CN106912622B

CN106912622B - Breast milk fat substitute and preparation method thereof

Info

Publication number: CN106912622B
Application number: CN201511002851.0A
Authority: CN
Inventors: 侯建平; 常桂芳; 贾梦茵; 许淑芳
Original assignee: Wilmar Shanghai Biotechnology Research and Development Center Co Ltd
Current assignee: Wilmar Shanghai Biotechnology Research and Development Center Co Ltd
Priority date: 2015-12-28
Filing date: 2015-12-28
Publication date: 2020-10-30
Anticipated expiration: 2035-12-28
Also published as: CN106912622A

Abstract

The invention provides a breast milk fat substitute and a preparation method thereof, wherein the breast milk fat substitute is a fat composition, wherein in the weight proportion of total fatty acids, the content of palmitic acid is 15-30%, the content of stearic acid is 5-15%, the content of unsaturated fatty acid is 30-65%, the total content of myristic acid and lauric acid is less than 20%, and the content of Sn-2 stearic acid in the total stearic acid is not less than 35%.

Description

Breast milk fat substitute and preparation method thereof

Technical Field

The invention relates to an edible oil composition and a preparation method thereof, in particular to a preparation method of a breast milk fat substitute.

Background

The breast milk fat provides about half of energy needed for the growth and development of infants, and the research on the breast milk fat is one of the main hotspots in the breast milk research field. Accordingly, the results of fat science research have also continuously driven the continuous improvement of infant formula.

Breast milk has about 4% fat, of which more than 98% is triglycerides. Besides being a main source of energy, breast milk fat is also an important component of body tissues, and has the functions of providing essential fatty acid for the development of infants, promoting the absorption of fat-soluble components and the like.

Although there are some differences in the specific fatty acid content of breast milk in different regions, there is also greater similarity. Fatty acids with a high content of breast milk fat, mainly including the saturated fatty acids lauric acid (C12:0, La), myristic acid (C14:0, M), palmitic acid (C16:0, P), stearic acid (C18:0, S), monounsaturated fatty acid oleic acid (C18:1n-9, O) and polyunsaturated fatty acid linoleic acid (C18:2n-6, LA), are usually contained in an amount of more than 5% of the total fatty acids. In the breast milk fatty triglyceride, saturated fatty acid is mainly distributed at Sn-2 position, and unsaturated fatty acid is mainly distributed at Sn-1/3 position. The specificity of the fatty acid composition and distribution of breast milk fat determines its nutritional value, which is closely related to the digestive absorption characteristics of infants. Breast milk fat is hydrolyzed by gastric lipolytic enzyme and pancreatic lipase with Sn-1/3 specificity to produce free fatty acids and 2-monoglyceride. The free fatty acid is absorbed in small intestine, and 2-monoglyceride is absorbed by lymphatic system and enters blood circulation.

The breast milk fat substitute is a triglyceride mixture simulating the composition or distribution of the fatty acids of breast milk, and is added into infant formula milk. At present, most breast milk fat substitutes are obtained by modifying and separating vegetable oil or animal fat by adopting an enzyme method. Currently, the focus is on 1, 3-dioleoyl-2-palmitic acid triglyceride, a novel milk fat substitute called OPO.

CN101198261 discloses a breast milk substitute obtained by mixing OPO composition with other vegetable oils.

CN98116158 discloses a human milk fat analogue in which palmitic acid is distributed mainly at Sn-2 position.

CN200810066458.1 discloses a production method of breast milk fat substitute oil, which is prepared by blending lard or lard fraction with other animal and vegetable oil according to a certain proportion.

CN201010225899.9 discloses a breast milk fat substitute obtained by enzymatic transesterification of Mei Gong river catfish fat with mixed fatty acids derived from other vegetable oils.

CN201210279472.6 discloses a preparation method of grease with a parent emulsified structure, which is obtained by subjecting palm oil with palmitic acid content of more than 50% to intramolecular rearrangement under the action of a catalyst, and then subjecting triglyceride and mixed fatty acid to a directional ester exchange reaction under the action of Sn-1/3 position-specific lipase.

CN201210309025.0 discloses a method for preparing human milk substitute, which comprises subjecting chemical interesterified high melting point palm stearin as raw material and rapeseed oil fatty acid to catalytic acidolysis reaction with specific lipase, and adding other vegetable oil, algae oil and microbial oil into the intermediate product to obtain human milk fat substitute.

CN201410375590.6 discloses a milk fat substitute fat based on triglyceride composition, which is prepared by mixing lard as a basic raw material with other fat to obtain a mixed oil with a fatty acid composition close to that of milk, and then catalyzing the triglyceride mixture by using a specific lipase to perform fatty acid rearrangement to obtain a milk fat substitute.

All the fat substitutes for breast milk disclosed so far are concerned only with the fatty acid composition, or the content of palmitic acid in Sn-2 position in the total palmitic acid is increased as much as possible by the OPO triglyceride.

