White Oca
Estimated Inventory, lb : 0
Description/Taste
White oca varies in size and shape, depending on the specific variety, and averages 5 to 20 centimeters in length and 2 to 4 centimeters in diameter. The tubers typically appear in cylindrical, ellipsoidal, or oblong shapes with tapered or blunt, curved ends. White oca ranges in color from ivory, white, to yellow-white, and the skin is semi-thin, smooth, and waxy with a faint sheen. The surface is also covered in prominent eyes, with some varieties displaying red, purple, or black hues in each eye. These indentations give the tubers a slightly bumpy, textured feel. Underneath the skin, the flesh is dense, firm, starchy, and crisp, with a snappy consistency. Once cooked, the tubers soften in texture and have a mouthfeel similar to a combination of a carrot and a potato. White oca is edible raw or cooked and has a sweet, bitter, sour, acidic, and tangy taste, depending on the specific type. Raw oca will have a citrusy undertone, but cooked oca reduces this flavor and enhances the tuber’s sweet and nutty.
Seasons/Availability
White oca is available year-round, with a peak season in the spring in South America.
Current Facts
White oca, botanically classified as Oxalis tuberosa, is a category of multiple varieties belonging to the Oxadilaceae family. The edible tubers develop underground at the base of perennial plants reaching 20 to 45 centimeters in height and are hand-harvested as a culinary and medicinal ingredient. Oca is an ancient crop native to South America and has been cultivated for centuries as a food source in the Andes Mountains. Many varieties of oca are grown in South America, and the tubers are known as Oqa, Upa, Okka, O’qa, Kawi, and Apiña. In Peru, there are over fifty native varieties of oca, and three main categories are used to sell tubers in commercial markets: Oca Alba, Oca Flava, and Oca Roseo. Oca Alba is the name for ivory to white-hued ocas, Oca Flava for yellow-hued, and Oca Roseo for pigmented types. It is important to note that Oca Alba and Oca Flava can sometimes be sold as a single grouping, and each vendor will categorize the tubers according to their preferences. Oca is rarely sold under individual varietal names in Peruvian markets, as most types are used in similar culinary preparations. White oca is widely found throughout fresh markets in South America and is utilized in a wide array of sweet or savory preparations.
Nutritional Value
White oca varies in vitamins and minerals, depending on the specific variety. Oca, in general, is a source of fiber to regulate the digestive tract, iron to develop the protein hemoglobin for oxygen transport through the bloodstream, and potassium to balance fluid levels in the body. Oca also provides calcium to build bones and teeth, vitamin C to strengthen the immune system, vitamin A to maintain healthy organ functioning, phosphorus to repair tissues, and other nutrients, including riboflavin, thiamine, zinc, and niacin. The sour taste in some oca varieties is attributed to oxalic acid, a compound that may be harmful in large quantities. Most oca varieties have a low amount of oxalic acid, but care should be taken for individuals sensitive to the compound. In South America, multiple parts of the oca plant have been utilized in natural medicines to reduce inflammation. The leaves and stems are boiled or juiced to lessen pain in the stomach lining, soothe earaches, or topically applied to insect bites as a disinfectant.
Applications
White oca has a sweet, sour, to acidic taste, depending on the variety, and can be consumed fresh or cooked. In South America, the tubers are traditionally left in the sun as this exposure allows the starches to be converted into sugar, creating a sweeter taste. Oca can be sprinkled in salt or vinegar for a brighter taste and sliced into salads. The tubers do not need to be peeled, but some consumers may peel the skin to reduce bitterness. White oca can also be grated into slaws or chopped into salsas. In South America, White oca is popularly cooked and prepared similarly to potatoes. The tubers can be roasted, baked, fried, and boiled, sometimes used instead of potatoes in recipes. White oca can be roasted, sprinkled in salt and herbs, and served as a side dish to meats or added to casseroles. The tubers can also be incorporated into soups, stews, and chowders or cooked into gratins and purees. In the Andes regions of Peru, oca is traditionally roasted in earthen ovens called huatias. They are also utilized in sweet dishes, including mazamorra, dulce de ocas, jams, puddings, and chichas. Beyond using the tubers whole, White oca is dried and ground into a powder. This powder is mixed into porridges and bread and used as a thickener in desserts and soups. Beyond the tubers, the leaves are consumed in small quantities in salads, stir-fries, and stews. White oca pairs well with green beans, peas, potatoes, artichokes, bell peppers, carrots, spices such as cinnamon, cloves, and cumin, aromatics including onions, garlic, chile peppers, and capers, and meats such as beef, pork, and poultry. Whole, unwashed tubers will keep for a few weeks when stored in the refrigerator's crisper drawer or in a cool and dark location with ample air circulation.
Ethnic/Cultural Info
Oca diversity is being protected and cataloged by various germplasm banks in Peru. The largest collection of oca germplasm in Peru is thought to be located in Cusco, and it is estimated that over 400 types of oca have been preserved and documented. Several programs throughout Peru protect the genetic material of traditional Andean crops, but the most well-known organization is the Germplasm Bank of the National Institute of Agrarian Innovation. The genetic bank was established in the 1980s and was created to protect genetic material for future research, studies, and conversation. Since its creation, over 15,000 samples have been collected across 22 different Agricultural Experiment Stations throughout the country, and crops such as tuberous roots, tomatoes, camu camu, corn, quinoa, and chile peppers have been added to the genetic database. Oca is primarily considered the second most important tuber in Peru besides the potato. Germplasm banks are not only protecting genetic material in case of natural disasters, but they are also partnering with growers to breed and improve varieties for increased cultivation and commercial production.
Geography/History
White oca varieties produced in the modern day are descendants of species native to South America. Oca is an ancient crop that has been growing wild for thousands of years in the Andean regions throughout Colombia south to Chile. Remnants of tubers have been found in tombs along the western South American coastline, and the tubers have been featured on ceramics that pre-date the arrival of the Spanish in the 16th century. Oca was also revered by the Incas and was used as a nutritious food source. Over time, the tubers were domesticated and bred into new varieties with improved flavor and growth characteristics. In South America, the areas with the most oca diversity are thought to be central Peru and northern Bolivia. Later in the mid to late 18th century, oca was introduced to Mexico and was carried to Europe, New Zealand, and the United States in the early to mid-19th century. Today, White oca varieties grow between 2,800 to 4,000 meters in elevation and are often planted beside other root crops such as mashua, potatoes, and ulluco. The tubers are traditionally cultivated on small family plots and are sold through local markets and select distributors. White oca is found throughout Peru, especially in Puno, Huancayo, and Cusco, and is also grown in parts of Ecuador in the Cotopaxi, Imbabura, Chimborazo, Quito, and Tungurahua regions. The White oca featured in the photograph above was sourced through a local market in the Surquillo and Miraflores districts of Lima, Peru.
