WATERMELON – A MAMOTH OF A FRUIT
If you have ever tasted a watermelon, it is probably no surprise to you how it got its name. Watermelon has an approximately 92% water content, giving its flesh a juicy and thirst-quenching texture yet quite crunchy. It is a member of the Cucurbitaceae family, and is related to the cantaloupe, squash, pumpkin, cucumber, and gourd that grow on vines on the ground.
Watermelons come in different shapes. Round, oblong, or spherical in shape and feature thick green rinds that are often spotted or striped. It can range in size from quite small to giant. There are about a 100 different varieties of watermelon exist worldwide, but all of these varieties belong to the same scientific genus and species of plant, called Citrullus lanatus.
Whilst often associated with a deep red/pink colour, there are several varieties that feature orange, yellow, or white flesh. These varieties are typically lower in the carotenoid lycopene than red/pink varieties.
There is some controversy regarding the nature of seedless watermelons. Only a few years ago, it was quite rare to find seedless watermelons in the marketplace. Today, up to 85% of all watermelons are estimated to be seedless. Contrary to some information that you will find on various websites, seedless watermelons are not the result of genetic modifications. Seedless watermelons are the result of hybridisation. By crossing a diploid watermelon (with two sets of chromosomes) and a tetraploid watermelon (with four sets of chromosomes), it is possible to produce a watermelon that contains triploid seeds (with three chromosomal sets). When planted, these triploid seeds will grow into seedless watermelons. Seedless watermelons will typically appear to contain some white seeds even though they are labelled as seedless. These white seeds are not actually seeds, but only empty seed shells.
When it comes to nutrition…..
Alongside tomatoes, watermelon has moved up to the front of the line in recent research studies on high-lycopene foods. Lycopene is a carotenoid phytonutrient that's especially important for cardiovascular health and for bone health. Watermelon now accounts for more intake of lycopene (by weight of fruit eaten) than any other fruit. Pink grapefruit and guava are two other important fruit sources of lycopene, although these fruits are more often consumed in the form of juice.
Watermelon also contains citrulline. This is an amino acid that is commonly converted by the kidneys and other organ-systems into arginine (another amino acid). The flesh of a watermelon contains about 250 milligrams of citrulline per cup. When our body absorbs citrulline it can be converted into arginine. Particularly if an individual’s body is not making enough arginine, increased levels of arginine can help improve blood flow and other aspects of our cardiovascular health. There is another possible dietary benefit coming to light from emerging evidence in animal studies that greater conversion of citrulline into arginine may help prevent excess accumulation of fat in fat cells due to blocked activity of an enzyme called tissue-nonspecific alkaline phosphatase (TNAP).
If you thought that the red juicy centre of the water is more nutrient-rich than the lightly-coloured flesh that is farther out near the watermelon rind, think again. In a recent study, nutrient content of flesh from different parts of a watermelon were compared and it found that impressive concentrations of phenolic antioxidants, flavonoids, lycopene, and vitamin C exist in all the different parts. The exact distribution of nutrients was also highly dependent on the variety of watermelon. In many of the watermelon varieties that were included in the study, the flesh's outer periphery contained impressive concentrations of most nutrients.
Other recent studies have confirmed the nutritional importance of allowing a watermelon to fully ripen. When the colour change from pink to red, the lycopene content becomes more concentrated. Prior to ripening, when the flesh of a watermelon is primarily white in colour, its beta-carotene content is near nil. In a ripe watermelon, the beta-carotene content is quite high. Like lycopene and beta-carotene, total phenolic antioxidants in a watermelon also increase consistently during ripening, all the way up until the appearance of fully red flesh. The bottom line: the riper it is the greater the nutritional benefits.
Nutritional values (100gr serving)
Vitamin C - 16%
Pantothenic acid - 7%
Copper - 7%
Vitamin A - 5%
Potassium - 5%
Biotin - 5%
Magnesium - 4%
Vitamin B6 - 4%
Vitamin B1 - 4%