Isolation and identification of lactic acid bacteria from pastırma

The present study was focused on isolation and identification of lactic acid bacteria from pastırma (a Turkish dry-cured meat product). In this regard, one hundred and six lactic acid bacteria were isolated from pastırma obtained from fourteen different manufacturers and 16S rDNA sequencing was performed to identify these lactic acid bacteria isolates. Besides, samples were subjected to enumerations of lactic acid bacteria, Micrococcus/Staphylococcus, Enterobacteriaceae and yeast-mould and analysis of pH and water activity (a_w). As a result of 16S rDNA sequence analysis, 27.4%, 24.5% and 19.8% of isolates were identified as Lactobacillus sakei, Weisella cibaria and W. confusa, respectively. Pediococcus pentosaceus (5.7%), P. acidilactici (4.7%), Leuconostoc carnosum (3.8%), W. hellenica (2.8%), L. plantarum (1.9%), L. paraplantarum (1.9%), L. curvatus (1.9%), W. halotolerans (1.9%), L. graminis (0.9%), L. carnosus (0.9%), Leu. citreum (0.9%), Leu. mesenteroides (0.9%) were also isolated from pastırma samples. In pastırma samples, the counts of Micrococcus/Staphylococcus, lactic acid bacteria and yeast-mould ranged between 5.28 and 7.69, 3.30 and 7.90, 2.30 and 6.42 log cfu/g, respectively. The count of Enterobacteriaceae was usually determined as under the detectable level (<2 log cfu/g). pH and a_w values of pastırma samples varied from 5.29 to 6.65 and 0.862 to 0.924, respectively.     

Biodiversity,dynamics and antimicrobial activity of lactic acid bacteria involved in the fermentation of maize flour for doklu production in Côte d'Ivoire

Doklu is a maize-based spontaneously fermented dough produced and consumed in parts of West Africa, particularly in Côte d'Ivoire. The characterization of the microbial ecosystem of doklu was carried out using a polyphasic approach. First, culture-dependent methods were used for bacterial enumeration and the phenotypic and molecular identification of 250 lactic acid bacteria (LAB) isolates. Then, culture-independent methods, including PCR-TTGE (V3 region of the 16S rRNA gene), provided a fingerprinting of bacterial DNA directly extracted from doklu. Bio preservative abilities were also tested and strains producing antimicrobial compounds were genotyped using PFGE. During maize dough fermentation, LAB became dominant and their load increased from 4.2 ± 0.2 log CFU/g to 9.0 ± 0.7 log CFU/g only after 48 h. Culture-dependent methods highlighted the presence of five LAB groups with the species Lactobacillus plantarum (28%), Lactobacillus fermentum (41.6%), Pediococcus acidilactici (6.8%), Pediococcus pentosaceus (18%) et Weissella cibaria (5.6%), succeeding during the fermentation. Lb. fermentum being practically the only species present at the end of fermentation, is with Lb. plantarum, the predominant species of fermenting dough. Culture-independent analysis underlined the undoubted role of Lb. fermentum, actively involved in the dough fermentation. These Lb. fermentum species, with a diversity of strains also showed important antimicrobial activity, due to production of bacteriocins. Being able to produce antimicrobial compounds, Lb. fermentum species may act as both bio protective culture as well as fermenting agent in cereal products and could be exploited to create functional starter cultures.     

Quantitative risk assessment of Campylobacter in broiler chickens – Assessing interventions to reduce the level of contamination at the end of the rearing period

