Guest blog by: Sophie Mogg
I’ll soon be crossing the border into Southeast Asia and exploring the many wonderful plants there but there’s time for one last post!
Oryza sativa, which translates to “rice” and “cultivated”, remains a staple for half of the worlds population. It is a widely cultivated plant, growing in over 100 countries and on all continents with exception of Antarctica. There are currently 40,000 varieties of rice of which over 100 of these are grown globally. Oryza rufipogon grows through South and Southeast Asia, it is the wild relative of Oryza sativa. The earliest recorded cultivation of rice has been documented to be in China around 6000 BC.
Within the species sativa, two subspecies have been classified: japonica, indica.
Japonica varieties are short-grained and sticky, often grown in higher altitudes such as the uplands of Southeast Asia. Indica on the other hand are long-grained and non-sticky varieties grown in the lowlands and often submerged. Javanica, now known as tropical japonica, is a subgroup to japonica and is made up of broad-grained varieties grown in tropical conditions. However classification of rice has changed numerous times due to differing basis of classification such as the types of enzymes present or short sequence repeats in the DNA.
Oryza sativa can grow either 1M tall in dry conditions or 5M long in submerged conditions. The stem is composed of several nodes and from each node grows a long, slender leaf. The seeds, like other grass species, grow on long spikes which have the tendency to arch over with the weight of the seed. It is the endosperm of these seeds which we consume. Whilst rice can be found in many colours such as white, brown, red, purple and black we commonly eat either the white or brown rice. White rice is typically polished (milled) to remove the bran layer, where as wholegrain “brown” rice has the bran layer intact. The bran layer, present in all cereal crops, is rich in essential amino acids, dietary fibre and antioxidants.
96% of the rice that is grown worldwide is consumed by the same countries that grow it however these countries also suffer from Vitamin A deficiency. Scientists have tried to improve the nutritional quality of rice by introducing enzymes from other plants via genetic modification that are needed to synthesise beta-carotene. Beta-carotene is converted into Vitamin A in the intestines. The Golden Rice Project aims to reduce the incidence of Vitamin A deficiency (VAD) syndrome which is prevalent in these countries.
Generally rice is steamed or boiled however it can also be used to produce several other products. Rice can be pressed in order to produce rice milk, which is an excellent alternative for those avoiding dairy products who may also have a nut allergy however it is rich in carbohydrates and low in protein and so is not necessarily the best option for diabetics or the elderly. In Japan, sake is made from brewing milled rice somewhat similar to beer however the conversion of starch to sugar and then sugar to alcohol occurs simultaneously. Sake is customarily sipped from a small cup known as a sakazuki on special occasions.
Rice is also used in many traditional medicines such as Ayurveda such as in the treatment of diarrhea. Rice would be boiled and then strained, allowing the water to cool. The patient would then drink the rice water which would stop the diarrhoea or ease the stomach upset as well as re-hydrating them. Congee is a traditional dish made using a single grain, often brown rice, and slowly cooking it on low heat with a 1:5 or 1:6 ratio of rice to water. Congee is said to be very beneficial to those with low energy and issues regarding weight loss/gain and is made across India and China. Several studies such those using rice callus and extracts have shown that rice also has anticancer properties by inhibiting growth of human cancer cells.
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