5. Purple Corn Uses and Properties

Parts Used:

The whole plant: grain, stigmata, leaves, stem, pollen, cob, and roots.

· Stigmata (corn silk): Several preparations are obtained from corn silk. The preparations are commonly made from the fresh corn silk. In order to prepare a tincture, fresh or green stigmata, before it begins to change in color or only the portion having a green or greenish-yellow color are used. The diseases for which corn silk is recommended are generally of an inflammatory character.

The corn silks are cholagogue, demulcent, diuretic, lithontripic, mildly stimulant and vasodilator. They also act to reduce blood sugar levels and so are used in the treatment of diabetes mellitus as well as cystitis, gonorrhea, gout etc. The silks are harvested before pollination occurs and are best used when fresh because they tend to lose their diuretic effect when stored and also become purgative.

In the United States several preparations of the stigmata of Zea mays L —tincture, extract, syrup— are being used since more than a hundred years ago. They are used in order to treat catarrh of the bladder and similar diseases with very good results.

Corn-silk is diuretic and slightly anodyne, and, for the former purpose, has been found useful in many urinary troubles, associated with renal and cardiac disorders. In southern France, the inhabitants use it as a domestic remedy for calculi, gravel, and strangury. It has been found of value by physicians in the treatment of cystic irritation, due to phosphatic and uric acid concretions, and in both acute and chronic inflammations of the bladder, whether traumatic or idiopathic. Dropsy, when due to cardiac or renal origin, and particularly after such urinary disorders as those above mentioned, and pyelitis, catarrh of the bladder, and urinal retentionappear to be benefited by the diuretic action of this drug, which action is said to be quite positive.

A decoction of the leaves and roots is also used in the treatment of dysuria.

The fresh succulent 'silks' (the flowering parts of the cob) can also be eaten.

· Leaves: The leaves of Zea mays L., the same way as the stems, are a good fodder for cattle.

· Stems: The stems of Zea mays L. are used as fodder for cattle. The pith of the stem is chewed like sugar cane and is sometimes made into a syrup because of its high sugar content; this syrup is very similar to honey bee and very useful in food industry. From the stem, an organic plastic very similar to cellophane can be produced. Production of alcohol from the stem has also been proposed in order to use corn as renewable fuel source.

· Grain: Grain or kernel is the most important part of Zea mays L. It is principally used as food for humans, raw or cooked, although it can be also used as food for animals, especially for birds, besides as source of materials for several industries. Corn is used as vegetable, as corn-on-the-cob, fresh, canned or frozen. Kernels may be cut from the cob and used in many ways, in succotash, custards, fritters, soups and chowders. They are also used in mixed pickles and vegetable relishes.

Corn meal, grits, and hominy are prepared forms of corn kernels. Corn is also converted into various substances which have a wide range of usage, as starch, syrup, cornstarch, dextrin, corn oil, zein, and in the making of whiskey and other alcoholic products. These substances are used in the printing, confectionery, condensed milk, tanning leather, plastics, food, brewing, soap, paint, and textile industries. Corn has been used as currency (in Peru).

The grain can be eaten raw or cooked before it is fully ripe and there are cultivars especially developed for this purpose (the sweet corns) that have very sweet seeds and are delicious

The mature grain can be dried and used whole or ground into a flour. It has a very mild flavor and is used especially as a thickening agent in foods such as custards. The starch is often extracted from the grain and used in making confectionery, noodles etc. The dried seed of certain cultivars can be heated in an oven when they burst to make 'popcorn'. The seed can also be sprouted and used in making uncooked breads and cereals. A nutritional analysis is available.

From the sprouted grains of some cultivars of Zea mays L., an alcoholic beverage, a kind of beer, can be prepared. In Peru, this beverage is called chicha, and in the countryside in Argentina and Uruguay, abatí. With the grains and cob of Zea mays L. subsp. mays ‘kculli’ a refreshing non alcoholic beverage known as chicha morada can also be made. This refreshing drink is very popular in Peru.

From Zea mays L. subsp. mays ‘kculli’, or maíz morado, a purple colorant used in alimentary industry as natural colorant for elaborated products is obtained. These natural pigments present in Zea mays L. subsp. mays ‘kculli’ have also medicinal applications as anticancer, antioxidant and hypocholesterolemic agents.

From the embryo in the grain, a vegetable oil of very good quality can be obtained. This oil is used for cooking, as well as in order to produce elaborated aliments such as margarine. Besides, this oil is also used in order to produce paints, soaps and linoleum.

The grain contains up to 13% protein; moreover, the grain is very rich in carbohydrates. Combined with legumes, Zea mays L. is an excellent food for man. The grain is eaten toasted, popped, cooked in water with lime in order to mill it, as corn flakes, etc.

