scholarly journals Fungi and mycotoxins: Food contaminants

2013 ◽  
Vol 67 (4) ◽  
pp. 639-653 ◽  
Author(s):  
Suncica Kocic-Tanackov ◽  
Gordana Dimic
Keyword(s):  
Animal Origin ◽  
Food Contaminants ◽  
Penicillium Species ◽  
Nutritive Quality ◽  
Vegetable Products ◽  
Before And After ◽  
Biologic Effects ◽  
Food Species ◽  
Food Sterilization ◽  
Physical And Chemical

The growth of fungi on food causes physical and chemical changes which, further affect negatively the sensory and nutritive quality of food. Species from genera: Aspergillus, Penicillium, Fusarium, Alternari?, Cladosporium, Mucor, Rhizopus, Eurotium and Emericella are usually found. Some of them are potentially dangerous for humans and animals, due to possible synthesis and excretion of toxic secondary metabolites - mycotoxins into the food. Their toxic syndroms in animals and humans are known as mycotoxicoses. The pathologic changes can be observed in parenhimatic organs, and in bones and central nervous system also. Specific conditions are necessary for mycotoxin producing fungi to synthetize sufficient quantities of these compounds for demonstration of biologic effects. The main biochemical paths in the formation of mycotoxins include the polyketide (aflatoxins, sterigmatocystin, zearalenone, citrinine, patulin), terpenic (trichothecenes), aminoacid (glicotoxins, ergotamines, sporidesmin, malformin C), and carbonic acids path (rubratoxins). Aflatoxins are the most toxigenic metabolites of fungi, produced mostly by Aspergillus flavus and A. parasiticus species. Aflatoxins appear more frequently in food in the tropic and subtropic regions, while the food in Europe is more exposed to also very toxic ochratoxin A producing fungi (A. ochraceus and some Penicillium species). The agricultural products can be contaminated by fungi both before and after the harvest. The primary mycotoxicoses in humans are the result of direct intake of vegetable products contaminated by mycotoxins, while the secondary mycotoxicoses are caused by products of animal origin. The risk of the presence of fungi and mycotoxin in food is increasing, having in mind that some of them are highly thermoresistent, and the temperatures of usual food sterilization is not sufficient for their termination. The paper presents the review of most important mycotoxins, their biologic effects, the condition of their synthesis, occurence in food, permitted tolerant intake, as well as the possibility of their degradation.

scholarly journals Effect of natural disinfectant (Moringa oleifera) and a chemical disinfectant (calcium hypochlorite) on nematode eggs: bioefficiency and impact of physico-chemical variables

2020 ◽  
Vol 10 (2) ◽  
pp. 335-346
Author(s):  
Arnold Landry Fotseu Kouam ◽  
Gideon Aghaindum Ajeagah
Keyword(s):  
Petri Dish ◽  
Nematode Species ◽  
Optical Microscope ◽  
Chemical Parameters ◽  
Calcium Hypochlorite ◽  
Physico Chemical ◽  
Before And After ◽  
Nematode Eggs ◽  
Chemical Disinfectant ◽  
Physical And Chemical

Abstract The aim of this study is to determine the effectiveness of disinfectant on the viability of eggs from three nematode species (Ascaris, Trichuris, Ankylostoma). It was conducted in a microcosm from June 2018 to June 2019. The wastewater scan was sampled using 5 L sterile containers, the sample was arranged in four replicas, three tests and one control. The test samples received three disinfectants (Moringa, calcium hypochlorite and Moringa associated with calcium hypochlorite) at varying concentrations. The physical and chemical parameters were measured before and after the application of each disinfectant. The samples were then observed under an optical microscope. The viability of the eggs was determined by incubating the Petri dish samples at 30 °C for 30 days. The analyses show that some physicochemical parameters can significantly influence the efficacy of disinfectant on the eggs. The calcium hypochlorite associated with Moringa at 0.6 g/L showed greater efficacy on reducing viability and inactivation of eggs with 100% efficacy yield rates on Ankylostoma and Trichuris trichiuria and 97% on Ascaris lumbricoides eggs; this efficacy is significantly different from that observed on samples treated with Moringa and simple calcium hypochlorite. Of the three parasites tested, A. lumbricoides showed greater resistance to the disinfectant.

