On the table in the laboratory, there were several wide-mouthed glass bottles. The glass bottles seemed to be filled with liquid. The liquid in each glass bottle was soaked in different things. Xu Shao looked closely and found that it was the flesh of various fruits.

There are even lychees.

These fruits (including lychees) have been peeled and cored, and the flesh is soaked in the liquid in the bottle. They look fresh at first glance, without obvious signs of mold or rot.

Xu Shao looked carefully and found the difference between glass bottles: some glass bottles have wooden jars, while some glass bottles have a thin cover. The surface of the cover seems to be painted and painted with beautiful patterns.

He thought for a while and asked, "Your Majesty, is this a new type of canned food?"

Yuwen Wen nodded: "Yes, new canned food."

"You know that a few years ago, someone applied for a patent for long-term preservation of food, that is, canned food, which is actually a wide-mouth glass bottle sealed with cork. The principle is this."

"Put the cooked food into a wide-mouthed bottle, then put the bottle in boiling water and heat it for a while, plug the cork that has been steamed at high temperature while it is hot, then seal it with wax, and wait until the glass bottle cools, and the inside of the bottle is isolated from the outside of the glass bottle."

"The food in the glass bottle has been cooked, and then steamed with hot steam. It is so cooked that it cannot be cooked anymore. It kills bacteria once, and then plugs the bottle mouth with a cork while it is hot, and waits for the bottle body to cool down. In fact, a 'vacuum' is formed inside the bottle to isolate it from the outside air."

"The food in the bottle has been sterilized and is isolated from the outside air, so it is not easy to rot and can be stored for a long time."

"In terms of meat products, meat preserved by the new canned storage technology will last longer than fried meat floss. If the meat floss is preserved with cork wide-mouthed bottles, the shelf life of the meat floss will be greatly extended."

"Similarly, using canned food to preserve fruit products such as pickled products, candied fruits, etc., will also have a good effect."

"Also, the candy shops all know that sugar water has the effect of preserving food, so using canned food filled with sugar water to preserve the flesh of fresh fruits is also a good way to store it."

When Yuwen Wen said this, he changed the subject: "In fact, since ancient times, there has been a method of sealing mud in pots to preserve food, so using cork wax to seal glass bottles to preserve food is nothing more than the container and sealing method. Of course, the step of sterilization has been added."

"While the glass bottle is transparent, so people can see whether the food has obvious spoilage or mildew. This is an important advantage for canned foods, and the same is true for canned fruits."

When Xu Shao heard this, he roughly understood in his heart: Canned fruits that are resistant to preservation? Is it another product?

What Xu Shao thought was, of course Yuwen Wen didn't know, so he continued to explain: "However, the sealing effect of cork plus wax seal is still a bit worse. Of course, this difference is relative to the new technology."

After saying that, he pointed to several other glass bottles, which had a metal cover on the mouth, which obviously had a different appearance from the cork-stoppered glass bottle.

"The metal lid of this glass bottle is made of iron, but the iron is prone to rust, so you have to coat the outer layer with anti-rust agent to ensure that the lid can be sealed and stainless for a long time."

Xu Shao asked: "Your Majesty, is it painted? But if painted, the iron tool will not be rusted so easily."

"Of course, anti-rust is not based on paint, but on 'tin'." Yu Wenwen finished speaking and picked up the iron-covered glass can. "This iron cover is made of tin-plated iron sheet. The tin-plated iron sheet is anti-rust, and it is strong and thin. The sealing effect of the cover is better than that of cork."

"Of course, the outer part of the cover is painted and beautifully painted. When it comes to cost, tin-plated iron covers are more expensive than corks, but there is a reason to be expensive."

Yuwen Wen asked Xu Shao to carefully look at these iron-covered glass bottles: "Look carefully and see what the difference is between these glass cans."

Xu Shao looked carefully and found that the flesh in several glass bottles had slightly mildew, which seemed to be poorly sealed and moldy.

But he thinks the answer should not be this.

