KR100899900B1 - Method for improving oxidative stability of fat and oil by using enzymatic interesterification - Google Patents

Abstract

The present invention relates to a method for improving the oxidative stability of fats and oils, and more specifically, 1) mixing a solid fats and vegetable-derived liquid fats and oils; And 2) performing Enzymatic Interesterification (EI) in which the mixed oil is allowed to remain at 70 ° C. for 24 to 60 minutes in a Packed Bed Reactor (PBR) in which lipase is present. It relates to a method for improving the oxidation stability of fats and oils through.

Solid oils and fats, vegetable oils, lipases, transesterification, peroxide value, anisidine, conjugated biacid content, oxidation stability

Description

Method for improving oxidative stability of fat and oil by using enzymatic interesterification

The present invention relates to a method for improving the oxidative stability of fats and oils, and more specifically, 1) mixing a solid fats and vegetable-derived liquid fats and oils; And 2) performing Enzymatic Interesterification (EI) in which the mixed oil is allowed to remain at 70 ° C. for 24 to 60 minutes in a Packed Bed Reactor (PBR) in which lipase is present. It relates to a method for improving the oxidation stability of fats and oils through.

Foods containing high fats and fats are easily oxidized during processing and storage, resulting in loss and toxicity in terms of smell, taste, and nutrition. Therefore, the inhibition of fats and oils is recognized as an important problem in the food industry using them as raw materials. Oxidation of fats and oils is caused by thermal oxidation and photooxidation in addition to automatic oxidation by radicals. Peroxides produced by oxidation are unstable and progress to various secondary oxides by various reactions such as polymerization or decomposition. Various radicals and secondary oxides produced during peroxidation react variously with biological components such as proteins and vitamins around them and cause nutrient deterioration, bioactivity and biochemical function impairment.

The simplest method for inhibiting or delaying the oxidation of such undesirable fats and oils is the addition of antioxidants, in addition to blocking oxygen, light and heat, inhibiting photosensitizer action, inactivating singlet oxygen and free radicals. There are several ways, including stabilization.

In recent years, development of new geological materials to secure the problems of maintenance. In particular, reconstituted lipids that improve the physical and chemical properties of fats and oils by changing the fatty acid position of the fats and oils in the glycerol molecule without adding new substances are available for the manufacture of foods that are industrially and nutritionally functional. . In addition, such reconstituted lipids have the advantage that the oxidative stability can be improved as compared to the existing maintenance by changing the molecular structure in itself.

Transesterification is used to produce reconstituted lipids. At present, the most important and attempted method in fat manufacturing is chemical transesterification using chemical catalysts and enzymatic reaction using enzymes. Transesterification (EI). In the case of CI, an alkali catalyst is mainly used, and sodium methoxide is most widely used. Currently, not only overseas but also major domestic processing and maintenance companies produce various kinds of processing and maintenance products using CI method. In the case of EI using an enzyme, lipase is used as a catalyst, and activity and specificity are known to be different depending on the type of microorganism producing lipase. The advantages of EI are that the process is relatively simple, the product is easy to produce, the food is stable, and it is environmentally friendly. Therefore, preference for enzymatic transesterification is a global trend.

In order to overcome the problem that the previously used fats and oils are easily oxidized by the automatic oxidation or light or heating, the present inventors add a mixed oil mixed with solid fats and vegetable oils to a continuous reactor (PBR). The present invention has been completed by discovering that oil-enhanced fats and oils can be prepared by using an enzymatic transesterification reaction, which is added with lipase and allowed to react for a specific time at a specific temperature.

Accordingly, it is an object of the present invention to provide a method for improving the oxidative stability of fats and oils by synthesizing previously used fats and oils into new reconstituted lipids using enzymatic transesterification in a continuous reactor (PBR).

