Process for preparing beverage containing .beta.-carotene

The present invention offers a method for preparing a .beta.-carotene fortified beverage to prevent loss of the .beta.- carotene therefrom, more particularly by the admixture of vitamins C, B.sub.2 and E with .beta.-carotene to stabilize the latter even under ambient conditions to minimize its loss from a beverage. The admixture of such anti-oxidative vitamins is designed in a well-balanced fashion for human nutrition.

BACKGROUND OF THE INVENTION 
The present invention relates to a process for preparing a .beta.-carotene 
fortified beverage in order to prevent the loss of .beta.-carotene, more 
particularly by the admixture of vitamins C, B.sub.2 and E with 
.beta.-carotene to stabilize the latter even in ambient conditions to 
minimize its loss in the form of a beverage; in addition, the admixture of 
such anti-oxidative vitamins is designed in a well-balanced fashion for 
human nutrition. 
.beta.-carotene, now regarded as one of the primary functional components, 
has been considered to be provitamin A. However, recently its 
anti-oxidative property has drawn keen attention. Namely, .beta.-carotene 
has been found to neutralize singlet oxygen which otherwise primes 
preoxidation of unsaturated fatty compounds. The reactive oxygen is 
generated from inspired oxygen and results in pathological aging with 
excess oxidative stress. The effective modulation of reactive oxygen may 
mean anti-aging. Therefore, there would be no surprise even though the 
constant intake of .beta.-carotene has been shown to decrease the 
incidence of cancer, especially lung cancer, in epidemiological research. 
A lower content of serum .beta.-carotene in a smoker might be due to ample 
free-radicals in the puffed fume. Therefore, intake of enough B-carotene 
constitutes a good preventive measure for the most serious kinds of 
cancer. Thus, it has long been sought to provide any easily accessible 
source of .beta.-carotene in daily life. 
A known beverage containing .beta.-carotene includes carrot juice, as well 
as the mixture of carrot juice with other juice or juices, with or without 
fortification of its principal components, and is sold in can, bottle, 
carton, or plastic container. Even short surveys of this kind of product 
disclose very poor shelf-life, namely degrading color, flavor and taste 
over time. Especially, .beta.-carotene is prone to discolor or oxidize by 
the irradiation of light (C.A. Pesek and J. J. Warthesen, J. Food Science 
52 (3), 1987). Naturally, .beta.-carotene is not only photo-sensitive but 
also reactive with oxygen, reflected by its structure, which makes 
construction of a long-life beverage containing .beta.-carotene a matter 
of difficulty. 
It is no wonder that so far no effective protection method has been 
invented for preparing such a .beta.-carotene beverage. We extensively 
pursued the above aim, namely, how to stabilize the .beta.-carotene moiety 
in a long-life beverage under ambient conditions without vitiating its 
flavor and have thus completed the present invention. 
SUMMARY OF THE INVENTION 
The present invention comprises a method of preparing a beverage containing 
.beta.-carotene by coexisting three other anti-oxidative vitamins, namely 
vitamins C, B.sub.2 and E, in order to prevent the loss of 
.beta.-carotene; and a method of preparing a beverage containing 
.beta.-carotene, in an amount of 3-20 mg per 100g of beverage, by 
coexisting vitamins C, 60-120 mg, E, 5-10 mg, and B.sub.2, 0.5-1.0 mg, 
each amount per 100 g beverage.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In the present invention, .beta.-carotene may be derived from plants, 
carrots and green algae, by being crushed, squeezed, extracted and 
condensed into a puree or paste form, or chemically synthesized into a 
natural form from appropriate starting material. Other vitamins are 
procured from ordinary commercial sources. 
In the present invention, the relative composition of the vitamins to 
supplement the beverage should be at least in the following range (per 100 
g of beverage): 
.beta.-carotene: 3 to 20 mg 
vitamin C: 60 to 120 mg 
vitamin E: 2 to 10 mg 
vitamin B.sub.2 : 0.3 to 1.2 mg 
The effects of the present invention are as follows: 
1) In the presence of vitamin E, .beta.-carotene can stay intact at the 
expense of vitamin E oxidation; 
2) Then, oxidized vitamin E can be reduced by the vitamin C present and 
completely recycled for the protection of .beta.-carotene; and 
3) Vitamin B.sub.2 can protect .beta.-carotene from the irradiation of 
light with coexisting vitamin C by dispensing photons in the system. 
EXAMPLE 1 
The preparation of a .beta.-carotene beverage was performed by the 
following steps: 
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Raw materials (Basal mixture plus vitamins) 
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Stirring to form a mixture 
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Preheating and degassing 
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Homogenization 
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Sterilization & cooling 
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Aseptic filling into container 
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Composition of basal mixture 
Ingredients Percentage (by weight) 
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Carrot juice 75 
Apple juice 20 
Lemon juice 3 
Honey 2 
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.beta.-carotene to fortify as well as vitamins E, C and B.sub.2 were added 
to the basal mixture stepwise to organize the following specimens No. 1-4 
in aseptically filled brick packs (paper cartons). The vitamins were 
traced as to their contents after 4 weeks at 35.degree. C. and 6 months at 
10.degree. and room temperature. 
Specimen No. 1: Basal mixture plus .beta.-carotene to fortify 
Specimen No. 2: No. 1 plus vitamin C 
Specimen No. 3: No. 1 plus vitamin E 
Specimen No. 4: No. 1 plus vitamin C, E & B.sub.2 
As shown in FIGS. 1-1 to 4-2, .beta.-carotene stays reasonably intact in 
the presence of protective vitamins. 
EXAMPLE 2 
Specimen No. 5 was prepared as described above except for the addition of 
.beta.-carotene with (No. 5-2) or without (No. 5-1) vitamins B.sub.2 and C 
to the basal mixture and aseptically packed in a transparent glass bottle. 
The bottle was exposed to the irradiation of a fluorescent lamp (30W) for 
2 weeks at room temperature. Table 1 shows changes in .beta.-carotene and 
the coexisting vitamins, before and after 2 weeks of irradiation. The 
vitamin content was expressed in relative intensity with 100 signifying 
"before irradiation". Table 1 clearly shows the protective effect of 
vitamins C and B.sub.2 for .beta.-carotene under the irradiation of a 
fluorescent lamp. 
TABLE 1 
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Changes in .beta.-carotene content under irradiation 
with coexisting vitamins B.sub.2 and C 
Specimen 
Irradiation 
.beta.-carotene 
vitamin B.sub.2 
vitamin C 
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No. 5-1 
Before 100 (%) / / 
After 63 / / 
No. 5-2 
Before 100 100 100 
After 91 51 10 
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The present invention makes possible a handsome intake of .beta.-carotene, 
which is a necessary nutrient in modern life, without significant loss in 
storage and with a well-balanced assortment of anti-oxidative vitamins C, 
E and B2.