Free Amino Acids Present in Commercially Available Seedlings Sold for Human Consumption. A Potential Hazard for Consumers

The importance of fresh seedlings for human consumption on European markets continues to increase. Although the contents of free amino acids and potentially toxic free nonprotein amino acids in these fresh and supposedly healthy seedlings is very different from those of the seeds, the crude composition is never mentioned on commercial packages. A commercial product containing seven different kinds of fresh seedlings including kamut, adzuki bean, chickpea, mungbean, pinto bean, garden pea, and lentil has been analyzed by HPLC. Per 100 g of fresh product, 548.2 mg of total free amino acids was found, of which 56.7 mg is free nonprotein amino acids including beta-(isoxazolin-5-on-2-yl)alanine, homoserine, and isowillardiine and the plant hormone trigonelline (N-methylnicotinic acid). The highest amounts of free nonprotein amino acids and trigonelline are found in garden pea (28.3 mg/100 g), mungbean (9.59 mg/100 g), and lentil (7.50 mg/100 g) seedlings. Trigonelline is present in all legume seedlings examined.