I don't know if you have noticed an interesting phenomenon: freshly picked flowers originally had a fresh and soft color, but after being dried in a microwave tunnel oven, the petals become darker, richer, and even more vibrant than when they were fresh. Many people may wonder, why is this?
In fact, this is not the deterioration of flowers or the discoloration caused by equipment, but the normal physical and chemical changes of substances inside the petals under microwave action, which is not complicated to understand.
Firstly, we can start with the most intuitive physical change: the color "concentration" caused by water loss. Fresh petals contain a large amount of water, which makes them appear plump and transparent, while also diluting the pigments in the petals themselves. Just like a cup of colored fruit juice, the more water added, the lighter the color becomes, and the color naturally darkens when the water content decreases. Fresh flowers quickly dehydrate in a microwave tunnel, causing the petals to shrink in volume. The natural pigments that were originally dispersed in a large amount of water are concentrated, resulting in a deeper color visually.
Secondly, the characteristic of microwave heating can further deepen the color of petals. Microwave tunnel oven is different from traditional sun drying and drying. It does not slowly heat from the surface, but directly acts on the water molecules inside the petals, causing them to vibrate and generate heat. This heating method has fast speed and uniform temperature, which can raise the temperature inside the petals in a short period of time. During the mild heating process, the pigment substances in the petals become more stable, while some cell structures slightly contract, and the arrangement of pigment particles becomes tighter, further deepening the visual color depth.
In addition, some substances contained in fresh flowers themselves undergo slight oxidation during dehydration, which is also an important reason for the darkening of color. Fresh petals have sufficient internal moisture, making it difficult for oxygen to enter and resulting in slow oxidation reactions. Once drying begins, moisture is quickly lost and oxygen is more likely to come into contact with the internal substances of the petals. Slight oxidation can cause the color of the petals to transition towards darker tones.
Many people worry that the darkening of the color may be due to baking damage, but in fact, the opposite is true. The microwave tunnel oven has a fast drying speed and can quickly lock in fresh flower pigments, avoiding fading, yellowing, and mold caused by prolonged drying. It quickly dehydrates while retaining the original pigment components of the petals as much as possible, but through physical concentration and slight oxidation, the color is expressed more strongly.
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