Common Names: Kiwi, Chinese Gooseberry, Kiwifruit, Monkey Peach, Sheep Peach

This interesting species is native to the Yangtze Valley, China and was known as the Chinese gooseberry. It was cultivated on a small scale at least 300 years ago, but still today most of the crop is derived from wild vines. The Chinese have never shown much interest in exploiting the fruit. Kiwi was developed commercially in New Zealand and named after their national bird. Commercial crops are grown mainly in New Zealand, the United States and France. Kiwi fruit is, however, a latecomer to Western cuisines and the extent of its use varies radically according to fashion.

The Kiwi plant is a tough, woody, deciduous twining vine or climbing shrub. The elongated, oblong fruit, up to 8cm long, has russet-brown skin densely covered with short, stiff brown hairs. The flesh is usually bright green and pleasantly acidic in flavour. The minute, dark-purple or nearly black seeds are unnoticeable in eating. Cross-sections are very attractive.

Kiwis are available year-round because the fruits hold so well in storage and are grown in both the Northern and Southern Hemispheres. The fruits are eaten out of hand and served as appetizers, in salads, in fish, fowl and meat dishes, and in pies, puddings and cakes. As the fruit contains enzymes similar to papain, the raw fruit can act as a meat tenderiser. After peeling (usually with lye), fruits are canned, frozen, or freeze-dried. Kiwi is used in sauces, jams, ice creams, breads and various beverages, including wine. Blending with Apple juice or malic acid tends to be important in Kiwi processing, for reduction of Kiwis’ acidity. Slightly underripe fruits, which are high in pectin, are chosen for making jelly, jam and chutney. In China the leaves are a famine food. Kiwi is rich in Vitamin C.

The scraped stems of the vine are used as rope in China, and paper has been made from the leaves and bark. The bark at the base of the vine can be processed into pencils.

The Chinese regard the Kiwi fruit mainly as a tonic for growing children and for women after childbirth. The branches and leaves are boiled in water and the liquid used for treating mange in dogs. The fruit and the juice of the stalk are esteemed for expelling gravel.

Because of shortages of the bees needed for pollination, pollen may be sprayed onto the plants in a suspension.

Sometimes confused with Chinese lantern; see Cape gooseberry.

Kiwi fruit, shows an increased rate of ripening in response to the application of exogenous ethylene. Moreover, late in ripening the fruit produced a burst of ethylene biosynthesis. (Whittaker 1997 ref.7685 1)

Allergens/Function:

Allergens:
Act c 1, a 30 kDa major protein, a cysteine protease named actinidin. (Pastorello 1998 ref.2059 5)
Act c 2, a 24 kDa (Gavrovic-Jankulovic 2002 ref.7043 1) (Wang 2002 ref.7672 1)

Act c 1: Cross-reacting with papain from Papaya latex and bromelain from pineapple
Act c 2: Cross-reacting allergens are found in latex, avocado and banana.

A Chitinase has been detected. (Diaz-Perales 1999 ref.3692 1)
A Lipid Transfer Protein has been detected. (Asero 2000 ref.3711 1)
A Profilin has been detected. (Rudeschko 1998 ref.2165 3)

Besides the 30 kDa protein, other allergens were detected at 12, 24, and 28 kd. (Pastorello 1998 ref.2059 5)

In 27 patients with OAS for kiwi, 12 IgE-binding components with molecular weights ranging from 12 to 64 kd were identified in the kiwi extract, but only a 30 kd component acted as major allergen, being recognized by sera of 100% of these patients. Inhibition of kiwi immunoblots with timothy and birch pollen extracts demonstrated strong cross-reactivity with some of the kiwi allergens, suggesting complete identity between certain food and pollen allergens; whereas others, particularly the 30 kd allergen, were only partially inhibited, suggesting much weaker cross-reactivity. (Pastorello 1996 ref.82 232)

Actinidin has physical and chemical properties similar to those of Papain, which can perhaps explain some hypersensitivity reactions. (Dore 1990 ref.1953 3)

This study reports that the major allergen for kiwi allergy is the 30 kDa protein (probably actinidin). (Fahlbusch 1998 ref.7678 2)

