Potential toxicity of selected native vegetables from Sabah and their human risk exposure

Yvonne Sipain (2015) Potential toxicity of selected native vegetables from Sabah and their human risk exposure. Masters thesis, Universiti Malaysia Sabah.

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Abstract

Native vegetables are still widely consumed by the people in North Borneo. However, some plants may contain plant toxicants which could lead to adverse health effects. This study was carried out to survey the native vegetables consumed by the Dusun ethnic group in Sabah and to their potentially toxicity. Determination of the potentially toxic native vegetables was done through interviews of plant informants. The potentially toxic native vegetables identified for this study were Giganthochloa levis, Schizostachyum brachycladum, Schismatoglottis ahmadii, Colocasia esculenta, Colocasia gigantean, Schizostachyum blumei, Schismatoglottis motleyana, and Bambusa bulgaris. Quantification of cyanogenic glycoside and oxalate were done by using picrate method of analysis and oxalate kit, respectively. Qualitative tests were conducted to detect the presence of glycoside and oxalate in the native vegetables samples. There were nine species of potentially toxic native vegetables from the Poaceae and Araceae family identified by the plant informants in Ranau, Tambunan and Kuala Penyu. The total hydrogen cyanide (HCN) content for raw samples of Poaceae and Araceae species ranged from 298 - 948 ppm and 14 – 175 ppm, respectively. A decrease in the total cyanide content was observed after the samples were boiled whereby the percentage of total cyanide content reduction in all samples ranged from 71.4 – 95.2%. For oxalate, the total oxalate content ranged from 19.65 – 64.06 mg/100g for raw samples which decreased to 2.33 – 5.40 mg/100g after boiling. Exposure assessment calculation showed that the exposure to cyanogenic glycoside and oxalate from native vegetables consumption among the Dusun ethnic in Ranau, Tambunan and Kuala Penyu are considered below the safe level. The highest exposure dose for cyanogenic glycoside calculated accounted only 15.23% from the ARfD among the male respondents and 18.60% from the ARfD among the female respondents. For oxalate exposure, the highest dose of exposure calculated for male respondents was 0.0270% from the reported fatal dose and 0.058% from the reported fatal dose among female respondents. In conclusion, all nine species of native vegetables in this study contain cyanogenic glycoside and oxalate. However, boiling the native vegetables before consumption may reduce the potential toxicity of the native vegetables and reduce the exposure to a safer level.

Item Type:	Thesis (Masters)
Keyword:	Plant toxicants, Native vegetables, North Borneo
Subjects:	Q Science > QK Botany > QK1-989 Botany > QK710-899 Plant physiology
Department:	FACULTY > Faculty of Food Science and Nutrition
Depositing User:	DG MASNIAH AHMAD -
Date Deposited:	21 Aug 2024 16:33
Last Modified:	21 Aug 2024 16:33
URI:	https://eprints.ums.edu.my/id/eprint/40601

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