Identification of Amber and the Copal under Heat Pressurized Process

2012 ◽  
Vol 554-556 ◽  
pp. 2112-2115
Author(s):  
Hui Li ◽  
Xuan Wang ◽  
Yong Zhu ◽  
Qin Ren
Keyword(s):  
Chemical Properties ◽  
Peak Position ◽  
Exothermic Peak ◽  
Endothermic Peak ◽  
Scanning Calorimetry ◽  
Natural Resin ◽  
Before And After ◽  
Artificial Heat ◽  
Physical And Chemical ◽  
And Chemical Properties

Amber and copal belong to the natural resin, which are similar and transitional in the physical and chemical properties. The artificial heat-pressurized treatment is contributed to the polymerization of the natural copal, and turns into green, yellow-green and deep orange-yellow copal. It is very difficult to identify amber from the heat- pressurized treatment copal only based on the gemological parameters.The thermal behavior of amber and the copal before and after heat-pressurized treatment were analyzed by means of differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy(FTIR) and nuclear magnetic resonance(NMR). The results show that amber exists an evident endothermic peak around 123~132°C, and copal reveals an obvious endothermic peak at about 174~178°C, and the heat pressurized treatment copal occurs a clear exothermic peak around 150~152°C. The differences between endothermic or exothermic transition and peak position reveal occurring thermal oxidation or the bond breaking or the melting, which are of great significance in the identification.

scholarly journals Cashew Growth and Canopy Dynamics as Influenced by Manuring in a Guinea Savanna Agro-Ecology of Nigeria

2020 ◽  
pp. 80-88
Author(s):  
Beatrice Abanum Nduka ◽  
Olorunfemi Sunday Ojo Akanbi ◽  
Idrisu Mohammed ◽  
Seun Adewale Adeosun ◽  
Osasogie Ugioro ◽  
...  
Keyword(s):  
Block Design ◽  
Organic Fertilizer ◽  
Chemical Properties ◽  
Soil Nutrient ◽  
Ground Cover ◽  
Canopy Development ◽  
Canopy Volume ◽  
Before And After ◽  
Soil Status ◽  
Physical And Chemical

A two-year experiment was conducted to study the response of manuring on growth and canopy development on three-year-old Cashew trees. The experiment was laid in a randomized complete block design, with three replications. Soil characteristics including the chemical and physical properties were analyzed before and after the experiments. Fecti-plus organic pelletized fertilizer was applied at different rates of 0,750.6 and 1,501.2 kg/ha-1 respectively around the circumference of the tree. Before the application, the fertilizer sample was also analyzed. Data collected were plant height, stem girth, canopy dynamics which includes: Canopy diameter, canopy radius, canopy spread (North-South and East-West directions), canopy volume, canopy ground cover and percentage ground cover. The results from the pre soil sample show a relatively low status but were significantly enhanced after the application of the pelletized organic fertilizer (Ferti-plus). The soil nutrient composition of Oc, Om, N, K, Na, Ca and Mg+ was significantly highest in the plots having 1,501.2 kg/ha-1 treatments. Generally, there was a significant increase in the soil nutrient with the addition of pelletized fertilizer in respective of the rate of application. Also the results on the canopy dynamic in terms of canopy volume, spread and diameter revealed better development with the use of 1501.2 kg/ha-1 pelletized fertilizer and significantly different to 750.6 kg/ha-1 and those in the no-manure (control)plots. Meanwhile, the use of pelletized organic fertilizer gave superior growth and canopy development. It also influenced the growth of the Cashew plants, as well as the physical and chemical properties of the soil status.

scholarly journals Produksi Biofuel Dari Limbah Cpo Dengan Katalis Berbasis Titanium Oksida Dan Implementasinya Pada Pembelajaran Kimia

2017 ◽  
Vol 1 (1) ◽  
pp. 19-24
Author(s):  
Nurlia Latifah ◽  
Agus Sundaryono ◽  
Rina Elvia
Keyword(s):  
Methyl Ester ◽  
Learning Outcomes ◽  
Alternative Energy ◽  
Chemical Properties ◽  
Student Learning Outcomes ◽  
Tio2 Catalyst ◽  
Before And After ◽  
Cracking Process ◽  
Physical And Chemical ◽  
And Chemical Properties

Conversion of CPO waste into biofuel is one of the efforts to find alternative energy to overcome Indonesia's energy crisis. The resulting methyl ester was further processed into biofuel by cracking process with Ni/TiO2 and Co/TiO2 catalysts at temperature > 350oC for 2.5 hours followed by distillation. Educational research was done by doing the learning process by using biofuel module. The optimum biofuel yield was obtained from cracking methyl ester with 5% Ni/TiO2 catalyst and 3% Co/TiO2 catalyst respectively of 66,67 and 61,90%. The physical and chemical properties of cracked biofuels with Ni/TiO2 and Co/ TiO2 catalysts have complied with ASTM standards for biofuel except acid numbers. There is an increase in student learning outcomes before and after using the module. 

