An unusual combination in papaya (Carica papaya): The good (glucosinolates) and the bad (cyanogenic glycosides)

• Published in: Journal of food composition and analysis Vol. 29; no. 1; pp. 82 - 86
• Main Authors: Williams, David J., Pun, Sharon, Chaliha, Mridusmita, Scheelings, Pieter, O’Hare, Timothy
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Inc 01.02.2013; Elsevier
• Subjects: anticarcinogenic activity; Benzyl isothiocyanates; Biological and medical sciences; Brassica; broccoli; cabbage; Carica papaya; cauliflower; Cyanogenic glycosides; enzymes; Food composition; Food industries; Food safety; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; General aspects; glucose; Glucosinolates; Glucotropaeolin; herbivores; Human health; humans; hydrogen cyanide; isothiocyanates; metabolites; Methods of analysis, processing and quality control, regulation, standards; Papaya; papayas; pests; Plant defence metabolites; toxicity; Glucotropaeolin; Benzyl isothiocyanates; Human health; Papaya; Glucosinolates; Food composition; Food safety; Carica papaya; Plant defence metabolites; Cyanogenic glycosides; Human; Sulfur compounds; Glucosinolate; Fruit; Metabolite; Health; Caricaceae; Dicotyledones; Angiospermae; Spermatophyta; Glycoside; Isothiocyanates; Food
• ISSN: 0889-1575; 1096-0481
• DOI: 10.1016/j.jfca.2012.06.007

► Unusual combination of papaya glucosinolates+cyanogenic glycosides were reviewed. ► Both originate from same amino acid and synthesised via initially similar pathway. ► Glucosinolates are precusors to the human chemoprotective isothiocyanates. ► Cyanogenic glycosides potentially detrimental to human health. Glucosinolates are a group of sulphur-containing glycosides found in the plant order Brassicales which includes the Brassica vegetables such as broccoli, cabbage and cauliflower. When brought into contact with the plant enzymes, myrosinases, the glucosinolates break down releasing glucose and other products which serve principally in plant defence against herbivores. The most important of the products from a human nutritional viewpoint, are the isothiocyanates. These potent inducers of detoxifying enzymes bestow the distinct anti-cancer properties on these plants. Unique among tropical fruits, papaya is known to contain an abundance of one particular glucosinolate, glucotropaeolin. Other compounds that play a pivotal role in the chemical defence system of many plants are the cyanogenic glycosides. Cyanogenic glycosides are activated by plant enzymes in the event of pest attack, releasing the deterrent: toxic hydrogen cyanide. Papaya, in addition to glucosinolates, also contains low levels of cyanogenic glycosides, an unusual occurrence because it was assumed that the two classes of metabolites were mutually exclusive. Studies measuring the levels of both in the edible parts of the papaya fruit and other utilised tissues are discussed and considered in the context of potential human health ramifications.