Tender, flexible green beans are delight of vegetarian lovers for their wholesome nutritional qualities. They are unripe or immature pods obtained from the bean plant belonging to common fabaceae family and known scientifically as Phaseolus vulgaris.
Broadly, tender beans are classified depending on their growth habits as "bush beans" which stand erect without support and "Pole Beans" that need climb supports. The other varieties of unripe fruits of beans family include Shell beans, Pinto or mottled beans, White beans, Red or kidney beans, Black beans, Pink beans and Yellow wax beans. All most all the varieties are available year around across the world.
Fava or broad beans (Vicia faba) are large, flattened light green pods usually eaten shelled for their delicious beans. Lima beans (Phaseolus lunatus) are large, plump, pale green pods with kidney shaped seeds.
Health benefits of Green beans
- Fresh green beans are very low in calories (31 kcal per 100 g of raw beans) and contain no saturated fat; but are very good source of vitamins, minerals, and plant derived micronutrients.
- They are very rich source of dietary fiber (9% per100g RDA) which acts as bulk laxative that helps to protect the mucous membrane of the colon by decreasing its exposure time to toxic substances as well as by binding to cancer causing chemicals in the colon. Dietary fiber has also been shown to reduce blood cholesterol levels by decreasing re-absorption of cholesterol binding bile acids in the colon.
- Green beans contain excellent levels of vitamin A, and many health promoting flavonoid poly phenolic antioxidants such as lutein, zeaxanthin and ß-carotene in good amounts. These compounds help act as protective scavengers against oxygen-derived free radicals and reactive oxygen species (ROS) that play a role in aging and various disease process.
- Zea-xanthin, an important dietary carotenoid in the beans, selectively absorbed into the retinal macula lutea in the eyes where it thought to provide antioxidant and protective UV light filtering functions. It is, therefore, green beans offer some protection in preventing age related macular disease (ARMD) in the elderly.
- Fresh snap beans are good source of folates. 100 g fresh beans provide 37 µg or 9% of folates. Folate along with vitamin B-12 is one of the essential components of DNA synthesis and cell division. Good folate diet when given during preconception periods and during pregnancy helps prevent from neural-tube defects in the offspring.
- They also contain good amounts of vitamin-B6 (pyridoxine), thiamin (vitamin B-1), and vitamin-C. Consumption of foods rich in vitamin C helps body develop resistance against infectious agents and scavenge harmful oxygen free radicals.
- In addition, beans contain healthy amounts of minerals like iron, calcium, magnesium, manganese, and potassium, which are very essential for body metabolism. Manganese is a co-factor for the anti oxidant enzyme superoxide dismutase, which is a very powerful free radical scavenger. Potassium is an important component of cell and body fluids that helps controlling heart rate and blood pressure.