JPH1084866A - Improvement of oxidation stability of dairy products - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide dairy products which are preservable over a long period of time by drastically lessening the formation of uncomfortable smell by photooxidation. SOLUTION: The formation of the uncomfortable smell of the dairy products by the photooxidation is prevented and the oxidation stability thereof is improved by adding <=0.1wt.% ascorbic acid to the dairy products, such as cow's milk.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for improving the oxidative stability of dairy products, and more particularly, the present invention simply and economically improves the oxidative stability of dairy products and suppresses the generation of off-flavors. About the method.

[0002]

2. Description of the Related Art Off-flavors are generated when milk products such as milk are exposed to sunlight and light beams such as fluorescent lamps. Attempts have been made to elucidate the mechanism for this. As a result, it has become apparent that photo-oxidation and the autoxidation induced by it cause severe off-flavors when the dairy product is exposed to light, which eventually makes it difficult to store the dairy product for a long time.

In recent years, riboflavin (ribobo) in dairy products has been
flavin) absorbs light energy,
It was reported that methionine was formed from methionine, and this methional induced off-flavor (Patto).
n, S. et al,. J. Dairy Sci. , 3
7: 446-452 (1954); Enns, K .; et
al. , J. et al. Am. Chem. Soc. , 87 (2
4): 5766-5770 (1965); Allen,
C. et al. , J. et al. Dairy Sci. , 58
(11): 1609 to 1611 (1975)).

Furthermore, the oxidation of tryptophan by light is associated with off-flavor generation of dairy products (Si
Ngleton, T .; A. et al. , J. et al. Dair
ySci. , 46: 1050-1053 (1963)), and that mercaptans, sulfides, disulfides and the like produced by the photooxidation of cysteine are involved in the generation of off-flavors (Harper, W. et al.
J. et al. , J. et al. Dairy Sci. , 47:
548 (1964)).

In this connection, the main causative agents that induce off-flavors in dairy products have not been clearly established to date, but methionine, which can produce dimethyl disulfide, dimethyl sulfide and methanethiol, Methional and cysteine are known as major causative agents of inducing off-flavors in dairy products (Fross,
D. A. , J. et al. Dairy Res. , 46: 691
(1979)).

[0006] On the other hand, riboflavin is generally a photosensitizer, and mainly acts directly on a substrate to form singlet oxygen (single oxygen).
It is known as a substance that promotes photooxidation through the type I pathway without the production of let oxygen. However, recently, riboflavin present in dairy products such as milk absorbs and transmits light energy of sunlight or fluorescent light, and triplet oxygen (tripl) contained in dairy products in a large amount.
et oxygen) was found to be converted to singlet oxygen, which is in a highly reactive state that has a very high energy state and can immediately oxidize other substances.

[0007] Accordingly, singlet oxygen is generated in the dairy product due to the absorption of light energy of riboflavin present in the dairy product, and the dairy product is photo-oxidized and autoxidized by the oxidizing action of the singlet oxygen. Inside, dimethyl disulfide, which is a substance causing off-flavor, is generated.

The prior art for suppressing the generation of off-flavors due to the photo-oxidation of dairy products is based on the fact that dairy packaging containers are mainly made of various materials that do not allow light to pass therethrough, and the dairy products are made of various materials that do not transmit light. Research is focused on ways to prevent photo-oxidation of products (Hansen, AP et.
al. , J. et al. Milk Food Techno
l. , 38 (7): 388-392 (1975); Fa.
nelli, A .; J. et al. , J. et al. Food Pr
protection, 48 (2): 112-117 (19
85)), and there is almost no research to improve the oxidative stability of dairy products.

[0009]

However, the method for suppressing photo-oxidation in the prior art has a restriction that the dairy product must be stored in a packaging container that blocks transmission of light, so that the dairy product is stored in a plastic container or a glass bottle. Cannot be stored in a container that transmits all or part of the light, and the transmission of light must be prevented during the dairy manufacturing process. Had the problem of rising.
Therefore, exposure to light during the production, transportation and storage of dairy products cannot be prevented, and there has been a need for a method capable of effectively suppressing the generation of off-flavors of dairy products.

It is an object of the present invention to provide a method for simply and economically improving the oxidative stability of dairy products so that off-flavors of dairy products due to photo-oxidation can be prevented.

[0011]

SUMMARY OF THE INVENTION The present inventors have found that ascorbic acid (Chou, PTE), which is known to have the ability to quench singlet oxygen.
t al. , Biochem. Biophys. Re
s. Comm. , 115 (3): 932-937 (19
83); Rooney, M .; L. , Photoche
m. Photobiol. , 38 (5): 619-62.
1 (1983); Bodames, R .; S. et a
l. , FEBS Lett. , 105 (2): 195-
196 (1979)) can be chemically quenched to remove singlet oxygen generated by riboflavin present in the dairy product, thereby improving the oxidative stability of the dairy product. The production of off-flavors in dairy products due to light rays.
The present invention has been completed.

