See also: Sunflower seed, and Sunflower seed oil.

The Common sunflower is that from which we obtain sunflower oil and seeds. There are two other species of sunfower which are not food-related, H. debilis (sunflower), and H. decapetalus (perennial sunflower). H. debilis is a more slender plant, much branched, with rough, reddish stems.

The sunflower is native to Central America but is now grown in many semi-arid regions of the world from Argentina to Canada and from central Africa into the Soviet Union, mostly for its oilseeds. The leaves are usually used as fodder, and may be grown for this purpose alone, particularly where the season is too short and cool for maize.

The Common Sunflower is an annual, broadleaf plant with a tall hirsute stem, often un-branched, growing to 3 m at a fast rate and bearing a single, yellow, circular, large flower with a black centre. The leaves are hairy and oval shaped and 10 - 30 cm long and 5 - 20 cm wide.

The flowering head is at the terminal end off the main stem, 10 - 40 cm in diameter, rotating to face the sun (heliotropism), sometimes drooping. Sunflower heads consist of 1,000 to 2,000 individual flowers joined together by a receptacle base. The large petals around the edge of a head are actually individual ray flowers. Pollination and seed development begin at the periphery of the grain head and move toward the centre. Flowers are produced through summer and autumn and are hermaphrodite (have both male and female organs). The plant may produce heads on lateral branches, which are smaller. Insects pollinate the plant. The plant not is self-fertile.

The seeds ripen from September to October; usually taking about 30 days from the time the last flower is pollinated until maturity. The angular seeds are up to 6 mm long, and are spirally arranged and densely packed in the flat, terminal head. The seeds are variable in size, single-coloured or striped.

Sunflower may escape from cultivation, occurring on roadsides and wastelands.

Uses: For oil production, coffee, flowers and edible uses.

Low residual proteins may be found in the oil (Halsey 1996 ref.560 56), enough to result in anaphylaxis. (Kanny 1994 ref.750 92)

Allergens/Function:

Allergens:
Hel a 2, a 15.7 kDa protein, a pollen profilin. (Asturias 1997 ref.5108 6) (Martinez 2002 ref.6956 1)

Four allergens have been detected, with mol. mass of 32, 24, 55, and 55 kDa. Cross-reactivity among the four allergens is very high, and each allergen recognizes IgE in a high proportion of patients sensitized to sunflower pollen. (de la Hoz 1994 ref.105 01)

In sera of 20 patients with Compositae pollen allergy, 2 bands, with molecular weights of 24 and 25 kd, contained major allergens that reacted strongly with 100% (24 kd) and 95% (25 kd) of the sera, respectively. (Fernandez 1993 ref.118 27)

A allergenic active fraction of sunflower pollen with a molecular weight of 14 kDa has been islolated. (Ostroumov 1979 ref.4950 0) (? The profilin. Ed.)

Sunflower pollen profilin reactivity was shown by 30% of Compositae allergic individuals. (Martinez 2002 ref.6956 1)

Thirteen patients with RAST values > or = class 2 showed 2 IgE-binding fractions at 34.0 and 42.8 kD in 65% of sera and 3 IgE-binding fractions at pI 4.9, 9.6 and 10.2 in 54% of sera. By means of micropreparative high-resolution chromatography, it was possible to purify a 34-kD major allergen. (Jimenez 1994 ref.2103 0)

Oil used in food, salad oils and in resin and soap manufacturing.

Adverse Reactions:

IGE AND IMMUNE:
See also: Sunflower seed, and Sunflower seed oil.

Allergic reactions. Asthma, rhinitis to sunflower pollen. (Bousquet 1985 ref.69 928) (Jimenez 1994 ref.2103 1)

Anaphylaxis after ingestion of sunflower seed, sunflower oil and honey containing sunflower pollen. (Noyes 1979 ref.561 02) (Axelsson 1994 ref.1322 9) (Kanny 1994 ref.750 92) (Birnbaum 1989 ref.532 62)

A report of systemic allergic reaction (rhinitis, nasal congestion, tearing, facial and generalised oedema) to sunflower pollen concealed in a commercial product of sunflower seeds. (Rottem 1998 ref.2286 0) The patient had eaten sunflower seeds without adverse effects previously. Analysis showed a high level of contamination of the packet by sunflower pollen.

This article reports on a 22 year old woman who developed rhinitis, nasal congestion, tearing, and facial and generalised urticaria to sunflower pollen concealed in a commercial product of peeled sunflower seeds. (Rottem 1998 ref.2286 0)

Contact dermatitis to sunflower leaves and flowers, producing a vesicobullour reaction at 2 days after patch testing. (Gomez 1996 ref.5109 8)

OCCUPATIONAL EXPOSURE:
Animal feed industry, gardening - unexpected exposure, farming

The most frequent positive skin prick reactions to occupational allergens in a group of 35 men working in an animal food processing plant were to fish flour (82.9%), followed by carotene (77.1%), corn (65.7%), four-leaf clover (62.9%), sunflower (54.3%), chicken meat (31.4%), soy (28.6%), and yeast (22.7%). (Zuskin 1992 ref.2807 4)

Sunflower pollen has high allergenic potential, especially from close contact, e.g., occupational contact. 23.5% of 102 individuals working in a sunflower processing plant were found to be sensitized to sunflower pollen. (Atis 2002 ref.6030 7)

Helianthus pollen should be considered not only as an occupational allergen but as an allergenic source to be investigated in the general population living in sunflower-growing regions suffering from seasonal Summer allergy (Jimenez 1994 ref.2103 1)

A report of a baker who developed rhinitis and asthma after exposure to sunflower seed dust in his workplace. (Vandenplas 1998 ref.2596 8) Occupational allergy. (Bousquet 1985 ref.69 825)

A 24-yr-old man developed rhinitis and conjunctivitis over 5 yr of occupational exposure to sunflower pollens, and asthma developed during the fifth year. All respiratory and occular symptoms disappeared after he was removed from exposure, but he had a food allergic reaction while he was eating honey containing 30% sunflower pollens. (Bousquet 1985 ref.69 825)

NON IMMUNE:
Unknown or Nil