Abstract: A system and method for producing a caramel food colorant according to one example embodiment exhibits improved stability against precipitation and provides a rich brown color. The colorant is particularly useful for modifying the color of alcoholic beverages but has many other potential uses, including uses as an antioxidant. The novel caramel food colorant is produced from a variety of Sorghum bicolor that accumulates deoxyanthocyanidins in the leaves, and varieties that accumulate deoxyanthocyanidins in seed bran. The pigments are extracted from the leaves or bran in acidified water or a solution containing water, alcohol and acid, the pH is then adjusted to basic pH, the solution is briefly heated, then the pigment is used without further purification or purified by adsorption to a commercially available hydrophobic resin, and eluted from the resin with a solution containing water and alcohol.

Abstract: A method of processing plant cellulose includes providing plant cellulose that is from a plant expressing a CESA polypeptide variant having at least one amino acid mutation in its carboxy-terminal transmembrane region; and saccharifying the plant cellulose to produce fermentable sugars. The method can also include fermenting the fermentable sugars to produce alcohol. A method of producing a plant having beneficial saccharification properties includes introducing into a plant a polynucleotide encoding a CESA polypeptide variant having at least one amino acid mutation in its carboxy-terminal transmembrane region; and expressing in the plant the CESA polypeptide variant, wherein plant cellulose of the plant expressing the CESA polypeptide variant has beneficial saccharification properties as compared to a wild-type plant.