JP2008263893A - High zinc corn grain - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide corn containing zinc in brown cereals at high concentration, and to provide a method for producing the corn. <P>SOLUTION: Corn mature grains contain ≥2.0 mg/100g of zinc in brown cereals. The method for producing the corn which contains ≥2.0 mg/100g of zinc in brown cereals includes the step of scattering a liquid which has a zinc concentration of 0.01-2 wt.%, on a leaf surface, or a leaf surface and a female ear adhesion part from a corn female ear forming period. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a corn containing a high concentration of zinc in a grain and useful as a food or food material and a method for producing the same.

  In order to maintain human life, iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), cobalt (Co), molybdenum (Mo), vanadium (V), selenium (Se), chromium It is necessary to ingest trace metal elements such as (Cr), nickel (Ni), iodine (I), silicon (Si), fluorine (F), arsenic (As), and lead (Pb) from outside the body. Is called an essential element (Non-patent Document 1). Among them, zinc (Zn) is abundantly contained in the human body after iron as a trace metal element, and is contained in important enzymes such as carboxypeptidase, carbonic acid dehydrogenase, and alcohol dehydrogenase, It is known to play an important role. In addition, lack of zinc is known to cause problems such as growth failure, decreased sexual function, skin and hair damage, and abnormal taste. Furthermore, while the zinc requirement for adults is 12-15 mg per day, the average Japanese food is said to be able to ingest only about 9 mg of zinc per day. Non-patent document 2). Therefore, in 2002, the Ministry of Health, Labor and Welfare added zinc as a nutrient functional food ingredient, and in 2004, the Ministry of Education, Culture, Sports, Science and Technology set a target value for the zinc content during school meals. Has been taken.

  As described above, since zinc (Zn) is important for the human body to carry out life activities, it is desired to take an appropriate amount by daily eating. However, foods rich in these elements are relatively limited. For example, zinc (Zn) is contained at a high concentration of 13.2 mg / 100 g in oysters (oysters) and 3.8 mg / 100 g in beef liver (Non-patent Document 3). However, it is not common to take these ingredients every day in the current Japanese dietary habits. In contrast, corn is processed into noodles such as bread, udon and spaghetti, and can be said to be a daily food. From this point of view, it would be useful if the content of these trace metal elements could be increased in corn, but in the technical field related to corn cultivation methods, research on trace metal elements such as the minimum required fertilization method was conducted. However, it was not satisfactory for the technology to be actively incorporated into the edible part.

  Although it is not maize, recently a technique has been developed to overexpress the zinc transporter gene from Arabidopsis thaliana by genetic modification in order to increase the zinc content in rye grains. However, even when fertilized with this genetically modified product, the rate of zinc absorption did not increase (Non-Patent Document 4). About this cause, even if the zinc transporter gene is expressed, if zinc is present, the zinc transporter protein disappears due to post-translational regulation, as seen in other metal transporter proteins (Non-patent Document 5). It is considered that. In this way, it is difficult to incorporate trace metal elements such as zinc into the edible part of crops even using genetically modified technology, which is the most advanced technology at present.

In addition, a foliar spray method has been put to practical use as one of the conventional fertilization techniques. In this method, the fertilizer component can be taken into the cells that are directly in contact with the spray solution, so that the leaf element deficiency symptoms can be prevented or improved. However, there has been no technique for accumulating metal element content at a high concentration in seeds that are not directly contacted by the spray solution by translocation from the leaves into the seeds, that is, by transferring between cells. It was. In particular, zinc is not an easily commutable element such as nitrogen, phosphorus, potassium, magnesium, etc. (Non-patent Document 6), and therefore it has been difficult to accumulate high concentrations in seeds by the conventional foliar application method.
Sakurai and Tanaka (edited) 1993. Bioinorganic chemistry. Yodogawa Shoten Iwata 1998. Energetic minerals The secret of zinc power. Air publication Kagawa (Director) 2003. "Fiveth Food Analysis Table 2003"Women's Nutrition University Press Ramesh et al. 2004. Plant Mol. Biol. Connolly et al. 2002. Plant Cell Marschner 1995. Mineral Nutrition of Higher Plants (2nd ed.) Academic Press

  An object of the present invention is to provide a corn edible part, that is, a corn containing a high concentration of zinc in a grain and a method for producing the same.