Early studies suggested that saturated fatty acids, especially the long chain saturated fatty acids palmitic and stearic, have adverse effects on health and chronic diseases, increasing total serum cholesterol levels, especially low density cholesterol levels. However, many studies have shown that breast-fed infants and their adults, which contain large amounts of long-chain saturated fatty acids palmitic and stearic acids, do not show an increase in risk factors for cardiovascular disease (hypertension, hyperlipidemia, insulin resistance, or increased waist circumference, etc.) (Piril S, Taskinen M, Viljakainen H, et al, Breast-fed deficiencies and the later cardiac waist: a proactive from human birth to 32 years [ J ]. Br J Nutr,2013,8: 1-8). In previous studies on long-chain saturated fatty acids, unrealistic results are often caused due to their content or the one-sidedness of the influencing factors. The us 2015Dietary Guidelines recommended Report clearly indicates that there is no significant link between saturated fatty acid intake and vascular disease and its risk factors (USDA Scientific Report of the 2015Dietary Guidelines advisorde, Advisory Report to the society of health and Human Services and society of agriculture, part d. chair 6: Cross-clinical topics of public health concern 2015).

The fat absorption directly affects the growth and development of infants. The absorption of the unesterified fatty acid in the infant intestinal tract is that for unsaturated fatty acid, oleic acid accounts for 90-92%, and linoleic acid accounts for 92-94%; the absorption of myristic acid is more than 88% for saturated fatty acids, whereas 74% for palmitic acid and 63% for stearic acid (Jensen C, Buist N, Wilson T.Absorption of inductive fatty acids from one long chain or medium chain acids [ J ]. The American Journal of clinical Nutrition,1986,43(5):745 751). The main reason for the low absorption of saturated fatty acids, especially palmitic and stearic acids, is because the unesterified palmitic and stearic acids tend to form fatty acid soaps with metal ions such as calcium, magnesium, etc. and are lost in the feces. Medium-short chain fatty acids such as myristic acid and lauric acid, which have relatively low fatty acid carbon chain length, are hydrolyzed quickly and easily digested, absorbed and metabolized by human bodies (the national committee on health and family planning of the people's republic of China, the general rules of formula food for special medical use, questions and answers 2015-04-15). Therefore, absorption of palmitic acid and stearic acid is a major problem affecting fat absorption in infants, and is one of the main causes affecting constipation in infants and affecting the decrease in mineral absorption efficiency in infants.

Besides being an important source of energy, long-chain saturated fatty acids play an important role in synthesizing secretory lipids such as cell membranes, adipose tissues, lipoproteins and lung surfactant, and in protein and signal molecules. There is ample reason to consider that insufficient long chain saturated fatty acids are detrimental to the infant body, such as reduced tissue repair and regeneration, and the susceptibility to inflammation (Shei lam. Innis, Palmitic Acid In Early Human development. critical Reviews In food science and nutrition. position online: 2015).

Based on the absorption rate of long-chain saturated fatty acids, especially palmitic acid and stearic acid, and the important effect thereof on the growth and health of infants, it is extremely necessary to develop an oil composition with a fatty acid composition and distribution comprehensively close to breast milk fat, and a breast milk fat substitute for improving the absorption rate of saturated fatty acids, especially palmitic acid and stearic acid.

In the existing preparation method of the breast milk fat substitute, vegetable oil is mostly adopted to supplement required fatty acid, but in natural oil, the content of stearic acid is low, and the content of Sn-2 stearic acid in the total stearic acid is also low, so that the breast milk fat substitute can not meet the requirements of breast milk fat composition. At present, none of the solutions addresses the problem of breast milk fat substitutes with respect to stearic acid. In order to overcome the defects of the breast milk fat substitute, the invention provides the fat composition which is more comprehensively similar to breast milk fat in fatty acid composition and position distribution.

Disclosure of Invention

The invention provides an oil composition which is more nutritious on the composition and the position distribution of long-chain saturated fatty acid and is comprehensively close to breast milk fat, and a preparation method thereof.

In one aspect, the present invention relates to a method for preparing a fat composition, the method comprising the steps of:

(1) mixing the oil and fat containing palmitic acid and the oil and fat rich in stearic acid, wherein the ratio of the oil and fat containing palmitic acid to the oil and fat rich in stearic acid is as follows: 1: 4-10: 1, preferably 1: 2-8: 1, more preferably 1: 1-6: 1, obtaining the ester exchange oil, wherein the random ester exchange reaction is carried out under the action of a catalyst. The triglyceride containing palmitic acid contains more than 40% of palmitic acid, and is selected from triglyceride stearate, cacao butter, shea butter, and mango oil, optionally, the oil rich in stearic acid further comprises myristic acid, and the triglyceride of myristic acid can be derived from myristyl oil, myristic acid triglyceride, etc. Further optionally, the fat rich in stearic acid contains oleic acid not less than 20% and palmitic acid not less than 2% by weight of fatty acid; preferably, not less than 25% oleic acid, not less than 5% palmitic acid.