In order to achieve the above object, the present invention comprises the steps of: 1) mixing a solid fat and vegetable-derived liquid fat; And 2) performing an enzymatic transesterification reaction in which the mixed oil is allowed to react at 70 ° C. for 24 to 60 minutes in a continuous enzyme reactor (PBR) in which lipase is present, thereby improving the oxidation stability of the fat or oil. To provide.

In the present invention, as part of the development of a new lipid material, by performing the transesterification reaction using an enzyme, not only can improve the physical and chemical properties of the fats and oils, but also produce enzymes with improved nutritional functionality, It is eco-friendly and has specificity, so it has high yield, saves energy and secures food safety.

In addition, as the molecular structure inside itself was changed by the transesterification reaction, oxidative stability was improved as compared with conventional fats and oils. In particular, the present invention improves the quality of fats and oils by increasing the oxidation stability of the fats and oils without other treatments such as addition of antioxidants or additional process treatments such as blocking of oxygen, light and heat.

Hereinafter, the present invention will be described in more detail.

The present invention provides a method for improving the oxidative stability of fats and oils through the following steps:

1) mixing solid fats and vegetable derived liquid fats; And

2) performing an enzymatic transesterification reaction in which the mixed oil is allowed to stay at 70 ° C. for 24 to 60 minutes in a continuous enzyme reactor (PBR) in which lipase is present.

As used herein, the term "solid fats" refers to fats and oils that maintain a solid state at room temperature, and is generally palm oil, palm stearin oil, palm kernel oil, palm kernel oil, extremely hardened oil, vegetable-derived hardened oil, tallow, lard, palm oil. Coconut oil and extremely hard oil.

In addition, the term "vegetable-derived liquid fats" used in the present invention refers to vegetable-derived fats that are maintained in a liquid state at room temperature and generally include high oleic acid sunflower seed oil, sunflower seed oil, grape seed oil, olive oil and soybean oil. The high oleic acid sunflower seed oil is derived from the sunflower seed improved by increasing the oleic acid content can be easily selected by those skilled in the art.
Among the expressions "fats and oils" described herein, those which are not classified as "solid fats" or "liquid fats" or whose origins are not described mean fats or oils prepared by mixing or transesterifying the solid fats and liquid fats. do.

In the present invention, it is preferable to use an extremely hardened oil derived from soybean oil as a solid fat or oil, and a high oleic acid sunflower seed oil as a liquid fat derived from a vegetable, but the present invention is not limited thereto. It can be seen that the same effect as the oxidation stability improvement through the enzymatic transesterification reaction presented in the present invention, which also belongs to the scope of the present invention. The mixing ratio of the solid fats and vegetable-derived liquid fats and oils is preferably 8: 2 to 6: 4 by weight, most preferably 6: 4.

The lipase used in the present invention can be used either from microorganisms, plants and animals, for example Rhizopus delemar , Mucor miehei and Alcaligenes lipases having selectivity at positions 1 and 3 of glycerides derived from microorganisms such as sp. Aspergillus niger , Candida antarctica , Candida cylindracea , and Geotrichum candidum Random lipases derived from microorganisms such as these; Lipases derived from plants such as soybean minuka hima seed; And pancreatic lipases of animals. In general, it is convenient to use commercially available products, and immobilized lipases obtained according to certain rules, such as lipase itself, adsorption ion or covalent bonding method, such as lipase itself, for example, a Novo company lipozyme ( Lipozyme) RM IM ( Rhizomucor miehei ), lipozyme TL IM ( Thermomyces lanuginosus ) or Novozym 435 ( Candida antarctica ); Lipase PS-C ( Burkholderia cepacia ) or lipase PS-D ( Burkholderia cepacia ) from Amano; Or microorganisms such as fungi, yeasts and bacteria that have the ability to produce lipases can be used.

In practice, the longer the residence time in the reactor of the fat or oil in the reactor, the more the reaction occurs, but the oxidation stability may be rather deteriorated because the position of the fatty acid in the fat or oil molecule is continuously changed. Therefore, in order to secure the oxidative stability of fats and oils, the reaction must be terminated when the transesterification reaction does not occur excessively.

