JP2953091B2 - Method of controlling oxidation of fats and oils - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-in-water emulsion having an oily phase composed of a fatty acid containing a polyunsaturated fatty acid as an oily phase, wherein superoxide dismutase (hereinafter abbreviated as SOD) is added to the aqueous phase. Coexistence with sodium caseinate to dramatically increase the active oxygen scavenging activity of SOD and suppress the oxidative degradation of unsaturated fatty acids by active oxygen, effectively utilizing the physiological activity of unsaturated fatty acids This is a novel method for suppressing the oxidative deterioration of fats and oils that can be used for oil and fat.

[0002]

2. Description of the Related Art Recently, as the physiological activities of polyunsaturated fatty acids have been elucidated, fats and oils containing them have attracted attention. For example, perilla oil containing α-linolenic acid, evening primrose oil containing γ-linolenic acid, fish oil containing EPA (eicosapentaenoic acid) / DHA (docosahexaenoic acid), and polyunsaturated fatty acids produced by microbial fermentation There are oils and fats. However, these fats and oils containing polyunsaturated fatty acids easily generate peroxides by light or catalysts, and the decomposition causes the autoxidation reaction, which is a radical chain reaction, to easily cause quality deterioration. As a result, it was very difficult to use it in an actual food form.

[0003] Further, many antioxidants have been studied in order to suppress this oxidative deterioration, and tocopherol is generally used at present. Tocopherol is excellent not only in its antioxidant properties but also in safety. Among them, α-tocopherol has a physiological effect as vitamin E and is an excellent antioxidant. However, although tocopherol is excellent in oil, it is also known that it works as an antioxidant in a system in which water coexists (JAOCS 57: 225 (1)
980), JAOCS 61: 1212 (198).
4)), it cannot be expected to be very effective as an antioxidant in emulsified foods in which water and oil coexist.

[0004] Although spices have been studied as having an antioxidant effect in an emulsifying system, the effect has not reached a practical level with fats and oils containing a large amount of polyunsaturated fatty acids, and at present it is effective. There is no method for suppressing the oxidation reaction.

[0005] As a method for solving this problem, a method for suppressing the oxidation of fats and oils by using an enzyme SOD having an active oxygen scavenging activity has recently been reported. For example, it has been shown that the method disclosed in JP-A-60-1295 suppresses the oxidation reaction of ricinoleic acid, a fatty acid,
J. Agric. Food Chem. 1989, 3
In the method shown in 7, 23-28, linoleic acid and the like are studied.

However, in these experimental examples, the enzyme S
The active oxygen scavenging activity of OD is not sufficiently expressed,
If the amount of OD added to fatty acids is large, and if it is intended to apply to fats and oils containing polyunsaturated fatty acids, the amount of addition must be increased further, and there is a problem in actual application to foods.

Further, as shown in Example 1 of the present invention, there is a problem that in the presence of an emulsifier (sugar ester / lecithin), an oil-in-water emulsion has only a very small effect of inhibiting oxidation of polyunsaturated fatty acids in an oil-in-water emulsion. there were.

[0008]

The problem to be solved is to sufficiently express the ability of SOD, an in vivo enzyme, to scavenge active oxygen in the form of food, and to suppress the oxidation of fats and oils containing polyunsaturated fatty acids. Thus, the physiological activity of polyunsaturated fatty acids can be effectively used for foods and the like.

[0009]

The present inventors have found that the coexistence of sodium caseinate in the aqueous phase of an oil-in-water emulsion significantly improves the active oxygen scavenging activity of SOD, and has completed the present invention. It has arrived. That is, the present invention relates to an oil-in-water emulsion,
A method for suppressing oxidation of fats and oils, wherein D and sodium caseinate coexist. Using the method of the present invention,
The purpose of suppressing the oxidative deterioration of fats and oils containing polyunsaturated fatty acids by utilizing the active oxygen scavenging ability of SOD in foods, by a simple method, without impairing the characteristics of foods such as taste, color tone and smell It was realized. Hereinafter, the present invention will be described in more detail.

It is well known that polyunsaturated fatty acids are easily oxidized by light, metal catalyst, heat, etc.

[0011] SOD is also called superoxide disproportionating enzyme (EC 1.15.1.1.), And is known as an enzyme that catalyzes the disproportionation reaction of the superoxide anion radical. It suppresses the oxidation reaction of lipids etc. (according to the enzyme handbook). Also, SOD is widely present in the living world, and has metals such as iron, manganese, copper, and zinc as its active center depending on the type of organism, but it is known that it exhibits the same activity regardless of the type of metal. .

