Oryza sativa Seeds | Brown Rice
LATIN NAME: Oryza sativa
COMMON NAME: Brown Rice
Plant Profile
A rice grain is built in layers. Outside is the husk, the palea and lemma; under it sit the pericarp, the seed coat and the nucellus, then the aleurone layer, then the starchy endosperm that makes up most of the weight, with the embryo tucked into one side. Removing the husk alone gives brown rice.
The bran is a rich source of gamma-oryzanol, a mixture of ferulate esters of triterpene alcohols in which cycloartenyl ferulate and 24-methylenecycloartanyl ferulate dominate. Alongside it sit ferulic acid and p-coumaric acid, much of them bound to the cell walls and released during cooking, plus the tocopherols and the tocotrienols, with gamma-tocotrienol the most abundant of that group.
Beyond the lipids, the bran supplies B vitamins, magnesium, phosphorus and phytic acid, and it is the physical barrier that slows the action of amylase on the endosperm. That is why brown rice gives a flatter rise in blood glucose than the same rice milled white, and why it takes longer to cook.
The same grain yields a family of products depending on where the mill stops: a light polish leaves most of the bran and is sold as half-milled rice, while a full polish sends the bran, aleurone and embryo into the bran stream. Black rice carries its anthocyanins in the pericarp, red rice takes its colour from proanthocyanidins in the same layers, and waxy rice has almost no amylose.
Rice blast is the most important fungal disease of the crop, appearing as diamond-shaped leaf lesions and dark necks on the panicles, worst where nitrogen is excessive and the canopy stays wet overnight. Stem borers tunnel into the stems and leave a dead central shoot; pull and destroy the affected tillers. In flooded ground, the golden apple snail grazes young transplants, and a shallower flood and hand-picking the snails keep the damage modest.
Science & Biotechnology
Milling breaks cells and releases lipases that would otherwise stay compartmentalised. Those enzymes hydrolyse the triacylglycerols of the bran into free fatty acids, which then oxidise and turn the grain stale and bitter. White rice has had the fat removed with the bran and keeps for years; brown rice keeps for months.
Uses & Benefits
Abrading away the bran, the aleurone and the embryo leaves white rice, and the extent of that removal is what the trade calls the degree of polish. The layers discarded carry almost all the oil, fibre, vitamins and minerals in the grain. The embryo is a small complete plantlet, which is why a grain of brown rice will grow and the same grain milled white will not.
Whole grain also takes fermentation well: soaked and ground, it ferments into the batters used for steamed cakes and flatbreads, and fermentation releases ferulic acid from the cell walls. Puffed brown rice is made by heating the grain under pressure so the endosperm expands.
Growing from Seed
Rinse the grain well, soak it for an hour or more, and cook it in more water than white rice with a longer simmer. Two parts water to one part grain is a workable starting point.
Cooking brown rice in too little water gives a grain that is chalky inside and split outside. Keep the pan covered and the heat low, adding water only in small amounts if it threatens to dry out, because stirring breaks the grain.
Rice will grow from a grain of shop-bought brown rice as long as the embryo is intact. For a plot, soak the grain, sow it thickly in shallow trays of loam and compost, and keep the trays flooded once the shoots stand. Move the seedlings out when they carry three or four true leaves and stand about 15 cm tall, planting them in clumps of two or three.
Transplant into a puddled bed with the clumps 20 to 25 cm apart, pressing them just into the mud. Keep the plot flooded to two or five centimetres once the plants are established and the soil holds water, or grow it as upland rice on irrigated ground. A short mid-season drain lets the roots anchor.
Shallow water does most of the weeding, since it suppresses weeds, and keeping the depth steady matters more than keeping it deep. Feed nitrogen in two or three small doses rather than one large one, because excess nitrogen produces soft growth that lodges. Harvest when the panicles bend and most grains have turned straw-coloured. For brown rice at home, thresh and remove only the husk, and stop as soon as the grain looks pale brown rather than white.
Our Take
Grow rice once and you will never look at a bag of it the same way; whole grain is the most rewarding version to mill at home, because the work stops before the interesting part is thrown away. The coloured rices make the point well: black rice keeps its pigment in exactly the bran layers brown rice keeps, red rice takes its colour from proanthocyanidins in the same place, and upland rice is the form for a plot that cannot be flooded.
Related Reading
Gardeners who grow Brown Rice often pair it with these related subjects: