JPS63173531A - Plant belonging to stevia new variety - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new variety of stevia with improved sweetness component content.

Stevia is a perennial plant of the Asteraceae family that is native to Paraguay in South America, and its scientific name is Stevia Rebaudiana Bert.
oni). Stevia contains a sweet component that is more than 300 times sweeter than sugar, so it is cultivated to extract this sweet component and use it as a natural sweetener.

Sweet components of stevia include stevioside (molecule ff1804) having the following structural formula and rebaudioside AC molecule f! having the following structural formula. :966) as well as rebaudioside C, D, E, zulcoside A, etc. Among these, the main component is stevioside, and rebaudioside moneylenders are about three-tenths of stevioside, and some varieties do not contain rebaudioside A, C, etc.

Stevioside is used in the food industry as a natural sweetener because it is 300 times sweeter than sugar. Its sweet taste is relatively similar to sugar, but it has the disadvantage of leaving an unpleasant aftertaste such as bitterness. On the other hand, rebaudioside A has a sweetness level 1.3 to 1.5 times that of stevioside, and its sweetness is similar to sugar, mellow, and does not leave an unpleasant taste. However, since the amount of rebaudioside A contained in stevia is small, it has been difficult to extract and separate it and use it alone industrially.

The inventor set out to create a new variety of stevia with a high content of rebaudioside A. As a result of intensive research, we found that 1% rebaudioside A was added to stevioside.
．． We succeeded in developing a new variety containing 50 to 2.55 times more stevia, and confirmed that the content remained unchanged even if the new variety was propagated by division, cuttings, etc.
Completed Ming.

In other words, this invention uses sweet ingredients contained in leaves as
1 part stevioside to 8 parts rebaudioside 1.5 times
This plant belongs to the new feed containing 0 to 2.55 times stevia.

The breeding process of this new variety of Stevia according to Invention 1 is as follows.

From October to December 1971, Stevia native product A, which has a rebaudioside A content of 6/10 that of stevioside, was stored in a plastic greenhouse at Morita Chemical Industries Co., Ltd.'s Niimi factory in Ashimi, Niimi City, Okayama Prefecture. The resulting seeds were sown in a greenhouse for raising seedlings at the same site in early March 1980, and the germinated seedlings were transplanted to the field in early May of the same year. Seedlings with large branched leaves were selected, and the sweet component content was investigated starting in August of the same year. Seedlings containing rebaudioside A to stevioside of 1=1 or more were selected and designated as AF. The characteristics of A and AF are shown in the table below. In addition, in the table below, ST indicates stevioside and KA indicates rebaudioside A.

AF□ is propagated by cuttings, and from October to December of the same year, they are artificially crossed and fertilized in a plastic greenhouse, with one flower to be fertilized placed on top of the other, facing each other, and pollinated by vibrating. ), the obtained plates were sown in a greenhouse for raising seedlings in February 1981, and transplanted to the field in late April of the same year.
From early June of the same year, the sweet component content was investigated, and seedlings containing stevioside to rebaudioside A at a ratio of 1:1.5 or more were selected and designated as the new variety AF2. 4th and 5th photo of the whole and one leaf respectively.
Shown as Figure. The characteristics of AF2 are as follows.

AF2 was propagated by cuttings, allowed to overwinter, and the overwintered stock was propagated by Toyagi, and the sweet component content was investigated every month from May 1980. As a result, as shown in the table below, it was found that the content rates were the same as those of the parent strain. The table below shows the average value for 100 trees in each area.

Next, sweet ingredients extracted from dried leaves of AF2 (containing 2.6% stevioside, 6.2% rebaudioside 8, and 17% rebaudioside CO) and stevia (stevioside 7.5%) from Shibushi-cho, Soo District, Kagoshima Prefecture were added. %, rebaudioside A2
．． The sweetness level and sweetness quality of the sweet component extracted from the same sample (containing 3% and 0.8% CO) were tested.