The SOD used in the present invention is not particularly limited to its origin. For example, it is possible to use SOD obtained from bovine erythrocytes and liver, or SOD obtained from microorganisms such as yeasts and bacteria. it can.

In the present invention, the amount of SOD added depends on the type and content of the polyunsaturated fatty acid in the fat or oil, but is generally 5 to 100 units / gram, preferably 10 to 50 units / gram relative to the fat or oil. A corresponding amount may be added to the aqueous phase forming an oil-in-water emulsion.

As the sodium caseinate coexisting with the SOD used in the present invention, a commercially available one can be used as it is, and its addition amount is 0.01% to 10% with respect to the aqueous phase forming an oil-in-water emulsion. Preferably 0.
What is necessary is just to add 1%-3%. Excessive addition of sodium caseinate does not suppress the activity of SOD, but excessive addition is not preferred in view of contamination by various bacteria.

As fats and oils containing polyunsaturated fatty acids, α
-Condensation of polyunsaturated fatty acids from perilla oil containing linolenic acid, evening primrose oil containing γ-linolenic acid, fish oil containing EPA / DHA, and polyunsaturated fatty acids produced by microbial fermentation Although oils and the like can be used, there is no particular limitation to these oils and fats, and there is no problem even if safflower oil, rapeseed oil, soybean oil, etc., which are generally used as edible oils, are used.

In order to produce an oil-in-water emulsion, oils and fats containing polyunsaturated fatty acids may be emulsified in an oil-in-water type in an aqueous solution containing an emulsifier, sodium caseinate and SOD. As a method of adding SOD, there are the above-mentioned method of dissolving in an aqueous phase before emulsification, and a method of adding after emulsification. In the latter case, when the enzyme powder is directly added to the emulsion, it is uniformly dispersed. In some cases, it is difficult to dissolve the SOD, and in this case, it is preferable to dissolve the SOD in distilled water or a buffer in advance and add the SOD to the emulsion.

The type of the emulsifier used in the present invention is not particularly limited, but sucrose fatty acid esters, polyglycerin fatty acid esters, lecithin, sorbitan fatty acid esters and the like, which are generally approved as food additives, are used alone or in combination. I just need. The amount of the emulsifier to be added is not particularly limited, but is usually 0.1 to 5.0 with respect to the emulsion.
% By weight, preferably 0.4 to 3.0%.
Hereinafter, examples of the present invention will be described, and it will be clarified that the oxidation of fats and oils containing polyunsaturated fatty acids shown in the examples is significantly suppressed by SOD in the presence of sodium caseinate. Of course, the present invention is not limited to the examples.

[0018]

Example 1 When preparing an oil-in-water emulsion, the difference in antioxidant power of SOD between the system with and without sodium caseinate using sugar ester of stearic acid (HLB = 11) as an emulsifier. I saw As the oil phase component of the emulsion, a refined fish oil obtained from a sardine containing EPA / DHA which is a polyunsaturated fatty acid was used. The EPA
-The DHA content was 21% in total. Distilled water 20
0 g of sugar ester of stearic acid as an emulsifier in 4 g
g and 2 g of sodium caseinate were added and dissolved sufficiently by heating and stirring, then cooled to room temperature, and 4000 units (20 units / oil.g) of purified powder SOD obtained from the liver of a cow was added and dissolved. Preliminary emulsification was performed by dropping 200 g of the above-mentioned fish oil into this aqueous enzyme solution with stirring, and then emulsified into an oil-in-water emulsion using a high-pressure homogenizer.
Separately from the above preparation conditions, those prepared without the addition of both casein sodium and SOD, those prepared without the SOD only, those prepared without the sodium caseinate only, and these were used as controls and prepared in the same manner (Table 1). ). The four emulsified solutions were stored in a dark place at 35 ° C., and the fat and oil components were extracted and removed with a mixed solvent of chloroform-methanol, and then the peroxide value was measured to determine the oxidation rate. Table 2 shows the results.

[0019]

[Table 1]

[0020]

[Table 2]

Table 2 shows the change with time of the peroxide value. Compared with Comparative Examples 1-1 and 1-3, the antioxidant effect was remarkably recognized despite the addition of the enzyme SOD. Not. However, in Example 1 in which sodium caseinate was added to the enzyme SOD, the oxidation reaction did not substantially proceed at all, indicating that the addition of sodium caseinate significantly increased the enzyme activity.
The reason why the oxidation rate of Comparative Example 1-2 is slightly lower than that of Comparative Example 1-1 is probably that sodium caseinate itself has an antioxidant effect.