In the present invention, in order to find the end point of the reaction to improve the oxidative stability of the prepared fats and oils are prepared through various reaction times, the peroxide value (p-anisidine value) and conjugated (p-anisidine value) and conjugated The degree of oxidative stability improvement of fats and oils was evaluated using the conjugated dienoic acid value.

The transesterification reaction was based on the content of SOS, POP and POS produced by the exchange of solid fats (SSS: tristearin, PPP: tripalmitin) and liquid fats (OOO: triolein). If the exchange reaction lasts more than the proper reaction time, the SOS, POP, and POS generated are the side reactions of acyl migration, ie, the excessive reactions and the exchange reaction of fatty acid molecules in neutral lipids. Change to PPO The triglyceride sn -1, sn -2, sn -3 SOS, POP and POS with a O in the sn -2 position of the location is known, but high oxidation stability, Ah due to movement of the second spot group, i.e. sn -2 Oxidation stability is reduced by exchange with fatty acids other than O in place (O: oleic acid, P: palmitic acid, S: stearic acid) [Charment O. Moussata and Casimir C. Akoh, Influence of lipase-catalyzed interesterification on the oxidative stability of melon seed oil triacylglycerols, JAOCS , vol 75, No. 9, 1155-1159, 1998].

Hereinafter, the content of the present invention will be described in more detail with reference to Examples. However, these examples are only presented to understand the contents of the present invention, but the scope of the present invention is not limited to these embodiments.

Comparative Example 1

A sample was prepared in which an extremely hardened oil derived from soybean oil and a high oleic acid sunflower seed oil were mixed at a weight ratio of 6: 4.

Comparative Example 2

A sample containing a mixture of extreme hardened oil derived from soybean oil and high oleic sunflower seed oil at a weight ratio of 6: 4 was completely filled with a enzyme ( lipozyme TLIM, Thermomyces lanuginosus ) in a continuous reactor (PBR, length: 20 cm, inner diameter: 1.5 cm). Thereafter, the mixture was reacted by flowing the mixed oil at a constant rate so that the mixed oil could contact the enzyme in the reactor for 3 minutes.

Comparative Example 3

A sample containing a mixture of extreme hardened oil derived from soybean oil and high oleic sunflower seed oil at a weight ratio of 6: 4 was completely filled with a enzyme ( lipozyme TLIM, Thermomyces lanuginosus ) in a continuous reactor (PBR, length: 20 cm, inner diameter: 1.5 cm). Thereafter, the mixture oil was reacted by flowing the mixed oil at a constant rate so that the mixed oil could contact the enzyme in the reactor for 9 minutes.

[Comparative Example 4]

A sample of a mixture of extreme hardened oil derived from soybean oil and high oleic sunflower seed oil at a weight ratio of 6: 4 was completely filled with enzyme ( lipozyme TLIM, Thermomyces lanuginosus ) in a continuous reactor (PBR, length: 20 cm; inner diameter: 1.5 cm). Thereafter, the mixture oil was reacted by flowing the mixed oil at a constant rate so that the mixed oil could contact the enzyme in the reactor for 100 minutes.

Example 1

A sample containing a mixture of extreme hardened oil derived from soybean oil and high oleic sunflower seed oil at a weight ratio of 6: 4 was completely filled with a enzyme ( lipozyme TLIM, Thermomyces lanuginosus ) in a continuous reactor (PBR, length: 20 cm, inner diameter: 1.5 cm). Thereafter, the mixture oil was reacted by flowing the mixed oil at a constant rate so as to be in contact with the enzyme in the reactor for 24 minutes.

Example 2

A sample containing a mixture of extreme hardened oil derived from soybean oil and high oleic sunflower seed oil at a weight ratio of 6: 4 was completely filled with a enzyme ( lipozyme TLIM, Thermomyces lanuginosus ) in a continuous reactor (PBR, length: 20 cm, inner diameter: 1.5 cm). Thereafter, the mixture oil was reacted by flowing the mixed oil at a constant rate so as to be in contact with the enzyme in the reactor for 60 minutes.