  Therefore, as a result of various studies to incorporate zinc into corn grains at a high concentration, the present inventor unexpectedly applied a zinc-containing solution to the foliage or ear-growing sites, thereby applying soil to the soil. As a result, it was found that a corn having a high concentration of unconventional zinc was obtained by incorporating into a grain at a higher concentration than when applied, and the present invention was completed.

That is, the present invention provides a mature corn that contains 2.0 mg / 100 g or more of zinc in the grain.
Moreover, this invention provides the sweet corn immature grain which contains 1.5 mg / 100g (fresh weight) or more of zinc.

In addition, the present invention provides a fully matured fruit genus characterized in that a solution containing 0.01 to 2% by weight of zinc as a zinc concentration is sprayed on the foliage or the foliage and the ear growth site from the ear stage of corn. The present invention provides a method for producing corn containing 2.0 mg / 100 g or more of zinc in cereal.
Further, in the immature grain according to the present invention, a solution containing 0.01 to 2% by weight of zinc as a zinc concentration is sprayed on a leaf surface or a leaf surface and an ear growing part from the ear stage of corn. The present invention provides a method for producing sweet corn containing 1.5 mg / 100 g (fresh weight) or more of zinc.

Further, the present invention is a liquid for spraying corn foliage or ear-growing parts containing 0.01 to 2% by weight of zinc as a zinc concentration, and containing 2.0 mg / 100 g or more of zinc in ripe corn grains To provide corn manufacturing materials.
Furthermore, the present invention is a liquid for spraying corn foliage or ear-growing parts containing 0.01 to 2% by weight of zinc as a zinc concentration, and 1.5 mg / 100 g (fresh weight) of zinc in immature grains The material for manufacturing sweet corn containing the above is provided.

The corn grain of the present invention contains a high concentration of zinc that could not be produced by conventional genetic recombination techniques, and is useful as a food and food material with high nutritional value.
In addition, since the method for producing corn of the present invention is not applied to the soil but is applied to the foliage and the like, it is said to occur when fertilizing a large amount of zinc in the soil, and the absorption and transfer of iron in the soil The problem of so-called “heavy metal-induced chlorosis” (Kumazawa and Nishizawa 1976. Absorption of plant nutrients. The University of Tokyo Press) does not occur. In addition, when applied to soil in large quantities, runoff into rivers becomes a problem for environmental conservation. For example, in Japan, the zinc concentration standard in rivers and seawater is set to 10 to 30 μg / L or less by the amendment of the Basic Environment Law in 2003. However, according to the method of the present invention, such a problem does not occur.

  The matured corn of the present invention contains 2.0 mg / 100 g or more of zinc in the brown grain. Normally, the concentration of zinc in ripe corn grain is 1.5 to 1.9 mg / 100 g, and no mature corn grain containing a high concentration of zinc as in the present invention is known. More preferable zinc concentration in ripe corn unpolished grains is 2.0 to 8.0 mg / 100 g, more preferably 2.5 to 8.0 mg / 100 g, particularly preferably 2.5 to 5.0 mg / 100 g. . Here, the zinc concentration can be measured by atomic absorption method, ICP emission spectrometry, and ICP mass spectrometry, and this concentration is the zinc content (mg) in 100 g of the dried product.

  The sweet corn immature grain of the present invention contains 1.5 mg / 100 g (fresh weight) or more of zinc. Usually, the zinc concentration in immature sweet corn grains is 0.8 to 1.2 mg / 100 g, and no mature corn grains containing high concentrations of zinc as in the present invention are known. A more preferable zinc concentration in ripe corn unpolished grains is 1.5 to 5.0 mg / 100 g, particularly preferably 1.5 to 3.0 mg / 100 g.

