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Analytical Methods for Virus Detection in Water and Food Texte intégral
2011
Bosch, Albert | Sanchez, Gloria | Abbaszadegan, Morteza | Carducci, Annalaura | Guix, Susana | Le Guyader, Soizick | Netshikweta, Rembuluwani | Pinto, Rosa M. | Van Der Poel, Wim H. M. | Rutjes, Saskia | Sano, Daisuke | Taylor, Maureen B. | Van Zyl, Walda B. | Rodriguez-lazaro, David | Kovac, Katarina | Sellwood, Jane
Potential ways to address the issues that relate to the techniques for analyzing food and environmental samples for the presence of enteric viruses are discussed. It is not the authors' remit to produce or recommend standard or reference methods but to address specific issues in the analytical procedures. Foods of primary importance are bivalve molluscs, particularly, oysters, clams, and mussels; salad crops such as lettuce, green onions and other greens; and soft fruits such as raspberries and strawberries. All types of water, not only drinking water but also recreational water (fresh, marine, and swimming pool), river water (irrigation water), raw and treated sewage are potential vehicles for virus transmission. Well over 100 different enteric viruses could be food or water contaminants; however, with few exceptions, most well-characterized foodborne or waterborne viral outbreaks are restricted to hepatitis A virus (HAV) and calicivirus, essentially norovirus (NoV). Target viruses for analytical methods include, in addition to NoV and HAV, hepatitis E virus (HEV), enteroviruses (e.g., poliovirus), adenovirus, rotavirus, astrovirus, and any other relevant virus likely to be transmitted by food or water. A survey of the currently available methods for detection of viruses in food and environmental matrices was conducted, gathering information on protocols for extraction of viruses from various matrices and on the various specific detection techniques for each virus type.
Afficher plus [+] Moins [-]Dispersion of food proteins in water-alcohol mixed dispersants
2001
Boulet, M. | Britten, M. | Lamarche, F.
Dispersions of commercial casein and whey protein and laboratory-prepared soybean protein were studied in mixed dispersants of water with various aliphatic alcohols, methanol, ethanol, n-propanol and 2-propanol. Supernatant and protein sediments were separated by centrifugation in two steps: 1800 rpm 10 min, followed by centrifugation of the supernatant at 50000 rpm for 60 min (125000xg). A gel-like protein sediment obtained at low alcohol concentration by high-g centrifugation increased in amounts as a function of the alcohol concentration until it progressively transformed, with higher alcohol concentrations, into an opaque flock (precipitate), sedimenting at 1800 rpm. It was concluded that the sediment obtained by ultracentrifugation was a protein of increased density which was produced by partial and progressive dehydration and alcohol binding. The conversion of the sediment into a flock or precipitate is discussed in terms of the hydrophilic-lipophilic balance of the protein and of the polar-nonpolar character of the dispersant.
Afficher plus [+] Moins [-]Biodiesel production from algae grown on food industry waste water
2014
Mureed, K.
Energy crisis is a worldwide problem; Pakistan is facing severe shortage of this, especially in summer. To overcome these crises, huge amount of fossil fuels is being utilized which ultimately resulting in their exhaustion. In order to cope up the increasing energy requirements, alternative energy sources are required that should be cost-effective, environment friendly and technically feasible. In this scenario biodiesel production from algae has attracted scientist's attention worldwide. At present, the major constraint in biodiesel production from algae is nutritional cost for algal growth. Present research work was planned to minimize nutritional requirements of algae by using food industry waste water as a medium for algal growth towards economical biodiesel production. For this purpose four algal strains (A1, A2, A3 and A4) collected from different fresh water sources were evaluated for their potential use in biodiesel production. The waste water was pre-analyzed to determine the concentrations of different nutrients. All algal strains were grown in Bristol media and different dilutions (10, 20, 40, 80 and 100%) of food industry waste water. Growth data was recorded for one week. The results showed that algal biomass gradually decreased with increasing dilution of food industry waste water and was found higher in 100% waste water concentration than other dilutions. Cultivated algae were harvested for biodiesel production with n-Hexane as oil extractant and NaOH as a catalyst in different combinations through a chemical process ca\led transesterification. The FFA (free fatty acid) profile of algae 1 (A1) by using 75% hexane and 0.5% NaOH combination was found to be higher than other combinations. Higher concentration of NaOH (1%) resulted in soap formation. The aforesaid situations, plus owing to the best biomass production using 100% waste water concentration, deemed algae 1 (A1) as the best candidate among all four strains evaluated for biodiesel production.
Afficher plus [+] Moins [-]Virus detection methods for different kinds of food and water samples – The importance of molecular techniques Texte intégral
2022
Hrdy, Jakub | Vasickova, Petra
The microbiological safety of food and the environment in which we live is currently an intensely discussed topic. Increasing production and the demand-driven global market exert pressure on ensuring sufficient high-quality food and safe drinking water. Compared to the past, increased attention in this area is now paid to important viral agents associated with food/water contaminations in both intensive research and routine diagnostics. This interest in viral agents has also increased in recent years due to the ongoing global pandemic caused by the novel coronavirus. Food- and water-borne viruses usually cause only mild and short-term diseases. The most common is gastroenteritis manifested by fever, vomiting and watery diarrhoea. However, in addition to mild febrile illness, these agents can also cause more serious conditions – respiratory infections, hepatitis, conjunctivitis, aseptic meningitis, myocarditis, encephalitis and paralysis. Globally, these diseases have significant economic impacts and are still among the leading causes of death in developing countries.This manuscript provides an overview of food- and water-borne viruses and technologies developed and currently used for their identification as causative agents. Methods for the detection of these pathogens represent an important tool for the assessment and mitigation of potential risks associated with the contamination of food and water resources. There is currently a wide range of possible approaches. Their use is differently targeted and their sensitivity, effectiveness and specificity also vary. In the case of a specific application, it is therefore necessary to choose the appropriate method, optimize it, and then verify its applicability and limits. The chosen method should be sufficiently robust, sensitive, specific and, if possible, also time and labor saving.
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