Before pressed into juice, the fruits and vegetables should be done certain pretreatment in the juice processing. To get the quality guarantee of fruit and vegetable juice, first of all, ensure the quality of raw material. How to select and sort the fruits and vegetables are mainly several aspects as follow.
1) Maturity of raw materials
The fragrance of fruit juice, which pressed from the immature or dysplastic fruit and vegetable, is not as good as the juices made from than growth good mature fruit. And because of the low content of sugar and soluble solid, the flavor of juice is very poor.
If the raw material is overripe, the pulp is too soft or lack of juice, the protopectin in the raw materials changes into water-solubility pectin. It gets juicing assignments and clarifying operation becomes more difficult, causes a low juice yield, and even makes raw materials corrupt.
To achieve the best processing of raw materials, these appearance characteristics are between picking maturity and quality maturity.
2) Freshness of fruit and vegetable
For the general fruits and vegetables, it is best to press when they are fresh juice. If they are not immediately used, they must be frozen for storage (below – 18 ℃).
3) Integrity and non-destructive of fruit and vegetable
In order to ensure the quality of the original fruit and vegetable juice, there should be no destruction, no metamorphism and no insect damage of the raw materials.