The grain is diuretic and a mild stimulant. It is a good emollient poultice for ulcers, swellings and rheumatic pains, and is widely used in the treatment of cancer, tumors and warts. It contains the cell-proliferant and wound-healing substance allantoin, which is widely used in herbal medicine (especially from the herb comfrey, Symphytum officinale) to speed the healing process.

· Pollen: The pollen is used as an ingredient of soups. Rich in protein, it is harvested by tapping the flowering heads over a flat surface such as a bowl. Harvesting the pollen will actually help to improve fertilization of the seeds.

· Cob: A decoction of the cob is used in the treatment of nose bleeds and menorrhagia.

Properties:

Zea mays L. is used as:

• alcoholic beverage
• alexeritic
• alterative
• analgesic
• anodyne
• anticancer
• anti-inflammatory
• anti-mutagenic
• antioxidant
• antiseptic
• astringent
• cardiac
• cholagogue
• choleretic
• cyanogenetic
• demulcent
• diuretic
• food
• hypocholesterolemic
• hypoglycemic
• hypotensive
• litholytic
• lithontripic
• natural colorant
• stimulant
• stomachic
• vasodilator

Zea mays L. ‘Kculli is used for/against:

• amenorrhea
• atherosclerosis
• Bright's disease
• cancer (certain types)
• cardiovascular diseases
• catarrh of the bladder
• corns
• cystitis
• diabetes
• dropsy
• dysentery
• dysmenorrhea
• encourage connective tissue regeneration
• gingivitis
• gonorrhea
• gout
• gravel
• hepatitis
• hypertension
• hyperglycemia
• hyperinsulinemia
• hyperleptinemia
• improves microcirculation
• inflammation
• influenza
• menorrhagia
• metritis
• nephritis
• obesity
• oliguria
• pneumonia
• promotes blood flow
• prostatitis
• reduces cholesterol
• renitis
• rheumatism
• stones
• strangury
• tumors
• urogenital ailments
• warts

Oil

Oil of maize is a bland, non-drying, yellowish oil, having a specific gravity of. 0.92. It is readily saponifiable, and does not easily become rancid upon exposure to the air. Corn oil, extracted from the embryo of the plant seeds, is eaten as nutritive fat, both raw for cooking and solidified in the form of margarine. This oil is also used for the production of paints, soaps and linoleum.

On average, corn grains are 3.3% oil (15% moisture basis). Refined corn oil has a pleasant taste and does not develop off-flavors in cooking and frying. The high content of polyunsaturated fats is a nutritional advantage.

Corn oil also contains 1 to 2% unsaponifiables particularly rich in sterols and tocopherols.

Keep away from light and heat.

Human Nutrition

For nutrition purposes, Zea mays L. is eaten roasted, popped, cooked in water with lime for milling, as flakes, etc. This grain constitutes an excellent source of glucides or carbohydrates. Besides, it contains up to 13% protein and 7% oil.

Mutant genes capable to turn endosperm of normal corn into flourish endosperm have been discovered. This alteration comes together with an increasing of tryptophan and lysine, two essential amino acids normally scarce in the proteins present in corn. The presence of any of these mutant genes originates the so called lysine-rich corns, with a nutritional value equivalent to skimmed milk in human diet.
Per 100 g, the green fruit is reported to contain:

The seedling, per 100 g, is reported to contain:

The approximate composition of the kernel, per 100 g weight of food (fresh weight):

Per 100 g, the seed is reported to contain:

· Corn meal: Corn meal forms a very palatable and nutritious gruel for the sick, and, in the form of mush, is an excellent diet for convalescents, as well as a good emollient poultice for ulcers, swellings, rheumatic pains, etc.

· Huitlacoche: There exist a disease in Zea mays L. called ‘corn blight’, caused by a parasitic fungus that forms a big mass of mycelia on several parts of the plant, such as stem and male and female inflorescences. When ripe, the mycelium becomes a mass of black spores. In some regions of Central and South America, the galls or excrescences of corn blight that still are not sporulated are eaten as food. In Mexico, they are known as huitlacoche fungus, and is said to be a delicatessen.

· Canned and frozen corn: In the United States, corn industry is very well developed. In that country, there exist several companies that freeze and can corn as food for humans. Generally, they are accustomed to use hybrid cultivars of Zea mays.

· Tamales: The grain of some Zea mays L. cultivars can be used in order to prepare a mass that is then wrapped with banana leaves or its own husk and finally cooked with vapor. This way of preparing Zea mays L. is very popular in many parts of Latin America.

·Tortillas: Cooked in water with lime and then milled, Zea mays L. grains are used in order to prepare thin discs that are then cooked on a gadget that in Mexico is known as cornal; those are the famous Mexican tortillas.

Functional food

Functional foods are those integral components of the diet that not only behave as a simple food, but also contribute added health benefits such as prevention of cancer, heart diseases, hypercholesterolemia, etc. Functional foods are those such as green tea, soy isoflavones, compounds in nuts, carotenoids, fish oils, and various other natural substances in our diet with antioxidant and other potential disease-preventive properties.