The European Food Safety Authority (EFSA) has estimated that a proportion ranging from 20% to 30% of campylobacteriosis in humans may be attributed to the consumption of broiler meat and a reduction in the numbers of Campylobacter in the intestines of infected birds at slaughter by 3 log units would reduce the public health risk by at least 90%. In this study, a stochastic model was implemented to reproduce the dynamics of Campylobacter transmission in broiler flocks and explore the effects of several management conditions and/or on-farm mitigation strategies on the estimated level of contamination of infected flocks at slaughter. Results were expressed as ‘proportion of highly contaminated flocks’ (%HCFs) and estimated as a function of the proportion of infected birds in the flock the day of final depopulation and the individual level of contamination in infected birds. The effects of the mitigation strategies aimed at reducing the level of contamination in infected birds were modelled assuming that those effects are exerted on the distribution describing the bacterial load in infected birds. The impact of management conditions such as the adoption of enhanced biosecurity measures (B+) and/or partial depopulation during the production cycle (T+) were quantified using results of an extensive epidemiological study conducted in UK. A standard broiler flock was reproduced and used as baseline to make comparisons and simulate the effects of the mitigation strategies of interest. The baseline model predicted 18.8% probability of HCFs at slaughter. A positive effect ranging from −32.44% to −4.78% was attributed to B+ while T+ had negative effect ranging from +17.55% to +86.70%. When both the effects were tested simultaneously (B+T+), results were not conclusive with %HCFs ranging from −20.21% to +77.65%. When mitigation strategies operating on Campylobacter concentration in intestine were tested, a reduction of 100% and 99.6% in %HFCs were estimated following a generic treatment with bacteriocins and bacteriophages. Reduction in %HCFs as a function of immunization measures were explored and a reduction of 15% in the rate of transmission led to a %HCFs at slaughter reduced by almost 50%. The model was developed to be flexible, easily reproducible, updatable and adaptable to several baseline scenarios. The main parameters and assumptions underlying the baseline model were tested and a sensitivity analysis was performed to identify and discuss the impact that the uncertainty in the baseline information might have on the outcomes.     

Ochratoxin A contamination of the autochthonous dry-cured meat product “Slavonski Kulen” during a six-month production process

The aim of the study was to investigate OTA contamination of “Slavonski Kulen” during a six-month production process. Raw meat & spices (n = 7) used with the production and final products with either intact or damaged casings (n = 99) were sampled on the production day 30, 60, 90, 120, 150 and 180, and analysed for OTA presence using an enzyme-linked immunosorbent assay (ELISA) and high performance liquid chromatography with fluorescence detection (HPLC-FLD). No statistically significant differences (p > 0.05) were observed among the intact samples on any above-given production day, the maximal OTA value attributable to raw material contamination thereby being 3.18 μg/kg. As for the damaged samples, the mean OTA concentration established on the production day 180 was 7.92 ± 6.50 μg/kg, while the maximal observed OTA value equalled to 17.0 μg/kg. The results demonstrated that casing damaging witnessed during a long-term dry-cured meat products' ripening can result in OTA entry from the surface into the product, causing a significant OTA contamination.     

Innovative technologies to manage aflatoxins in foods and feeds and the profitability of application – A review

Aflatoxins are mainly produced by certain strains of Aspergillus flavus, which are found in diverse agricultural crops. In many lower-income countries, aflatoxins pose serious public health issues since the occurrence of these toxins can be considerably common and even extreme. Aflatoxins can negatively affect health of livestock and poultry due to contaminated feeds. Additionally, they significantly limit the development of international trade as a result of strict regulation in high-value markets. Due to their high stability, aflatoxins are not only a problem during cropping, but also during storage, transport, processing, and handling steps. Consequently, innovative evidence-based technologies are urgently required to minimize aflatoxin exposure. Thus far, biological control has been developed as the most innovative potential technology of controlling aflatoxin contamination in crops, which uses competitive exclusion of toxigenic strains by non-toxigenic ones. This technology is commercially applied in groundnuts maize, cottonseed, and pistachios during pre-harvest stages. Some other effective technologies such as irradiation, ozone fumigation, chemical and biological control agents, and improved packaging materials can also minimize post-harvest aflatoxins contamination in agricultural products. However, integrated adoption of these pre- and post-harvest technologies is still required for sustainable solutions to reduce aflatoxins contamination, which enhances food security, alleviates malnutrition, and strengthens economic sustainability.     

Performance of ultrasonic – Treated nano-zeolites employed in the preparation of dimethyl ether

Catalytic dehydration of methanol to dimethyl ether was carried out over nano-zeolites and their modified samples via ultrasonic technique. Parent H-Beta and Parent H-Mordenite zeolites are used as synthesized and after sonication. H-Mordenite sonicated for 20 and 120 min whereas H-Beta sonicated for 20 min only. The reaction temperature was varied between 100 and 225 °C at three different contact times. The different catalyst samples were characterized using: XRD, FTIR, TEM, SEM and NH₃-TPD techniques. The results revealed that sonication of parent zeolite samples affects on the unit cell dimensions and their crystal size. FTIR-spectroscopic analysis indicated that sonication may decrease the pore opening and cause framework structure defects. TEM and SEM micrographs showed that sonication broke-up and re-ordered zeolite crystals with longer time resulted in a different morphology relative to parents and also change the particle size. Sonicated samples have a good performance in methanol dehydration with complete conversion and complete selectivity to dimethyl ether at lower temperature relative to the corresponding parent zeolites. TPD results indicated that the concentration of strong acid sites decreased in sonicated H-Mordenite samples leading to an increase of their catalytic activity and the selectivity to DME. On the other hand, ultrasonic treatment of H-Beta sample decreased its catalytic activity.     