Test Example 1 Analysis of Transesterification Degree

In order to determine the degree of transesterification by the enzymes of the fats and oils prepared in Examples 1 to 2 and Comparative Examples 1 to 4, the triolein content of each fat or oil was analyzed by using a liquid chromatography method. According to the degree of transesterification (DC: Degree of Conversion,%) was calculated, the results are shown in FIG.

In the results of Figure 1, the longer the transesterification reaction time was confirmed that the degree of transesterification was improved, in particular, in Example 1, Example 2 and Comparative Example 4 reacting more than 24 minutes it can be confirmed that the degree of transesterification is high. there was.

Test Example 2 Peroxide Value Measurement

In order to confirm the oxidative stability of the fats and oils prepared in Examples 1 and 2 and Comparative Examples 1 to 4, the peroxide value showing the degree of formation of the peroxide as the primary oxide was measured while storing the fats and oils in a 70 ° C. incubator for 20 days (AOCS Official Method Cd 8-53). Oils stored in the incubator were taken out at intervals of 5 days, titrated with 0.01 N Na ₂ S ₂ O ₃ , and the peroxide values were calculated according to the following Equation 2, and the results are shown in Table 1 below.

B = ₃ ml of 0.01 N Na ₂ S ₂ O consumed during the blank titration

S = ₃ ml of 0.01 N Na ₂ S ₂ O consumed in the sample titration

N = normal concentration of Na ₂ S ₂ O ₃ used in the titration

Peroxide Value (mq / kg) Storage period (day) Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 0 3.98 5.54 1.99 4.03 1.83 3.80 5 29.80 28.65 25.26 28.54 23.30 23.39 10 39.92 39.55 39.35 39.52 37.39 36.76 15 215.05 192.38 142.10 170.22 48.97 53.21 20 385.21 365.55 263.63 303.58 119.70 175.30

In the results of Table 1, all of Examples 1 to 2 according to the present invention showed a lower peroxide value compared to Comparative Examples 1 to 4. In addition, as the transesterification time increased, the peroxide content was lowered. However, in comparison with Examples 1 and 2, the peroxide content of Example 2, which was reacted for 60 minutes, was higher than that of Example 1, and the comparative example was reacted for 100 minutes. At 4, the peroxide content increased dramatically. This is because prolonged transesterification results in lowered oxidative stability due to the continuous change of position of fatty acids bound to glycerol. Therefore, it was confirmed that Example 1 is the most ideal condition for improving the oxidation stability.

Test Example 3 Anicidin

In order to confirm the oxidative stability of the fats and oils prepared in Examples 1 and 2 and Comparative Examples 1 to 4, the anisidine value showing the degree of formation of the secondary oxide anisidine was measured while storing the fats and oils in a 70 ° C. incubator for 20 days. (AOCS Official Method Cd 18-90). The oils stored in the incubator were taken out at intervals of 5 days, reacted with the p-anisidine reagent, and then absorbance was measured with a spectrophotometer at 350 nm, respectively, to calculate an p-anisidine value according to Equation 3 below. The results are shown in Table 2 below.

As = absorbance value of the sample mixture after reaction with p-anisidine reagent

Ab = absorbance value of the sample mixture

m = mass (g) used in the experiment

Anisidin Storage period (day) Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 0 6.25 6.02 5.35 5.40 4.20 5.75 5 15.91 15.01 13.29 13.98 11.82 11.90 10 29.23 27.13 22.64 26.10 14.35 18.26 15 96.97 71.20 65.33 67.85 38.29 40.99 20 131.08 95.81 80.39 88.70 62.21 72.76

In the results of Table 2, Examples 1 to 2 according to the present invention all showed lower anicidine measured values than Comparative Examples 1 to 4. In addition, as the transesterification time increased, the content of anidine was lower, but when comparing the Examples 1 and 2, rather than the reaction time for 60 minutes in Example 2 was higher than Example 1, and reacted for 100 minutes In Comparative Example 4, the anicidine content increased rapidly. This is because prolonged transesterification results in lowered oxidative stability due to the continuous change of position of fatty acids bound to glycerol. Therefore, it was confirmed that Example 1 is the most ideal condition for improving the oxidation stability.

