Rice & its By-Products


Rice is a cereal grain consumed by more people globally than any other food. It is the number one staple food throughout Asia, and has literally tens of thousands of varieties. It is a quick energy food and easily digestible. Besides the common white rice, the more recently touted brown rice, and all the other varieties, there is rice grass juice and syrup, rice wine and vinegar, rice flour and miso. Numerous by-products are made from rice bran, rice bran oil, and rice straw.


Grass juice extract powders have been made available on the market for green drinks and supplement blends, and rice grass juice is one of them. Brown rice syrup (also called rice malt) is a nutritive sweetener that is about half the sweetness of sugar; some claim that it is the healthiest sweetener of all. Rice wine is made from the fermentation of rice starch converted to sugar; it is commonly used in Chinese cuisine. Rice vinegar, made either from rice or rice wine, is of many types, and is milder and sweeter than regular Western vinegars. Rice flour is a type of gluten-free flour made from finely milled rice, often used in Oriental cooking to thicken sauces and make desserts. In Japan, rice is fermented, along with other ingredients, to make miso, a popularly used seasoning in a wide range of dishes; miso soup is very common at Japanese meals. Green tea with roasted whole grains of brown rice, called genmaicha, is also a popular drink in Japan.


Approximately 30% by weight of the paddy rice that is processed goes into a wide variety of by-product uses. Rice bran is the most valuable food by-product of the process, containing 12-15% protein and 14-25% oil. It is a rich source of B-vitamins and minerals, with some antioxidant properties. The bran is a functional dietary fiber that benefits in the digestion of foods, having a soothing quality and a buffering effect on the body’s glucose response; it is able to slow glucose absorption. It can be made into breads, biscuits, cakes, cookies, and be used in candies. Bran is also used as feed for livestock animals and poultry. Another food-based by-product is rice protein, which has comparison to whey protein; but it is more highly recommended for people with compromised digestive systems. And it is easily digestible high protein for making muscle.


Stabilized rice tocotrienols (tocos), also called rice solubles, are another food-based by-product that are a particularly rich source of vitamin E, in addition to B-vitamins, various minerals, protein, and amino acids. Rice tocos have a light, fluffy texture, are fast dissolving, and add a delicious, creamy flavor to other foods. They are a highly nutritious addition to smoothies, cereal blends, oatmeal, desserts, custom nutritional drinks, and numerous other creative food uses. Rice bran oil is also highly nutritious and can be used in cooking and baking, and as a salad oil. And both tocos and bran oil can be used in making candies.


There are also a multitude of non-food uses for both rice bran and rice oil. A few examples are: soap making, especially soft and liquid soaps, hair shampoos, floor and automobile cleaning, detergents, especially for washing delicate surfaces, textiles and fabrics, emulsifiers, plasticizers, paints, chalk, protective coatings, shoe cream, cosmetics, synthetic fibers, matches, and photographic film. They can be used as carrier agents in insecticides and fungicides, and can be used in fertilizers. They also have medical uses for those with digestive and glycemic conditions.


Rice straw also has many uses: as sustainable building materials for particle, fiber, and straw board, cement-bonded board, composites and biocomposites, straw bale houses and thatched roofs. Rice straw is also an ingredient in high end products, from textiles to lithium ion batteries. It is also good as mulch for growing mushrooms. Rice husk goes into cement and gypsum board, and rice husk ash can go into making the cementitious material called CLSM (controlled low-strength material), which is used primarily as backfill. Rice husk is also being used for fuel. Last, rice paper can actually refer to two distinct things. First, it is a thin, edible, paper-like sheet made from the straw of rice and used as wrapping for making rolls, such as spring rolls. The other, true rice paper is made from the pith of the rice plant; most often blended with other plant materials, it is made into a fine arts and crafts paper.