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Control of Listeria innocua Biofilms on Food Contact Surfaces with Slightly Acidic Electrolyzed Water and the Risk of Biofilm Cells Transfer to Duck Meat Texto completo
2018
Jeon, Hye Ri | Kwon, Mi Jin | Yoon, Ki Sun
Biofilm formation on food contact surfaces is a potential hazard leading to cross-contamination during food processing. We investigated Listeria innocua biofilm formation on various food contact surfaces and compared the washing effect of slightly acidic electrolyzed water (SAEW) at 30, 50, 70, and 120 ppm with that of 200 ppm of sodium hypochlorite (NaClO) on biofilm cells. The risk of L. innocua biofilm transfer and growth on food at retail markets was also investigated. The viability of biofilms that formed on food contact surfaces and then transferred cells to duck meat was confirmed by fluorescence microscopy. L. innocua biofilm formation was greatest on rubber, followed by polypropylene, glass, and stainless steel. Regardless of sanitizer type, washing removed biofilms from polypropylene and stainless steel better than from rubber and glass. Among the various SAEW concentrations, washing with 70 ppm of SAEW for 5 min significantly reduced L. innocua biofilms on food contact surfaces during food processing. Efficiency of transfer of L. innocua biofilm cells was the highest on polypropylene and lowest on stainless steel. The transferred biofilm cells grew to the maximum population density, and the lag time of transferred biofilm cells was longer than that of planktonic cells. The biofilm cells that transferred to duck meat coexisted with live, injured, and dead cells, which indicates that effective washing is essential to remove biofilm on food contact surfaces during food processing to reduce the risk of foodborne disease outbreaks.
Mostrar más [+] Menos [-]Heavy metals in food crops, soil, and water in the Lihe River Watershed of the Taihu Region and their potential health risks when ingested Texto completo
2018
Chen, Lian | Zhou, Shenglu | Shi, Yaxing | Wang, Chunhui | Li, Baojie | Li, Yan | Wu, Shaohua
Environmental pollution by heavy metals resulting from rapid economic development is a major concern. Soil, water, wheat, and rice samples were collected from the Lihe River Watershed in the Taihu Region (east China). In this study area, many types of industrial plants, including ceramics factories, plants working with refractory materials, and chemical plants are densely distributed and cause serious heavy metal pollution. In addition, well-developed transportation and agricultural activities are also important sources of heavy metals. Thus, the concentrations of selected heavy metals including cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) in the samples were analyzed to evaluate their potential integral risk (IR) to the health of the local population. Accordingly, the spatial distribution pattern of the IR values was determined in the study. The soil in the study area showed heavy Cd pollution, whereas the pollution by other elements was relatively slight. When the proportions of grain samples in which the concentrations exceeded the tolerance limits were examined, the grains were primarily contaminated with Pb, Ni, Cd, and Zn; and less contaminated with Cu and Cr. The drinking water of the local inhabitants was safe. The average IR value was 3.53 for adults and 3.91 for children, indicating that both adults and children may experience adverse health effects. The spatial distribution pattern of the IR values among the exposed populations in the study area showed high values in the eastern and middle parts, with maximum values >5, and low values in the western part, with minimum values <2. This is consistent with the distributions of the industries and the population. The study may provide a basis for comparison to other regions both in China and worldwide.