Test Example 4 Content of Conjugated Double Acid

In order to confirm the oxidative stability of the fats and oils prepared in Examples 1 and 2 and Comparative Examples 1 to 4, the content of conjugated biacid as a secondary oxide was measured while storing the fats and oils in a 70 ° C. incubator for 20 days (AOCS Official Method Ti 1a-64). The oil and fats stored in the incubator were taken out at intervals of 5 days, and the absorbance was measured with a spectrophotometer at 233 nm, respectively. The content of the conjugated biacid was calculated according to Equation 4 below, and the results are shown in Table 3 below.

K ₀ = Absorption rate by acid or ester group (acid: 0.03 / ester: 0.07)

Absorbance value of the sample at A _s = 233 nm

b = length of the cuvette in cm

c = concentration of sample (g / L)

Conjugated biacid content Storage period (day) Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 0 0.08 0.08 0.06 0.06 0.05 0.05 5 0.19 0.11 0.08 0.08 0.05 0.05 10 0.42 0.36 0.30 0.31 0.14 0.19 15 1.96 1.80 1.67 0.70 0.50 0.69 20 3.02 2.67 2.35 2.41 1.4 2.03

In the results of Table 3, Examples 1 to 2 according to the present invention all showed a low conjugated double acid measured value compared to Comparative Examples 1 to 4. In addition, as the transesterification time increased, the content of conjugated biacid was lowered. However, when compared with Examples 1 and 2, the conjugated biacid content of Example 2, which was reacted for 60 minutes, was higher than that of Example 1, and reacted for 100 minutes. In Comparative Example 4, the content of conjugated biacid was increased rapidly. This is because prolonged transesterification results in lowered oxidative stability due to the continuous change of position of fatty acids bound to glycerol. Therefore, it was confirmed that Example 1 is the most ideal condition for improving the oxidation stability.

Based on the above results, it was confirmed that by carrying out the enzymatic transesterification reaction according to the present invention, fats with low peroxide value, anisidine and conjugated biacid content, that is, fats with improved oxidation stability, could be prepared.

1 is a graph showing the degree of transesterification of the fats and oils prepared in Examples 1-2 and Comparative Examples 1-4.

Claims (5)

1) mixing solid fats and vegetable-derived liquid fats and oils in a weight ratio of 8: 2 to 6: 4; And 2) performing Enzymatic Interesterification (EI) in which the mixed oil is allowed to remain at 70 ° C. for 24 to 60 minutes in a Packed Bed Reactor (PBR) in which lipase is present; Method to improve the oxidative stability of fats and oils through an enzymatic transesterification reaction comprising a. The oxidation of oil or fat according to claim 1, wherein the solid fat or oil is selected from the group consisting of palm oil, palm stearin oil, palm kernel oil, palm kernel oil extreme hardened oil, vegetable derived extreme hardened oil, tallow, lard, palm oil and palm oil extreme hardened oil. How to improve stability. The method of claim 1, wherein the vegetable-derived liquid oil or fat is selected from the group consisting of high oleic acid sunflower seed oil, sunflower seed oil, grape seed oil, olive oil and soybean oil. delete The method of claim 1, wherein the lipase is Rhizopus delemar , Mucor miehei , Alcaligenes sp. , Aspergillus niger , Candida antarctica, Candida cylindracea and Geotricum Candidum Lipases derived from microorganisms including Geotrichum candidum ); Lipases derived from plants including soybean minuka hima seed; And at least one member selected from the group consisting of pancreatic lipases from animals.

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