Onion

Throughout history, onions have held symbolic and practical importance in many cultures. Ancient Egyptians revered them as symbols of eternity, while in modern times, onions appear in folklore, proverbs, and national cuisines from France to India. Their ubiquity in global cooking and frequent appearance in art, literature, and even religious rituals underscore their enduring cultural resonance.

• Onions are one of the oldest cultivated vegetables, with archaeological evidence of use dating back millennia.
• Cutting onions releases sulfur compounds that can cause eye irritation and tears.
• They are grown on every continent except Antarctica, making them a true global crop.
• Onions come in a spectrum of colors and flavors, from sweet to pungent, and can be stored for months under the right conditions.

Onions are low in calories yet rich in vitamin C, dietary fiber, and antioxidants. They contain beneficial sulfur compounds, which may support heart health and immune function. Their nutritional profile makes them a valuable addition to a balanced diet.

Onions are used in nearly every cuisine, providing a flavor base for soups, stews, sauces, and stir-fries. They can be sautéed, caramelized, roasted, grilled, pickled, or eaten raw. Dehydrated and powdered forms are common in spice blends, while sweet and specialty onions shine in salads and as garnishes. Their versatility makes them indispensable in both home and professional kitchens.

Onions are typically grown as annuals, though they are biennial by nature. They thrive in well-drained soils and moderate climates, with optimal growth temperatures between 13–24°C. Cultivation requires careful management of watering and disease, and yields can range from 20 to 60 metric tons per hectare depending on variety and conditions. Some cultivars are bred for long storage life, while others are valued for sweetness or disease resistance.

• Fresh: Whole bulbs sold for immediate culinary use.
• Processed: Chopped, sliced, dehydrated, or powdered onions for convenience and industrial use.
• Specialty: Includes sweet onions, pearl onions, and other unique varieties prized for specific flavors or culinary roles.

• Spanish onion: Large, mild-flavored, and often used raw.
• Vidalia: Sweet onion from Georgia, USA, known for its low pungency.
• Walla Walla: Another sweet, mild variety from Washington State.
• Bermuda: Flat, mild onions popular in salads and sandwiches.
• Red onion: Vibrant color and sharp flavor, often used raw or grilled.
• Pearl onion: Small, sweet, and commonly pickled or used whole in dishes.
• Sweet onion: General term for low-pungency, high-sugar cultivars.

Onions show tolerance to some fungal pathogens like Fusarium and pests such as onion thrips, but remain susceptible to downy mildew and bacterial soft rot. Breeding efforts continue to improve resistance, but careful crop rotation and field hygiene are essential for healthy yields.

Onions are known by many names worldwide—cebolla in Spanish, oignon in French, Zwiebel in German—and are adapted to diverse climates and cuisines. Leading producers include China, India, and the United States, each with distinctive local cultivars and culinary traditions. Regional preferences influence onion color, flavor, and typical uses, from sweet Vidalias in the American South to pungent red onions in Mediterranean salads.

For best quality, select onions that are firm, heavy for their size, and free of soft spots or sprouting. Store whole bulbs in a cool, dry, well-ventilated place—never in plastic bags or near potatoes. Properly stored, many varieties will keep for months. Once cut, onions should be refrigerated and used within a few days. Specialty types like sweet or fresh onions may have shorter shelf lives and require gentler handling.