Chemical and microbial properties of kiln-smoked catfish in selected locations in Ilorin Metropolis, Nigeria

The use of smoking kiln for drying catfish is on the increase in Nigeria due to its effectiveness in reducing moisture and contamination with toxic compounds during smoking. Chemical properties of kiln-smoked catfish in selected locations in Ilorin metropolis were determined in this study. Kiln-smoked catfish were obtained from four major locations (Oyun, Asa-Dam, Tanke and Agbo-Oba) in Ilorin, Nigeria. The samples were subjected to chemical and polycyclic hydrocarbon content analyses. Dried catfish from all the locations had low moisture and crude fibre contents. There were no significant differences (p>0.05) in the crude fibre contents of the kiln-smoked catfish. Protein contents ranging from 53.72-56.49% were obtained for the kilnsmoked catfish samples. Fat contents ranged from 9.92-11.77% while the carbohydrate contents ranged from 19.02-23.59%. Potassium was the most abundant mineral in the samples with no traces of lead and cadmium. Agbo-Oba samples contained the highest pyrene (2983.215 ng/ml) and total polycyclic hydrocarbon (PAHs) (3349.090 ng/ml). Data on steroid fractions indicated that 17b-estradiol was significantly greater in quantity than those recorded from other steroid fractions. Microbial analyses of the samples revealed the presence of the following pathogenic organisms: Klebsiella spp, Salmonella spp, Shigella spp, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Vibrio spp, Aspergillus niger, penicilium spp, Trichoderma spp which are harmful to man. The use of smoking kiln method improved the nutrients and reduced PAHs in catfish. Keywords: Smoking kiln, Catfish, Chemical properties, Polycyclic hydrocarbon, Mineral elements

Air pollution health risk assessment: the role of benzene

Benzene is an aromatic polycyclic hydrocarbon (C6H6) ubiquitously present in the environment which results from the emissions of fires and volcanoes. However, the primary source is anthropogenic, mainly from industrial emissions and combustion. The aim of this study is to summarize the current evidence on benzene exposure in the Italian regions and the main health effects. A retrospective observational study was conducted. Environmental data provided by ISPRA (Higher Institute for Environmental Protection and Research) relating to benzene pollution and the trend of national emissions of substance by region and sector of origin were analyzed. Data available to date (1990-2016) show a significant decrease, over 91%, mainly due to the reduction in the transport sector. In 2016, the main share of substance relates to road transport (1,492 t), followed by use of solvents (1,100 t), and production processes (463 t). Much lower are the emissions due to the extraction and distribution of fossil fuels/geothermal (19 t) and combustion in the energy and transformation industries (5 t). The highest absolute values in 2015 were recorded in the Italian regions of Lombardia (751.4 t), Lazio (367.2 t), and Puglia (339.0 t). The lower values were in Valle d'Aosta (7.9 t), Molise (15,5 t) and Basilicata (25,3 t). The largest decrease in benzene exposure between 1990 and 2015 was recorded in Campania (-94.5%), Calabria (-93.9%) and Valle d'Aosta (-93.4%). All Italian regions recorded a significant decrease in the absolute values of benzene emissions, mainly due to both the decrease of benzene in fuel composition during the 1990s and to the renewal of circulating cars equipped with energy saving systems (start and stop) and more optimized for low fuel consumption. The global reduction of energy sources based on fossil fuels, as well as a primary environmental objective to reduce Global Warming, would certainly constitute a way to decrease the impact of benzene on the environment. Key messages Additional efforts are needed to reduce energy sources based on fossil fuels. An information, training and health education policy through the environment aimed at implementing awareness and empowerment of the population would be desirable.

Pyrolysis of Polyethylene Terephthalate over Carbon-Supported Pd Catalyst

Pyrolysis of polyethylene terephthalate (PET) produces polycyclic hydrocarbons and biphenyl derivatives that are harmful to human health and the environment. Therefore, a palladium metal catalyst (5 wt.% Pd loaded on activated carbon) was used to prevent the formation of harmful materials. When a Pd catalyst/PET ratio of 0.01 was applied in pyrolysis of PET, it did not show a meaningful difference in the generation of polycyclic hydrocarbons and biphenyl derivatives. However, when a Pd catalyst/PET ratio of 0.05 was used during pyrolysis, it prevented their formation and generation at experimental temperature ranges (400–700 °C). For example, the concentration of 2-naphthalenecarboxylic acid produced, which is a typical polycyclic hydrocarbon material, was reduced by 44%. In addition, the concentration of biphenyl-4-carboxylic acid, which is contained in biphenyl derivatives, was reduced by 79% compared to non-catalytic pyrolysis at 800 °C. This was because the ring-opening reaction and free radical mechanism caused by the Pd catalyst and thermal cracking were dominant during the pyrolysis of PET. Apart from these materials, amine compounds were generated as products of the pyrolysis of PET. Amine concentration showed a similar trend with polycyclic hydrocarbons and benzene derivatives. Based on these results, the total concentration of polycyclic hydrocarbons and biphenyl derivatives was compared; the results confirmed that the concentrations of all substances were reduced. This research suggests that a metal-supported catalyst will help create a more environmentally friendly and reliable method of industrial plastic waste disposal.

Kualitas Organoleptik dan Isotermis Sorpsi Air (ISA) Ikan Cakalang (Katsuwonus pelamis L.) Presto Asap Cair

Skipjack tuna is widely consumed by the people in North Sulawesi in many forms. One famous product is Cakalang Fufu or Smoked Skipjack. Conventional smoked skipjack fish processing has many shortcomings i.e. longer processing time and the presence of tar residues and aromatic polycyclic hydrocarbon compounds (benzo(a)pyrene) which are harmful to human health. The use of liquid smoke is safer since the concentration of liquid smoke can be controlled. Additionally, it is equipped with a cooking method to produce fish with soft fins and bones so that it can be directly consumed. The purpose of this study was to obtain the best formula in the process of making liquid smoked skipjack. Two concentrations of liquid smoke 0.8% and 1.2, three various cooking time using pressure cooker presto (60, 90 and 120 minutes), and two ways of administering liquid smoke were used as treatments. Sensory hedonic test, duo-trio test, MSI test, moisture content, pH and phenol value were measured in this study.The results showed that the best formula in this study was to soaked skipjack tuna in 1.2% liquid smoke, cooked with pressure cooker for 90 minutes and then heated at a temperature of 150°C for 30 minutes. The Duo Trio Test results showed that skipjack tuna in 0,8% and 1.2% liquid smoke concentration either by soaked the fish in advance and cooked by pressure cooker, or cooked by pressure cooker in liquid smoke were tastier than conventional smoked fish samples.Moisture Sorption Isotherm (MSI) test results show that all skipjack tuna with liquid smoke, at RH> 60% will begin to absorb the water, so packaging is needed in this part. The MSI Oswin curve model accurately describes the actual curve with an MRD value of 7.51