How Rice Cookers Work

Induction Heating and Rice Cookers

Some rice cookers take precision a step further with the help of a technology called induction heating. While other rice cookers apply heat directly from an electrical plate underneath the inner cooking pan, induction-heating rice cookers get their heat from an alternating electric current from the wall outlet.

Induction heating, used for many applications beyond rice cookers, is achieved when this current passes through metal coils, typically made of copper. The movement of the current through these coils creates a magnetic field. It is into this magnetic field that the rice cooker's pan is inserted. The magnetic field produces an electrical current inside the cooking pan, and this generates heat. Heat can also be produced from this process if the rice cooker's pan is made out of a magnetic material. This is due to a phenomenon called hysteresis, in which magnetic materials show a resistance to any fast-paced changes of their magnetic level. This resistance creates friction, which contributes to the cooking heat.

Induction heating improves rice cookers in three main ways:

The temperature-sensing methods can be more accurate, allowing for fine-tuned adjustments in temperature.
The heat distribution area can encompass the inner cooking pan, not just radiate upwards from below, to produce more evenly cooked food.
The level of heat being created in the cooking pan can be changed in an instant by strengthening or weakening the magnetic field that is generating it.

These elements create the biggest bonus of the induction heating rice cooker. In the event of a human measuring error, an induction heating rice cooker can make minute adjustments to both the time and the temperature of the selected program because of its sensitivity to temperature, and its precise ability to control it.

The Rice Genome and Genetically-Modified Rice

A six-year gene sequencing project, which finished in December 2004, catalogued 95 percent of the rice genome [source: Nature]. A team of Japanese scientists led this 10-country effort, costing more than $100 million [source: Washington Post]. Conclusions of the study found that rice's dense genetic map has the smallest number of genes in comparison with other important plants in the cereal family. Project results will help further understanding of the development of other cereals and provide a basis for discovering ways to promote greater rice crop yields.

The need for the International Rice Genome Sequencing Project was based on estimates that rice production must be increased by 30 percent in the next 20 years to feed the world's growing population [source: Nature]. Researchers are now hoping to develop hardier genetic variations of rice which can be grown in a greater variety of climates, including ones that are colder and drier [source: Washington Post].

Another genetic rice project was the development of golden rice, a genetically modified form of rice with increased nutrients such as beta-carotene. The golden rice project goal is to improve the nutritional intake of the approximately 3 billion people who largely subsist -- getting 80 percent or more of their daily caloric intake -- on rice [source: The Golden Rice Project].