(2) Mixing the ester-exchanged oil and fat with fatty acid rich in unsaturated fatty acid or mixture of ester thereof, performing acidolysis reaction under 1, 3-directional catalysis, deacidifying, and refining to obtain breast milk fat substitute. The mixture of the fatty acid or the ester thereof rich in the unsaturated fatty acid contains more than 70% of the unsaturated fatty acid, and the proportion of the transesterified oil and the mixture of the fatty acid or the ester thereof rich in the unsaturated fatty acid is 1: 0.3-1: 5, preferably 1: 0.5-1: 4, more preferably 1: 1-1: 2; . Of the fatty acid content in the unsaturated fatty acid or ester thereof-rich mixture, the unsaturated fatty acid content is preferably 80%, more preferably 90%. The unsaturated fatty acid may be selected from oleic acid, linoleic acid or a combination thereof. Fatty acid esters of unsaturated fatty acids, including short carbon chain fatty acid esters of unsaturated acids, may be selected from methyl, ethyl, propyl or glycerides of unsaturated fatty acids. The mixture of unsaturated fatty acids or esters thereof is selected from at least one of sunflower oil, soybean oil, rapeseed oil or oleic acid mixtures of corresponding origin.

(3) Preferably, the oil and fat in step (2) is refined, preferably deacidified, decolored and deodorized, and further, optionally, one or more of fish oil, algae oil or microbial oil is added into the breast milk fat substitute to provide long-chain polyunsaturated fatty acid. The adding proportion is 1 to 2 percent

The oil and fat containing palmitic acid is triglyceride containing palmitic acid, and the oil and fat rich in stearic acid is triglyceride rich in stearic acid.

The grease composition prepared by the method can be used as a breast milk fat substitute, and the invention also discloses a preparation method of the breast milk fat substitute, which comprises the steps.

The invention also discloses a non-breast milk derived grease composition, wherein:

(1) the content of Sn-2 long-chain saturated fatty acid in the total saturated fatty acid is more than 40%, wherein the content of Sn-2 palmitic acid in the total palmitic acid is more than 40%, and the content of Sn-2 stearic acid in the total stearic acid is more than 35%.

(2) Of the fatty acid compositions, palmitic acid: 15% -30%, stearic acid: 3-15%, unsaturated fatty acid: 30-65% of fatty acid, and the total amount of myristic acid and lauric acid is less than 20% of total fatty acid.

Preferably, in the weight proportion of the total fatty acids in the grease composition, the palmitic acid content is 15-30%, the stearic acid content is 5-15%, the unsaturated fatty acid content is 30-65%, the total content of myristic acid and lauric acid is less than 20%, the stearic acid content is preferably 5-10%, and the Sn-2 stearic acid accounts for not less than 35%, preferably not less than 37%, and more preferably not less than 40% of the total stearic acid content; preferably, the content of Sn-2 palmitic acid in the grease accounts for not less than 35% of the total palmitic acid.

The non-human milk-derived fat composition of the present invention can be produced by the above-described method for producing a fat composition.

The grease composition prepared by the method has the advantages that:

1. the composition and distribution of fatty acid are more comprehensively close to the distribution of breast milk fat, especially long-chain saturated fatty acid;

2. the grease composition meets the existing national regulation standard, improves the absorption of long-chain saturated fatty acid, especially palmitic acid and stearic acid, and has potential nutritive value for balancing cholesterol;

3. the oil composition meets the existing national regulation standard, improves the absorption of medium-chain saturated fatty acid myristic acid, long-chain saturated fatty acid palmitic acid and stearic acid, and has potential nutritive value for balancing cholesterol;

4. the preparation method of the oil and fat composition has the advantage of low cost compared with other methods for preparing breast milk fat substitutes.

Detailed Description

The inventor researches and improves a preparation process, and aims to overcome the defect that the conventional breast milk substitute fat cannot be comprehensively simulated, the invention aims to comprehensively improve the problem of comprehensive nutrition absorption of the breast milk fat substitute, and particularly provides the breast milk fat substitute comprehensively simulated by the long carbon chain saturated fatty acid in the problem of comprehensively simulating the composition of the long carbon chain fatty acid and the structure of the long carbon chain fatty acid on Sn-2. The present invention has been completed based on this finding.

The technical concept of the invention is as follows:

as used herein, the term "comprising" or "includes" means that the various ingredients can be used together in a mixture or composition of the invention. Thus, the terms "consisting essentially of and" consisting of are encompassed by the terms "comprising" or "including".

Various aspects of the invention are described in detail below:

raw materials

In the present application, the palmitic acid-containing fat or oil is a fat or oil containing 40% or more of palmitic acid, and preferably, the fat or oil may be derived from: palm oil, palm oil fractions, palm oil hydride, or any combination thereof.

In the present application, the oil rich in stearic acid source has a stearic acid content of 20% by weight or more, preferably not less than 25%, more preferably not less than 30%, and most preferably not less than 35%. In particular, it may be derived from synthetic or natural fats and oils, including but not limited to: any one of or any combination of triglycerides of stearic acid, Cocoa butter (Cocoa butter), mango butter (Mangobutter), Shea butter (Shea butter). Without limiting the purpose, the compositions of the fats and oils in the Cocoa butter (Cocoa butter), Mango butter (Mango butter) and Shea butter (Shea butter) used in the present application may be varied within a reasonable range according to different production places or processing techniques, and the specific compositions of the fats and oils in the examples are not limited to the fatty acid content of the oil species. In one embodiment of the invention, the oil rich in stearic acid source contains not less than 20% of oleic acid and/or not less than 2% of palmitic acid; preferably, not less than 25% oleic acid and/or not less than 5% palmitic acid.

