Friday, February 4, 2011

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.

Sunflower seeds and kernel
There are three types of commonly used sunflower seeds. Linoleic (most common), high oleic, and Nusun. Each variety has its own unique levels of monounsaturated, saturated, and polyunsaturated fats. The information in this article refers mainly to the linoleic variety.

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. Striped sunflower seeds are primarily used for food; as a result, they may be called confectionery sunflower 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. However eating expired sunflower seeds may cause stomach irritation such as bloating or diarrhea due to the rottening of the seed.

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

In-shell sunflower seeds are particularly popular in Mediterranean and Asian countries, like Egypt, Syria, Israel, Turkey, and Malaysia, where they are commonly called garinim, ayçekirdeği, and kuaci respectively. In Turkey, Syria, and Israel, they can be bought freshly roasted in shops and markets and are a common stadium food while in Malaysia, it can be bought freshly packed in various roasted flavors at grocery and convenient stores nationwide. They are also popular in countries worldwide like Russia, Ukraine, Bulgaria, Romania, Spain, China, Iran, Canada, and the United States.

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 in boxes and small bags.

The hulls, or shells, are mostly composed of cellulose. They decompose slowly. They are sometimes burned as biomass fuel.


In addition to linoleic acid (an essential fatty acid), sunflower seeds are also an excellent source of dietary fiber, some amino acids (especially tryptophan), Vitamin E, B Vitamins (especially vitamin B1 or thiamine, vitamin B5 or pantothenic acid and folate), and minerals such as copper, manganese, potassium, magnesium, iron, phosphorus, selenium, calcium and zinc. Additionally, they are rich in cholesterol-lowering phytosterols.