Examples of corn in the present invention include dent corn (Dent corn, Zea mays var. Indentata), flint corn (Flint corn, Zea mays var. Indurata), popcorn (Popcorn, Zea mays var. Everta), sweet corn (Sweet corn, Zea mays var. saccharata) and hybrids thereof, among which dent corn, flint corn and sweet corn are preferable, and dent corn and sweet corn are particularly preferable.

The corn containing high-concentration zinc in the seeds of the present invention sprays a solution containing 0.01 to 2% by weight of zinc as a zinc concentration on the foliage surface or foliage surface and on the ear growth site from the ear formation stage. Can be manufactured. Hereinafter, corn in the production method and corn production material includes immature grains.
According to the study by the present inventors, it has been found that foliar or ear-growth site spraying is preferable, rather than soil treatment, in order to absorb zinc in corn grains at a high concentration. Therefore, the zinc concentration is 0.01 to 2% by weight, and the liquid for spraying the corn leaves or leaves and the ear growth area is 2.0 mg / 100 g or more of zinc in the fully mature grain cereal, immature seeds It is useful as a corn production material containing 1.5 mg / 100 g (fresh weight) or more.

The liquid used for spraying (hereinafter sometimes referred to as foliar spray material) is preferably a liquid containing 0.01 to 2% by weight of zinc. Zinc used for preparing the liquid is not particularly limited as long as it has water solubility, and examples thereof include zinc sulfate, zinc chloride, zinc nitrate, zinc formate, zinc acetate, and chelate zinc such as EDTA zinc. Of these, zinc sulfate is particularly preferred from the viewpoint of zinc migration to the grain.
The zinc concentration in the foliar spray material is preferably 0.02 to 1% by weight, particularly 0.1 to 0.5% by weight as zinc.

Moreover, the foliar spray material used by this invention improves the zinc transfer rate to a corn grain by containing a seaweed extract. As the seaweed, brown algae are preferable, and in particular, the order of the order is Laminariales. Furthermore, the Algaceae family is preferable. Most preferred is Alaria praelonga . These seaweeds as raw materials may contain moisture or may be dried, but a dried product is more preferable in consideration of ease of treatment.

  The content in the leaf spray material of the seaweed extract is preferably 0.1 to 20% by weight, more preferably 1 to 10% by weight, and particularly preferably 3 to 5% by weight in terms of dry matter.

  The seaweed extract can be prepared, for example, as follows. Seaweed as a material is hydrolyzed by adding an acid such as dilute sulfuric acid or dilute hydrochloric acid and heating to 60 ° C. or higher. In this case, the type of acid used is preferably sulfuric acid, and the concentration is preferably 0.5 to 2N. About the temperature to heat, it is preferable to boil from the speed of a decomposition rate. After adjusting the pH of the obtained hydrolyzate by adding an alkali as appropriate, the solid content is removed by centrifugation or filtration to obtain a seaweed extract. In order to obtain a preferable foliar spray material, zinc may be appropriately added to the seaweed extract itself or a diluted solution.

  It is preferable to add a spreading agent and a surfactant that are usually used in agriculture to enhance the adhesion to the foliage and ear growth sites in the foliar spray material. The spreading agent and surfactant used are not particularly limited, and any of nonionic, anionic, cationic and amphoteric surfactants can be used as the surfactant. For example, polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, oxyethylene polymer, oxypropylene polymer, polyoxyethylene alkyl phosphate ester , Fatty acid salt, alkyl sulfate ester salt, alkyl sulfonate salt, alkyl aryl sulfonate salt, alkyl phosphate salt, alkyl phosphate ester salt, polyoxyethylene alkyl sulfate ester, quaternary ammonium salt, oxyalkylamine, lecithin, Such as saponin. If necessary, gelatin, casein, starch, agar, polyvinyl alcohol, sodium alginate and the like can be used as auxiliary agents.

