Grading apples or other fruits used to be operated manually in food processing plants. How many people are needed to grade apples in large quantities? Jingjiang Weineng machinery is now developed in science and technology, equipment update is also faster and faster, to apple grading can now use the fruit classifier to operate grading.

 

(1) The size of apple fruit is usually confirmed by grading board. There are 80 mm, 75 mm, 70 mm round holes on the grading board, so the fruit can be divided into several grades according to size. The shape, color and surface of the fruit are determined by visual observation and experience. Therefore, it is necessary for the grading personnel to master the grading standard. When grading, attention should be focused and strictly carried out according to the standard. In addition, the quality supervision personnel should select several special fruits, first-class fruits and second-class fruits as standard samples for each grading personnel to refer to.

 

Each grading personnel should put four packing boxes of special grade fruit, first grade fruit, second grade fruit and extra grade fruit in order. Each apple should be handed over once and put into the packing box according to the quality. Generally, there is no condition to wash the fruit in manual grading. The grading personnel should have clean wet towel and wipe it away in time in case of dust pollution on the fruit surface. According to the actual situation in our country, the artificial grading should be carried out before storage after harvest, which can not only reduce the number of artificial fruit dumping after harvest, prevent the mechanical damage caused by repeated picking, but also make the growers know their apples well, which is convenient for grading, stacking, storage and sale.

 

For example, Fuji special fruit has a diameter of 7.5 cm, 8.0 cm and 8.5 cm. The fruit should be packed separately according to several different standards, which is not only convenient for packaging, but also conducive to pricing according to quality.

 

The grading site shall be inspected by the quality inspector, and the problems found shall be corrected in time. In addition, we should also check the apples packed by each grading personnel to ensure the accuracy and consistency of grading.

 

(2) In recent years, China has introduced many kinds of apple grading pipelines, which greatly improves the accuracy and speed of apple grading and enhances the competitiveness of apple in the international market. The flow of Apple mechanical grading line is as follows:

 

① Unloading and cleaning.

 

Forklift will be filled with large wooden boxes of apples, from the storehouse to the starting point of the grading line of fruit unloading conveyor drum. With the roller rolling, the wooden box slowly enters the pool along the slope. Because the specific gravity of the apple is less than that of water, the apple will surface, and the empty wooden box will be sent out of the pool from the other end along the bottom of the pool. The water contains 50-200 mg / kg chlorine, which can kill mold spores. There are also 500-2000 mg / kg Diphenylamine in the water. When the white residual powder with calcium on the fruit surface is difficult to be removed by clean water, it must be removed by "acid bath". The method is to wash the fruit with 1% hydrochloric acid solution for about 1 minute, then neutralize the acid on the surface of the fruit with 1% sodium carbonate solution, and then rinse with water. Acid washing must be used properly, otherwise it will damage the apple. For example, when the acid is touched with an apple for 5 minutes, it is enough to cause the pigment to dissolve and the pores to turn black. When the pH of the sodium carbonate solution neutralizing the remaining acid solution is 10, it will also cause skin pore damage. Therefore, it is necessary to take precautions when using. In addition to the above methods, you can also use fine soft silk cloth or wet cloth to wipe the fruit surface dirt. The use of bagging method to produce fruit, because the fruit surface is clean, so you do not need to wash the fruit. ② Rough selection.

 

The mesh belt conveyed the apple from the water tank. In the process of forward transmission, it was washed by clean water and pumped by rollers containing foam plastic or sponge, and sent to the next process. The apples whose diameter is smaller than the mesh (the smallest diameter of fresh apples) fall onto the conveyor belt below, gather in the fruit box and send to the juice processing plant. ③ Waxing.

 

The method of applying a layer of wax on the fruit surface is called waxing. After waxing, it can restrain respiration and transpiration, reduce decay, maintain freshness and extend supply time. What's more, the surface of the fruit was changed. The quality of the fruit remained unchanged, but the surface became clean, beautiful and beautiful. This method has been used as an important method in modern fruit marketing, especially for premium fruit. It is widely used in many foreign countries, such as Israel, the United States, Spain, Germany, Britain, Japan, Italy and so on. Although it is not widely used in China, it will be gradually promoted as a necessary method in the future in order to beautify the appearance of fruits and enhance competitiveness.

 

The main types of waxing coatings are white wax, such as emulsified wax, shellac wax, fruit wax, etc.; natural coating agents, such as gum, whey protein, natural wax, gelatin, starch, etc. Now fruit wax mainly depends on imports. ④ Manual picking.

 

The waxed fruits are transported by conveyor belt. When passing through the fruit selection table, the workers standing on both sides of the table pick out the fruits which are lack of coloring, deformed, have obvious defects in appearance and are mechanically damaged, and then put them on another conveyor belt above for juice extraction. ⑤ Grading.

 

When an apple passes through a computer-controlled optical scanner, the computer records the degree of coloring and the size of each apple one by one. Each apple goes into a small cup and moves forward. Under the instruction of the computer, the fruit of the same size and color falls from the cup in the same direction to the conveyor belt moving horizontally below and enters the packaging process. Some assembly lines also have labeling devices that label each apple. The label generally indicates the title, grade and number code of the packer.