What is the relationship between climate and diet?

As the saying goes, "Food is the most important thing for the people". The distribution of natural food, the storage, processing and transportation of food, and the relationship between seasons and diet are all closely related to climate.

Climate and food distribution

Although human beings have a lot of food, the distribution of natural food in various places is greatly restricted by the climate. Extremely speaking, Inuit people in the Arctic mainly eat animal food in the ice and snow. The equatorial tropical region is rich in plant food sources, and the main productive labor of indigenous people in some areas is gathering.

Northerners live on cakes and so on.

In China, the most typical influence of climate on people's staple food is "rice in the south and wheat in the north". Because it is generally in the south of Qinling-Huaihe River, with abundant spring rain and plum rain, it is very suitable for planting rice that needs more water. Therefore, rice and its products have always been the staple food in southern history, such as rice, rice cakes and rice balls. The Qinling Mountains-the northern area north of Huaihe River is short of spring rain, which is known as "spring drought for ten years and nine months". Therefore, drought-tolerant wheat has been planted in history, and people mainly use noodles, steamed bread, jiaozi, cakes and other flour products. In Inner Mongolia, Northwest China and Qinghai-Tibet Plateau with less precipitation, crops and trees can no longer grow there because of drought or cold, and only grass can grow there. The local people mainly graze cattle and sheep, so they live on beef, mutton and milk.

The ancient political, economic and cultural center of China was mainly in the north. At that time, drought-tolerant, cold-tolerant and nutritious millet widely planted in the north was the staple food of the general public. In ancient times, "country" represented the country, "society" was the land god, and "millet" was millet. It can be seen that Xiaomi was very suitable for the climate in the north at that time. Because, as the Book of Songs said, crops are "the land of the living and the sky of the breeder", in which "sky" refers to meteorological conditions.

The geographical distribution of fruits is stricter than that of grains. In China, tropical and subtropical fruits such as coconut, mango, pineapple, longan, litchi, grapefruit and banana are most afraid of the low temperature of 0℃, so they are only distributed in South China. Subtropical fruits, such as citrus, loquat, etc., can resist light cold, but they will still cause serious freezing damage at a low temperature of about MINUS 9℃ or even lower, and are generally only distributed in the south of Qinling-Huaihe River. The temperate zone north of Qinling-Huaihe River is rich in temperate fruits such as apples, pears, persimmons and grapes. In the north of the Great Wall in China and the north of Xinjiang, it is difficult to grow temperate fruits such as apples because it is too cold in winter. Now, using grafting, hybridization and other methods, apples have begun to expand further north.

There are also great differences in vegetable varieties between the north and the south. Take winter cooking as an example. In the north, because there are no greenhouse vegetables, Chinese cabbage is eaten all winter. But this kind of Chinese cabbage doesn't grow well in the south. Cold-loving northern potatoes will soon go bad after being transported to the south for planting. If new potato varieties can't be introduced in time, they can only be planted in alpine mountain areas.

The cash crops in the north and the south are also very different. Take sugar raw materials as an example. There are sugar cane that likes warm in the south and sugar beet that likes cool in the north. Beets are now mainly distributed in the north of latitude 40. There were no beets in ancient China, and northern residents used to eat salty ones, so it was called "sweet in the south and salty in the north" in history.

However, even crops that can grow in the north and the south have different quality and yield. For example, the protein content of wheat in the north is higher than that in the south, and the milled flour tastes good. In arid areas such as Xinjiang, the sunshine is strong, the daily temperature difference is large, and the growing period is rich in calories, so fruits and vegetables are particularly sweet. Hami melon in Shanshan, grapes in Turpan and fragrant pears in Korla are famous at home and abroad.

Food storage, processing, transportation and meteorology

Many human foods have to be stored for a long or short period of time.

For our country, the most important thing in grain storage is grain, because the stock of grain is extremely huge. Once eaten by insects and spoiled, the nutritional value will be reduced, but it can't be eaten, causing huge losses. When the temperature of grain depot is above 20℃, the relative humidity is above 90%, and the moisture content of grain is between 16% and 18% or above, it is most suitable for the growth and reproduction of microorganisms such as mold, and high temperature and high humidity are also beneficial to the growth of pests such as rice weevil. So the grain depot should be ventilated, cooled and dehumidified in time. It is said that there are two ways to store rice in Japan (Japanese mainly eat rice): normal temperature and low temperature, with low temperature being the best. Mainly put the ventilation pipe into the bulk rice and input cold air to keep the grain temperature at 65438 05℃ and the air relative humidity at 75%. Because the grain is dormant at low temperature, not only pests and mildew will not occur, but also the storage period can be greatly extended because of the weak respiration of the grain at this time. After two years, the quality of rice is basically the same as that of new rice. In a modern grain depot in Uppsala, central Sweden, the way for Swedes to safely store grain is to dry it before storage, so that the water content of grain can be reduced to below 14%, which can ensure that the grain will not deteriorate within 1 year; If the water content is kept below 13% (the granary has automatic display equipment for grain temperature and air humidity), the temperature is lower than 20℃, and it can even be stored for 20 ~ 30 years (the grain temperature is kept above 5 ~ 6℃ in winter).

Although grain storage needs low temperature, low temperature is not conducive to microbial reproduction, because special microbial help is needed in pasta fermentation, soy sauce making, soybean tofu making and cheese processing and ripening. For example, when the temperature is below 10℃, the yeast activity will be weakened or even stopped.

