NU FS373 Lecture Notes - Lecture 16: Tetrapyrrole, Xanthophyll, Lycopene
13 Apr 2017
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Document Summary
Green leaves-chlorophyll masks other pigment colours from anthocyanins and carotenoids. So decreasing light levels to decrease chlorophyll levels, and rising sugar concentration leads to anthocyanin levels increase. B/c high anthocyanin content will give red leaves, Decrease chlorophyll will actually decrease the ability of anthocyanins and carotene. When anthocyanins levels decrease, carotenoid colours appears and make the orange colour eventually yellow. There are some natural colour in foods: anthocyanins, curcumin in turmeric, lycopene. Ripening can also change both colour and aroma of the food: Colour is a good indication for the state of the food products. Betalains gives yellow and red soluble pigments from beets, resonance of conjugated cation, which makes this conjugated hydrocarbon become soluble. Have cavity in the middle of the ring, and can fit iron inside, which results in changing colour. *chlorophyll*: soluble in moderately polar solvent such as acetone. The mg atoms in chlorophyll can be replaced by weak acids or cu2+ and other divalent.