Aquathermolysis of heavy oil in reservoir conditions with the use of oil-soluble catalysts: part III – changes in composition resins and asphaltenes

Abstract

This paper discusses aquathermolysis process of heavy crude oil from Boca de Jaruco reservoir, which is developed by CSS method. The catalysts based on cobalt, nickel, iron and cupper are used to intensify the in-situ conversion processes. The active form of catalysts generates after steam injection. The third part of paper discusses conversion of resins and asphaltenes. The influence of thermo-catalytic conditions and composition of catalysts are also studied. The destruction of resins and asphaltenes are observed after thermocatalytic treatments. The changes in composition of resins and asphaltenes are revealed by IR-spectroscopy data.     

Plant essential oils as food preservatives to control moulds,mycotoxin contamination and oxidative deterioration of agri-food commodities – Potentials and challenges

Stored food items are frequently contaminated by fungal infestations, mycotoxins secreted by toxigenic fungi, and free radical generation due to oxidative stress. In order to ensure the safety of food items, there is a need for control measures which are effective by antimicrobial, mycotoxin inhibitory as well as antioxidative action. Some synthetic chemicals used as preservatives have been reported to cause harmful effects to consumers and the environment. Different plant essential oils (EOs), naturally occurring plant-based volatile components, have often been reported to possess strong antimicrobial and antioxidant potential. Some EO formulations are currently used as food preservatives and are kept in the category “GRAS” in view of their favourable safety profile. Being volatile in nature, such EOs may be used as plant-based fumigants for stored food commodities. Hence, EOs may play a significant role in overcoming storage losses and in enhancing food shelf- life. This review presents an overview on EOs reported to have prominent efficacy against storage fungi, mycotoxins, and as antioxidants. In addition, safety concerns and future prospects as plant-based preservatives are also discussed.     

The role of government agencies in assessing HACCP – the Malaysian procedure

HACCP implementation by food companies in Malaysia is voluntary. To encourage companies to implement HACCP as a safety assurance system, the Ministry of Health is developing a HACCP Certification Scheme to allow companies to benefit from it. At the same time the Scheme verifies the company's proper implementation of HACCP. This paper outlines the procedure being used in Malaysia.     

Imports and Exports in the First Half of 2002

In the first half of 2002, oil processing volume in China reached 107.1 million tons, 1% more than that in the same period of last year. The imported crude took up 30.8% of the total volume processed, which is about the same as 30.2% for last year. Crude imports saw a decline last year due to slowdown of growth in demands for finished oil products in the domestic market, increase of inventory and drop in processing volume. The processing volume in the     

Experimental and theoretical studies on the corrosion inhibition of vitamins – Thiamine hydrochloride or biotin in corrosion of mild steel in aqueous chloride environment

The corrosion inhibition of thiamine hydrochloride (vitamin B1) or biotin (vitamin B7) on corrosion of mild steel in 240 ppm chloride ions solution was studied using weight loss method, potentiodynamic polarization curves and electrochemical impedance spectroscopy. UV–Vis, FTIR and surface analysis using SEM and EDS characterization were carried out to understand the corrosion inhibition property of these inhibitors in 240 ppm aqueous chloride medium. Experimental results show that both thiamine hydrochloride and biotin act as a good corrosion inhibitors. Quantum chemical parameters obtained from density functional theory (DFT) calculations were discussed with experimental results.     

Stability of vegetable based oils used in the formulation of ecofriendly lubricants – a review

Human need for energy is insatiable. ManBackspace use of conventional and unconventional hydrocarbon sources has served human energy requirements but not without associated challenges of renewability, toxicity, depletion, degradability, and environmental hazards. Since a complete substitute for fossilized-energy sources is yet to be realized, one viable options available to man is alternative, renewable, ecofriendly, and biodegradable energy sources – thus, minimizing complete reliance on mineral based energy sources. Lubricants are finding relevance in product processing, transportation, agriculture, and other key sectors of industrial developments as a result of use of machines to aid human operations. While more than 70% of commercially available lubricants are from crude oil/hydrocarbon, commercial formulation of lubricants using vegetable base oils are gaining global interests. Lubricants obtained from bio-based oils are eco-compatible but are widely reported to be thermally and oxidatively unstable, especially when such biolubricants are produced from crude form of vegetable oils. The aim of this review is to reappraise various scholarly works on thermal-oxidative stability of vegetable oils so as to validate their usefulness as potential alternative and renewable sources of energy used in the production of lubricants as against continuous usage of mineral based energy sources which is ecologically non benign.     

