Vegetables leafy

Potassium nitrate is being used increasingly on intensive crops such as tomatoes, potatoes, tobacco, leafy vegetables, citms, and peaches. The properties that make it particularly desirable for these crops are low salt index, nitrate nitrogen, favorable N K20 ratio, negligible CU content, and alkaline residual reaction in the soil. The low hygroscopicity of KNO (Table 9) leads to its use in direct appHcation and in mixtures. It is an excellent fertilizer but the high cost of production limits its use to specialty fertilizers. 

As a coen2yme component in tissue oxidation—reduction and respiration, riboflavin is distributed in some degree in virtually aU naturally occurring foods. Liver, heart, kidney, milk, eggs, lean meats, malted barley, and fresh leafy vegetables are particularly good sources of riboflavin (see Table 1). It does not seem to have long stabiUty in food products (8). 

Vitamin K is typically found ia green, leafy vegetables such as cabbage, broccoH, and spiaach at levels of 95—200 p.g/100 g of fresh vegetables. Cauhflowet at a level of 136 p.g/100 g also represents an excellent source of dietary vitamin K. Additionally, animal sources such as fiver and eggs provide good sources of vitamin K (11). 

Phylloquinone (vitamin Kl) is the form of vitamin K synthetized by mainly green leafy vegetables and such also appears in plant oils (soybean, cottonseed, canola, olive). Both are good sources for a daily supply, although the need of such a supply is still under discussion. Table 1 shows some good sources and their content of vitamin Kl. 

The body maintains an antioxidant network consisting of vitamins A, C, and E, antioxidant enzymes, and a group of related compounds called coenzyme Q, for which the general formula is shown below. The n represents the number of times that a particular group is repeated it can be 6, 8, or 10. Antioxidants are molecules that are easily oxidized, so they react readily with radicals before the radicals can react with other compounds in the body. Many common foods, such as green leafy vegetables, orange juice, and chocolate, contain antioxidants, as do coffee and tea. 

If the objective were to maximize energy production in producing food, all efforts would go toward grain and bean production where five times the energy is produced as is used, or to the extreme, do all the tasks manually in which 30 to 40 times the energy is produced as used. In the later case, all the able-bodied men, women, and children would be needed to produce the food now available. In that scenario we would also deny our diet of the variety of leafy vegetables, fruits and nuts for fiber and vitamins, and animal and fish products for a variety of proteins. 

However, some of our deer individuals from the arid Joshua Tree National Park in California indicate unusual D-enrichment. This may derive from evapotranspiration in local plants that were part of the diet of the deer and/or in the body fluids of the animals themselves, as is expected in extremely diy environments (Cormie et al., 1994c Bowen et al., 2005). Deer occupy an ecological niche that is relatively simple from the perspective of hydrogen, as their diet consists of leafy vegetation and their water is obtained from surface waters (lakes and streams) that in many cases have D values closely representing mean annual precipitation. In contrast, omnivorous and carnivorous animals consume more diverse diets with more widely varying... 

They are low in salads and fresh, green, leafy vegetables... 

In a clinical trial performed in China, the administration of 300 mg/day of copper chlorophyllin to humans who had detectable levels of serum aflatoxin due to unavoidable food contamination resnlted in a 50% reduction of median urinary levels of aflatoxin-DNA adducts. If health benefits from consuming natural chlorophylls were confirmed, it wonld be easy to add green leafy vegetables to a daily diet to obtain the benefit. Since leafy vegetables contain usually up to 200 mg chloro-phylls/100 g fresh weight, the intake of approximately 1 to 2 cups of raw spinach/day... 

Singh, G., Kawatra, A., and Sehgal, S., Nutritional composition of selected green leafy vegetables, herbs and carrots. Plant Foods Human Nutr., 56, 359, 2001. 

Carrots were also the main sonrces of a-carotene, whereas tomatoes and tomato prodncts were the major sources of lycopene. Lutein was mainly provided by peas in the Republic of Ireland and United Kingdom. Spinach was found to serve as the major source in other countries. Lutein and zeaxanthin xanthophylls are found in a wide variety of fruits and vegetables, particularly green leafy vegetables, but also in some animal products such as egg yolks. In all countries, P-cryptoxanthin was obtained primarily from citrus fruits. 

Hedren, E., Mulokozi, G., and Svanberg, U., In vitro accessibility of carotenes from green leafy vegetables cooked with sunflower oil or red palm oil, Int. J. Food Sci. Nutr., 53, 445, 2002. 

De Pee, S. et al.. Orange fruit is more effective than are dark-green, leafy vegetables in increasing serum concentrations of retinol and (3-carotene in school children in Indonesia, Am. J. Clin. Nutr, 68, 1058, 1998. 

Jayaranjan, P., Reddy, J.P. and Mohanram, M., Effect of dietary fat on absorption of (3-carotene from green leafy vegetables in children, Indian J. Med. Res., 70, 53, 1980. 

Leafy vegetables and some fruits in particular are rich sources of chlorophylls. However, they are ranked among the most perishable post-harvest products and must be consumed within a few days after harvest or subjected to preservation methods to extend their freshness. Their typical green color is, if not the most important sensory attribute, an extremely important parameter of quality. Any discoloration can lead to rejection by consumers as the bright green color is intuitively linked with freshness. 

Kaur, B. and Manjerkar, S.P., Effect of dehydration on the stability of chlorophyll and P-carotene content of green leafy vegetables available in northern India, J. Food Sci. TechnoL (India), 12, 321, 1975. 

On the other hand, widely consumed vegetables and fruits are poor sources of zeaxanthin. The most commonly consumed are corn, - green leafy vegetables,as,io,4 persimmons, and orange juice (Table 4.2.5). The cis isomers of zeaxanthin were determined in very few foods 9-cis- and 13-c(i-zeaxanthin were found in com. - ... 

Mercadante, A.Z. and Rodriguez-Amaya, D.B., Carotenoid composition and vitamin A value of some native Brazilian green leafy vegetables, Int. J. Food Sci. Technol, 25, 213, 1990. 

Gomez, M.I., Carotene content of some green leafy vegetables of Kenya and effects of dehydration and storage on carotene retention, J. Plant Foods, 3, 231, 1981. 

Although saponification was found to be unnecessary for the separation and quantification of carotenoids from leafy vegetables by high performance liquid chromatography (HPLC) or open column chromatography (OCC), saponification is usually employed to clean the extract when subsequent purification steps are required such as for nuclear magnetic resonance (NMR) spectroscopy and production of standards from natural sources. 

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