  When foliar spraying material is sprayed, it may be mixed with a foliar fertilizer usually used in agriculture. In this case, although there is no restriction | limiting in particular as a fertilizer component, since the thing which shows alkalinity after melt | dissolution causes zinc to precipitate as a salt, it is not preferable. Examples of preferable fertilizer components when mixing include urea, ammonium phosphate, ammonium hydrochloride, ammonium sulfate, phosphoric acid, pyrophosphoric acid, and the like. Among them, the use of urea is preferable because it may increase the amount of zinc absorbed (Mortvedt and Gilkes 1993. Zinc fertilizer. “Zinc in soils and plants” Kluwer academic publishers).

  The basic fertilizer and topdressing applied to the soil when cultivating the corn of the present invention may be based on the fertilizing amount and fertilizing method performed in the region. However, it goes without saying that if the soil is treated with zinc, the zinc content in the grain can be further increased.

  The planting density in the case of cultivating the corn of the present invention may be the density recommended in the region, but when the zinc concentration in the foliar spray material is 0.1% by weight or more, the purpose of reducing the decrease in sales It is preferable to increase the planting density (seeding amount per unit area) by 1.2 to 1.5 times.

  As a method for spraying the foliar spraying material, it is desirable that the foliar spraying material spreads to the ear growing part and the back surface of the leaf. When using a sprayer, it is desirable that the amount of sprayed liquid is 1000 liters or more per hectare, preferably 1000 to 3000 liters, more preferably 1500 to 2500 liters. In that case, it is preferable to set the pressurization of the sprayer as high as 2 to 3 MPa. Needless to say, it is better to use an apparatus that reduces the particle diameter of the sprayed liquid, such as reducing the nozzle hole. It is also desirable to use a so-called electrostatic sprayer or an electrostatic spray nozzle port that promotes adhesion of the spray liquid to the plant body by utilizing static electricity.

  The application time of the foliar application material is from the ear formation period to the time when the husk is yellowed, and the period from the booting stage to just before the yellowing is particularly preferable. The interval between the foliar spraying materials is preferably once a day to once every two weeks. Further, it is more preferable to spray once every one to two weeks. Further, the total number of spraying during the crop growing period is preferably 2 to 8 times.

  EXAMPLES Next, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited to a following example.

Production Example 1
Preparation of seaweed extract Ainu sea turtle ( Alaria praelonga ), chigaiso ( Alaria crassifola ), macombu ( Laminaria japonica ), sujime ( Costraia costata ) dried products were each cut into 5 cm squares with scissors. 2,550 mL of 1N sulfuric acid was added to 450 g of these shredded products and boiled with stirring for 2 hours. The obtained liquid was cooled by putting the container in crushed ice, and then centrifuged at 8,000 G × 60 minutes by a centrifuge. 1 L of water was added to 1.5 L of the resulting supernatant for dilution, and 2.5 kg of zinc sulfate heptahydrate was added to dissolve. Potassium hydroxide was added to this solution to adjust to pH 2.0. Among these, what uses Ainu-wakame as a raw material is hereinafter referred to as zinc-containing Ainu-wakame extract. In addition, since the zinc content in the actual Ainu turtle is 2.34 mg / kg, the zinc derived from the Ainu turtle itself in the zinc-containing Ainu turtle extract is only 0.11 mg / kg and can be substantially ignored.

