Simply crush them and filter the solution.
The substance is the monoglucoside of malvidin.
Anthocyanin is a natural pigment found in many fruits and vegetables such as red cabbage, berries, and grapes. It can act as a pH indicator, changing color in response to changes in acidity or alkalinity.
The only natural crops of France I can think of is wheat and grapes. they need wheat to make bread, and they need grapes to make their famous wine.
Red Cabbage and Beetroot can be used but what else?
The Natural Resources in Greece was mainly olives and grapes. Grapes were also used to make wine.
commonly used natural indicator include indicators used mainly at our homes, labs and laboratories . natural indicators are obtained from plants. RED CABBAGE ONIONS LITMUS CURRY POWDER TURMERIC POWDER CHERRY TAMARIND GRAPES GERANIUM PETALS CARROT MORNING GLORY PETALS PEAR
Olives and Grapes.Olive oil was used around home and for cooking and Grapes were used to make wine.
If you are asking how to extract a chemical pH indicator from some plant type, I don't know. If you want to know a plant that indicates the relative pH of the soil it grows in, Hydrangea. Its flower's coloration is exactly like litmus paper's reaction to acids and alkalis.
Grapes and Olives , the grapes were turned into fine wine .
litmus is a natural indicator because it is obtained from a natural source e.g. lichens mainly roccella tinctoria.it is not synthesized in the laboratory.
They make 19 grapes.
To make an eggplant indicator, you can use a simple process involving an eggplant and a pH indicator solution. First, cut the eggplant into small pieces and blend it with water to extract its natural pigments. Strain the mixture to obtain a liquid that can serve as a pH indicator. This natural indicator will change color depending on the acidity or alkalinity of the solution it is mixed with, typically turning purple in neutral solutions and shifting to shades of pink or green in acidic or basic solutions, respectively.