In the preparation process, the proportion of the grease containing palmitic acid and the grease rich in stearic acid is as follows: 1: 4-10: 1, preferably 1: 2-8: 1, more preferably 1: 1-6: 1, obtaining a transesterified fat 1: 4-10: 1, preferably 1: 2-8: 1, more preferably 1: 1-6: 1.

the catalyst used in the random transesterification step may be selected from at least one of hydroxides, carbonates, bicarbonates, alkoxides of alkali metals or alkaline earth metals. The hydroxide of an alkali metal or alkaline earth metal is selected from KOH, NaOH, Ca (OH)₂At least one of (1). The carbonate of an alkali metal is selected from K₂CO₃、Na₂CO₃At least one of (1). The alkali metal bicarbonate is selected from KHCO₃、NaHCO₃At least one of (1). Alkoxides of alkali metals, e.g. NaOCH₃. The amount of the catalyst to be added is not particularly limited, and for example, the catalyst is added in an amount of 0.01 to 1 wt%, for example, 0.1 wt% based on the total amount of the fat and oil.

The random transesterification step may also be carried out in the presence of a lipase. The lipase can be immobilized lipase or non-immobilized lipase. The lipase may be derived from animals, plants, or microorganisms, such as Thermomyces lanuginosus (Thermomyces lanuginosus), Rhizopus oryzae (Rhizopus oryzae), Rhizomucor miehei (Rhizomucor miehei), Candida antarctica (Candida antarctica), Aspergillus niger (Aspergillus niger), Burkholderia sp), Candida rugosa (Candida rugosa), Alcaligenes Alcaligenes sp, Mucor javanicus (Mucor javanicus), Rhizopus niveus (Rhizopus niveus), Geotrichum candidum (Cryococcus neoformans), or genetically modified strains thereof.

The reaction of the random transesterification step is preferably terminated with a terminator. The terminator may be an organic acid or an inorganic acid. Examples of the organic acid include citric acid and tartaric acid. Examples of the inorganic acid include hydrochloric acid, phosphoric acid, and sulfuric acid. Citric acid is preferred. The amount of the terminator to be added is not particularly limited as long as the reaction can be terminated, and for example, 0.1 to 1% by weight, for example, 0.3% by weight of the terminator is added to the total amount of the fat and oil (reaction mixture).

The Sn-1, 3-oriented transesterification catalyst is preferably esterase from rhizopus oryzae and/or esterase from rhizomucor oryzae.

The lipase catalyst is preferably immobilized lipase, and the carrier of the lipase catalyst comprises a conventional carrier such as silica.

The mixture of unsaturated fatty acid or its ester can be selected from unsaturated fatty acid mixture, unsaturated fatty acid ester mixture, or mixture of both. The unsaturated fatty acid is selected from one or any combination of oleic acid, linoleic acid and/or linolenic acid. The weight ratio of the ester exchange oil ester to the unsaturated fatty acid-rich fatty acid or the mixture of the ester exchange oil ester and the unsaturated fatty acid-rich fatty acid is 1: 0: 0.5-1: 4, more preferably 1: 1-1: 2;

wherein the mixture of esters of unsaturated fatty acids, including short carbon chain fatty acid esters of unsaturated fatty acids, may be selected from: methyl, ethyl, propyl esters of unsaturated fatty acids or glycerides thereof. As a non-limiting source, a hydrolyzed fatty acid mixture that can be derived from oleic acid mixtures, soybean oil, sunflower oil, or soybean oil/sunflower oil, or any combination thereof.

Oil and fat composition

The fat or oil composition according to the present application has a fatty acid composition comprising 15% to 30% of palmitic acid, stearic acid: 3-15%, unsaturated fatty acid: 30-65% and the total amount of myristic acid and lauric acid is less than 20%.

In a preferred embodiment of the present application, the stearic acid is contained in an amount of: 15% -30% of palmitic acid, stearic acid: 5-15%, unsaturated fatty acid: 30-65% and the total amount of myristic acid and lauric acid is less than 20%. More preferred compositions are: 15% -30% of palmitic acid, stearic acid: 5-10%, unsaturated fatty acid: 30-65% and the total amount of myristic acid and lauric acid is less than 20%.

In one embodiment of the present invention, the fatty acid composition of the fat and oil composition has a stearic acid content of 7 to 15%, more preferably 8 to 15%.

In one embodiment of the present application, in the fatty acid composition of the fat composition, the content of stearic acid is 8.5 to 15%.

In the structured fat of the fat and oil composition of the present application, the content of Sn-2 palmitic acid in the total palmitic acid is 35% or more, preferably, Sn-2 stearic acid is 40% or more of the total stearic acid content, and more preferably, Sn-2 stearic acid is 41% or more of the total stearic acid content.

