III. Types and Forms of Rice
Paddy Rice or Rough Rice
Rice Bran and Stabilized Rice Bran
IQF Frozen Rice
Rice Bran and Stabilized Rice Bran. The percentage of rice bran in paddy rice ranges from 10% to 12%. There is no clear distinction between the bran layer and endosperm. The harder the rice is milled, the more bran is generated. Obviously some of the endosperm is going into the bran and so the properties unique to rice bran are diluted as the rice is milled harder. Rice Bran is a very nutritional product. It contains a higher content of protein and its protein has a better amino acid profile that the proteins found in rice and most plant sources. Rice Bran contains about 16% to 18% oil. Rice bran oil is loaded with vitamin E components. It is exceptionally high in Tocopherols and Tocotreinols. Rice bran is also high in oryzanol. Studies have shown that rice bran and rice bran oil lower cholesterol levels and improve cardiovascular health. Rice bran also contains high levels of vitamin B, and other vitamins, minerals, and essential fatty acids.
Unfortunately, rice bran goes rancid soon after milling. Lipase enzyme attacks the oil once the bran structure has been destroyed, and free fatty acid levels build up very quickly. The bran quickly develops a bad taste and odor. In the mid 1980s, a USDA Research group in California developed a method to stabilize the bran. A simple dry heat extruder is used to reach a temperature of about 270 F for a short period of time. This temperature deactivates the lipase enzyme. The temperature range is critical. Too low and the lipase is not deactivated, too high and vitamin E components are destroyed. The vitamin E components prevent oxidative rancidity over a long period of time. The process is relatively simple and when done properly, the bran is safe from both enzymatic and oxidative rancidity. Unfortunately, stabilized bran does not have a particularly great taste, and has not yet become popular in the human market. Sage V Foods (when founded as Comet Rice Ingredients) was involved in the original technology and has been stabilizing bran for over ten years.
Organic Rice. The number of acres planted to organic rice in the U.S is very small, but growing. For rice to be certified organic by organizations such as CCOF, the field used must have gone for three years without use of pesticides, herbicides, fertilizers, or any chemicals. Then the crop must be grown, harvested, stored, and milled under organic conditions. The field yields for organic rice are unpredictable and average about half of conventional rice. Much of the rice is removed in the milling process because of damages due to insects and weeds. It is very difficult to store organic rice and avoid insect problems. The final cost of milled organic rice is about three times that of conventional rice.
Today in the U.S. there is no federal standard for organic rice. (This may change soon.) There are several non profit and private organizations who certify rice as organic. They have strict requirements and the public has learned to trust and respect many of their logos on organic products. Sage V Foods is certified by CCOF and other organizations.
Parboiled Rice. Parboiled rice has been through a special cooking process, called parboiling, prior to milling. While in the paddy form, the rice is soaked and then steam cooked. This process does not allow the kernel to swell during the cooking and the moisture level does not exceed 40%, versus cooked table rice, which is most often cooked to a moisture level of 64%. The starch granule is cooked (technically gelatinized), but not allowed to swell. The rice is then dried while still in the paddy form and then passed through a standard milling process to remove the hull and bran.
This process has been going on for centuries in many countries and is believed to have started in ancient India. Researchers learned in the early 1900ís that parboiled rice retained some of the vitamins that exist in bran, but are lost in the milling of milled rice. The incidence of beriberi was reduced when diets were changed from white rice to parboiled rice because of increased levels of thiamin in parboiled rice. Uncle Ben made the process famous in the United States with its converted (same as parboiled) rice. The process may have originated to sterilize the rice and allow longer storage conditions. (All rice comes from the field with insect eggs in the germ of the rice. These eggs hatch when the temperature is warm and moisture is available.) The high temperatures occurring during parboiling kill any insect eggs in the rice and essentially sterilize it. Parboiling also mends the cracks in the rice (glues broken rice back together) and dramatically improves the milling yield of whole kernels in the rice. This improvement in milling yield, especially for poor quality paddy, can justify the cost of the process.
Parboiling changes the texture of the rice. It becomes firmer and less sticky. It is a much more durable kernel. It takes just as long to cook (actually a little longer) as white rice, but is much easier to cook. It is almost fool proof. It can be overcooked without being mushy or losing its grain shape. It does not have to be steamed. It can be cooked by blanching only. It has a long steam table life, which is important for restaurants. For these reasons, parboiled rice was adopted as the preferred rice of the restaurant industry long ago and so many consumers have become accustomed to the taste and texture parboiled rice. It is the only type of rice that can withstand the harsh treatment of most industrial processes that involve cooking and then freezing, canning, or drying. Most rice that is sold in the supermarket in some sort of cooked or partially cooked form has been parboiled.
In the U.S., some parboiled rice is sold into the consumer market, but most is sold into the food service (for use in restaurants) and industrial markets (for use in prepared meals). A great deal is exported to Saudi Arabia, South Africa, Europe and other countries.
Instant Rice. Instant Rice or Quick Cooking Rice is rice that has been precooked and then dried so that the consumers can recook the rice in a short period of time. Kraft General Foodís "Minute Rice" is instant rice. Regular white rice takes about 15 minutes to cook. Parboil Rice takes about 18 minutes to cook. Instant rice can be ready in a little as 3 minutes.
Cooking rice involves getting moisture to the center of the kernel then getting that moisture to a temperature of over about 160 F to gelatinize the starch. Raw starch in uncooked rice is tightly compacted and so it takes about 15 minutes for boiling hot water to migrate to the center of the kernel. There are several processes to make instant rice, but the one most commonly used starts much like the home cooking process. Rice is blanched in hot water, steamed, and then rinsed. Then the rice is then dried in a hot oven drier. The degree of cooking and degree of puffing in the drier determine the final cook time for the instant rice.
When the rice is cooked again by the consumer, the water migrates faster through the kernel because the starch has been gelatinized and there are many small cracks and fissures in the kernel. Quality of the final cooked rice is affected by the instantizing process. The faster the rice cooks, the lower the quality. Instant rice that cooks in 10 minutes is very close to the real thing. Instant rice that cooks in 5 minutes has a much poorer texture that rice cooked in a home rice cooker. Rice that is ready in hot water (like cup of noodles) is very mushy. All companies involved are trying to improve the process, but it is impossible to make a dry instant rice that cooks in under five minutes that is equal in quality to rice cooked in the home in a rice cooker.
Most companies that manufature instant rice sell the rice to the consumer though grocery stores.
IQF Rice. Individually Quick Frozen Rice is rice that has been fully cooked (to about 64% moisture) and then quick frozen. The rice can be thawed and heated in a microwave (in two to four minutes) and is ready to eat. Unlike instant rice, there has been no damage (cracking or fissuring of the kernel), and so the quality of this product is as good or better than rice cooked at home in a rice cooker.
The process for making this rice is very similar to the cooking process used at home. Once the rice is cooked and ready to eat, it is then quick-frozen. Sage V Foods is the leader in this new and developing industry. Most IQF rice is sold today in 1400 lb bulk totes to large industrial users who use the rice to put into frozen entrees containing rice. The IQF rice is easy to handle and can flow through conveying and portion scaling systems. Sage V Foods can flavor, mix with vegetables, and package IQF rice in small microwaveable pouches.