I bought a elizabeth melon the night before, cut it open and ate half of it, and put the other half on the windowsill. The next morning, I peeled and cut the other half and put it in a glass bowl. ...

I have heard similar reports before, and the authoritative explanation is that the agricultural experts of the Academy of Agricultural Sciences have analyzed that the wounds of melons will turn pale red after being injured during the growth period, and phenolic organic compounds will be oxidized into quinones in the air, showing reddish brown. Generally, fruits will change color by oxidation reaction in the air, but the color change will not be so great and there will be no fading phenomenon. Experts believe that this kind of melon may be the mark caused by the seed coat dye alkaline rose essence or alkaline red when melon farmers apply hormones to improve the fruit setting rate. When melon is smeared, alkaline rose essence or alkaline red remains in melon meat, thus showing red color. Experts say it is best not to eat melons with abnormal colors.