Test method: Weigh 20 pieces of each dry leaf, extract with 20 times the volume of warm water until the sweetness is no longer felt, and combine the extracts to form a non-polar porous resin (Amberly I-XAD-
2) Pass through a column filled with Loom/ to adsorb sweet components, wash with water, and elute with methanol. The eluate is concentrated and dried under reduced pressure to powder. The powder was made into a 0.4% aqueous solution and tested by 10 panelists, and the following results were obtained.

In addition, SS is stevia produced in Shibushi Town, and numbers indicate the number of people.

From the above results, it was found that the sweetness component of the new cultivar AF2 of the present invention was superior to the conventional cultivar in terms of sweetness level and sweetness quality.

Furthermore, the sweetness components of A, AF Process, and AF2 were analyzed by thin layer chromatography, and the results shown in Figs. 1 to 3 were obtained.

Analysis method: Accurately weigh 20 pieces of each dry leaf, extract with 20 times the volume of warm water until the sweetness disappears, pass the extract through a column packed with 100 d of non-polar porous resin (Amberlite XAD-2), and wash with water. The eluate was then eluted with 300 methanol, and the eluate was concentrated to 100 rnl, used as a measurement sample, and measured under the following conditions.

Model used Shimadzu chromato scanner model 910 TLC plate Merck silica gel plate 0F254 Development Solvent Chloroform: Methanol: Water 3
0:20:4 Coloring agent 50% sulfuric acid Measurement wavelength 35Qnm (reflection zigzag scanning Jung method) Scanning speed 20m/min From Figures 1 to 3, the sweet component content of A, AF, AF 2 mentioned earlier was confirmed.

The points to note when cultivating AF2 are as follows.

The new variety AF2 is made by taking the 4th to 5th nodes of a new bud that sprouted in March to April as a seedling, and after removing about 1 node of the lower leaf,
Pour a layer of soil with good water retention (for example, Kanuma soil, river sand, or a mixture thereof) and leave in the sun for about a week.

In cold regions, the temperature of the wooden floor should be kept between 15 and 25 degrees Celsius. The cuttings will root in 2 to 3 weeks, so after confirming rooting, transplant them to the field. The field is compost 150% as base fertilizer.
Apply chemical fertilizer (nitrogen, phosphoric acid, and potassium content of 10 KSI/10 are each) to the entire layer, and plant when the late frost has disappeared. The appropriate planting density is about 8,000 to 10,000 trees per 10 ares, but there is no problem even if the planting density is higher or lower than this. Apply additional fertilizer in late June depending on growth conditions, and water at appropriate times depending on soil dryness.

Fertilizing salmon does not affect the content of sweet ingredients, but it has a large effect on yield, so it is desirable to fertilize as much as possible.

Harvesting can be done at any time after planting, but it is appropriate to perform the first harvest in early to late July when the harvest is high, and the second harvest in mid to late September when flowering begins. However, in areas where sunlight hours are long and flowering is delayed, flowering may be delayed.
[It is Tekiru to delay the harvest until the beginning of E.
The number of harvests can be increased or decreased depending on growth conditions. After harvesting in the fall, they are left in the field until the first frost, and in cold regions they are dug up and stored in plastic greenhouses to overwinter. Although it is possible to overwinter almost in situ in warm regions, it is preferable to cover the plant with earth. Leaving out rice straw, rice husks, etc. for the purpose of protection from the cold will lead to over-humidity and reduce the wintering rate. Overwintering plants can be propagated by cuttings or division.

[Brief explanation of the drawing]

Figures 1 to 3 show the results of thin layer chromatography analysis of the sweetness components of A, AF, and AF2, respectively. In the figure, ST indicates stevioside and ttA indicates rebaudioside A. FIG. 4 is a photograph showing the morphology of the whole plant of AF, and FIG. 5 is a photograph showing one of its leaves, both of which are photographs showing the morphology of the organism.

Claims (1)

[Claims] A plant belonging to a new variety of stevia whose leaves contain 1.50 to 2.55 times more rebaudioside A than stevioside as a sweet component.