random transesterification reaction is to obtain triglycerides rich in palmitic acid at the Sn-2 position.

The invention unexpectedly discovers that the water content of a reaction system is controlled to be below 0.1%, and the content of OPO prepared by using grease rich in palmitic acid at Sn-2 position and an acyl donor as raw materials through a transesterification method can be improved by using non-1, 3-position specific lipase.

Wherein, the invention controls the water content of the enzymatic reaction system to be less than 0.1 percent, and comprises the following process steps:

carrying out vacuum pumping dehydration on palm oil stearin, non-1, 3-site specific lipase and oleic acid or non-glyceride thereof subjected to random ester exchange at the temperature of 60-70 ℃, controlling the vacuum degree to be less than 1000Pa, and further preferably controlling the vacuum degree to be less than 500Pa for 1-3 hours; or the like, or, alternatively,

vacuumizing palm oil stearin and oleic acid or non-glyceride thereof subjected to random ester exchange at 150-160 ℃, wherein the vacuum degree is controlled to be 2-20 kPa, and the vacuumizing is carried out for 0.5-1 hour; then cooling the system to below 70 ℃, and adding non-1, 3-site specific lipase; or the like, or, alternatively,

carrying out random ester exchange on palm oil stearin and oleic acid or non-glyceride thereof at the temperature of 150-160 ℃, controlling the water content of a system to be less than 0.1% by inert gas partial pressure, cooling the system to below 70 ℃, and adding non-1, 3-site specific lipase; wherein, the flow rate of the inert gas per 100 g of the material is controlled to be 10-100 ml/min, and the material is preferably not carried out.

Preferably, the enzymatic reaction is carried out in an inert gas atmosphere, the water content of a reaction system is 0.01-0.05%, the enzymatic reaction temperature is 55-60 ℃, and the end point is to measure that the content of palmitic acid triglyceride in the total triglyceride is less than 8%.

The non-1, 3-site specific lipase is Novozym 435 or Lipozyme TM IM and the like, and the dosage of the lipase accounts for 2-30% of the total mass of all materials in the enzymatic reaction.

The weight ratio of the palm oil stearin to the oleic acid or the non-glyceride thereof is 1: 1-10. The oleic acid non-glyceride is an ester of oleic acid and a saturated alkyl alcohol, such as an alkyl ester of oleic acid and an alcohol having 1 to 6 carbon atoms; preferably, the non-glyceride oleate is methyl oleate, ethyl oleate or the like.

Further, the purity of the oleic acid or the non-glyceride ester thereof in the enzymatic reaction is 50-90%.

The enzymatic transesterification is carried out batchwise or continuously, optionally in an organic solvent system or in a solvent-free system, wherein the same or different non-1, 3-specific lipases are used batchwise and in stages.

Further, in one embodiment, the method of the present invention comprises:

(i) carrying out enzymatic transesterification on palm olein and oleic acid or non-glyceride thereof subjected to random transesterification under the action of non-1, 3-site specific lipase 1 to prepare a composition containing 1, 3-dioleoyl-2-palmitic acid triglyceride;

(ii) (ii) after separating excess oleic acid and palmitic acid formed by the reaction, repeating step (i) with new oleic acid or a non-glyceride thereof under the action of a non-1, 3-specific lipase 2 to obtain a high 1, 3-dioleic acid-2-palmitic acid triglyceride composition;

wherein the non-1, 3-position specific lipases 1 and 2 are Novozym 435 or Lipozyme TM IM, etc., and the non-1, 3-position specific lipase 1 and the non-1, 3-position specific lipase 2 are the same or different.

The ester exchange step by step can improve the content of the by-product in the low-boiling components needing rectification and separation and greatly reduce the total amount of low-boiling substances, thereby greatly reducing the rectification energy consumption.

In order to increase the OPO content in the 1, 3-dioleate-2-palmitic acid triglyceride composition, the enzymatic reaction product is subjected to separation and refining treatment, specifically vacuum distillation, fractional distillation, molecular distillation and/or chemical refining, so that the enzymatic reaction product is close to the fat with a human milk fat structure.

Further, the absolute pressure of the vacuum distillation, the fractional distillation and the molecular distillation is 1-500 Pa, and the temperature is 140-260 ℃.

Further, the chemical refining adopts dilute alkali refining.

The composition containing OPO triglyceride prepared by the method comprises, by weight, 40-52% of OPO, 52-65% of Sn-2 and less than 8% of PPP; meets the quality requirements of GB30604-2015 on 1, 3-dioleoyl-2-palmitoyl triglyceride: wherein, the content of Sn-2 in the composition is required to be more than or equal to 52 percent; the content of OPO is more than or equal to 40 percent. Therefore, the method provided by the invention breaks through the limitation that only 1, 3-bit specific lipase can be adopted to prepare the OPO product meeting the national standard in the traditional preparation of the OPO product.

The composition containing OPO triglyceride prepared by the invention can be used as a high-quality fat substrate suitable for replacing infant food, and is applied to preparing infant dairy products.

Moreover, the non-localized lipase has wide sources and low price in the market, and the preparation method provided by the invention can greatly reduce the production cost of the target product, has obvious economic benefit and has wide development prospect.

Drawings

FIG. 1 is a flow chart of a stepwise process for synthesizing a 1, 3-dioleoyl-2-palmitoyl triglyceride composition by using a non-localized enzyme in examples 6 to 7 of the present invention.

Detailed Description

For further understanding of the present invention, the following examples are given to illustrate the synthesis of 1, 3-dioleoyl-2-palmitoyl triglyceride by non-localized enzyme, but the present invention is not limited to these examples, and those skilled in the art who have the core teaching of the present invention will make insubstantial modifications and adjustments, which still fall within the scope of the present invention.