Burgos-Hernandez et al. (2001) determined the presence of anti-mutagenic factors in Zea mays L. Five different cultivars of yellow corn were subjected to several analyses for chemical/structural elucidation. The anti-mutagenic activity of these fractions was tested against aflatoxin B(1) (AFB(1)) and 1-methyl-3-nitro-1-nitrosoguanidine (MNNG), a mutagen that does not require bioactivation. Two concentrations of this agent in the corn fractions were tested for anti-mutagenicity in the Salmonella/microsomal mutagenicity assay, using tester strain TA100 with no metabolic activation. Corn fractions tested showed evidence of anti-mutagenic activity by producing a dose-response type of relationship between a constant amount of MNNG and several concentrations of tested corn fraction.

Variety of the corn did not show an effect on the reduction of the mutagenic potential of AFB(1) suggesting that anti-mutagenic compounds are intrinsic to corn. Four corn fractions, previously obtained after the isolation process were analyzed by MALDI-MS and GC-MS. MALDI-MS showed the presence of two groups of molecules or molecular fragments. The molecular mass of one group ranged from 250 to 370 m/z, the other ranged from 540 to 640 m/z. GC-MS identified linoleic acid as one of the compounds responsible for the anti-mutagenic activity present in corn.

Zea mays L. ‘purple corn’ is now considered a functional food because of its content of polyphenolic substances, which are known to reduce cancer risk in animals and probably in humans. Zea mays L. ‘purple corn’ is recommended especially to oppose large intestine diseases. Moreover, it is considered a natural antioxidant.

Animal feeding

In the US and Europe Zea mays L. is used almost entirely for animal feeding, as grain or fodder.

· Lysine-rich corns: Scientists have discovered mutant genes that induce transformation of normal endosperm in normal corn to flourish endosperm in cultivars with these genes. This alteration is accompanied by an increasing in the tryptophan and lysine content, two essential amino acids normally scarce in corn proteins. The presence of any of these mutant genes produces the so called lysine-rich corns, with a nutritional value comparable with skimmed milk in human diet.

Pigs fed this type of Zea mays gain weight three times faster than those fed normal varieties of Zea mays.

Antioxidant

Anthocyanins in general have antioxidant activity. Zea mays L. ‘Kculli has an important amount of anthocyanins. Research has also shown that Zea mays L. ‘Kculli’ contains cell-protecting antioxidants with the ability to inhibit carcinogen-induced tumors in rats.

The most abundant anthocyanin found in purple corn, called “C3G”, has demonstrated, in a number of tests designed to detect the potential health benefits of this anthocyanin, to have similar properties to red wine (red wine also contains appreciable amounts of C3G).

This compound stands out among the other 13 anthocyanins present in Zea mays L. ‘purple corn’. The antioxidant activity of C3G was shown both in test tube experiments and in rats fed the compound as part of their diet. Its strength was 3.5 times that of Trolox, a potent analogue of vitamin E. In one lab test it showed over 6 times the potency of vitamin E (a-tocopherol).

In another study, in which C3G was tested for the ability to inhibit the oxidation of fat cells by ultraviolet B light, it was at least 40 times as potent as vitamin E. Oxidative stress and immune suppression caused by UV light are well-known for their role in the induction of skin cancers. For people living at high elevations like the Andes, something in the diet to inhibit the damaging effects of UV light could be a true cancer preventive.

Oxidative stress on the system produces a state in which there is an excess of oxygen-based free radicals. To avoid the damage they can cause to cells, the body produces antioxidants that neutralize the free radicals. If they prove insufficient however, the body suffers. In lab model of oxidative stress, rats fed a diet containing C3G for 2 weeks beforehand showed significantly less strain on their livers, including more rapid restoration of liver stores of the vitamin. In a similar study, rats fed C3G in liquid form also showed significant protection from markers of oxidative stress, and liver and tissue injury was lowered.

Acquaviva et al. (2003) also investigated the antioxidant activity of phenol phytochemicals. They evaluated the effects of cyanidin and cyanidin 3-O-beta-D-glucoside on DNA cleavage, on their free radical scavenging capacity and on xanthine oxidase activity. Cyanidin and cyanidin 3-O-beta-D-glucoside showed a protective effect on DNA cleavage, a dose-dependent free radical scavenging activity and significant inhibition of xanthine oxidase activity. These effects suggest that anthocyanins exhibit interesting antioxidant properties, and could therefore represent a promising class of compounds useful in the treatment of pathologies where free radical production plays a key role.

Beverages

· Alcoholic: Since many years ago, the grains of Zea mays L. have been used in order to make a fermented drink that in Peru is known as chicha (although its Quechuan names were acca or añu) and in some parts of Argentina and Uruguay, abatí.
Formerly, an alcoholic drink was also commonly elaborated in Peru by fermenting the purple grains of Zea mays L. ‘Kculli’. This drink was then known as chicha morada.
Corn kernels can also be used in order to make whiskey.

