Swallow hard: tobacco is nutritious.

Swallow hard: Tobacco is nutritious

The enzyme that helps green leaves incorporte carbon dioxide is also a good dietary protein, containing a balanced mix of the amino acids essential for maintaining human health, suggests new research by Shuh J. Sheen, a plant geneticist at the University of Kentucky in Lexington. and tobacco appears to represent an ideal source of this protein, Shuh reports.

The enzyme is ribulose 1,5-bisphosphate carboxylase-oxygenase, also known as fraction-1 protein. Sheen has identified the amino acid groups making up this water-soluble protein in tobacco and several other crops, including soybeans and alfalfa. In each, the protein is almost--but not entirely--identical. Some slight, crucial difference in the makeup of tobacco's version apparently accounts for its being so much easier to extract as pure hexagonal crystals, Sheen says. Because crystallizing this colorless, tasteless and odorless protein excludes nicotine and other potentially toxic "antinutrients," tobacco's fraction-1 protein could offer a safe food additive or pharmaceutical-grade (ultrapure) nutrient, he says.

Young, preflowering plants represent the richest source of the protein, so adapting agricultural practices to maximize its production should quadruple the leafy yield tobacco farmers currently reap per acre by allowing repeated harvests from the same plants. This suggests that tobacco farming could provide a rich, low-cost protein source, especially in the developing world, Sheen says. Moreover, he says, the protein has the potential to serve as a foaming or emulsifying agent in processed consumer products like ice cream, salad dressings and whipped desserts.