Example 1
Corn cultivar "Richmond" (Snow Brand Seedlings) was cultivated in a test field within Hokkaido Research Farm, Naganuma Town, Hokkaido. The basic fertilization was conducted according to the silage corn fertilization standards of the “Hokkaido Fertilization Guide” (Hokkaido Agricultural Administration Division 2002, Hokkaido Agricultural Improvement Promotion Association) (standard fertilization zone), but part of it was zinc sulfate (ZnSO ₄ ) With zinc content of 5.7 and 11.4 kg / ha, and zinc oxide soil application with zinc oxide (ZnO) of 20.6 and 41.2 kg / ha. . The sowing was performed on May 6th, and it was set as a stand of 66 cm × 22 cm between strains and one strain per strain. The plant growing in the standard fertilized area is subjected to 0.5% and 1% aqueous solution of zinc sulfate heptahydrate 6 times every 2 weeks from July 10th, which is the ear development period. .11% and 0.22%), and 1% and 2% aqueous solutions of zinc-containing Ainu Wakame extract shown in Production Example 1 (the zinc concentration is also 0.11% and 0.22%). 200 mL / m ^{2 of} foliar spray was added to 0.1% of oxyethylene hexitan fatty acid ester-containing spreading agent Approach BI (manufactured by Kao Corporation). The test was repeated twice for each treatment. Sampling was carried out on November 3, which is the harvest period, and the plants were air-dried and the cereals were separated with a threshing machine. The obtained unpolished grains were weighed and then dried at 90 ° C. for 3 days in a dryer. The dry weight of the dried grains was immediately measured, and the dry matter rate was calculated. The dried product was pulverized with an ultracentrifugal mill MRK-RETSCH (Mitamura Riken Kogyo Co., Ltd.), 0.5 g was weighed, 5 mL of nitric acid for precision analysis (Wako Pure Chemical Industries, Ltd.) was added, and Teflon (registered trademark) sealed. Decomposed in a pressure decomposition vessel. The decomposition solution was made up to a constant volume, and the zinc content of the solution was measured using an ICP emission spectroscopic analyzer SPS4000 (manufactured by Seiko Instruments Inc.). The zinc content in the actual product was calculated by calculating back the quantitative value using the dry matter rate.

  The results are shown in Table 1. Compared with the area where zinc sulfate was applied to the soil and the foliar application was not performed, the area with the highest zinc content in the grain was 11.4 kg / ha, and the zinc content in the grain was 1.89 mg / It was 10% higher than the no application area at 100 g. Compared to the plots where zinc oxide was applied to the soil and no foliar was applied, the highest grain zinc content was 41.2 kg / ha, but the grain content of zinc was 2 0.08 mg / 100 g (the reason why the effect of zinc sulfate was higher than that of zinc oxide is considered to be due to the extremely high water solubility of zinc sulfate than zinc oxide).

  On the other hand, the zinc content in the corn grain obtained in the area where zinc was not applied to the soil and the zinc sulfate heptahydrate aqueous solution was sprayed on the surface was 2.04 to 2.72 mg / 100 g, and any soil application It was higher than the ward. Furthermore, it was revealed that the zinc-containing Ainu wakame extract spraying area shown in Production Example 1 has a high zinc content in the brown grain even when the zinc concentration in the spraying liquid is the same. Based on the above results, the foliar spraying method from the ear development stage is more effective when incorporating zinc into corn grain, compared to soil application, which is a common fertilizer application method. Furthermore, it was clarified that the effect was further enhanced by adding a seaweed extract to the foliar spray.

Example 2
Sweet corn variety “Idaho Sweet 88” (Snow Brand Seedlings) was cultivated at a test field in Hokkaido Research Farm, Naganuma Town, Hokkaido, Hokkaido. The basic fertilization was performed according to the fertilizer standards for sweet corn in the “Hokkaido Fertilizer Guide” (Hokkaido Agricultural Administration Division 2002, Hokkaido Agricultural Improvement Promotion Association). The seeding was performed on May 30th, with a span of 66 cm × a strain of 40 cm, and one stand. During cultivation, 7 times every other week from July 26, which is the ear formation period, zinc sulfate heptahydrate as in Example 1, and polyoxyethylene in the zinc-containing Ainu Wakame extract shown in Production Example 1 150 mL / m ^{2 of} foliar spray was applied with 0.1% of a hexitan fatty acid ester-containing spreading agent approach BI (manufactured by Kao Corporation). The test was repeated twice for each treatment. Sampling was performed on September 11th, which is the harvest period, and immature grains were separated, immediately measured for fresh weight, and then dried in a dryer at 90 ° C. for 3 days. The immature seeds after drying were measured for dry matter weight and the dry matter rate was calculated. The dried product was pulverized with an ultracentrifugal pulverizer MRK-RETSCH (manufactured by Mitamura Riken Kogyo Co., Ltd.), 0.5 g was weighed, and the zinc content was measured in the same manner as in Example 1. The zinc content in the actual product was calculated by calculating back the quantitative value using the dry matter rate.