Mostrar más [+] Menos [-]Use of hydrolytic enzymes as green and effective extraction agents for ultrasound assisted-enzyme based hydrolytic water phase microextraction of arsenic in food samples Texto completo
2018
Yilmaz, Erkan
In order to contribute to the development and improvement of green sample preparation techniques, a new special approach combining the principles and advantages of microextraction techniques, hydrolytic enzymes and ultrasonic radiation power is presented. This new approach is called as ultrasound assisted-enzyme based hydrolytic water phase microextraction method (UA-EH-WPME). In this study, We developed and used a solvent-free UA-EH-WPME method as innovative, green and simple sample preparation method for the extraction of arsenic (As) in rice and flour samples prior to Inductively Coupled Plasma–Mass Spectrometer (ICP-MS) determination. The UA-EH-WPME method based on the extraction of total As in 10.0 mg of food samples to 300 µL of pH 7.0 aqueous phase with the help of the 3.0 mg of α-amylase in as little as 5 min. In this method, α-amylase acts as a bond breaker agent to break down certain bonds of bio-molecules in food matrix, which lead to extraction of As from food matrix to aqueous phase. 1568A Rice Flour certified reference material was used to optimize the important analytical parameters, which were type of hydrolytic enzyme, pH, volume of aqueous phase, amount of enzyme, temperature of extraction medium and time of ultrasonic radiation, for the quantitative extraction of As from food matrix to aqueous phase. This innovative solvent-free method leads to emerge new ideas in the sample preparation field, by using the benefits of microextraction techniques, hydrolytic enzymes and ultrasonic radiation power, such as elimination of the toxic solvent usage, necessity of mg level of enzyme and food samples, very short and simple extraction process. The LOD, inter-day RSD and intra-day RSD values for the developed UA-EH-WPME/ICP-MS procedure were found as 27.3 µg kg⁻¹, 4.27% and 6.13%, respectively.
Mostrar más [+] Menos [-]Towards a relational understanding of the water-energy-food nexus: an analysis of embeddedness and governance in the Upper Blue Nile region of Ethiopia Texto completo
2018
jennie barron | claudia pahl-wostl | christian stein
Christian Stein, Claudia Pahl-Wostl, Jennie Barron, 'Towards a relational understanding of the water-energy-food nexus: an analysis of embeddedness and governance in the Upper Blue Nile region of Ethiopia', Environmental Science & Policy, vol. 90, pp.173-182, Elsevier BV, 2018 | Given the need for transformative changes towards more sustainable, integrated management of water, energy and food systems, the water-energy-food nexus concept seems highly relevant. However, while intuitively compelling, the nexus has also been criticized for abstracting and thereby dis-embedding the collaboration processes through which further integration could be achieved. There is a lack of empirical analysis and contextsensitive understanding, of the opportunities and constraints of, collaboration and cross-sector coordination, as faced by actors governing interconnected water, energy and food systems. In this paper we analyse how actors involved in the governance of water, energy and food systems are embedded in social networks, and discuss how that embeddedness shapes collaboration and coordination processes that are relevant for addressing interconnected sustainability challenges. Drawing on the notion of problemsheds, we delineate an analytical space that captures the interactions between water, energy and food systems and the actors influencing them in the Upper Blue Nile of Ethiopia. Our empirical data suggest that the claim that actors from different sectors are disconnected from each other is overly simplistic. The ways in which actors are embedded in hierarchical structures may help to explain why coordination challenges persist, despite the presence of cross-sectoral linkages among them
Mostrar más [+] Menos [-]Fabrication of polyethyleneimine modified cobalt ferrite as a new magnetic sorbent for the micro-solid phase extraction of tartrazine from food and water samples Texto completo
2018
Noormohamadi, Hamid Reza | Fat'hi, Mohamad Reza | Ghaedi, Mehrorang
In this research, a facile synthesis route was used for preparation of cobalt ferrite@SiO2@polyethyleneimine magnetic nanoparticles (Co-Fe2O4@PEI) as a new sorbent in the service of ultrasound assisted dispersive micro-solid phase extraction (UA-DMSPME) for influential clean-up, preconcentration, and determination of tartrazine (TA) prior to UV–Vis spectrophotometric detection. The understudy sorbent was fully characterized by transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Energy dispersive X-ray analysis (EDX), and vibrating sample magnetometer (VSM). Different operating parameters which affected the extraction efficiency of TA viz. sorbent dosage, extraction time, pH, and volume of eluent were investigated and optimized by using central composite design (CCD). Under optimal conditions, the enrichment and preconcentration factor, limit of detection (LOD), quantification (LOQ), and precision were obtained 98.01, 66.67, 5.09, and 16.96 ng mL−1, and <5.5% respectively. Good linear response (20–4000 ng mL−1) over the tested concentration range was achieved with the value of R2 = 0.9977. Satisfactory recoveries (>99.5%) of TA in complicated samples including saffron spray, cotton candy and water samples were achieved. This superior validation implies high applicability of the purposed method in terms of it being simple, fast, effective, and accessible: all of these allow for accurate analysis at the trace level.
