Botanical Name
Solanum tuberosum Linn.
Synonyms
No documentation
Family
Solanaceae
Vernacular Names
| Malaysia | Ubi kentang, Ubi benggala, Ubi Belanda |
| Indonesia | Ubi kentang, Kentang welonda, Huwu Wolanda |
| India | Alu (Hindi); Golalu, Belathialoo (Bengali); Batata (Bombay); Papeta (Gujerati); Urlakalngu, Uri-laikkizhangu (Tamil); Urlagadda (Telagu) |
| China | Yang shu, Fan shu |
| Japan | Bareisho, Jagatara imo, Orando imo, Ryuku imo |
| Tibet | P’an su, p’i-lin skio |
| Arabic | Kalkas Firenze |
| English | Potato |
| French | Pomme de terre |
| German | Kartappe |
| Hawaiian | Uala Kahiki. [1] [6] [8] |
Description
Solanum tuberosum is a member of the Solanaceae family. It is annual, sprawling plant with weak stems and can reach up to 1 m high. The leaves are pinnate with 5 – 9 ovate leaflets. The petioles and petiolules are angular in section and sometimes winged. The inflorescence is a leaf-opposed cymose panicle with up to 8 flowers. Flowers are lavender to white with yellow stamens. The tubular calyx is 5 mm long and the calyx lobes 5 – 8 cm long, lanceolate, acuminate. The corolla is subrotate to rotate-pentagonal. The fruits are 1.5 – 2 cm in diameter, globular, greenish and sparsely produced in cultivation. [7]
Distribution
Solanum tuberosum is a plant native to South America. Today it is planted throughout the globe as food crop.
Plant Use
The tuber forms a staple diet in most European countries, North and South America.
Toxic Parts
Uncooked sprout and sun-greened skin. [1]
Toxin
Solanine glycoalkaloids [1]. Alpha-solanine and alpha-chaconine was found to be reversible inhibitors of human plasma cholinesterase. However, solanine toxicity is not classically associated with cholinergic syndromes. This is probably due to the fact that solanine is poorly absorbed in the gastrointestinal tract rendering its elimination rapid. They are considered corrosive to the gastrointestinal tract, acutely toxic upon absorption due to several mechanisms.
All parts of potato can contain two major glycoalkaloids, alpha-solanine and alpha-chaconine. Normal potatoes contain small amounts of the alkaloids in the peel but none in the flesh. Food processing does not significantly alter the glycoalkaloid content. Boiling removed <3.5 % of the main glycoalkaloids in potatoes, whereas microwaving decreases the concentrations of these compounds by about 15%. Significant degradation of these compounds occur at temperatures above 170oC, and deep frying at 150oC does not significantly alter the concentrations of these glycoalkaloids.
Solanine content in boiled peeled potatoes range from 0 to 9 mg/100g fresh weight. Because of the bitter taste of the alkaloids, solanine poisoning is rare except in times of famine when stressed or green potatoes are consumed. Normal food processing methods do not remove substantial amounts of glycoalkaloids from potatoes. Boiling of sprouted potatoes allows the diffusion of glycoalkaloids from the sprouts to the tuber and therefore increases the glycoalkaloid contents of the tuber. [3] [4] [7] [10]
Risk Management
Potatoes form a staple food for many society. To avoid the incidence of solanine poisoning, those involved in the preparation of food must be wary of the distinct features of the presence of these compounds in potatoes. Knowledge of proper storage to potatoes should be known to housewives, food handlers and cooks. Excess formation of the alkaloids is favoured when potatoes are damaged or are improperly stored with exposure to light (ultra-violet radiation) or when they are sun-greened or allowed to sprout. There can be a 10-fold increase in the amount of solanine present in the tuber and the flesh of the potato when any of these conditions exists. A characteristic bitter taste may accompany solanine ingestion. [3] [7] [10]
Clinical Findings
Symptoms of solanine toxicity are initially characterized by hyperthermia and a cluster of symptoms that mimic acute gastroenteritis, including nausea, vomiting, diarrhoea and abdominal cramps, which may progress to haemorrhagic injury of the GIT. Other signs and symptoms from severe solanine poisoning are neurological effects, such as headache, dizziness, mental confusion, hallucination, and seizures. Mild bradycardia or hypotension may result from the weak cardiac activity of solanine.
The onset of symptoms after ingestion of plants containing solanine may take 4 to 24 hours. Hyperthermia may be an early sign of solanine toxicity. Neurological effects often predominante in the initial clinical presentation and may include headache, apathy, dizziness, drowsiness, that may progress to mental confusion, hallucinations, and seizures in severe exposures. Excitement, delirium, and hallucination are particularly likely in young children. [2]
The neurological symptoms seem to be related to the acetylcholinesterase inhibitory activity of these glycoalkaloids. Such severe effects are seldom seen. In fact, the risk almost solely arise if potatoes that have been exposed to light (often green peel) or have sprouted are eaten in greater amounts. Light stimulates the synthesis of the glycosides and sprouts show much higher contents than the tuber. Alpha-chaconine and alpha-solanine are teratogenic in one or more animals. However, an association between the consumption of blighted potatoes by pregnant women and the incidence of suspected malformations like spina bifida could not be substantiated. [1] [2] [4]
Management
Intravenous hydration, antiemetics and electrolyte replacement in severe gastrointestinal effects, particularly in children. CNS effects are managed with supportive measures and typically resolve without sequelae. [1]
Death has occurred from eating green parts of potatoes. To prevent poisoning from occurring from sunburned tubers, the green spots should be removed before cooking. Discard spoiled potatoes. [5]
References
1. Nelson LS, Shih RD, Ballick MJ. Handbook of poisonous and Injurios Plants, Springer Verlah, Berlin pg. 274 – 278
2. Brent J. Critical care Toxicology: Diagnosis and Management of the Critically ill, Elservier Health Science, pg. 1302.
3. Barceloux DG. Medical Toxicology of Natural Substances: Foods, Fungi, Medicinal Herbs, Plants and Venomous Animals, John Wiley & Sons, Hoboken, 2012
4. Brimer L. Chemical Food Safety, CABI Wallingford 2011 pg. 112
5. Moore B. Growing with Gardening: A Twelve-Month Guide for Therapy, Recreation and Education. UNC Press Chapel Hill, 1989 pg. 218
6. Salaman RN. The History and Social Influence of the Potato, Cambridge University Press, Cambridge 1985 pg. 137 – 138
7. Barceloux DG. Medical Toxicology of Natural Substances: Food, Fungi, Medicinal Herbs, Wiley & Son, Hoboken 2008 pg. 78
8. Panda H. Herba Cultivation and Medicinal Uses, National Institute of Industrial Research, New Delhi 2000 pg. 563
9.Factsheet – Solanum tuberosum Available from http://www.flora.sa.gov.au/efsa/lucid/Solanaceae/Solanum%20species/key/Australian%20Solanum%20species/Media/Html/Solanum_tuberosum.htm. Accessed on: 23rd February 2013
10. Brandenberger H, Maes R. Analytical Toxicology: For Clinical, Forensic, and Pharmaceutical Chemist, Walter de Gruyter Berlin 1997 pg. 639
