Quantification of all trans-lycopene, cis-lycopene and β-carotene from tomato varieties found in Zanzibar

Haji Khamis1*, Kituyi Lusweti2, Haji Mwevura3
1,2Department of Chemistry and Biochemistry, P.0.Box 1125-30100, University of Eldoret, Chepkoilel, Kenya
 3The State University of Zanzibar (SUZA), P. O. Box 146, Zanzibar, Tanzania
Corresponding author: Haji Khamis Email : khamish03@yahoo.com


Tomatoes contain lycopene and β-carotene which have important health benefits. Different varieties are available in Zanzibar Islands and used in daily meal. However, there is little information in Zanzibar about quantity of all trans-lycopene, cis-lycopene and β- carotene available in those tomato varieties. The objective of this study was to quantify all trans-lycopene, cis-lycopene and β- carotene from tomato varieties. Samples were collected and extracted using hexane/acetone/ethyl acetate (4:2:1 v/v/v). Extracts were filtered and lycopene layer separated, washed, dried, dissolved in hexane and fractionated by silica gel column. Fractions were collected, dried by blowing with a stream of nitrogen gas and measured their masses by electronic balance. Results showed that mass (in g/g) of all trans-lycopene varied from 316 to 827 and from 136 to 931, cis-lycopene from 60 to 528 and from 35 to 845, β- carotene from 41 to 405 and from 44.1 to 573, from Lycopersicon esculentum and Solanum quitoense respectively.Tomatoes contain valuable quantities of lycopene and β-carotene necessary for human nutrients. Best growing conditions which facilitate highest possible quantity of lycopeneand β-carotene should be investigated and used during tomato cultivation.

Keywords: lycopene, quantify, β-carotene, Lycopersicon esculentum, Solanum quitoense

Kelle et al. JKCS 15-1 (2022), 3-13

Monitoring and health risk assessment of organochlorine pesticide residue in some leafy and fruiting vegetables from Lagos State, Southwestern Nigeria

Henrietta I. Kelle1*, Emeka C. Ogoko1, Oluade O. Abiola2, Daniel Achem2, Ifeoma P. Udeozo3
1Department of Chemistry, Faculty of Sciences, National Open University of Nigeria, Jabi, Abuja, Nigeria
2Department of Chemistry, Faculty of Science, University of Lagos, Akoka, Lagos State, Nigeria.
3Department of Industrial Chemistry, Faculty of Natural and Applied Sciences, Enugu State University of Technology, Enugu State, Nigeria.

This study investigated the health risk of pesticide residue in some leafy and fruiting vegetables namely fluted pumpkin (f. Telfairia occidentalis), green amaranth (Amaranthus viridis) and scotch bonnet (capsicum chinense) which are commonly eaten in Nigeria. Pesticide can impart harmful effect on health, it can be a source of exposure to health issues to Nigerians. Fluted pumpkin, green amaranth and scotch bonnet were purchased from the major wholesale market in Lagos state, Nigeria through which food stuffs are distributed in Lagos to retailers. Pesticide residues including alpha lindane, delta lindane, heptachlor, heptachlor epoxide, aldrin, trans– chlordane, p,p’- DDE, dieldrin, endrin, endrin ketone, endosulfan, endosulfan sulfate, endosulfan ether and methoxychlor were extracted from each sample using dichloromethane, and anhydrous sodium sulphate and sodium chloride to enhance liquid-liquid partitioning. Solid phase extraction using agilent cartridges was used to clean-up the extracts. The extracts were analysed for pesticide residues using gas chromatography coupled to mass spectrometer (GC-MS). From the results of the study, most of the pesticide residues were below detectable limit. Endosulfan ether was the only pesticide detected in all the vegetables from all the sources of the vegetables. The mean concentration (mg/kg) of the pesticide residues ranged from 0.0003-4.06 mg/kg. The mean
concentration of some of the pesticide residues in the leafy and fruiting vegetables were either above, within and below the maximum residue limit mg/kg (MRL) recommended by FAO/WHO. The estimated daily intake (EDI) mg/kg bw/day of the pesticide residues ranged from 4.25 x 10−7 to 5.76 x 10−3 mg/kg bw/day. The EDI of all the pesticide residues in the samples are below the acceptable daily intake (ADI) mg/kg bw/day of the pesticide residues as recommended by FAO/WHO, except the EDI of heptachlor in all the samples which are above the recommended ADI. The hazard quotient and hazard index of the pesticide residues in the vegetables ranged from 8.50 x 10−7 – 2.50 for hazard quotient and 0.07 – 3.2 for hazard index. Incremental lifetime cancer risk (ILCR) values for carcinogenic pesticide residues in the vegetables ranged from 1.3 x 10−5 – 2.1 x 10−3. Few of the vegetables had ILCR values for the carcinogenic pesticide residues above acceptable values recommended for ILCR. Consumption of the vegetables with high EDI, HQ, HI and ILCR values may pose health issues to consumers. There is need for continuous monitoring of pesticide residues in food samples in Nigeria.

Fluted pumpkin, green amaranth, hazard index, incremental lifetime cancer risk, pesticide residue

Kelle et al. JKCS 15-1 (2022), 3-13
Supporting Information Kelle et al., JKCS 15-1 (2022), 3-13