· Non-alcoholic: Nowadays, a non-alcoholic refreshing drink prepared from the corncob of Zea mays L. ‘Kculli’ called chicha morada, is very popular throughout Peru. Anciently, Zea mays L. ‘purple’ was prepared into a fermented alcoholic beverage, but now this name is applied to a refreshing, non-alcoholic drink confectioned also with cinnamon, lemon juice, and sugar.
Chicha morada is a typical drink in Peru. This drink is made with water in which Zea mays L. ‘purple corn’ has been simmered until this water is colored.

· Coffee: The roasted seed of some cultivars can be used as a coffee substitute.

Breast cancer

The tea made from the seed is said to be a cure for breast cancer.

Colorectal cancer

There exist around 20 types of carcinogenic substances currently found in our cooked meats and fish. These carcinogens present in our daily diet are responsible of many cases of colorectal cancer (colon and rectum cancers).

The results of several epidemiologic studies indicate that regular ingestion of foods rich in polyphenolic compounds is associated with reduced risk of developing certain types of cancer, such as colon and rectum cancers. Colon and rectum cancers are among the most deadly of all types of cancer. Actually, colon and rectal cancer are the second most lethal cancer of all. Colon cancer is more frequent in women, whereas rectal cancer is more common in men.

Surgery is the only way to get rid of colorectal tumors. When the disease cannot be controlled with surgery, chemotherapy is unavoidable; however, chances of recovery are extremely scarce. Surgery can diminish symptoms; nonetheless, survival will not exceed 7 months.

In order to prevent colorectal cancer risk, it is advisable to eat fiber-rich foods, as well as low-fat ones. It is also recommended to have calcium, vitamin D and vegetables like cabbage, Brussels sprouts and broccoli. Zea mays L. ‘purple corn’ can also be added to the list.

Effectively, the purple matter obtained from Zea mays L. ‘purple corn’ has been reported to decrease the carcinogenesis in rat colon induced by PhIP, a heterocyclic amine (2-amino-1-methyl-6-phenyl-imidazo [4,5-b] pyridine).

A group of researchers at the School of Medicine of the Nagoya University, in Nagoya, Japan, showed in an in vivo study that the natural purple pigment present in Zea mays L. ‘purple corn’ is able to modify the development of colon cancer in male F344/DuCrj rats initially treated with 1,2-dimethylhydrazine (DMH).

In their study with animals, the test group received food mixed with 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a natural cancerigenic substance found in the charred parts of roasted meat and fish. After DMH initiation, one of these test groups also received 5% pigment of Zea mays L. ‘purple corn’ in combination with 0.02% PhIP until week 36.

Incidences and multiplicities of colorectal adenomas and carcinomas in rats initiated with DMH were clearly increased by PhIP. In contrast, lesion development was suppressed by Zea mays L. ‘purple corn’ colorant administration. Sure enough, both the early signs of colorectal cancers and the numbers of malignant and benign tumors that formed in the colons of rats that had the purple pigment in their feed were reduced, and there were no adverse effects (i. e. changes in clinical signs, body weight and food consumption).

In the group that was fed the cancer-causing substance, 85% developed colon cancer, compared with only 40% that also received the pigment.

Furthermore, in the non-DMH initiation groups, induction of aberrant crypt foci by PhIP tended to be decreased by the PCC supplementation. The results thus demonstrate that while PhIP clearly exerts promoting effects on DMH-induced colorectal carcinogenesis, these can be reduced by 5.0% Zea mays L. ‘purple corn’ colorant in the diet, under these experimental conditions.

Circulatory system

· Atherosclerosis: The oxidation of fats or lipids in blood serum contributes to a condition known as atherosclerosis. Recent experimental studies in both animals and humans have shown that increasing polyphenol intake can protect LDL cholesterol from becoming oxidized, a key step in developing atherosclerosis.
In an in vivo Japanese study carried out in rats, researchers determined that when fed a diet containing a high amount of C3G (2 grams per kilo of feed; C3G is the major anthocyanin present in Zea mays L. ‘Kculli’), their blood serum showed a significantly lower level of oxidation along with a significant decrease in the susceptibility of their serum lipids to undergo oxidation. Moreover, their body’s natural antioxidants remained unaffected.

· Blood Cholesterol level: Anthocyanins present in Zea mays L. ‘purple’ reduce blood cholesterol levels in rats. According to a Japanese in vivo study, rats fed a diet supplemented with C3G, the major anthocyanin present in Zea mays L. ‘purple’, in their feed, showed significant decreases in levels of total cholesterol — about 16% less compared with the control group.

· Cardiac stimulant: Besides its diuretic effects, corn-silk seems to be a cardiac stimulant as well. In fact, its diuretic action is largely due to its tonic action upon the heart and blood vessels.