In a preferred embodiment of the present application, the content of Sn-2 palmitic acid in total palmitic acid is above 40% and Sn-2 stearic acid is above 35% of the total stearic acid content. More preferably, in the fat and oil composition, the content of Sn-2 palmitic acid in the total palmitic acid is more than 40%, and the content of Sn-2 stearic acid in the total stearic acid is more than 45%.

In a specific embodiment of the application, in the grease composition, the content of Sn-2 long-chain saturated fatty acid in the total saturated fatty acid is more than 40%, wherein the content of Sn-2 palmitic acid in the total palmitic acid is more than 40%, and the content of Sn-2 stearic acid in the total stearic acid is more than 35%; of the fatty acid compositions, palmitic acid: 15% -30%, stearic acid: 3-15%, unsaturated fatty acid: 30-65% and the total amount of myristic acid and lauric acid is less than 20%.

The oil and fat composition of the present invention is derived from non-human milk, and the oil and fat composition is prepared by the preparation method of the present invention manually for the first time. The oil composition prepared by the method is more comprehensive and more nutritious and closer to breast milk, and can be applied to infant formula milk powder, infant formula food, breast milk fat substitutes or dietary ingredients.

Unless otherwise specified, various starting materials of the present invention are commercially available; or prepared according to conventional methods in the art. Unless defined or stated otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In addition, any methods and materials similar or equivalent to those described herein can be used in the methods of the present invention.

Other aspects of the invention will be apparent to those skilled in the art in view of the disclosure herein.

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The experimental methods of the following examples, which are not specified under specific conditions, are generally determined according to national standards. If there is no corresponding national standard, it is carried out according to the usual international standards, to the conventional conditions or to the conditions recommended by the manufacturer. Unless otherwise indicated, all parts are parts by weight and all percentages are percentages by weight.

Unless defined or stated otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In addition, any methods and materials similar or equivalent to those described herein can be used in the methods of the present invention.

The detection method of FAC is GBT 17377; the detection method of the triglyceride 2-position fatty acid comprises the following steps: GBT 24894.

Unless otherwise mentioned, the raw materials used in the examples of the present invention are derived from Jiali special fat or Chinese medicine group, Inc., and the immobilized lipase Lipozyme RM IM is derived from Novoxin.

The oil or fat or fatty acid mixture in the following examples shows the main fatty acid content (other fatty acid components are trace fatty acids, such as C12, C14, C20, C22, etc.).

Example 1

Mixing 0.7kg palm oil stearin (palmitic acid 76%, oleic acid 14%) and 0.3kg stearic acid triglyceride (content is more than 80%), stirring under vacuum, heating to 105 deg.C, and dehydrating for 30 min. 0.001kg of sodium methoxide was added thereto, followed by vacuum stirring at 105 ℃ for 30min, and then 0.02kg of 15% (w/w) aqueous citric acid solution was added thereto and stirred for 20 min. Washing with hot water repeatedly. And finally dehydrating for 30min at 105 ℃ under vacuum stirring to obtain the ester exchange oil.

0.5kg of transesterified fat and 1kg of an oleic acid mixture (5% palmitic acid, 1% stearic acid, 80% oleic acid, 11% linoleic acid, 3% other fatty acids) from high oleic sunflower oil were thoroughly mixed and passed through a reaction column packed with 0.1kg of Lipozyme RM IM enzyme at a flow rate of 0.2kg/h, the enzyme reaction column being controlled at 60 ℃. Collecting the product flowing out of the enzyme reaction column, and removing the fatty acid of the product by molecular distillation. The deacidified fat was decolorized and deodorized to obtain the refined breast milk fat substitute of example 1. The fatty acid composition and the Sn-2 fatty acid composition are shown in Table 1.

Example 2

0.8kg of palm oil (fatty acid content: 43% palmitic acid, 40% oleic acid, 10% linoleic acid) and 0.2kg of stearic triglyceride were mixed, 0.1kg of Lipozyme TL IM was added, reaction was carried out at 65 ℃ for 8 hours, and lipase was filtered to obtain a transesterified fat.

0.5kg of the above transesterified fat and 0.25kg of a fatty acid mixture derived from soybean oil (10% palmitic acid, 22% oleic acid, 50% linoleic acid, 18% other fatty acids) were mixed, and passed through a reaction column packed with 0.15kg of lipozyme RM IM enzyme at a flow rate of 0.25kg/h, the enzyme reaction column being controlled at 60 ℃. Collecting the product flowing out of the enzyme reaction column, and removing the fatty acid of the product by molecular distillation. The deacidified fat was decolorized and deodorized to obtain a refined breast milk fat substitute of example 2. The fatty acid composition and the Sn-2 fatty acid composition are shown in Table 1.

Example 3

0.5kg of palm oil and 0.5kg of cocoa butter (35% stearic acid, 32% oleic acid, 30% palmitic acid) were mixed and heated to 105 ℃ under vacuum with stirring and dehydrated for 30 min. 0.001kg of sodium methoxide was added thereto, followed by vacuum stirring at 105 ℃ for 30min, and then 0.02kg of 15% (w/w) aqueous citric acid solution was added thereto and stirred for 20 min. Washing with hot water repeatedly. And finally dehydrating for 30min at 105 ℃ under vacuum stirring to obtain the ester exchange oil.