Example 2 Next, an oil-in-water emulsion was prepared in the same manner as in Example 1 except that the stearic acid sugar ester as an emulsifier was changed to lecithin, and the effect of sodium caseinate on SOD activity was examined. As in Example 1, as a comparative example, sodium caseinate and SOD-free additive, SO
Three samples were prepared by the same method without the addition of D alone and three samples except for sodium caseinate alone (Table 3). Table 4 shows the change with time of each peroxide value.

[0023]

[Table 3]

[0024]

[Table 4]

When lecithin was used as an emulsifier, the enzyme activity of SOD was not expressed at all unless sodium caseinate was added (Comparative Example 2-3). In Example 1 in which sugar ester was used as an emulsifier, considering that a slight antioxidant effect was observed even in a system in which sodium caseinate was not added, it is clear that the SOD activity expression is greatly affected by the emulsified state. It is. However, as shown in Table 4, even when lecithin is used as an emulsifier, the addition of sodium caseinate allows the enzyme activity to be expressed and the oxidation reaction to be completely suppressed.

Example 3 Next, the effect was examined by changing the addition amount of SOD. The addition amount was SOD-free, 5 units / oil. g, 10 units / oil. g, 20 units / oil. g. 200 g of purified sardine oil and 200 g of distilled water were used as fats and oils, and 4 g of sodium caseinate and 2 g of lecithin were used. The preparation was carried out in the same manner as in Example 1, and the effect of inhibiting oxidation was observed in the same manner. Table 5 shows the results.

[0027]

[Table 5]

As shown in Table 5, a significant effect was observed in the SOD-added group. Especially SOD10 unit / oil. The effect was remarkable with the addition of g or more.

Example 4 The effect of adding SOD was examined using an sesame oil containing α-linolenic acid as the oil to be emulsified. The perilla oil obtained by pressing was subjected to a silica gel column treatment, and the neutral oil fraction was separated and used for the test. The emulsifier and the preparation were carried out in the same manner as in Example 1, and the added amount of SOD was 20 units / oil. g. As a comparative control, Table 6 also shows the results of the perilla oil without emulsification and the results of the perilla oil in an emulsified solution without SOD and sodium caseinate.

[0030]

[Table 6]

From Table 6, it is shown that emulsified perilla oil tends to be slightly more susceptible to oxidation with the emulsifier sugar ester alone than perilla oil itself.
In the case where D and sodium caseinate were added, oxidation was not progressed at all, and the effect was high.

Example 5 Next, using SOD of microbial origin, comparison was made with SOD obtained from cattle liver. The origin of the microorganism is Saccharomyces cerevi, which is a yeast.
siae var. ellipsoidus ATCC
560 Agric. Food Chem. 19
89, 37, 23-28. The emulsified solution was prepared using the same oil and fat raw materials and emulsifier as in Example 1, and the amount of SOD added was 10 units / oil. The procedure was performed in the same manner except that g was used. As a comparative example, SOD obtained from beef liver was performed under the same conditions. The results are shown in FIG. 7, and the SOD of microbial origin showed a higher antioxidant effect despite the same number of added units.

[0033]

[Table 7]

[0034]

As described above, the present invention relates to the activity of superoxide dismutase in oil-in-water emulsions by allowing superoxide dismutase to coexist in the aqueous phase with sodium caseinate which is inexpensive and does not impair the characteristics of food. By dramatically increasing the oxygen scavenging activity and suppressing the oxidation of fats and oils, there is an advantage that the physiological activity inherent in polyunsaturated fatty acids can be effectively used for foods and the like. Actual foods that have the form of an oil-in-water emulsion include dressings, mayonnaise, creams, and artificial milks, which have been impossible to add due to the oxidative deterioration of polyunsaturated fatty acids. Can also be applied without deterioration in quality such as flavor.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ identification code FI A23L 1/24 A23L 1/24 A C11B 5/00 C11B 5/00 (58) Investigated field (Int.Cl. ⁶ , DB name ) C09K 15/04 A23C 11/00 A23C 13/10 A23D 9/06 A23L 1/19 A23L 1/24 C11B 5/00 BIOSIS (DIALOG) JICST file (JOIS) WPI (DIALOG)

Claims (1)

(57) [Claims] 1. A method for inhibiting oxidation of fats and oils, wherein superoxide dismutase and sodium caseinate coexist in an aqueous phase in an oil-in-water emulsion.