· Cardiovascular system: Anthocyanins present in Zea mays L. ‘purple’ promote blood circulation. They seem to stabilize and protect blood vessels in general and capillaries in particular, from oxidative damage and thus improving microcirculation. The results of several epidemiologic studies indicate that regular consumption of foods rich in polyphenolic compounds is associated with reduced risk of developing cardiovascular diseases. Zea mays L. is a polyphenolic compound rich food.

· Dropsy: The diuretic action of corn-silk appear to be beneficial in dropsy, especially that of cardiac or renal origin.

· Hypertension: Zea mays L. ‘purple corn’ may be employed in order to control high blood pressure. Recent experimental studies in both animals and humans have shown that increasing polyphenol intake can lower blood pressure in hypertensive subjects, reduce the tendency of the blood to clot and elevate total antioxidant capacity of the blood. Since the purple matter present in Zea mays L. ‘purple corn’ is rich in polyphenols, regular ingestion of this Peruvian plant could be useful for individuals suffering of hypertension. The corn silks are also vasodilator.

Anti-inflammatory

C3G, the major anthocyanin present in Zea mays L. ‘purple’, has demonstrated anti-inflammatory activity. In an in vivo study, acute inflammation in rats, brought on by over-active immune cells and the elevated free radical activity that attended the pro-inflammatory state, was significantly suppressed when they were fed with C3G extracted from Zea mays L. ‘purple’.

Effectively, Tsuda et al. (2002) have demonstrated that a typical anthocyanin, cyanidin 3-O-beta-D-glucoside (C3G), suppressed the zymosan-induced inflammatory response in rats when it was orally administered. The elevation of the peritoneal exudate NOx, tumor necrosis factor (TNF) alpha interleukin-1beta (IL-1beta), IL-6, and the cytokine-induced neutrophil chemoattractant-1 (CINC-1) concentrations were significantly suppressed by the administration of C3G.

The zymosan treatment resulted in an increase in the serum alpha2-macroglobulin and decreases in the serum albumin and transferrin levels, which are recognized as acute phase proteins. However, these levels were normalized by the administration of C3G. The inducible nitric oxide synthase (iNOS) protein level in the peritoneal exudate cells was markedly elevated in the control group treated with zymosan. However, the administration of C3G significantly reduced the level of iNOS in the peritoneal exudate cells.

Taken altogether, these findings provide a biochemical basis for the use of C3G as a functional food factor and can also have important implications for the prevention of the NO-mediated inflammatory diseases.

Connective tissue regeneration

Anthocyanins present in Zea mays L. ‘purple’ encourage connective tissue regeneration and promote collagen formation.

Diabetes

When studying the possible effects of C3G, the major anthocyanin constituent in Zea mays L. ‘purple’, on colorectal cancer in rats, Japanese scientists discovered that rats fed a high-fat diet gained significantly less body weight compared with another group fed the same diet but with the addition of the purple pigment. The high-fat diet also induced a state of hyperglycemia along with an over-production of insulin. But this was not so in the mice with the pigment in their feed. In fact, both problems were completely normalized.

In a preclinical study, Tsuda & al. (2003) analyzed the effects of Zea mays L. ‘purple corn’ on obesity and diabetes. They compared two sample groups with a control group. Both sample groups had a fat-rich diet during 12 weeks, but one of the sample groups also received a Zea mays L. ‘purple corn’ extract.

Compared with the control group, the group that received the extract of Zea mays L. ‘purple corn’ did not show hyperglycemia, hyperinsulinemia, or hyperleptinemia.

In comparison, the group that did not receive the extract and ate only a fat rich diet, showed an increase of more than 100% in all those parameters.

Zea mays L. ‘purple corn’ added in the diet can also suppress enzymes in the body that help synthesize fatty acid substances. This may be beneficial for preventing diabetes.

The corn silks also act to reduce blood sugar levels and so are used in the treatment of diabetes mellitus.

Obesity

When studying the possible effects of C3G, the major anthocyanin constituent in Zea mays L. ‘purple’, on colorectal cancer in rats, Japanese scientists discovered that blood cholesterol levels got reduced in 16%. This unexpected result let them wonder what would happen if rats were fed C3G as part of a high-fat diet.

To find out, researchers compared the body weights of mice fed a high-fat diet with another group fed the same diet but with the addition of the purple pigment. After 12 weeks, the results were clear: mice with the Zea mays L. ‘purple corn’ pigment in their diet gained significantly less weight, both white and brown adipose tissue weights. Even the fat in their bodies weighed significantly less. In addition, fat in the mice that did not get the pigment in their feed was found to be growing in size, but showed no increase in the pigment-fed mice.

Feeding the high-fat diet markedly induced hypertrophy of the adipocytes in the epididymal white adipose tissue compared with the control group. In contrast, the induction did not occur in the group fed the high-fat diet plus Zea mays L. ‘purple corn’ pigments.