0.5kg of transesterified oil and fat and 1kg of high oleic sunflower oil (85% oleic acid, 12% linoleic acid) were thoroughly mixed and passed through a reaction column packed with 0.1kg of Lipozyme RM IM enzyme at a flow rate of 0.2kg/h, the enzyme reaction column being controlled at 60 ℃. Collecting the product flowing out of the enzyme reaction column, and removing the fatty acid of the product by molecular distillation. The deacidified fat was decolorized and deodorized to obtain a refined breast milk fat substitute of example 3. The fatty acid composition and the Sn-2 fatty acid composition are shown in Table 1.

Example 4

Mixing 0.5kg palm oil and 0.5kg mango oil (stearic acid 40%, oleic acid 38%, palmitic acid 12%), stirring under vacuum, heating to 105 deg.C, and dehydrating for 30 min. 0.001kg of sodium methoxide was added thereto, followed by vacuum stirring at 105 ℃ for 30min, and then 0.02kg of 15% (w/w) aqueous citric acid solution was added thereto and stirred for 20 min. Washing with hot water repeatedly. And finally dehydrating for 30min at 105 ℃ under vacuum stirring to obtain the ester exchange oil.

0.5kg of transesterified oil and fat and 1kg of high oleic sunflower oil (85% oleic acid, 12% linoleic acid) were thoroughly mixed and passed through a reaction column packed with 0.1kg of Lipozyme RM IM enzyme at a flow rate of 0.2kg/h, the enzyme reaction column being controlled at 60 ℃. Collecting the product flowing out of the enzyme reaction column, and removing the fatty acid of the product by molecular distillation. The deacidified fat was decolorized and deodorized to obtain a refined breast milk fat substitute of example 4. The fatty acid composition and the Sn-2 fatty acid composition are shown in Table 1.

Example 5

Mixing 0.5kg palm oil and 0.5kg shea butter (42% stearic acid, 42% oleic acid, 8% palmitic acid), vacuum stirring, heating to 105 deg.C, and dehydrating for 30 min. 0.001kg of sodium methoxide was added thereto, followed by vacuum stirring at 105 ℃ for 30min, and then 0.02kg of 15% (w/w) aqueous citric acid solution was added thereto and stirred for 20 min. Washing with hot water repeatedly. And finally dehydrating for 30min at 105 ℃ under vacuum stirring to obtain the ester exchange oil.

0.5kg of transesterified oil and fat and 1kg of high oleic sunflower oil (85% oleic acid, 12% linoleic acid) were thoroughly mixed and passed through a reaction column packed with 0.1kg of Lipozyme RM IM enzyme at a flow rate of 0.2kg/h, the enzyme reaction column being controlled at 60 ℃. Collecting the product flowing out of the enzyme reaction column, and removing the fatty acid of the product by molecular distillation. The deacidified fat was decolorized and deodorized to obtain a refined breast milk fat substitute of example 5. The fatty acid composition and the Sn-2 fatty acid composition are shown in Table 1.

Example 6

0.5kg of palm oil and 0.25kg of myristyl triglyceride are mixed with 0.25kg of stearic triglyceride and dehydrated for 30min by heating to 105 ℃ under vacuum with stirring. 0.001kg of sodium methoxide was added thereto, followed by vacuum stirring at 105 ℃ for 30min, and then 0.02kg of 15% (w/w) aqueous citric acid solution was added thereto and stirred for 20 min. Washing with hot water repeatedly. And finally dehydrating for 30min at 105 ℃ under vacuum stirring to obtain the ester exchange oil.

0.5kg of transesterified fat and 0.25kg of soybean oil were thoroughly mixed, and then passed through a reaction column packed with 0.1kg of Lipozyme RM IM enzyme at a flow rate of 0.2kg/h, the enzyme reaction column being controlled at 60 ℃. Collecting the product flowing out of the enzyme reaction column, and removing the fatty acid of the product by molecular distillation. And (3) decolorizing and deodorizing the deacidified grease to obtain a refined breast milk fat substitute 6. The fatty acid composition and the Sn-2 fatty acid composition are shown in Table 1.

Comparative example 1

0.5kg of palm oil was dehydrated for 30min by heating to 105 ℃ under vacuum with stirring. 0.001kg of sodium methoxide was added thereto, followed by vacuum stirring at 105 ℃ for 30min, and then 0.02kg of 15% (w/w) aqueous citric acid solution was added thereto and stirred for 20 min. Washing with hot water repeatedly. And finally dehydrating for 30min at 105 ℃ under vacuum stirring to obtain the ester exchange oil.

0.5kg of transesterified oil and fat and 1kg of oleic acid were thoroughly mixed and passed through a reaction column packed with 0.1kg of lipozyme RM IM enzyme at a flow rate of 0.2kg/h, the enzyme reaction column being controlled at 60 ℃. Collecting the product flowing out of the enzyme reaction column, and removing the fatty acid of the product by molecular distillation. The deacidified fat was decolorized and deodorized to obtain comparative example 1, i.e. refined OPO, the composition of which is shown in table 1.

