How was the birth and development of food graders?

Food for the people is for the sky, and the richness and diversification of food is an important indicator of testing the living standards of people in a country. With the improvement of living standards, people have higher and higher requirements for food. Under such circumstances, food machinery has been widely used and developed. The modernization of food machinery is an important indicator to measure the level of development of a country’s food industry. With the progress of human society, people have put forward higher requirements for the convenience, nutrition, and safety of diet. At the same time, the trend of sustainable development makes The utilization of by-products of agricultural products processing and agricultural waste has become very urgent. Different food machinery has been designed according to production requirements. In the food processing industry, vegetables and fruits of different sizes, shapes, densities, colors or qualities can be used to process different grades of finished products, so that not only can make full use of various materials, but also enable manufacturers to obtain more profits. Therefore, before processing vegetables and fruits, fruits and vegetables must be classified first. Because of this need for grading, food graders were born. Before food processing, in order to make the specifications and quality indicators of agricultural products that are the main source of food processing meet the standards, the materials need to be classified. Grading is to classify materials into grades only according to their size, shape, density, color or quality. This design is a drum classifier. The drum classifier uses the rotation of multiple drum screens with different apertures to classify fruits with different diameters. Because the drum grading machine works smoothly, does not cause mechanical damage to the fruit, has high grading efficiency and low noise, it conforms to the development trend of modern agricultural machinery. In the modern food industry, it mainly targets vegetables such as walnuts, hazelnuts, hawthorns, mushrooms, and green beans. Grading of fruits. In today's economic globalization, making full use of resources and making good use of the value of each material is a key factor in determining how much its value is realized. The fruits of different sizes separated by the classifier can be classified and processed according to the size of the materials required for different foods, which can better reflect the value of each raw material and the sustainability of social development. Traditional fruit grading methods include volume grading and quality grading. Since the purpose of grading is mainly to unify product appearance specifications, so as to package and improve the sales level, volume grading is the most widely used. Volume classification equipment includes drum classifiers, three-roller classifiers, belt classifiers, etc. The principles are similar, and they all use holes or gaps of several levels for screening. The quality grading equipment has developed from the early mechanical weighing and grading form to the current advanced high-speed dynamic electronic weighing and grading form. The fruit grading and waxing equipment of FMC in the United States mainly focuses on quality grading for citrus models. It can complete the cleaning, sorting, waxing, grading, and packaging processes through the entire line; the fruit grading and packaging equipment of MAF France in France , Not only can the fruits and vegetables be classified and packaged, but also can use the electronic and optical principles to sort the defects on the skin of the fruits and vegetables. It is fully computerized and has a high degree of automation. Now, a more advanced and ideal classification and quality technology has been applied in the above-mentioned foreign companies-the use of light curtain measurement technology or electronic scanning resolution technology and other new types of fruit classification and quality equipment. The fruit in operation is detected through the light curtain, the outline size is collected, and the central processing unit calculates, compares with the set grading size, and sends an instruction to drive the sorting mechanism to transfer the fruit to the appropriate rank. Using computer vision processing systems such as electronic scanning and distinguishing, it can identify fruits and vegetables with different colors and shapes, and sort the defects on the skin of fruits and vegetables, so as to achieve online classification and quality. This is an intelligent model that integrates light, machine, electricity and programming operations. This kind of grading and quality classification technology is a qualitative leap compared with the traditional aperture and quality classification methods, because it realizes a non-contact type of classification and quality classification, which is accurate and high-speed. In the late 1980s, my country introduced citrus fresh-keeping grading production lines from companies such as the United States and Japan, mainly in the form of quality and aperture grading. Later, after digestion and absorption by domestic scientific and technological personnel, domestically-made drum-type citrus fresh-keeping and grading production lines began to spread. However, there are currently no mature products in China for new types of fruit grading and quality equipment using light curtain measurement technology or electronic scanning resolution technology.