In a preclinical study, Tsuda & al. (2003) analyzed the effects of Zea mays L. ‘purple corn’ on obesity. They compared two sample groups with a control group. Both sample groups had a fat-rich diet during 12 weeks, but one of the sample groups also received a Zea mays L. ‘purple corn’ extract.

Compared with the control group, the group that received the extract of Zea mays L. ‘purple corn’, did not gain any weight, nor suffered hypertrophy in the adipocytes of the fat tissues, or increase in levels of the genetic codes that produce the tumor necrosis factor (TNF-alpha mRNA) or the enzymes related to the synthesis of fatty acids and triacylglycerol and lowered the sterol regulatory element binding protein-1 mRNA level in white adipose tissue. In comparison, the group that did not receive the extract and ate only a fat rich diet, showed an increase of more than 100% in all those parameters.

The presence of Zea mays L. ‘purple corn’ in diet can also suppress enzymes in the body that help synthesize fatty acid substances. This may be beneficial for preventing obesity.

Urinary disorders

· Bladder: Corn-silk has been found useful in both acute and chronic inflammations of the bladder, whether traumatic or idiopathic. It is especially of value in the bladder disorders of children.

· Calculi: In southern France, the inhabitants use corn-silk as a domestic remedy for calculi, gravel, and strangury.

· Cystic irritation: Corn-silk has been found of value by physicians in the treatment of cystic irritation, due to phosphatic and uric acid concretions.

· Diuretic: Corn-silk is diuretic, and has been found useful in many urinary troubles, associated with renal and cardiac disorders. Besides its diuretic effects, the drug seems to be a cardiac stimulant as well. In fact, its diuretic action is largely due to its tonic action upon the heart and blood vessels. In the United States, the silks are still sold as a diuretic.

· Dropsy: The diuretic action of corn-silk appears to be beneficial in dropsy, especially that of renal or cardiac origin, and particularly after such urinary disorders as calculi, strangury, cystic irritation, etc.

· Gonorrhea: Corn-silk is especially of valuein gonorrhea, and in cases where decomposition of the urine is prone to take place within the bladder.

· Pyelitis: Corn-silk is beneficial in order to diminish inflammation of the renal pelvis, or pyelitis.

Food colorant

The purple color of Zea mays L. ‘purple corn’ is obtained by extraction from purplish seeds of Zea mays L. ‘purple corn’ in hot water or weak acidic aqueous solution. This color is due to anthocyanins. These purple corn anthocyanins can be used as food colorants and are approved in Japan and listed in the “Existing Food Additive List” as purple corn color. Purple corn color has been using for coloring beverages, jellies, candies and so on in Japan.

Traditionally, anthocyanin pigments have been used to provide color to acidified food systems. However, anthocyanin-rich waste from purple corncobs (Zea mays L), is only soluble at neutral or slightly alkaline environments suggesting it could be used in food systems within such a pH range (Jing et Giusti, 2004).

Hence, anthocyanin-rich waste, soluble at neutral or alkaline environment, was used by Jing et Giusti (2004) to color whole-fat milk, skimmed milk, and a phosphate buffer solution (pH 6.8). Pigment stability was evaluated using an accelerated stability test, at 70°C for different time periods. Changes in color characteristics (CIELAB, hue and chroma), monomeric anthocyanin content and anthocyanin profiles were monitored during the study.

Purple corn anthocyanins provided an attractive purple hue (324 and 347 degrees for skimmed and whole fat milk, respectively) at neutral pH. Heat treatment favored degradation of anthocyanins, but a clear protective effect by milk constituents was evident comparing changes in pigment content and profiles in milk to in buffer solution. After 30min heat treatment, 47.9% of monomeric anthocyanins had degraded in the phosphate buffer, while only 9.7% and 4.5% in skimmed and whole-fat milk, respectively. Anthocyanins were more resistant to heat in the presence of fat and protein, suggesting that anthocyanins and macromolecules formed complexes that protected anthocyanins from hydroxyl ions attack.

The results showed the potential of ARW from purple corn (Zea mays L) as colorants. A protective effect of matrix constituents on the stability of anthocyanins at neutral pH was evident. Elucidating these mechanisms may provide light into how anthocyanins may interact in the small intestine in vivo, where the pH values are in the 7.5~8.5 range.

Starch

Starch makes up the nutritive reserves of many plants. During the growing season, the green leaves collect energy from the sun. This energy is transported as a sugar solution to the starch storage cells, and the sugar is converted to starch in the form of tiny granules occupying most of the cell interior.

Zea mays L. is a major source of starch for industry. World corn crop is 600 million ton per annum. Nearly 10% is made into starch or starch-derived sweeteners making corn starch the largest starch commodity in the world. More starch is produced from Zea mays L. than any other crop. Maize is the most important raw material for industrial starch.