scholarly journals Recent Trends in Controlling the Enzymatic Browning of Fruit and Vegetable Products

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2754 ◽  
Author(s):  
Kyoung Mi Moon ◽  
Eun-Bin Kwon ◽  
Bonggi Lee ◽  
Choon Young Kim
Keyword(s):  
Enzymatic Browning ◽  
Fruit And Vegetable ◽  
Food Ingredients ◽  
Polyphenol Oxidases ◽  
Current Trends ◽  
Vegetable Products ◽  
Chemical Inhibitors ◽  
Recent Trends ◽  
Physical And Chemical

Enzymatic browning because of polyphenol oxidases (PPOs) contributes to the color quality of fruit and vegetable (FV) products. Physical and chemical methods have been developed to inhibit the activity of PPOs, and several synthetic chemical compounds are commonly being used as PPO inhibitors in FV products. Recently, there has been an emphasis on consumer-oriented innovations in the food industry. Consumers tend to urge the use of natural and environment-friendly PPO inhibitors. The purpose of this review is to summarize the mechanisms underlying the anti-browning action of chemical PPO inhibitors and current trends in the research on these inhibitors. Based on their mechanisms of action, chemical inhibitors can be categorized as antioxidants, reducing agents, chelating agents, acidulants, and/or mixed-type PPO inhibitors. Here, we focused on the food ingredients, dietary components, food by-products, and waste associated with anti-browning activity.

scholarly journals Metallographical Aspects of the Application of Special Paint Layers for the Protection of Machine Part Sections against the Effect of lonitriding

2019 ◽  
Vol 290 ◽  
pp. 03002
Author(s):  
Marius Bibu ◽  
Florin Ciofu
Keyword(s):  
Copper Powder ◽  
Machine Part ◽  
Plasma Nitriding ◽  
Metallic Component ◽  
Copper Powders ◽  
Ionic Nitriding ◽  
Local Protection ◽  
Before And After ◽  
Gas Volume ◽  
Physical And Chemical

The paper presents aspects concerning the appreciation of the protection through special paints based on copper powders used against plasma nitriding. First of all the choice of copper is motivated as an important metallic component of protecting paints, with the characteristics that the copper presents in the context of the physical and chemical phenomena (from the cathode and from gas volume) specific for the ionic nitriding process. The paper contains comparatively some characteristics (the duration of drying on the coat, the compatibility of the components, the capacity of extension and of avoiding the leakage, the power of covering, the capacity of joining, and the emitting of gases, the resistance in friction before and after the ionic nitriding, the way of obtaining the copper powder and its quality, the capacity of removing after ionic nitriding etc.) of the mixtures, for the protection against ionic nitriding. Following the researches on making more efficient technologies of local protection of metal pieces on certain areas with isolated layers against plasma nitride, the authors realized 2 different kinds of special original paints noted V-1 and V-2 used for this purpose. These paints are made having a basis of copper powder combined with magnesium oxide and polystiren dissolved in carbon chloride.

Laser Damage Thresholds of Several Metal-Containing Acrylic Polymers at Four Different Wavelengths.

1991 ◽  
Vol 236 ◽  
Author(s):  
Pearl W. Yip
Keyword(s):  
Electron Spectroscopy ◽  
Light Transmission ◽  
Single Pulse ◽  
Laser Damage ◽  
Laser Materials ◽  
Acrylic Polymers ◽  
Multiple Pulse ◽  
Chemical Damage ◽  
Before And After ◽  
Physical And Chemical

AbstractSingle- and multiple-pulse laser damage thresholds of six different metal-containing acrylic polymers were determined at 10.6, 1.06, 0.53 and 0.355 μm. Light transmission of these samples before and after irradiation was measured. A variety of observed laser-materials interactions are discussed in this paper. Physical and chemical damage properties of these metal-containing acrylic polymers were examined and compared with poly (methyl methacrylate) and polycarbonate using scanning electron microscopy (SEM), infrared spectroscopy (IR), and electron spectroscopy for chemical analysis (ESCA). In general, it was found that the multiple-pulse damage thresholds were lower than the single-pulse, and damage thresholds decreased as wavelength of the testing laser beam became shorter.

