Rau Sam is the Vietnamese name for a common succulent plant known internationally as Purslane. Scientifically named Portulaca oleracea, this plant is often viewed as a common weed in many parts of the world, yet it has been cultivated for centuries in Asia and the Mediterranean for both its culinary and medicinal properties.
Rau Sam is highly valued for its thick, paddle-shaped leaves and plump, reddish stems, which are unusually rich in Omega-3 fatty acids (Alpha-Linolenic Acid, or ALA)—a rarity in land-based leafy greens—as well as essential vitamins (A, C, E) and minerals.
I. Flavor Profile and Culinary Texture
The unique texture and taste are what make Rau Sam distinctive in cooking:
Flavor: It has a clean, slightly tangy, or pleasantly sour taste, often described as having notes of lemon or watercress. This tanginess is due to its high content of organic acids.
Texture (Raw): When eaten raw, the leaves and stems are crunchy and succulent (mọng nước), similar to an aloe vera or cactus leaf.
Texture (Cooked): When cooked, Rau Sam becomes mucilaginous (hơi nhớt/có chất nhầy), similar to okra or jute mallow (Rau Mồng Tơi), which helps naturally thicken stews and soups.
II. Culinary Uses in Vietnam
While Rau Sam is sometimes considered a humble "wild vegetable" (rau dại) in some areas, it is frequently used as a cooling and detoxification vegetable in daily Vietnamese meals.
1. Món Canh Giải Nhiệt (Cooling Soups)
The primary culinary use is in light, clear soups served to cool the body and detoxify, especially during the hot summer months. The sour notes of the vegetable add a refreshing layer to the broth.
Canh Rau Sam Nấu Thịt/Tôm: Rau Sam is often boiled with simple ingredients like minced pork (thịt băm) or shrimp (tôm). The vegetable's mucilaginous quality helps create a slightly thickened, comforting broth that is savory, sweet, and tangy all at once.
Canh Chua Dân Dã: It can be used as a slightly souring agent in simple countryside sour soups.
2. Rau Sam Luộc/Xào (Boiled or Stir-Fried)
Rau Sam is prepared simply to let its natural flavor shine:
Luộc (Boiled/Blanched): The entire plant (leaves and stems) can be quickly boiled and served with a dipping sauce like fermented soybean paste (tương) or a simple fish sauce (nước mắm). This is a very light and healthy way to consume it.
Xào Tỏi (Stir-fried with Garlic): A quick stir-fry with fragrant garlic is also a popular preparation, similar to how other greens are prepared. It should be cooked briefly to retain some crunch and prevent it from becoming overly sticky.
III. Medicinal and Health Benefits
Rau Sam has long been recognized in traditional Vietnamese and Chinese medicine (Mã Xỉ Hiện - "Horse Tooth Amaranth") and is often called the "Longevity Vegetable" (rau trường thọ) due to its impressive nutritional profile:
Omega-3 Source: One of the best plant sources of essential Omega-3 fatty acids (ALA), which are beneficial for heart and brain health.
Antioxidants and Vitamins: Rich in potent antioxidants like Glutathione and Betalain (which gives the stem its reddish color), as well as a significant amount of Vitamins A and C.
Digestive Aid: Traditionally used to treat symptoms related to the digestive and urinary systems, acting as a mild diuretic and anti-inflammatory agent.
Due to its distinctive tangy flavor, crunchy texture, and outstanding nutritional value, Purslane (Rau Sam) is a prized vegetable in Vietnamese kitchens, transforming from a humble garden resident into a nourishing and delicious addition to the family meal.