Determination of dry matter is an adequate method to estimate the value of corn. The higher the dry matters the better the starch yield and the better the storage stability. An even faster method is to measure weight density. Starch yield and other wet-milling properties are not appreciably affected unless corn test weight drops below about 61.7 kg/hl.

Only dent corn is useful for the starch process - flint corn for example is extremely difficult to steep.

Cosmetic

Corn oil is allotted important regenerative properties due to its content in unsaponifiables. Like all the oils rich in essential fatty acids, it has a restructuring activity and reinforces the cutaneous barrier. It thus helps to maintain the epidermis hydrated. Corn oil is also a very good skin conditioner and is a compound of the oily phase when in formulation. Given all these properties, corn oil is a first choice ingredient in:

• sheathing products for dry hair
• body massage oils
• emollient hand creams
• face care products for baby skin, dry, normal and damaged skin
• face care products for mature, tired and dull skinafter-sun oils and creams
• nourishing lip balms

Corn oil can be used in any cosmetic product as an active principle or as a carrier in the oily phase, without any proportion limit.

Other uses

Corn ear and corn residues (leaves, stems, roots and husks) contain a big amount of furfural, a liquid used in the production of nylon fibers and phenol-formaldehyde plastics, the refining of resins from wood, the obtaining of lubricant oils from petroleum and the purification of butadiene in order to produce synthetic rubber.

With the milled cobs can be produced a soft abrasive. With the biggest cobs of certain cultivar of Zea mays L. tobacco pipes can be made.

Scientists searching for new sources of energy have focused on Zea mays L.; very rich in sugar, Zea mays L. can be used in order to obtain an alcohol that can be then mixed with petroleum in order to produce the so called gasohol. The dry vegetative parts of Zea mays L. are also an important potential source of biomass fuel.

A kind of glue is made from the starch in the grain. This starch is also used in cosmetics and the manufacture of glucose.

A semi-drying oil is obtained from the seed. It has many industrial uses, in the manufacture of linoleum, paints, varnishes, soaps etc.

The corn spathes are used in the production of paper, straw hats and small articles such as little baskets.

A fiber obtained from the stems and seed husks is used for making paper. They are harvested in late summer after the grain has been harvested; they are cut into usable pieces and soaked in clear water for 24 hours. They are then cooked for 2 hours in soda ash and then beaten in a ball mill for 1½ hours in a ball mill. The fibers make a light greenish cream paper. Be careful not to overcook the fiber otherwise it will produce a sticky pulp that is very hard to form into paper.

The dried cobs are used as a fuel.

The pith of the stems is used as a packing material.

Ear husks make mattresses.

Gluten makes a material close to rubber.

Linoleum and insulating material are made with the core of the stem and that even helps to make bowls of pipes in Missouri.

Phytochemicals:

Grain and cob
General Corn Composition (15% Moisture Basis, USA)

Active phytochemicals in Zea mays L. ‘purple corn’.

anthocyanins (at least six, monomeric)
· 3-O- β-D-glycoside
· pelargonidin 3-O- β-D-glycoside
· peonidin 3-O- β -D-glycoside
· cyanidin 3-O- β -D- (6-malonyl-glucoside)
· pelargonidin 3-O- β -D-(6-malonyl-glucoside)
· peonidin 3-O- β -D-(6-malonyl-glucoside)
· cyanidin 3-glucoside
· cyanidin galactoside
· pelargonidin glycoside
phenolics
protein
starch
tannins

The major beneficial constituents present in the grain and cob of Zea mays L. ‘purple’ are anthocyanins and phenol compounds, among other phytochemicals.

· Anthocyanin: Anthocyanins are natural, water-soluble colorants present in many plants. These pigments supply red, purple, or blue colors to fruits, flowers, etc. Chemically, anthocyanins are complex flavonoids and are found in diverse plant-foods including red grapes, black chokeberries, elderberries, and strawberries, red onions, black beans and red beans, blueberries, etc.

In Zea mays L. ‘purple corn’ cyanidin-3-b-glucoside is the major anthocyanin. Other anthocyanins are pelargonidin 3-O- β-D-glycoside, peonidin 3-O- β -D-glycoside, cyanidin 3-O- β -D-(6-malonyl-glucoside), pelargonidin 3-O- β -D-(6-malonyl-glucoside) and peonidin 3-O- β -D-(6-malonyl-glucoside). Pelargonidin 3-O- β -D-(6-malonyl-glucoside) was found in Zea mays L. ‘purple corn’ for the first time by Hiromitsu Aoki & al.

The cyanidin derivatives predominate in Zea mays L. ‘purple corn’ and seem to constitute around 70% in purple corn seed. Pelargonidin derivatives, as well as peonidin derivatives are thought to constitute a small fraction.

