Before vacuum frying, the mushroom normally needs to be pretreated, such as blanching, color protection, maltose soaking. Each step has its purpose.
1. Blanching
The mushroom is boiled for 8~14 minutes in boiling water. This mainly used for inactivating the enzyme activity to prevent browning due to enzyme oxidation during the frying process. At the same time, blanching can also remove the sticky substance on the surface of the mushroom to prevent adhesive together when frying. It can also cause the cells to coagulate, lose water and cell wall separation, increase the permeability of the membrane, promote the evaporation of water inside the cells, and accelerate the drying rate.
2. Color Protection
It has been proved by practice that salt has certain inhibition and destruction on the activity of the enzyme, and the solubility of oxygen in brine is smaller than that of air, so it has a certain color protection effect. Citric acid is the most widely used food acid, which lowers the pH of the treatment solution. Therefore, the mushroom was protected with a 0.5% salt and 0.3% citric acid, pH3 solution.
3. Freezing
Frozen pretreatment processing of mushroom chips is a key step. After freezing and then frying, the internal moisture overflows in the form of an explosion, and the structure of the ice crystals changes the structure of the ice crystals, which is beneficial to the diffusion of water vapor. The frozen chips are relatively bulky and crisp, and there is no foaming on the surface of the chips.
4. Maltose soaking
Maltose soaking also meaning osmotic dehydration. This normally uses the 30 Brix maltodextrin liquid at 50℃, immerse the mushroom around 30-60minutes, then take it out and use a Tindo vegetable washing machine to clean it to remove the maltose on the surface of mushrooms.
This treatment is also a commonly used treatment method in the processing of fruit and vegetable chips. The main function is to replace part of the moisture inside the mushroom by using the concentration difference between the immersion liquid and the water content inside the mushroom. At the same time, infiltrating the mushroom with the macromolecular substance can improve The solid content, increase the strength of the tissue, adjust the different flavors, and homogenize the raw material components.
