What does blanching do - how is it important?
Blanching – you might have come across this word many times while reading food magazines or articles and wondered, “What is blanching, and what does blanching do to food?” Don’t worry for I am going to answer all your queries about blanching.
Blanching can be described as a heat treatment or cooking technique wherein the food is dipped in boiling water for 2 to 3 mins and immediately plunged into cold or iced water. This treatment leads to a thermal shock that causes a number of changes in the food, both physical and chemical. I will discuss each of these changes in detail here:
• Skin softening: During blanching you cook only the skin and the under layers of the food. As a result the skin softens while the rest of the food product retains its firm texture. This in turn helps to easily peel the food. This technique is used for peeling nuts like almonds and pistachio, fruits, onions, and tomatoes.
• Flavor enhancement: Blanching releases the strong acids found naturally in sulfur containing vegetables like broccoli, cabbage, radish and turnips. This enhances the flavors of these vegetables and renders them more palatable in salad form.
• Color enhancement: As mentioned before blanching partially cooks the skin and under layer of the food. Due to this heat treatment the color pigments in the food are altered, making the fruits and vegetables appear brighter and shinier. Also blanching removes the superficial dirt from the food, which enhances the color of the food.
• Microbial destruction: Like pasteurization, the thermal shock caused by the process of blanching effectively inactivates and destroys several common micro-organisms found on the food surface, thereby enhancing the self life and quality of the food.
• Enzyme inactivation: Enzymes are chemicals found naturally in all food that promote the degradation process of the food, especially in case of fruits and vegetables. Freezing does not destroy these enzymes. Heat is the only way to get rid of them. However, normal heating techniques lend a cooked taste and flavor to the food. Hence, in food processing industry, fruits and vegetables are blanched before freezing or drying the fruits or vegetables. This helps the fruits and vegetables retain their original characters even after processing.
Thus, blanching effectively helps to preserve and enhance the natural flavor, texture, color, and shelf life of the fruits and vegetables.
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