Uninterested is the opposite of interested. It simply means you have no interest in something:
He's totally uninterested in traveling. He likes where he lives and never wants to leave.
We approached the other company and proposed a partnership, but they were uninterested.
In casual spoken English, we tend to say "not interested" for the word uninterested.
The word disinterested means somebody is neutral. They have no bias (opinions that could unfairly influence their judgment). If two people are having an argument, they should present the case to a disinterested third party who can give a clear and fair evaluation of the situation.
However, some people do mistakenly use "disinterested" where "uninterested" would be more accurate.
The pigments that give beets their rich colors are called betalains. There are two basic types of betalains: betacyanins and betaxanthins. Betacyanins are pigments are red violet in color. Betanin is the best studied of the betacyanins. Betaxanthins are yellowish in color. In light or dark red, crimson, or purple colored beets, betacyanins are the dominant pigments. In yellow beets, betaxanthins predominate, and particularly the betaxanthin called vulgaxanthin. All betalains come from the same original molecule (betalamic acid). The addition of amino acids or amino acid derivatives to betalamic acid is what determines the specific type of pigment that gets produced.