The method for improving the oxidative stability of a dairy product according to the present invention, which achieves the above object, includes a step of adding and mixing 0.1% by weight or less of ascorbic acid to the dairy product. At this time, a secondary processed dairy product such as milk or yogurt is used as the dairy product.

On the other hand, as the amount of ascorbic acid added to the dairy product increases, the oxidative stability of the dairy product improves.
If the added amount exceeds 0.1 wt%, the odor of ascorbic acid remains in the dairy product, and the flavor of the dairy product decreases. Therefore,
The upper limit of the amount of ascorbic acid added to dairy products is 0.
1 wt%, preferably 0.05 wt%. Also, the lower limit of the amount of ascorbic acid added to dairy products is
Usually 0.01 wt%, preferably 0.025 w
t%.

In the present invention, ascorbic acid added to dairy products is already edible and stable, and therefore has no adverse effect on the human body when eating or drinking dairy products.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to embodiments. These examples are for describing the present invention more specifically, and the scope of the present invention is not limited to these examples. Example 1 20 ml of skim milk was added to a 150 ml Erlenmeyer flask, and commercially available ascorbic acid was added in the amount shown in Table 1 and mixed homogeneously.
It was left at 0 ° C. for 8 hours. Chemical analysis of skim milk was performed every 4 hours. Chemical analysis was performed by DHA-GC (dynam
ic headspace analyzer-gas
Chromatography was performed by measuring the amount of dimethyl disulfide, which is a causative substance of volatile off-flavor, using a flame ionization detector as a detector. Table 1 shows the amounts of off-flavor causing substances produced when various amounts of ascorbic acid were added. In addition, as a comparative example, skim milk which was left under fluorescent light without adding ascorbic acid was used as a comparative example, and skim milk stored in a dark place without adding ascorbic acid was used as a control group to measure the amount of off-flavor causing substance produced. Are also shown in Table 1.

[0016]

[Table 1]

As can be seen from Table 1, skim milk to which ascorbic acid was added according to this example had a slightly higher amount of off-flavor-causing substances than skim milk stored in a dark place. The amount of off-flavor causatives decreased significantly as the time of exposure to fluorescence increased compared to non-fat skim milk, and the amount of off-flavor causatives increased significantly as the amount of ascorbic acid added increased. Was found to decrease.

Example 2 20 ml of skim milk was added to a 150 ml Erlenmeyer flask.
After ascorbic acid was added in the amount shown in Table 2 and mixed uniformly, the mixture was allowed to stand under sunlight for 1 hour from 4:00 pm on a sunny day with a lot of sunshine. Next, using DHA-GC and a flame ionization detector, the amount of dimethyl disulfide, which is a substance causing volatile off-flavor, was measured. In addition, a panel of 16 untrained consumers was scored on a 10-point perfume scale (hedonic sc).
ale), a sensory test was performed on the off-flavor of skim milk. The sensory test was performed with 1 point when there was no off-flavor and 10 points when the off-flavor was severe. Skim milk left without exposure to ascorbic acid in the sunlight was used as a comparative example, and skim milk stored in a dark place packed in aluminum foil without adding ascorbic acid was used as a control group. Table 2 shows the results of measuring the amount of disulfide produced and the results of the sensory test.

[0019]

[Table 2]

As is evident from Table 2, the skim milk to which ascorbic acid was added according to this example was exposed to sunlight as compared with the skim milk to which ascorbic acid was not added, similarly to the result of Example 1. It was found that the amount of off-flavor-causing substances produced when the treatment was carried out was significantly reduced, and the amount of off-flavor-causing substances produced was significantly reduced with an increase in the amount of ascorbic acid added. Therefore, DHA-G
It was confirmed that the analysis result by C mutually agreed with the result of the sensory test. On the other hand, the same off-flavor reduction effect as in the above example could be confirmed in a milkshake produced from milk to which ascorbic acid was added.

[0021]

According to the method for improving the oxidative stability of dairy products of the present invention, off-flavor generation of dairy products by photooxidation can be reduced significantly and simply.

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor David B. Min United States 43214 Columbus, Ohio Blairfield Drive 4751

Claims (1)

[Claims] 1. A method for improving the oxidative stability of a dairy product, comprising a step of adding and mixing 0.1% by weight or less of ascorbic acid to the dairy product.