  The results are shown in Table 2. The zinc content in immature grain is 1.53 to 1.70 mg / 100 g in the area sprayed with zinc sulfate heptahydrate aqueous solution compared to 0.98 mg / 100 g in the non-spread area, clearly brown grain The zinc uptake in the inside increased. Furthermore, it was revealed that the zinc-containing Ainu wakame extract spraying area shown in Production Example 1 has a high zinc content in the brown grain even when the zinc concentration in the spraying liquid is the same. From the above results, even when trying to incorporate zinc into immature seeds of sweet corn, the continuous foliar spray method of zinc from the ear formation stage is effective, and the seaweed extract is further added to the foliar spray solution. It became clear that the effect was further enhanced by adding.

Claims (17)

  A matured corn grain containing 2.0 mg / 100 g or more of zinc in the brown grain.   The matured corn of claim 1, wherein the content of zinc in the brown cereal is 2.0 to 8.0 mg / 100 g. Corn is Dent corn, Zea mays var. Indentata, Flint corn, Zea mays var. Indurata, Popcorn (Popcorn, Zea mays var. Everta), Sweet corn (Sweet corn, Zea mays var. Saccharata) ) And ripened corn according to claim 1 or 2 selected from hybrids thereof. Sweet corn ( Zea mays var. Saccharata) immature grain containing 1.5 mg / 100 g (fresh weight) or more of zinc. Sweet corn ( Zea mays var. Saccharata) immature grain according to claim 4, wherein zinc is 1.5 to 5.0 mg / 100 g (fresh weight).   1. A solution containing 0.01 to 2% by weight of zinc as a zinc concentration is sprayed on the foliage or foliage surface and the ear growth site of corn from the ear formation stage of corn. A method for producing corn containing 0 mg / 100 g or more.   1.5 mg of zinc in immature seeds, characterized in that a solution containing 0.01 to 2% by weight of zinc as a zinc concentration is sprayed on the foliage or foliar surface and the ear growth site from the ear stage of corn. / Manufacturing method of sweet corn containing 100g (fresh weight) or more.   The method according to claim 6 or 7, wherein the liquid containing zinc further contains a seaweed extract.   The production method according to any one of claims 6 to 8, wherein the amount of the zinc-containing liquid is 1000 liters or more per hectare.   The method according to any one of claims 6 to 9, wherein the zinc-containing solution is sprayed every 1 to 2 weeks from the ear formation stage.   The production method according to claim 6, wherein the zinc content in the ripe brown grain is 2.0 to 8.0 mg / 100 g. Corn is Dent corn, Zea mays var. Indentata, Flint corn, Zea mays var. Indurata, Popcorn (Popcorn, Zea mays var. Everta), Sweet corn (Sweet corn, Zea mays var. Saccharata) ) And hybrids thereof. The production method according to claim 6.   A material for producing corn, containing 0.01 to 2% by weight of zinc as a concentration of corn foliage or ears, and containing 2.0 mg / 100 g or more of zinc in ripe brown grains .   Furthermore, the material of Claim 13 containing a seaweed extract. Corn is Dent corn, Zea mays var. Indentata, Flint corn, Zea mays var. Indurata, Popcorn (Popcorn, Zea mays var. Everta), Sweet corn (Sweet corn, Zea mays var. Saccharata) ) And its hybrids. 15. The material according to claim 13 or 14.   Sweetening solution for spraying corn foliage or ear growing part containing 0.01 to 2% by weight of zinc, and containing 1.5 mg / 100 g (fresh weight) or more of zinc in immature grains Material for manufacturing corn.   Furthermore, the material of Claim 16 containing a seaweed extract.