Xu Shao looked at several glass cans carefully, and even held them in his hands one by one and looked over and over again. After looking at them, he didn't know how long he looked, and finally found some clues: "Your Majesty, these flesh have cans that are not obviously moldy, and the bottle caps are protruding outwards."

Yuwen Wen smiled and said, "Yes, the bottle caps of those glass cans that have not yet been moldy are slightly concave. This is because the caps are sealed after high temperature sterilization. When the bottle cools down, the internal air pressure is negative, so the bottle caps are concave."

"However, once the flesh in the bottle becomes moldy and fermentes, gases will be generated. These gases gather and reach a certain amount, they will push the cap and then protrude outward."

"The pulp or food in the can is slightly deteriorated, and the naked eye may not be able to see it. Therefore, the disadvantage of cork glass canned is that it is here. Eating people cannot use simple and direct methods to determine whether the food in the bottle is spoiled, but the glass canned with tin-plated iron lids have the function of identifying spoilage."

"Only in this way can we provide the minimum edible safety guarantee for canned food, and those who are still well-off will have the interest in buying canned food."

"It is basically impossible for Zhongyuan to eat lychees, longan and other fruits produced in Lingnan, because these fruits will become moldy during transportation and cannot be eaten after being transported to the destination."

"However, if you make lychees and longans into canned fruits soaked in sugar water, you can import them on a large scale. Those who have a few spare money can taste it."

"Similarly, even in the Central Plains, in various fruit producing areas, when the fruits are ripe in autumn, canned workshops can make canned fruits on a large scale, so that people can eat fruits in other seasons."

"The preservation technology of tin-plated iron cover glass bottles can also have many uses, which is used to preserve various types of food and sauces, so that famous food and sauces in various places can be sold in large quantities in commercial form. Of course, it must be sold in a convenient area to be adjacent to convenient transportation."

"The traditional way of preserving meat is nothing more than air-dried meat, bacon, bacon, sausage, ham, etc. Later, there were meat floss. Now with new food storage technology, the shelf life of meat products will be longer."

"This is a good storage technology for the food processing industry. If properly guided, we can vigorously develop the food processing industry in some areas, hire idle labor, and feed more people."

Xu Shao asked: "Your Majesty, I don't know the cost of canned fruits."

Yuwen Wen picked up a glass can and replied: "It used to be very high. Because there was no strong acid and alkali, the cleanliness of the iron sheet could not be ensured. Even if the iron sheet was plated with hot dipping process, such iron sheet would easily rust."

"But now it's different. The mass production of strong acids and strong alkalis has been much lower, so the advancement of chemical technology has greatly reduced the quality and production cost of tin-plated iron sheets. Then technicians have overcome the cover making and sealing technology, so there are relatively low-cost glass cans."

"But it's not enough to have a lid alone. The iron cover cannot be completely close to the glass bottle mouth, leaving no gaps, so the inner side of the bottle cap needs an Eucommia glue lining."

"It can be said that the small tin-plated iron glass can contains not low technical components, but large-scale and low-cost mass production is not small under the premise of ensuring quality, so this food preservation technology will not mature until the beginning of this year."

Xu Shao listened and asked again: "Your Majesty, this glass can is still a bit fragile. If it can be improved, it may be used in the army."

"This is a good idea." Yuwen Wen smiled and signaled the experimenter to bring a few cans. These cans are not made of glass and look like bamboo tubes.

Xu Shao took it in his hand and looked carefully for a while, and asked in surprise: "Your Majesty, could it be... Could it be that this can is a tin-plated tin can?"

"Yes, tin-plated iron cans are rolled out of tin-plated iron sheets. There are three tin-plated iron sheets in total. Such cans are not only resistant to storage but also resistant to transportation. The foods in them are cooked food, and they are eaten when opened."

"Of course, you can also place it on the fire and heat it directly, because the tank itself can be used as a cooking utensil."

"With such a magical power, that is, canned food storage technology, think about it, how good the development prospects of the food processing industry will be?"
Chapter completed!