Sunflower seed

The sunflower seed is the fruit of the sunflower (Helianthus annuus). The term "sunflower seed" is actually a misnomer when applied to the seed in its pericarp (hull). Botanically speaking, it is more properly referred to as an achene. When dehulled, the edible remainder is called the sunflower kernel.

For commercial purposes, sunflower seeds are usually classified by the pattern on their husks. If the husk is solid black, the seeds are called black oil sunflower seeds. The crops may be referred to as oilseed sunflower crops. These seeds are usually pressed into sunflower oil. Additionally, these seeds are usually considered the seed of choice for bird feeders.

If the husks are striped, the seeds are called striped sunflower seeds or "stripers." Due to their lower oil content, the crops are called non-oilseed sunflower crops. Striped sunflower seeds are primarily used for food; as a result, they may also be called confectionery sunflower seeds.

There is also a sunflower seed that is whitish in hue, which has no current commercial use.

Cultivation
These seeds have been cultivated for several thousand years, originally in the Mississippi River valley, the oldest known site being in Tennessee. They have been used by Native Americans for nearly 5,000 years. They were brought to Europe by the Spanish conquistadors.

When grown during its full season, big sunflower crops may yield more than 1000 pounds/acre (1121 kilograms/hectare). In some areas of the United States, sunflowers can also be grown as a double crop, so that the same area can be used for two harvests in the same season. However, it is not recommended that sunflowers be planted in the same area more than once every three to four years. .

Seeds
Sunflower seeds are more commonly eaten as a healthy snack than as part of a meal. They can also be used as garnishes or ingredients in various recipes. The seeds may be sold as in-shell seeds or dehulled kernels. The seeds can also be sprouted and eaten in salads.

When in-shell seeds are processed, they are first dried. Afterwards, they may also be roasted and/or dusted with salt or flour for preservation of flavor. Upon consumption, in-shell seeds should be dehulled and the hull should be discarded before swallowing the kernel. Dehulling is commonly performed by cracking the hull with one's teeth and spitting it out while keeping the kernel in the mouth.

In-shell sunflower seeds are particularly popular in Mediterranean countries, like Israel, where they are called garinim. In Israel, they can be bought freshly roasted in shops and markets and are a common stadium food.

Dehulled kernels have been mechanically processed to remove the hull. These kernels may be sold raw or roasted. These dehulled kernels are sometimes added to bread and other baked goods for their flavor. There is also sunflower butter, similar to peanut butter, but utilizing sunflower seeds instead of peanuts. Apart from human consumption, sunflower seeds are also sold as food for pets and wild birds.

Pressed oil
In modern society, sunflower oil is one of the most popular oils in the world. The oil may be used as is, or may be processed into polyunsaturated margarines. The oil is typically extracted by applying great pressure to the sunflower seeds and collecting the oil. After extraction, the pressed sunflower seed cake can be used, which is rich in proteins.

The original sunflower oil (linoleic sunflower oil) is high in polyunsaturated fatty acids (about 66% linoleic acid) and low in saturated fats, such as palmitic acid and stearic acid. However, various hybrids have been developed to alter the fatty acid profile of the crop for various purposes.

In the future, sunflower oil could become a renewable bio-source for hydrogen. A team for the University of Leeds has developed a workable method for the extraction of hydrogen from sunflower oil, through a chain of chemical reactions with nickel and carbon-based catalysts. However, while the plant's photosynthesis essentially captures the hydrogen, the energy necessary to liberate hydrogen gas from the hydrocarbons from sunflower oil is considerably greater than the energy of the liberated gas. Therefore, although sunflower oil could certainly be used for this purpose, it is not, by any means, a 'free' or even 'eco-friendly' source of energy.

Health benefits
In addition to linoleic acid (an essential fatty acid), sunflower seeds are also an excellent source of dietary fiber, protein, Vitamin E, B Vitamins, and minerals such as magnesium, iron, phosphorus, selenium and zinc. Additionally, they are rich in cholesterol-lowering phytosterols. They are also a good source of calories.