Inspecting historical vaulted ceilings by means of physical and chemical analyses: an integrated approach combining active infrared thermography and reflectance spectroscopy

2020 ◽  
Vol 62 (3) ◽  
pp. 144-151 ◽  
Author(s):  
S Sfarra ◽  
E Cheilakou ◽  
P Theodorakeas ◽  
C Ibarra-Castanedo ◽  
H Zhang ◽  
...  
Keyword(s):  
Infrared Thermography ◽  
Near Infrared ◽  
Diffuse Reflectance Spectroscopy ◽  
Central Italy ◽  
Integrated Approach ◽  
Reflectance Spectroscopy ◽  
Fibre Optics ◽  
Buried Structures ◽  
Before And After ◽  
Physical And Chemical

The present study discusses the experimental physicochemical results obtained from the historical vaulted ceilings of an ancient church located in central Italy. Infrared thermography (IRT) in the active configuration was used to map subsurface defects caused by a seismic event and to discover buried structures, while the visible and near-infrared (VIS-NIR) fibre-optics diffuse reflectance spectroscopy (FORS) technique was applied to identify the pigments of wall paintings decorating the vault. Historical photographs are useful to readers in order to clarify the state of conservation before and after the earthquake that took place in 2009. The combination of the experimental results can be useful in restoration processes.

Effect of a rainfall pulse on phytoplankton bloom succession in a hyper-eutrophic subtropical lagoon

2015 ◽  
Vol 66 (1) ◽  
pp. 60 ◽  
Author(s):  
Pei-Jie Meng ◽  
Hung-Jen Lee ◽  
Kwee Siong Tew ◽  
Chung-Chi Chen
Keyword(s):  
Nutrient Dynamics ◽  
Phytoplankton Bloom ◽  
Heavy Precipitation ◽  
Inorganic Nutrients ◽  
Phytoplankton Species ◽  
Nutrient Pulse ◽  
Chaetoceros Curvisetus ◽  
Before And After ◽  
Physical And Chemical ◽  
Subtropical Lagoon

In the present study, we sought to understand the succession of phytoplankton species, after a natural nutrient pulse, in a subtropical lagoon located in southern Taiwan. The lagoon was surrounded by aquaculture ponds. The present study was performed during the wet summer season, before and after an episode of heavy precipitation. Before rainfall commenced, both the phosphate concentration and the level of phytoplankton were relatively low. After heavy precipitation, physical and chemical measurements indicated that significant amounts of dissolved inorganic nutrients had drained into the lagoon. A phytoplankton bloom occurred; organism levels reached 77.6×105 cells L–1. The dominant organism was Chaetoceros curvisetus (99.3%). After the bloom ceased, the levels of inorganic nutrients, especially silicate, fell. Phytoplankton became of low abundance once more. At the end of our study period, the ecosystem was dominated once more by diatoms (75.8%); this may have been caused by a low-level nutrient pulse following rainfall that occurred one day before final sampling. Overall, our results suggest that the bloom succession of phytoplankton species was principally dependent on nutrient dynamics in the lagoon, which was associated with nutrients discharged from drainage after heavy rainfall.

scholarly journals Semen characteristics of breeding bulls at the Central Cattle Breeding and Dairy Farm of Bangladesh

2012 ◽  
Vol 41 (1) ◽  
pp. 1-5
Author(s):  
ME Hossain ◽  
MM Khatun ◽  
MM Islam ◽  
OF Miazi
Keyword(s):  
Sperm Concentration ◽  
Chemical Properties ◽  
Dairy Farm ◽  
Mean Value ◽  
Cattle Breeding ◽  
Bull Semen ◽  
Before And After ◽  
The Mean ◽  
Physical And Chemical ◽  
And Chemical Properties

The experiment was conducted on 97 breeding bulls at the central cattle breeding and dairy farm, Savar, Dhaka to find out the physical and chemical properties of different bull semen. Out of 97 bulls, 9 were Local (L), 9 were Friesian (F), 13 were Sahiwal (SL), 12 were Local×Friesian (L×F), 10 were Sahiwal×Friesian (SL×F), 26 were Local×Friesian×Friesian (LF1×F), 18 were Local×Friesian× Friesian×Friesian (LF2×F) bulls. The semen of different crossbred and local bulls was examined for ejaculate volume, concentration, pH and motility percent of sperm before and after freezing. It was observed that, the maximum average ejaculate was obtained from SL×F and the mean value was 12.9 ml. However, the minimum average ejaculate was obtained from LF×F and the mean value was 7.4 ml. Before freezing, the maximum average sperm concentration was obtained from SL and the mean value was 1858.4 million/ml. The minimum average sperm concentration was obtained from LF1×F and the mean value was 1286.6 million/ml. The maximum average pH was obtained from LF2×F and the mean value was 6.5. The maximum average motility was obtained from SL and the mean value was 68.8%. However, the minimum average motility was obtained from L×F and the mean value was 63.7%. After freezing, sperm concentration, pH and motility reduced substantially irrespective of type of breed. It could therefore be inferred that freezing of semen should be undertaken with special care to maintain optimum semen quality.http://dx.doi.org/10.3329/bjas.v41i1.11968

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