Comparative example 2

Comparative example 2 was obtained by mixing the OPO oil and fat of comparative example 1 in a weight ratio of 7:2 with a mixed oil of glyceryl stearate and myristica oil (myristic acid 90%) 1: 1. Comparative example 2 fatty acid composition and Sn-2 fatty acid composition are shown in table 1.

Table 1 example and comparative example fatty acid composition with sn-2 saturated fatty acid composition

FAC	Breast milk	Example 1	Example 2	Example 3	EXAMPLE 4	EXAMPLE 5	Example 6	Comparative example 1	Comparative example 2
										C12:0	6.4	3.0	2.5	1.6	1.3	2.8	2.0	0.5	1.8
C14:0	6.4	3.5	3.1	3.3	3.9	4.0	6.6	0.9	6.4
										C16:0	20.9	29.8	26.1	28.7	27.4	28.0	18.2	28.4	24.3
C18:0	7.2	7.0	10.1	6.0	6.2	6.6	6.8	2.1	9.6
										C18:1	31.7	45.0	34.6	39.4	37.5	40.1	50.5	53.7	43.0
C18:2	19.6	10.2	15.4	9.7	14.7	12.2	9.3	10.8	7.9
										％Sn-2M	54.1	50.1	55.4	56.0	54.8	59.0	56.7	40.0	11.4
％Sn-2P	60.5	60.5	42.2	52.1	57.3	51.6	54.5	52.6	50.67
										％Sn-2S	26.8	51.2	53.8	50.2	53.6	55.8	57.2	46.5	11.6
％Sn-2T	49.7	59.5	50.5	50.5	52.9	58.7	55.5	52.1	39.6

Note: % Sn-2M ═ Sn-2 myristic acid content/total myristic acid/3

% Sn-2P ═ Sn-2 palmitic acid content/Total palmitic acid/3

% Sn-2S ═ Sn-2 stearic acid content/total stearic acid/3

% Sn-2T ═ Sn-2 saturated fatty acid content/total saturated fatty acids/3;

as is apparent from the above comparative examples, the OPO grease of comparative example 1 obtained according to the conventional method has a lower content of either myristic acid and/or stearic acid or relative content thereof in Sn-2 than that of examples 1 to 6. When OPO oil and other oil rich in stearic acid and/or myristic acid, such as glyceryl stearate and/or myristic oil, were mixed, as shown in comparative example 2, although the ratio of Sn-2 palmitic acid to total palmitic acid was maintained at 50% or more, the ratio of these Sn-2 saturated fatty acids, Sn-2 stearic acid and/or Sn-2 myristic acid to total saturated fatty acids, stearic acid and/or myristic acid was greatly reduced to less than 15% of the corresponding fatty acids, as compared with examples 1-6. Then The absorption of The corresponding free saturated fatty acids from breast milk fat substitute digestion of comparative example 2 is also greatly reduced during digestion (Jensen C, Buist N, Wilson T. Absorption of inductive fatty acids from breast milk or medium fatty acids [ J ]. The American Journal of clinical Nutrition,1986,43(5): 745-751.). The reason why the absorption of saturated Fatty Acids in comparative example 2 during digestion is low is mainly because the structure of these Fatty Acids in the breast milk fat substitute of comparative example 2 is largely different from that of breast milk fat (Bar-Yoseph F, Lifshitz Y, Cohen T. review of sn-2 lipid oil interference for fat health [ J ]. prostagladins, Leuktries essential Fatty Acids,2013,89(4):139-143.), and the basic object of the present invention is to solve this difference. In examples 1-6, in the fat structure of the breast milk fat substitute obtained by the invention, the saturated fatty acids are mainly located in sn-2 of fatty triglyceride, which is significantly different from the breast milk fat substitute improved by OPO mixed fat of comparative example 2, and the breast milk fat substitute of comparative example 2 only considers the position of palmitic acid in fatty triglyceride, but lacks consideration for the structures of other saturated fatty acids. Therefore, compared with the method for preparing the breast milk fat substitute by mixing OPO oil and other vegetable oil, which is commonly used at present, the method can obtain the oil composition which is more nutritional on the fatty acid composition and the position distribution thereof and is comprehensively close to breast milk fat, and even more nutritional than breast milk, particularly, the oil composition improves the content of stearic acid on the Sn-2 position, reduces the formation of free stearic acid, and reduces the capability of stearic acid forming stearic acid soap with calcium, magnesium and other ions, so that the absorption rate of the oil composition in the process of eating by infants is correspondingly improved, and the absorption rate of the infants to mineral substances is also improved. The breast milk fat substitute obtained by the invention can better improve the digestion and absorption performance of saturated fatty acid, especially palmitic acid and stearic acid, and promote better growth and development of infants.

The foregoing is merely a preferred embodiment of the invention and is not intended to limit the scope of the invention, which is defined by the claims appended hereto, and any other technical entity or method that is encompassed by the claims as broadly defined herein, or equivalent variations thereof, is contemplated as being encompassed by the claims.

