Edamame: A Nutritious Vegetable Crop

Edamame, also called mao dou in China, is a large-seeded (seed dry wt. >250 mg/seed) green vegetable soybean [Glycine max (L.) Merr., Fabaceae] cooked and served in pods as snack-like peanuts (Arachis hypogaea) (Shurtleff 2001). In Asia, where edamame is an important vegetable (Fig. 1), farmers harvest stems with fresh green pods before full maturity when pods are fully filled, nearly 80% matured, and just before turning yellow (Shanmugasundaram et al. 1991). This stage corresponds to the R6 stage of soybean development (Fehr et al. 1971). Vegetable soybean was known in China for its nutritional and medicinal values and was consumed as a vegetable as early as second century BCE (Shanmugasundaram 2001). Vegetable soybean has been reported to be better tasting and suitable for human consumption than grain soybean (Weber 1956). Edamame has a sweet, nutty flavor and can be eaten as snack either boiled in salt water or roasted like peanut seed. Fresh or frozen vegetable soybean can be cooked just like sweet peas (Pisum sativum L.) or lima beans (Phaseolus limensis L.), either stir fried or added to stews and soups. Edamame is highly nutritious and rich in phytochemicals beneficial to the human being (Masuda 1991) and is therefore, considered a nutraceutical or a functional food crop (Messina 2001).