Traceability of organic fish – Authenticating the production origin of salmonids by chemical and isotopic analyses

To develop a practical methodology for the authentication of organic salmonid products, 130 fillet samples of trout and salmon originating from organic and conventional aquaculture as well as wild stocks (salmon) were collected from the German market over one year. Combined stable isotope analysis of δ¹⁵N and δ¹³C in defatted dry matter allowed differentiation of organically farmed from conventionally farmed salmon and brown trout, whether raw, smoked or graved. For the additional distinction of organic and wild salmon, a second analysis of δ¹³C in fish lipids was required. Fatty acid analysis completely differentiated the three production types of salmon just by the linoleic acid content in the fish lipids, which was lowest in wild and highest in conventional salmon. Moreover, the elevated myristic acid content allowed organic to be distinguished from wild and conventional salmon. Furthermore, organic and conventional brown trout could be distinguished by combining the oleic acid and gondoic acid contents. Analysis of the free astaxanthin isomeric pattern allowed a clear distinction of conventional and wild salmon, but organic salmon showed variable patterns that did not consistently allow the authentication of their origin. While a special feed composition is required in organic aquaculture, the composition of conventional aquaculture feed has changed considerably within the last decade. Consequently, the percentages of animal and vegetable components, which clearly vary between the production types, result in distinctive features in terms of stable isotope or fatty acid composition that are utilisable for the authentication of organic salmonid products. To account for potential changes in aquaculture feeding practices, the established distinctive limits should be traced and possibly adapted in future.     

Accelerating the Development of Hydrogenation Process and Technology in China

The crude oils processed at refineries worldwide are becom ing heavier with the contents of sulfur and heavy metals increasing since the 1990s. The environmental regulations promulgated by the governments of many countries are tight ening and there is an urgent need which calls the refiners'attention to adopt clean production processes and make clean fuels.     

Verification of the Effect of EVA’s Residues Addition and the Aging in Mechanical Properties of Asphalt Mixtures

The footwear industry discards residues in its most diverse phases of production, the ethylene vinyl acetate (EVA) being one of them. This work proposes an evaluation of the use of EVA residue discarded by the footwear industry of Campina Grande city in asphalt mixtures. The EVA residue incorporated to petroleum asphalt cement through the wet process in percentages of 0%, 2%, 3%, 4%, and 5% in mass. In the tests of tensile strength and resilient modulus, every mixture that used EVA residue in its composition fulfilled Department of Infrastructure of Transportation's criteria of resilience for usage in paving.     

Foreign Cooperation and Development Trends of the Russian Petroleum Industry and Prospects of Sino-Russian Cooperation in Oil and Gas

1.Introduction Russia is one of the countries with rich reserves of crude oil and natural gas. Among the petroleum-producer countries, Russia ranks the eighth with its proven remaining recoverable oil of 8.219 billion tons and the first with its proven remaining recoverable natural gas of 47.57 trillion m3 (Oil and Gas Journal, 2005). In today’s economic globalization, the whole world will greatly benefit from Russia’s rich oil and gas resources and its opening policy in petroleum industry…     

Aquathermolysis of heavy oil in reservoir conditions with the use of oil-soluble catalysts: part II – changes in composition of aromatic hydrocarbons

Abstract

This paper discusses aquathermolysis process of heavy crude oil from Boca de Jaruco reservoir, which is developed by CSS method. The catalysts based on cobalt, nickel, iron and cupper are used to intensify the in-situ conversion processes. The active form of catalysts generates after steam injection. In second part of work the conversion of aromatic hydrocarbons depending on thermo-catalytic conditions and composition of catalysts are investigated. The thermo-catalytic treatment destructs resin and asphaltene molecules. The destruction products transform into aromatic fractions. The correlation between the C4-phenanthrene/naphtabenzothiophen ratio and the yields of aromatics and resins are revealed. The increase in high-molecular aromatic hydrocarbon, particularly tetramethyl-phenanthrene content is observed. However, the content of heteroatom compounds such as naphtabenzothiophen is constant. Based on IR-spectroscopy, the changes in composition of aromatic fraction are revealed. The lowest value of aromaticity index is detected for experiments with only hydrogen donor (without catalysts) and for experiments with Ni-, Cu-based catalysts.