All documents referred to herein are incorporated by reference into this application as if each were individually incorporated by reference. Furthermore, it should be understood that various changes and modifications can be made by those skilled in the art after reading the above disclosure, and equivalents also fall within the scope of the invention as defined by the appended claims.

Claims

1. A method for preparing a fat composition, the composition being of non-human milk origin, the content of stearic acid in the fatty acid content being 3-15% by weight, Sn-2 stearic acid constituting more than 35% by weight of the total stearic acid, the method comprising the steps of:

(1) carrying out random ester exchange on grease containing palmitic acid and grease rich in stearic acid, wherein the weight ratio of the grease containing palmitic acid to the grease rich in stearic acid is as follows: 1: 4-10: 1, obtaining ester exchange grease;

(2) reacting the ester-exchanged oil obtained in the step (1) with a fatty acid rich in unsaturated fatty acid or a mixture of esters of the fatty acid rich in unsaturated fatty acid in the presence of a 1, 3-oriented ester exchange catalyst, wherein the ratio of the ester-exchanged oil to the mixture of the ester rich in unsaturated fatty acid or the ester of the unsaturated fatty acid is 1: 0.3-1: 5;

the palmitic acid containing oil is selected from palm oil, palm oil fraction, palm oil hydride or any combination thereof; the stearic acid-rich oil is one or any combination of cocoa butter, shea butter, mango oil and glyceryl stearate.

2. The method according to claim 1, wherein the weight ratio of the palmitic acid-containing fat to the stearic acid-rich fat is 1: 2-8: 1.

3. the method according to claim 1, wherein the weight ratio of the palmitic acid-containing fat to the stearic acid-rich fat is 1: 1-6: 1.

4. the production method according to claim 1, wherein in the step (2), the ratio of the transesterified oil and fat to the unsaturated fatty acid-rich or ester-rich mixture thereof is 1: 0.5-1: 4.

5. the production method according to claim 1, wherein in the step (2), the ratio of the transesterified oil and fat to the unsaturated fatty acid-rich or ester-rich mixture thereof is 1: 1-1: 2.

6. the production method according to claim 1, wherein the palmitic acid-containing fat or oil contains 40% by weight or more of palmitic acid.

7. The production method according to claim 1, wherein the stearic acid-rich oil contains not less than 25% of stearic acid, not less than 25% of oleic acid and/or not less than 5% of palmitic acid.

8. The production method according to claim 1, wherein the stearic acid-rich oil contains not less than 35% of stearic acid; not less than 25% oleic acid and/or not less than 5% palmitic acid.

9. The method according to claim 1, wherein the stearic acid-rich fat further contains myristic acid, and the weight ratio of myristic acid to stearic acid is less than 2.

10. The method according to claim 1, wherein the stearic acid-rich fat further contains myristic acid, and the weight ratio of myristic acid to stearic acid is less than 1.

11. The method according to claim 1, wherein the unsaturated fatty acid content of the mixture of unsaturated fatty acids or esters thereof is greater than 70%.

12. The method according to claim 1, wherein the unsaturated fatty acid content of the mixture of unsaturated fatty acids or esters thereof is greater than 80%.

13. The method according to claim 1, wherein the unsaturated fatty acid content of the mixture of unsaturated fatty acids or esters thereof is greater than 90%.

14. The method according to claim 1, wherein the mixture of unsaturated fatty acids or esters thereof is at least one selected from sunflower oil, soybean oil, rapeseed oil or a mixture of oleic acids from corresponding sources, in terms of fatty acid content.

15. The method according to claim 1, wherein the oil-and-fat composition contains Sn-2 stearic acid in an amount of 40% or more of the total stearic acid content.

16. The method according to claim 1, wherein after the step (2), the method further comprises deacidifying, decoloring and/or deodorizing the obtained fat.

17. The preparation method of claim 1, wherein after the step (2), one or more of fish oil, algae oil and microbial oil are added to the obtained oil, and the addition ratio is 1% -2%.

18. A non-human milk-derived fat composition obtained by the method according to any one of claims 1 to 17, wherein the fat composition contains 15 to 30% by weight of palmitic acid, 5 to 15% by weight of stearic acid, 30 to 65% by weight of unsaturated fatty acids, and less than 20% by weight of myristic acid and lauric acid in total, wherein the fat contains not less than 35% by weight of Sn-2 palmitic acid and not less than 35% by weight of Sn-2 stearic acid in total.

19. The fat and oil composition according to claim 18, wherein the Sn-2 stearic acid in the fat and oil accounts for not less than 37% of the total stearic acid in the weight ratio of the total fatty acids in the fat and oil composition.

20. The fat and oil composition according to claim 18, wherein the Sn-2 stearic acid in the fat and oil accounts for not less than 40% of the total stearic acid in the weight ratio of the total fatty acids in the fat and oil composition.

21. Use of the fat composition according to any one of claims 18 to 20 for the preparation of an infant formula, or a breast milk fat substitute, or a dietary ingredient.