The implications of ripening agents on chemical compositions of plantain (Musa paradisiaca).

Foods frequently eaten supply both micro and macro nutrients to humans which are important in the total assessment of public health status of an individual. The analysis of these foods will provide evidence on their nutritional values, guide to appropriate choice of meal and encourage intake of varieties of food with better qualities during illness while preventing diet-associated disorders. In this study, the proximate and mineral composition of unripe, naturally ripe and the effects of ripening agents on plantain (Musa paradisiaca) commonly consumed in Nigeria were examined. The plantain fruits were analysed for proximate and mineral composition. Proximate composition analysis revealed an increase in moisture content and fat content for all the plantain ripened with ripening agents when compared with the naturally ripened plantain. Furthermore, the mineral composition of the plantain fruits was determined by means of Atomic Absorption Spectrophotometry (AAS). The result showed that plantain is a good source of minerals such as calcium (Ca), potassium (K) and iron (Fe). A relatively high level of K of 1690.55 ± 0.02; 1672.35 ± 0.03 mg kg-1 were found for both unripe and natural ripe plantain while the ripening agents had K values of 1677.45 ± 0.01; 1656.10 ± 0.02; 1589.45 ± 0.01 mg kg-1 for Ethylene glycol, Potassium Dihydrogen Phosphate, Calcium carbide respectively. Also, low level of Fe was obtained in plantain ripened with the different ripening agents.

Thermodynamics and photochemical properties of alpha, beta, and gamma-hexabromocyclododecanes: a theoretical study.

The thermodynamics and photochemical properties of -alpha, +beta, and -gamma-hexabromocyclododecanes (HBCDs) have been investigated by density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. The optimized geometries of HBCDs are in agreement with recently published X-ray crystallographic data. The thermodynamic properties of three HBCDs indicate that alpha-HBCD is the most stable one. The TD-DFT calculations obtain the UV absorption spectra of the three HBCDs and provide a detailed assignment of the UV spectral features. Inspections of the frontier molecular orbitals reveal the n-->sigma* nature of the lowest-lying transition and predict the photodegradation and photostereoisomerization trends of HBCDs under the UV illumination with wavelengths shorter than 240 nm.

Polycyclic aromatic hydrocarbons in sediments and soils from oil exploration areas of the Niger Delta, Nigeria.

The distribution of polycyclic aromatic hydrocarbons (PAHs) in sediments from rivers and canals adjoining some oil exploration sites in the Niger Delta and surface soils from host communities were examined. The concentrations of 28 target PAHs ranged from 65 to 331 ng/g (average: 168 ng/g) and from 24 to 120 ng/g (average: 80 ng/g) in the sediment and soil samples, respectively. Two-ring PAHs were the dominant components accounting for approximately 45% of the total PAHs detected. Assessment of the PAH compound ratios, phenanthrene/athracene (Phe/Ant) and fluoranthene/pyrene (Flu/Pyr), suggested that the PAHs in most sediment samples were predominantly of petrogenic origin which may have resulted from incessant oil pipeline leakages in the area. On the other hand, PAHs of pyrogenic sources were present predominantly in surface soils, an indication that gas flaring associated with oil exploration work in the Delta mostly affects the surface soils. An assessment using a set of widely cited sediment quality guidelines indicated that the majority of the sediment samples collected from the rivers of the delta does not pose a serious threat to the ecosystem except for two locations, Imo river and Oginni canal where PAH-contaminated sediments were likely to be acutely toxic to certain sediment dwellers.

Fate of polybrominated diphenyl ethers in the environment of the Pearl River Estuary, South China.

Ninety-six riverine runoff samples collected at eight major outlets in the Pearl River Delta (PRD), South China, during 2005-2006 were analyzed for 17 brominated diphenyl ether (BDE) congeners (defined as Sigma17PBDE). Fourteen and 15 congeners were detected, respectively, in the dissolved and particulate phases. These data were further used to elucidate the partitioning behavior of BDE congeners in riverine runoff. Several related fate processes, i.e. air-water exchange, dry and wet deposition, degradation, and sedimentation, within the Pearl River Estuary (PRE), were examined to estimate the inputs of Sigma10PBDE (sum of the target BDE congeners, BDE-28, -47, -66, -85, -99, -100, -138, -153, -154, and -183) and BDE-209 from the PRD to the coastal ocean based on mass balance considerations. The results showed that annual outflows of Sigma10PBDE and BDE-209 were estimated at 126 and 940 kg/year, respectively from the PRE to coastal ocean. Besides sedimentation and degradation, the majority of Sigma10PBDE and BDE-209 discharged into the PRE via riverine runoff was transported to the coastal ocean.