What kind of rice is the "rice" in Travel Companion's "self-heating rice"?

During holidays, people often encounter inconveniences in dining, so the wide variety of self-heating foods in supermarkets, such as self-heating hot pots and self-heating rice, have become the best choice for travel. The main feature of these various fast food is that they can be heated and eaten quickly, and they do not require electricity or fire, making them very suitable for use outdoors, when traveling, or when you are busy.

However, while self-heating rice is popular among many people, it is also questioned by many people. These rice look different from the rice we eat at home. Is this rice made of rice? Is it safe? Let me unravel the mystery of self-heating rice for you.

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01 What kind of rice is used in self-heating rice?

There are rumors that the rice in self-heating rice is artificial? In fact, the rice in self-heating rice is not artificial rice, but it is not natural rice in the traditional sense. It is extruded reprocessed rice or reconstituted rice that is processed by industry. Because it takes a short time to heat when eaten, it is also called instant rice. This reprocessed rice is made from rice as the main raw material through industrial production.

Initially, natural rice is ground into rice flour, water is added to make rice paste, then steamed and dried, pressed into the shape of rice, and then polished. In this process, some ingredients and food additives are added, such as edible corn starch, mono- and di-glycerol fatty acid esters, and calcium dihydrogen phosphate, to improve the taste and preserve the quality of food. In other words, self-heating rice is actually cooked rice, and it is naturally faster to heat it again.

The difference is that some self-heating rice is dehydrated, so you need to add water before eating to "rehydrate" the rice and then heat it up. Some self-heating rice is not dehydrated and can be directly heated and eaten without adding water.

The taste of self-heating rice is different from that of traditional rice. Some people may feel that self-heating rice is not fragrant and chewy enough. This is because the molecular structure of starch changes during the processing, affecting the taste.

Compared with natural rice, the reconstituted rice in self-heating rice may also have differences in nutritional content, which mainly depends on the raw materials and processing methods used in the production process. For example, in the production process of reconstituted rice, there are steps such as grinding, adding water, steaming, and drying. These processing processes may cause the loss of some nutrients, such as B vitamins. However, some reprocessed rice will add fortified nutrients during the production process, which to a certain extent also makes up for the nutritional loss in the production process. Some will also add ingredients such as konjac flour to increase the dietary fiber content in the reprocessed rice. However, in the current self-heating rice in China, fortified reprocessed rice is relatively rare.

In addition, the starch structure of reconstituted rice is changed during processing, which affects the digestion and absorption rate of starch in the human body. For example, reconstituted rice may be converted into sugar more quickly, which will affect the blood sugar response. Especially for diabetics, eating self-heating rice may easily increase blood sugar, which is not conducive to controlling blood sugar stability.

In general, self-heating rice may not be as good as natural rice in some nutrients, but it can still provide certain energy and nutrition. It does not mean that its nutrition is "worse", but that the two are used in different scenarios and conditions. In terms of outdoor activities, long-distance travel, emergency storage, etc., self-heating rice is still a convenient and fast viable choice.

If you have the conditions to cook, you will have more choices for staple foods, such as adding black rice, millet, corn, brown rice and other varieties of grains to rice. The nutritional content is more diversified and it is more conducive to meeting the nutrients needed by the body.

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02 Self-heating is a chemical reaction

You may be curious about the heating principle of self-heating rice and why it can be cooked quickly. In fact, the heating principle of self-heating rice is mainly based on a chemical reaction. The self-heating rice package contains a small heating bag, which contains calcium oxide, also called quicklime, activated carbon, aluminum powder, sodium bicarbonate and other ingredients.

When heating is needed, open the water bag and mix it with calcium oxide. When calcium oxide comes into contact with water, a chemical reaction will occur to generate calcium hydroxide (Ca(OH)2), and this process will release a large amount of heat. When the heating bag meets water, it can quickly raise the temperature to a maximum of about 150°C. It takes 5-8 minutes for the center temperature of the food to reach 60°C. The heat released by the heating bag is transferred to the rice, thus forming the conditions for heating the rice. Generally speaking, it takes 10-15 minutes to fully heat the food to the degree and taste that it can be eaten.

This heating process is for single use. Once the calcium oxide reacts with water, the heating pack cannot be used again.

03 Heating pitfall avoidance guide

The temperature of self-heating rice is relatively high during the heating process, so when purchasing and using self-heating rice, special attention should be paid to the following points:

1. When purchasing self-heating rice, choose products produced by regular manufacturers and do not buy products with incomplete label information.

2. There are certain safety hazards in the heating process of self-heating rice. There are many accidents caused by heating packs, so you must pay attention. Before heating, make sure the heating pack is intact. If the heating pack is not damaged, the rice can be heated normally. However, if the heating pack is damaged, the heated rice may also be contaminated by the substances in the heating pack, making it inedible.

3. Only cold water can be added to the heating pack, not hot water, because using hot water may cause the water to boil violently and cause danger.

4. When heating, ensure that the air holes or exhaust holes on the outer packaging are unobstructed to avoid sudden cracking of the outer packaging due to excessive steam pressure, which may cause burns and other dangers.

5. When heating, place the self-heating rice on an insulating pad or a heat-resistant container, and make sure that the bottom does not directly contact non-heat-resistant materials such as glass, plastic, metal, etc. to prevent the container from breaking and causing burns.

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6. During the heating process, avoid touching the outer packaging. Wait until the self-heating bag no longer reacts and the food cools to a suitable temperature before eating to avoid burns.

7. Self-heating rice will generate a certain amount of heat and steam during the heating process, so you should choose a well-ventilated environment for heating and avoid using it in a confined or poorly ventilated space.

8. When the self-heating rice is finished, be careful to open the package to avoid steam burns. Wait until the steam dissipates before opening the lid and check whether the food is fully heated and cooked.

9. Self-heating rice contains chemical ingredients and should be placed out of the reach of children to prevent accidents.

Through the above content, I believe that everyone has a better understanding of self-heating rice. Finally, I would like to give you some advice. Convenient fast food such as self-heating rice can bring a lot of convenience to life, but it is not recommended to rely on this kind of food for a long time to provide energy and nutrition to the body!

Source: Chongqing Science and Technology Museum

Author: Zou Yu, Chinese registered dietitian RD

Audit expert: Li Chunli

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