Purple kale is a food that is rich in vitamin C and fiber, and consuming more of it has many benefits for our bodies. In fact, in addition to the edible value of purple kale, it can also be used to play fun little science experiments. Tear up the kale leaves and put them into a cup, add a little tap water, and keep poking the kale with a spoon or a stick to get the juice out of the kale. Label three small cups 1 and 2 and pour vinegar and tap water into cups 1 and 2. Pour baking soda and water into cup #3 to make a baking soda solution. Mash out of the kale juice were poured into three small cups of solution, you will be surprised to find that the kale juice vinegar encountered turned pink, encountered the tap water did not change color, encountered the baking soda solution turned blue. The main reason for the discoloration is because the purple kale contains anthocyanins, which is a kind of plant pigment, he will be with the different pH, so as to change the color. Because vinegar is acidic, tap water is neutral, baking soda solution is alkaline, so encountered in the purple kale anthocyanin occurred different color change.