Seasonal Variations in Trace Metals Contents of Some Vegetables Grown on Irrigated Farmlands along the Bank of River Benue within Makurdi Metropolis

The seasonal variation in trace metals contents of Telfairia occidentalis (Fluted pumpkin), Amaranthus hybridus (Spinach) and Abelmoschus esculentus (Okra) were assessed in other to determine the impact of human activities at the river bank. The results of the study indicate mean level of zinc to range between (2.67-0.53) mgkg-1 Talfairia occidentalis, (0.65-0.27)mgkg-1 Amarantus hybridus and (0.24-0.44 mgkg-1 for the first season, while in the second season, a range of (0.65-0.2) mgkg-1, (4.21- 0.19) mgkg-1 and 0.03-0.34 mgkg-1 for T.occidentalis, A.  hybridus and A. esculentus was obtained respectively. The average levels of lead  for the two seasons was found to range between 0.08 - 0.26 mgkg-1 and 0.01- 0.16 mgkg-1 for T. occidentalis, 0.04-0.14 mgkg-1 and 0.11- 0.27 mgkg-1 for A. hybridus and 0.09 – 0.18 mgkg-1 and 0.06 – 0.17 mgkg-1 for A. esculentus. The level cadmium in T. occidentalis, A. hybridus and A. esculentus was found to range between 0.01 - 0.20 mgkg-1 and 0.02 - 0.13 mgkg-1,  0.04-0.11 mgkg-1 and 0.06 - 0.14 mgkg-1, and  0.7 - 0.17 mgkg-1 and 0.04 - 0.15 mgkg-1 for the first and second seasons  respectively. Copper levels were observed to be between 0.02- 0.10 mgkg-1 and 0.01- 0.07 mgkg-1 in T. occidentalis, A. hybridus, 0.02 - 0.07 mgkg-1 and 0.02 - 0.17 mgkg-1,  While   A. esculentus had 0.07 - 0.12 mgkg-1 and 0.08 - 0.26 mgkg-1 for first and second seasons respectively. Chromium levels in the three vegetables was found to be between results in T. occidentalis (0.06-0.14 mgkg-1 ),  A. hybridus (0.02-0.44 mgkg-1), A.  esculentus (0.2-0.40 mgkg-1) during the first season, while in the second dry season, Chromium content of the vegetable varied as followed, T. occidentalis (0.01-0.02mgKg-1), A. hybridus (0.03-0.07mgkg-1),  A. esculentus (0.01-04 mgkg-1). There was significant difference (p<0.05) in chromium content of the plants. The result of the study revealed that the three vegetables were not harshly contaminated; hence the values obtained were far below the permissible levels accepted by the WHO/FAO. The implication is that farming activities at the river bank have not impacted sternly on the surrounding environment. Keyword: Heavy Metals, Vegetables, Farms, irrigation, Makurdi,

Heavy metals in the irrigation water, soils and vegetables in the Philippi horticultural area in the Western Cape Province of South Africa

The aims of this study were to investigate the extent of heavy metal contamination in the Philippi horticultural area in the Western Cape Province, South Africa. Concentrations of Cd, Cr, Cu, Mn, Ni, Pb and Zn were determined in the irrigation water, soils and vegetables in both winter and summer cropping seasons with an ICP-AES and tested against certified standards. Differences were found in heavy metal concentrations between the winter and summer cropping seasons in the irrigation water, soils and vegetables. Certain heavy metals exceeded the maximum permissible concentrations in the irrigation water, soils and vegetables produced in South Africa. These toxic concentrations were predominantly found in the summer cropping season for the soils and in the crops produced in winter. It is thus suggested that further studies are carried out in the Philippi horticultural area to determine the sources of the heavy metals to try and mitigate the inputs thereof and therefore reduce the amount of heavy metals entering the human food chain.ISI & Scopu

Effect of Chemical Preservative and Packaging Material during Storage

Antinutritional properties of yam flour treated with chemical preservatives during six months of storage were carried out. Yam samples were purchased from the wurukum market, processed to obtain yam flour treated with chemical preservatives and packaged in plastic and low-density polyethene. About 100 grams of each of the different samples were separated into five portions. The first portion (sample A) was treated in a water bath with 250 ml of water with 0.5% of sodium metabisulphite for 15 minutes, drained and dried in an automated drier at about 70oC until dried to brittleness, Second portion (Sample B)  was immersed in a solution of 0.5%  Ascorbic acid for 15 minutes respectively, Third portion(Sample C) was immersed in a solution of 0.5% of Citric acid for 15 minutes, Fourth portion ( Sample D) was immersed in a solution of 0.5% of Ascorbic and Citric Acid, Fifth portion was blanched at 70oC for 5 minutes respectively.  The yam slices were dried to brittleness and milled separately with a laboratory hammer mill and sieved using a 250-um mesh to obtain yam flour referred to as high–quality yam flour. The flour samples were analyzed for antinutritional using standard laboratory procedures. The anti-nutritional factors in the high‐quality yam flour were significantly different (p ≤ 0.05)  from each other in terms of pretreatment but there was no significant difference in packaging material across storage. Antinutritional factors of yam flour samples decreased as storage progressed. The alkaloid contents of the different yam flour samples ranged from 0.17mg/100 g  before storage to 0.39mg/100 g  two months after storage, The Tannin contents of the different yam flour samples ranged from 0.32–0.68 mg/100 g (month 0), 0.04–0.64 mg/100 g (month 2), 0.31–0.58 mg/100 g (month 4), and 0.28–0.52mg/100 g (month 6) and The saponnin contents of the different yam flour samples ranged from 0.21–0.39 mg/100 g (month 0), 0.20–0.34 mg/100 g (month 2), 0.19–0.35 mg/100 g (month 4), and 0.21–0.32 mg/100 g (month 6). The anti-nutritional factors in the treated and untreated yam flour samples were significantly (p < .05) affected by pretreatment, storage and packaging materials.  Chemical preservatives used in yam processing makes treated yam flour safe for consumption after six months of storage