Blanching is a crucial step in fruit and vegetable processing. It typically occurs after washing and cutting, but before freezing, drying, and canning. Blanching not only improves product quality but also extends shelf life. So, what are the steps of blanching of fruits and vegetables?
The blanching process generally proceeds as follows:
Raw material pretreatment: Fruits and vegetables are first sorted, washed, peeled, or cut to remove dirt, impurities, and undesirable ingredients. This prevents impurities from affecting the blanching effect.
Transfer to the blanching machine: The processed raw materials are fed into the blanching machine via a conveyor belt or manually. Hot water, typically between 85°C and 100°C, is used for blanching for a period of several seconds to several minutes, depending on the variety and size.
Cooling (cooling tank or spray cooling): After blanching, the material needs to be cooled immediately, typically by cooling it in a cooling tank or by using a cold water spray to quickly reduce the temperature to room temperature. This prevents further heat exposure, which could degrade the taste or color.
Purpose of Blanching:
Enzyme inactivation and color preservation: Fruits and vegetables contain a variety of active enzymes. Left untreated, these enzymes can lead to browning, flavor loss, and nutritional loss. Blanching inactivates enzymes (such as polyphenol oxidase) while preserving vibrant color.
Bacterial sterilization: High-temperature blanching kills some surface microorganisms, reducing the risk of microbial contamination during subsequent processing and improving product hygiene and safety.
Softening: Some ingredients, such as carrots, green beans, and corn kernels, are relatively firm, and blanching can moderately soften them.
Easy peeling: After blanching, the peels of some fruits (such as peaches, tomatoes, and bananas) loosen and become easier to peel, making manual and mechanical peeling easier.
If you have any other questions about blanching and blanching equipment, please contact us.