Too humid air tends to mold grains.

Too humid air tends to mold grains and deliquesce sugar and salt due to moisture absorption, but too dry air will accelerate the evaporation of food moisture and cause many troubles. For example, in the past, bulk cakes in Beijing were often difficult to bite in winter. People call Beijing's generally round snacks "discus" and long-shaped snacks such as rice noodles "iron bars". But people can use drying to quickly prepare dried food, such as dried bamboo shoots, dried laver, dried salted fish and so on. In the past, farmers in Shandong relied on dried sweet potatoes in autumn as their staple food for winter, but if there was too much autumn rain, dried sweet potatoes would become moldy. One winter's grain went up in smoke, and the consequences can be imagined. Turpan raisins depend on the local hot and extremely dry climate, and it takes about 40 days to dry out the unique "green pearls" in the world.

As mentioned earlier, in the past winter, Chinese cabbage was the main course in northern China, so every family stored a large amount of Chinese cabbage for winter. But high storage temperature will rot; Accidentally frozen, it will taste like chewing wax; Air-dried Chinese cabbage stored indoors is also inedible. Residents usually dig a cellar with a depth of 1 ~ 2 meters, and it is best to store it at about 5℃. In most parts of Northeast China, the temperature 3 ~ 4 meters underground is around 5℃ all the year round, and food will not rot for a long time, so it is a "natural big refrigerator". In Xinjiang, "eating watermelons around the stove" is also eating watermelons stored in the cellar when the fire is lit in winter.

Although the transportation time of food is short, it is also closely related to the weather. For example, sugar, salt and its products need strict rain protection to avoid excessive humidity and dryness; Fruits and liquid foods need air-conditioned transportation to prevent freezing in winter and keep fresh in summer.

Seasons and diet

Although the main foods in different climatic zones are very different, the winter and summer foods in the same climatic zone can also be very different. This is mainly in temperate regions, especially in China, which is hot in Leng Xia in winter.

Winter Food-Yunnan "Crossing the Bridge Rice Noodles"

In winter, people consume a lot of calories, so they have a good appetite. At this time, people eat more animal foods with high protein, especially hot mutton and dog meat. Middle-aged and elderly people also use drugs to supplement and eat more hot pot. Northerners use hot pot to rinse mutton while eating fresh; Southern hot pot mainly plays the role of cooking and heat preservation. In addition to hot pot, Yunnan's "crossing the bridge rice noodles" (vermicelli made of rice noodles) and Xi 'an's "mutton bread in soup" also have effective folk insulation methods, that is, putting a thick layer of oil on the noodle soup. When the oil evaporates slowly, the heat consumption of evaporation is greatly reduced.

Summer weather is hot, people's appetite is greatly reduced, so they like fresh, refreshing and digestible light food, and vegetables are also less meat and more vegetables. The sales volume of cold drinks such as popsicles and ice cream, and drinks such as beer and soda rose linearly with the increase of temperature. Watermelon and mung bean soup is a cool and refreshing folk product.

Interestingly, some places are often out of season. There used to be a dish in the northeast called "Fried Ice Valve". Mix the ice skates hanging under the outdoor eaves with white flour to make flour sticks, and then fry them in oil. Because of the quick action, the noodles outside have been fried before deicing, and a mouthful of white gas has a special flavor. Similar customs in Kanto include "cutting raw eggs with knives" and "hollow noodle soup".

"Fried Ice Valve" in Northeast China

"Fried ice petals" means eating ice in winter, and beef chafing dish eaten in Thailand in summer is eaten in winter and summer. Because it is carried out in the ice room, the temperature in the ice room is as low as ten degrees Celsius, so eating hot pot is of course very comfortable.

If the temperature difference mentioned above can lead to "poor food", that is, the greater the difference between the outside temperature and the body temperature in winter, the better the appetite, and the temperature in summer is close to the body temperature, so the appetite is the worst in a year, then the temperature difference can also lead to "poor taste". For example, someone did an experiment. In hot summer, let a group of people take turns to drink beer at different temperatures to identify the quality. As a result, everyone thinks that beer at 6 ~ 8℃ is the best. In fact, the beer they drink is all in the same barrel, but the temperature is different. When this experiment was carried out in winter, the best beer became 10 ~ 12℃. In addition, different foods have different tastes at different temperatures. For example, eating iced watermelon at 8℃ is the best, and drinking hot coffee at 70℃ is the best. The farther away from this suitable temperature, the worse the taste.

In the southwest of China, such as Sichuan, Hunan and Guizhou, local residents like to eat Chili. There is a folk saying that "Hunan people are not afraid of spicy food, Guizhou people are not afraid of spicy food, and Sichuan people are afraid of spicy food". This is because these areas are cold and humid all year round, especially in winter. Eating Chili peppers has the effects of expelling wind, removing dampness, dispelling cold and strengthening stomach. Sichuan people's favorite spicy noodles (Chili) also have the same effect. Often a bowl of noodles, a sweat, and a cold will be fine. Some alpine weather stations, such as the top of Wutai Mountain in Shanxi, are 2,896 meters above sea level, and they often build stoves and quilts there in summer. The average temperature in July is only 9.5℃, and the climate is humid. There are no meteorologists in Sichuan, but most of them eat peppers, of which dispelling cold and resisting rheumatism are the main reasons.