Brazil nuts

Amazon’s dense forest holds some of the unique plant species like Brazil nuts, acai berry, etc., that can be found nowhere else on the planet earth. Botanically, brazil-nut tree belongs within the family of Lecythidaceae, in the genus:Bertholletia. Scientific name: Bertholletia excelsa.

Native Amazonians cherished these delicious nuts since ages, which provided them much-needed protein, fats, and other essential nutrients. Some of the common names in local dialects are castanha-do-pará, castania, para-nut, cream-nut, Castaña-de-Brazil (chestnuts of Brazil)…etc.

Brazil nuts (cream nuts). Note for their creamy butter appearance due to high fat content.Castania tree (Bertholletia excelsa). Note for acai palm on the background. 

Photo courtesy: mauroguanandi

Brazil nut trees are conspicuous in the non-flooded forests of Brazil, Bolivia, and Peru. They, indeed, are one of the tallest, and long-living plant species among all the tropical rain forests. Each tree can grow upto 50 meters in height with large erect stem and wide umbrella like foliage canopy near its top 1/3. Its lifespan may thought to be of about 500 to 700 years.

Each mature tree bears up to 300 fruit pods in a season. A brazil nut pod features thick outer shell as in coconuts, and may weigh up to 2.5 kg in weight. It takes about 14 months for the fruit to mature after pollination. Upon maturity, the pod falls itself from the tree, usually with a thud. The pods may remain intact even after falling from such a height. At their natural habitat, brazil nut pods exclusively depend upon caviomorph rodents (agoutis, Dasyprocta spp. that have the ability to gnaw open woody shell) to free and disperse leftover seeds for germination.

Internally, each fruit pod features 10-25 seeds (kernels), arranged in segments. Each kernel in turn is encased within its own thick dark-brown thin shell. An edible white meat kernel features triangular base with sloping sides, and sweet nutty flavor and weigh about 5 g.

Health benefits of Brazil nuts

Brazil nuts are high in calories, contain good quantities of vitamins, anti-oxidants and minerals. Its kernels, in-fact, have been staple energy sources of native Amazonians even today.

100 g of brazil nuts provide about 656 calories. Their high caloric content chiefly comes from their fats. However, much of this fat content is mono-unsaturated fatty acids (MUFA) like palmitoleic acid (16:1) and oleic acid (18:1) that helps lower LDL or “bad cholesterol” and increase HDL or “good cholesterol” levels in the blood. Research studies suggest that Mediterranean diet that is rich in monounsaturated fatty acids offers protection from coronary artery disease and strokes by favoring healthy blood lipid profile.

The nuts are also a very good source of vitamin-E; contain about 7.87 mg per 100 g (about 52% of RDA). Vitamin-E is a powerful lipid soluble antioxidant. It is required for maintaining the integrity of cell membrane of mucusa and skin by protecting it from harmful oxygen-free radicals.

Brazil nuts hold exceptionally high levels of selenium. 100 g nuts provide about 1917 µg or 3485% recommended daily intake of selenium, rating them as the highest natural source of this mineral. Selenium is an important cofactor for anti-oxidant enzyme, glutathione-peroxidase. Just 1-2 nuts a day provides enough of this trace element. Adequate selenium in the diet help prevent coronary artery disease, liver cirrhosis, and cancers.

Furthermore, just as in almonds and pine nuts, brazil nuts too are free from gluten protein. The nuts, therefore, are one of the popular ingredients in the preparation of gluten-free food formulas. These formula preparations are, in-fact, healthy alternatives in people with wheat food allergy and celiac disease.

Additionally, these creamy nuts are an excellent source of B-complex group of vitamins such as thiamin (51% of RDA per 100 g), riboflavin, niacin, pantothenic acid, vitamin B-6 (pyridoxine), and folates. Altogether, these vitamins work as co-factors for enzymes during cellular substrate metabolism inside the body.

In addition to selenium, they hold very good levels of other minerals such as copper, magnesium, manganese, potassium, calcium, iron, phosphorus, and zinc. Copper helps prevent anemia and bone weakness (osteoporosis). Manganese is an all-important co-factor for the antioxidant enzyme, superoxide dismutase.

Brazil nut oil, extracted from these nuts, has many traditional medicinal applications as an emollient and massage oil. It has clear yellow color with a pleasant sweet smell and taste. Its emollient property helps keep skin well protected from dryness. It has also been used in the cooking, and as “carrier or base oil” in traditional medicines in aromatherapy, in pharmaceutical and cosmetic industry.

Selection and storage

Unshelled brazil nuts. Note for dark brown color shell enclosing cream color edible kernel inside. 

photo courtesy: nickton

Brazil nuts can be available raw (unshelled or shelled), roasted, and salted in the stores. Since the nuts are high in polyunsaturated fats, they may turn rancid and deteriorate rather early if remain exposed to air, humidity, and sunlight. It is, therefore, recommended to purchase unshelled nuts and shell them as and when required to enjoy their edible meaty kernel.

Buy whole, brown color nuts that feature full, compact, and heavy in hand. Avoid shriveled and damaged ones as they may be affected by fungal mold.

Unshelled brazil nuts will keep well in cool, dry place for few months. The best way to store is to put them in air-seal bags and place inside the refrigerator. This method will prevent them from turning rancid.

Culinary uses

Raw nuts are generally cut open from processing units using larger sheller machines. For domestic purposes, small size nut shelling machine or hand held pliers are used.

Here are some serving tips:

Brazil nuts can be eaten all alone. Additionally, they can also be enjoyed roasted, salted, or sweetened.

They are also used in fudge, puddings, pesto, chocolates-bars and crunchy-bar preparations.

Coarsely ground brazil nuts can be sprinkled over fruit/vegetable salads.

They are also used in desserts, particularly in fruitcakes.

They can also be added to soup as well as meat and vegetable dishes.

Brazil nut oil is used in salad dressing and in cooking.

Safety profile

Brazil nut allergy, like other tree-nut allergies may occur in some sensitive individuals. The reaction symptoms may range from simple skin itching (hives) to severe form of anaphylactic manifestations, including breathing difficulty, pain abdomen, vomiting, and diarrhea. Cross-reactions may occur to some other nuts and fruits, especially of Anacardiaceae family such as mango, cashew nuts, pistachio…etc. Persons with known allergic reactions to any of these nuts may, therefore, need to observe caution.

Excess consumption of these nuts may result in selenium toxicity. Oftentimes the symptoms may be severe, including nausea, vomiting, garlic odor in breath, emotional disturbances. Other likely manifestations may include dental caries, alopecia (loss of hair), neuropathic pain, dermatitis…etc. It is, therefore, advised to eat only few nuts (2-4 nuts) per day (each nut weighs about 5 g). (Medical disclaimer).