Blackberry, also known as dew berry, originated in North America and belongs to Rosaceae Rubus perennial vine. Since ancient Greece more than 1000 years ago, local people have formed the custom of eating thorny BlackBerry. It is the representative variety of the third generation of fruits popular in recent years. It is recognized as the third generation of new special fruit by the FAO and praised as the "fruit of life" by European and American countries "Black diamond". In 1986, after several years of cultivation research, the Institute of Botany, Jiangsu Academy of Agricultural Sciences, Chinese Academy of Sciences finally succeeded in introducing and planting blackberries in Lishui Town, Nanjing. Blackberries are very difficult to preserve. They must be cleaned, sterilized and frozen within 4 hours after picking, otherwise a large amount of nutrients will be lost and fermented. Freeze dried blackberry powder retains its nutrients well.
BlackBerry is a widely distributed and shrub; Raspberry plants, usually biennial, with erect, semi erect or climbing stems, thorns, and some cultivated species have no thorns. It can grow up to 3 meters high and produce soft fruit - often used as dessert, jam, seedless jelly and sometimes fruit wine. The leaves are trifoliate or palmately compound leaves, with three to five leaflets. The leaflets are wide, oval, petiolate, thick tooth crack at the leaf margin, and most of the leaves survive the winter. The flower is white or pink, the fruit is aggregate fruit, and the small black or red purple drupe is inserted on the juicy receptacle.
BlackBerry is rich in procyanidins, anthocyanins, SOD, selenium, ellagic acid, flavonoids and other substances, 20 kinds of amino acids and trace elements. At present, it has been found that it contains nutrients for more than 40 hours. Among them, procyanidins, anthocyanins, SOD, amino acids, calcium, iron, zinc, selenium and vitamins are several times or even hundreds of times that of blueberries, so it is praised by European and American countries "Fruit of life", "black diamond".
Freeze drying is to cool and freeze the material containing a large amount of water into a solid in advance, and then sublimate the solid water directly under the condition of vacuum, while the material itself remains in the frozen ice shelf, so its volume remains unchanged after drying. Solid water should absorb heat during sublimation, causing the temperature of the product itself to decrease and slow down the sublimation speed. In order to increase the sublimation speed and shorten the drying time, the product must be properly heated. The whole drying is carried out at a lower temperature. Freeze drying is carried out at low temperature, so it is especially suitable for many heat sensitive substances. For example, proteins and microorganisms will not denature or lose biological vitality. Therefore, it has been widely used in medicine. When drying at low temperature, the loss of some volatile components in the material is very small, which is suitable for the drying of some chemical products, drugs and food. Freeze dried blackberry powder maintains the original flavor of blackberry and contains a variety of vitamins and acids.