10 of which cross-reacted with birch, timothy, rye, and mugwort pollen, while two (25 and 30 kDa) were not inhibited homologously or by pollen. EIA inhibition additionally revealed kiwi-specific allergens. Three proteins of the kiwi extract (25, 30 and 43 kDa) were considered to contain a carbohydrate moiety. Profilin seems to be relevant in cross-reactivity of kiwi allergens. (Rudeschko 1998 ref.2165 6)

This study reported isolation and full characterization of a new kiwi allergen, a 24 kDa thaumatin-like protein, named Act c 2. The allergen elicited positive skin prick test responses in 4 (80 %) of 5 patients with OAS. The protein was rapidly digestible. The isolated protein expressed antifungal activity toward Saccharomyces carlsbergensis, and Candida albicans. The isolated protein consisted of 2 isoforms. (Gavrovic-Jankulovic 2002 ref.7043 1) (Wang 2002 ref.7672 1)

Adverse Reactions:

IGE AND IMMUNE:
Diarrhoea, vomiting, and abdominal pain. Burning of lips and mouth. Pruritis of the eyes, ears, tongue, pharynx, mouth. Angioedema. Dermatitis and atopic dermatitis. Respiratory complaints. Pharyngeal swelling. Colic.

A 26 year-old patient with a localized pruritic reaction a few minutes after eating kiwi fruit, repeated a few months later, accompanied by dysphagia, vomiting and urticaria. (Garcia1989 ref. 536 34)

In 22 patients allergic to kiwi fruit, 10 with severe systemic reactions and 12 with localized symptoms confined to oral and pharyngeal mucosa (oral allergy syndrome), prick tests showed positive reactions to kiwi fruit in all patients, whereas specific IgE to kiwi fruit could be demonstrated only in patients with generalized severe symptoms. Surprisingly, all 22 patients with clinical kiwi allergy showed positive prick test results and elevated IgE to birch pollen. Clinically, all complained of rhinitis during birch pollen season. Many patients showed sensitization to grass and mugwort pollen. Also, food allergy was found to be associated with kiwi allergy: we found strong reactions to apple and hazelnut; moderate reactions to carrot, potato, and avocado; and weak reactions to wheat and rye flour, pineapple and papaya, and their enzymes bromelain and papain. RAST inhibition studies revealed cross-reacting antigens between birch pollen and kiwi fruit. Interestingly, patients with birch pollen allergy without clinical signs of kiwi allergy had positive prick test reactions to kiwi. Patients with kiwi allergy showed higher concentrations to birch pollen IgE compared with patients with isolated birch pollen allergy. (Gall 1994 ref.535 34

Oral allergy syndrome. (OAS) (Gavrovic-Jankulovic 2002 ref.7043 1) (Arai 1998 ref.7680 5) (Pastorello 1996 ref.82 232) Oral allergy syndrome from kiwi fruit after a lover's kiss. (Mancuso 2001 ref.4321 8)

Sensitization to kiwi skin. (Huertas 7679 6)

Anaphylaxis. (Joral 1992 ref.2750 4) (Falliers 1983 ref.211 34) Anaphylaxis to kiwi fruit in a 12-year-old boy. (Shimizu 1995 ref.2061) Anaphylaxis in a 57-year-old man to a skin prick test with kiwi. (Novembre 1995 ref.7701 1)

Food-dependant exercise-induced anaphylaxis. (Perkins 2002 ref.6599 4)

Allergic contact dermatitis. (Rademaker 1996 ref.2060 3) Contact urticaria. (Veraldi 1990 ref.539 34) (Zina 1983 ref.541 21)

Acute pancreatitis in a 48-year-old man. (Gastaminza 1998 ref.3061 8)

In evaluating 163 asthmatic children with food allergy for food-induced asthma, using DBPCFC the most frequent offending foods were, sometimes in association, peanut (30.6%), egg (23.1%), cow's milk (9.3%), mustard (6.9%), codfish (6%), shrimp (4.5%), kiwi fruit (3.6%), hazelnut (2.7%), cashew nut (2.1%), almond (1.5%), garlic (1.2%). (Rance 2002 ref.7671 1)

Crossreactive.

NON IMMUNE:
Actinidic acid, a triterpene phytoalexin has been isolated from unripe kiwi fruit. (Lahlou 2001 ref.7674 2) This substance may result in contact dermatitis.