Rice husk is the outermost layer of protecyion encasing a rice grain. It is a yellow colour and has a convex shape. It is slightly larger than a grain of rice, thus lengths up to 7mm are possible. Typical dimensions are 4mm by 6 mm. IT is lightweight, having a ground bulk density of 340kg/m3 to 400kg/m3.

CHEMISTRY
Rice hulls can be used to produce mesoporous molecular sieves (e.g., MCM), which are applied as catalysts for various chemical reactions, as a support for drug delivery system and as adsorbent in waste water treatment.

PET FOOD FIBER
Rice hulls are the outermost covering of the rice and come as organic rice hulls and natural rice hulls. Rice hulls are an inexpensive byproduct of human food processing, serving as a source of fiber that is considered a filler ingredient in cheap pet foods.

BUILDING MATERIAL
Rice hulls are a class A insulating material because they are difficult to burn and less likely to allow moisture to propagate mold or fungi. It has been found out that when burned, rice hull produces significant amounts of silica. For these reasons it provides excellent thermal insulation.

PILLOW STUFFING
Rice hulls are used as pillow stuffing. The pillows are loosely stuffed and considered therapeutic as they retain the shape of the head.

FERTILIZER
Rice hulls are organic material and can be composted. However, their high lignin content can make this a slow process. Sometimes earthworms are used to accelerate the process. Using vermicomposting techniques, the hulls can be converted to fertilizer in about four months.

SIC PRODUCTION
Rice hulls are a low-cost material from which silicon carbide "whiskers" can be manufactured. The SiC whiskers are then used to reinforce ceramic cutting tools, increasing their strength tenfold.

FUEL
With proper techniques, rice hulls can be burned and used to power steam engines. Some rice mills originally disposed of hulls in this way. However the direct combustion of rice hulls tends to produce a lot of smoke. A far better alternative is to gasify rice hulls. Rice hulls are easily gasified in top-lit updraft gasifiers. The combustion of this rice hull gas produces a beautiful blue flame, and rice hull biochar makes a wonderful soil amendment.

BREWING
Rice hulls can be used in brewing beer to increase the lautering ability of a mash.

JUICE EXTRACTION
Rice hulls are used as a "press aid" to improve extraction efficiency of apple pressing

The ash produced after the husks have been burned, (abbreviated to RHA), is high in silica. A number of possible uses are being investigated for this. These uses include :

• aggregates and fillers for concrete and board production
• economical substitute for microsilica / silica fumes
• absorbents for oils and chemicals
• Soil ameliorants
• as a source of silicon
• as insulation powder in steel mills
• as repellents in the form of "vinegar-tar"
• as a release agent in the ceramics industry
• as an insulation material for homes and refrigerants

in Kerala, India- Rice husks (Umikari- in malayalam)was universally used for over centuries in cleaning teeth - before toothpaste replaced it

When cooking brown rice or other whole grain rice, always follow package directions; if they are not available, use this easy method:

• 1 cup (250 mL) uncooked brown rice
• 2 to 2-1/4 cups (550 mL) liquid such as water, broth, or juice
• 1 teaspoon (5 mL) butter or margarine, optional
• 1 teaspoon (5 mL) salt, optional
• Combine ingredients in 2 to 3 quart (2 to 3 L) saucepan. Bring to a boil; stir once or twice. Reduce heat, cover, simmer 45 to 50 minutes, or until rice is tender and liquid is absorbed. Fluff with fork. Yield: 3 to 4 cups (750 mL to 1 L).

Microwave Oven Instructions:

Combine all ingredients in deep 2 to 3 quart (2 to 3 L) microwaveable dish. Cover and cook on HIGH for 5 minutes or until boiling. Reduce setting to MEDIUM (50% power) and cook for 30 minutes, or until rice is tender. Fluff with fork.

Storage Tips:

• Brown rice has the outer hull removed but the bran layers are intact, providing additional vitamins (especially B’s) minerals and fibre.
• Brown rice and other whole grain rice such as red (Wehani) and black (Japonica) have a pleasant chewy texture and nut-like flavour. Whole grain rice takes longer to cook than white (polished) rice but is just as easy and once cooked can be refrigerated up to a week and frozen up to 6 months to have on hand for meals or recipes.
• Uncooked brown rice keeps on the shelf up to six months. Refrigerate for longer shelf life.
• To reheat cooked rice, add 2 tablespoons (30 mL) of liquid per 1 cup (250 mL) of rice. Cover and heat about 5 minutes on top of the range or in the oven. Or, in the microwave oven, cook on HIGH about 1-1/2 minutes per 1 cup (250 mL).

Glutinous rice has low amylose and high amylopectin contents. Hence, glutinous rice is more sticky (viscosity). White rice has about 20%-28% amylose which makes the cooked rice less sticky.

Both unpolished red rice and brown rice have similar superior nutrition properties than white rice. However, red rice contains Antocyanin which is an antioxidant that is able to remove cancer-causing free radicals in the human body cells.