If you describe it in one sentence, it must be "a small body contains a huge amount of energy". The blue-purple appearance gives it an elegant and mysterious character, and it is also a symbol of romance and calmness; and sweet and sour is its unique and exclusive taste, it is the "king of berries" - blueberry.

Blueberries are native to North America and East Asia, distributed in North Korea, Japan, Mongolia, Russia, Europe, North America, Heilongjiang, Inner Mongolia, Jilin Changbai Mountain and other countries and regions in China, and grow in areas with an altitude of 900 ~ 2300 M. Blueberry fruit size and color vary with species. The fruits of most varieties are dark blue or violet when mature, such as rabbit eye blueberry, high cluster blueberry and low cluster blueberry, and a few varieties are red. The fruit is spherical, oval, oblate or pear shaped, with an average single fruit weight of 0.5 ~ 2.5 g and a diameter of 0.8 ~ 1.5 cm. The maximum single fruit weight of rabbit eye blueberry can reach 25 g.

Because the blueberry fruit is relatively fragile, fruit farmers generally adopt the method of manual picking, The picked fruits are graded according to the size of fruit diameter, and then the graded blueberries are packaged and refrigerated, and finally transported. When grading blueberries, fruit farmers generally use modern mechanical equipment that does not harm the fruit. For example, fstsort blueberry classifier is composed of conveyor belt fruit picking platform, fan and grading part. It is fed manually, pre cooled and dehumidified by fan, and the secondary fruit and impurities are picked out from the conveyor belt, and then enter the grading part.

Each grading drum of the grading part is provided with round holes with different diameters, which are evenly arranged on the drum (the level closest to the feed inlet is the minimum level, according to the hole diameter on the drum, it is the second and third level, and the blueberry size of the last level is the largest).