Anthocyanin pigments extracted from purple corncob (Zea mays L) have been found to form complexes with proteins and tannins with limited solubility. Heat treatment favors degradation of anthocyanins, but a clear protective effect is obtained by milk constituents. After 30 min heat treatment, Jing and Giusti (2004) found that 47.9% of monomeric anthocyanins had degraded in a phosphate buffer, while only 9.7% and 4.5% in skimmed and whole-fat milk, respectively. Anthocyanins were more resistant to heat in the presence of fat and protein, suggesting that anthocyanins and macromolecules formed complexes that protected anthocyanins from hydroxyl ions attack.

Recently, anthocyanins have been reported to have various biological activities. Effectively, anthocyanins encourage connective tissue regeneration and are anti-inflammatory. They promote blood circulation and reduce cholesterol, possess antioxidant, anti-mutagenic, and anti-cancer activities. Anthocyanins seem to stabilize and protect capillaries from oxidative damage and have been shown to stabilize connective tissue, promote collagen formation, improve microcirculation and help protect blood vessels from oxidative damage.

Anthocyanins are actively absorbed by the stomach (Passamonti & al., 2003), so that they are rapidly integrated in the blood.

Anthocyanin pigments extracted from purple corncob (Zea mays L) tend to form complexes with proteins and tannins with limited solubility. The yields of monomeric anthocyanins are higher in extracts obtained with non-acidified water, suggesting that acidic conditions could favor precipitation of anthocyanins.

The anthocyanin content of whole, fresh purple corn from Peru was found to be 16.4 mg/g, which was much higher than fresh blueberries (1.3-3.8 mg/g), and the capacity of purple corn extract to scavenge free radicals was greater than that of blueberries (Cevallos-Casals and Cisneros-Zevallos, 2003).

Jing & Giusti (2004) tested several solvents in order to extract monomeric anthocyanins from Peruvian purple corncob Zea mays L. subsp. mays ‘purple’ (ddwater, 0.01% HCl acidified ddwater, 0.01% HCl acidified ethanol and 70% aqueous acetone) and temperatures (room temperature, 50, 75 and 100°C) and concluded that the highest concentration of monomeric anthocyanins in extract was obtained with 70% aqueous acetone (0.98 mg/100 mg powder) with low yields of protein and tannins. However, double-distilled water was a good and economic solvent with a high yield of monomeric anthocyanins (about 0.94 mg/100 mg powder) and moderate yields of tannins and proteins at 50°C.

Research shows that crops with the highest total phenol and anthocyanin content also have the highest antioxidant activity.

· Phenols: Phenolics are known to have many bioactive and functional properties. Research shows that crops with the highest total phenol and anthocyanin content also have the highest antioxidant activity.

· Protein: The protein concentration of commercial extracts increases as extraction temperature rises from room temperature to 75°C and drops at 100°C, possibly due to protein denaturalization at 100°C. There exists evidence suggesting that acidic conditions could favor precipitation of proteins.

· Tannins: According to Jing & Giusti (2004) tannin concentration increases up to three folds when the extraction temperature is increased to 100°C both in water and acidified water. These scientists suggest that acidic conditions could favor precipitation of tannins.

Stigmata maydis (corn silk)

Fresh corn silk contains 83.3% of moisture. When well dried, it reabsorbs water from the atmosphere quite readily. Dry corn silk yielded 12.5 per cent. of ash containing carbonates, chlorides, phosphates and sulphates of potassium, magnesium and calcium, alumina and silica.

Corn silk also contains 5.25% of a light-yellow fixed oil, resin, a crystallizable acid (maizenic acid of Vautier), soluble in water, ether, and alcohol, insoluble in petroleum spirit; and sugar, gum, albuminoids, etc. No volatile oil could be found. By distillation with alkali, a basic distillate is obtained, yielding a crystalline acetate, which forms precipitates with solution of iodine and with Mayer's solution. Sugar was observed in green but not in the dried corn-silk.

Sugar was found in green, but not in dried corn silk. Distillation with water did not yield a volatile oil; on distilling with potash, an alkaline liquid was obtained, which on being evaporated with acetic acid yielded crystals, and the solution of which was precipitated by iodine and by Mayor's solution.

Leaves

It has been reported that purple corn leaves contain cyanidin 3-rahmnoside and cyanidin 3-glucoside acylated with malonic acid. Recently, Fossen et al. identified cyanidin 3-glucoside, peonidin 3-glucoside and their derivatives acylated with malonic acid in purple corn leaves.

Cyanidin derivatives are reported to be more than 90% of total anthocyanins in leaves. A little difference between the proportion of anthocyanins in seed and that in leaves has been observed.

Flowers

Recently, Fossen et al. identified cyanidin 3-glucoside, peonidin 3-glucoside and their derivatives acylated with malonic acid in purple corn flowers. The flowers have been reported to contain more than 90% of cyanidin derivatives. A little difference between the proportion of anthocyanins in seed and that in flowers has been observed.