Mostrar más [+] Menos [-]A hybrid monolithic column based on layered double hydroxide-alginate hydrogel for selective solid phase extraction of lead ions in food and water samples Texto completo
2018
Wang, Jing | Yang, Qingfeng | Zhang, Liang | Liu, Manshun | Hu, Na | Zhang, Wentao | Zhu, Wenxin | Wang, Rong | Suo, Yourui | Wang, Jianlong
In order to develop an accurate and precise determination method based on solid phase extraction of Pb(II) in food and water samples, a hybrid monolithic column based on layered double hydroxides (LDHs) nanosheets-alginate hydrogel has been synthesized. Combining the advantages of porous 3D framework of hydrogel with selective adsorption of LDHs toward Pb(II), the hydrogel-based hybrid monolithic column shows enhanced enrichment selectivity and efficiency for target ions. Effects of hydrogel composition, pH, concentration and type of eluent, sample volume, and interfering ions on the recoveries of the analytes were also investigated. Under the optimal experiment conditions of method, the limit of detection, preconcentration factor and precision as RSD% are found to be 0.39 μg L−1, 53.7 and 2.65%, respectively. Trace Pb(II) can be quantitatively preconcentrated at pH 6.0 with recoveries >97%. Finally, the method was successfully verified by analyzing spiked Pb2+ in water and drinking samples.
Mostrar más [+] Menos [-]Food Conditions and Water Salinity Affect Survival and Growth of Golden Mandarin Fish, Siniperca sherzeri, Larvae through Transcriptional Regulation of Growth and Lipometabolic Genes Texto completo
2018
Yuan, Xiao‐Chen | He, Shan | Liang, Xu‐Fang | Luo, Xiaonian | Li, Aixuan | Zhou, Yi
Failing to initiate first feeding during the transition from endogenous nutrition to exogenous feeding will lead to starvation of fish larvae. However, little is known about the mechanism of first feeding selection of fish. Golden mandarin fish larvae (3 d after hatch, 2.05 ± 0.03 mg) were fed with four different foods for 7 d, including the following: M – Megalobrama amblycephala (prey fish larvae as natural food); S – surimi of M. amblycephala; A – Artemia (zooplankton); and MA –mixed M. amblycephala with Artemia (mixed food). Larvae fed with the mixed food achieved an appropriate balance between high survival and good growth through elevating the expression of growth genes (GH, IGF‐I, and IGF‐II) and fatty acid synthesis genes (FAD and ELO). Growth performance of fish fed with MA reared at different salinities (0, 5, and 10 ppt) was examined. The salinity of 5 ppt produced the best growth performance of the three salinity levels tested. Fish larvae adapted to high‐ or low‐salinity environments through increasing the expression of lipolysis genes (HSL, LPL, and HL). Therefore, both food type and salinity affect the growth, survival, and lipometabolism of golden mandarin fish larvae during initial feeding stage, and mixed food and 5 ppt salinity improved its survival and growth.
Mostrar más [+] Menos [-]Towards a relational understanding of the water-energy-food nexus: an analysis of embeddedness and governance in the upper blue Nile region of Ethiopia Texto completo
2018
Stein, C. | Pahl-Wostl, Claudia | Barron, Jennie
Given the need for transformative changes towards more sustainable, integrated management of water, energy and food systems, the water-energy-food nexus concept seems highly relevant. However, while intuitively compelling, the nexus has also been criticized for abstracting and thereby dis-embedding the collaboration processes through which further integration could be achieved. There is a lack of empirical analysis and contextsensitive understanding, of the opportunities and constraints of, collaboration and cross-sector coordination, as faced by actors governing interconnected water, energy and food systems. In this paper we analyse how actors involved in the governance of water, energy and food systems are embedded in social networks, and discuss how that embeddedness shapes collaboration and coordination processes that are relevant for addressing interconnected sustainability challenges. Drawing on the notion of problemsheds, we delineate an analytical space that captures the interactions between water, energy and food systems and the actors influencing them in the Upper Blue Nile of Ethiopia. Our empirical data suggest that the claim that actors from different sectors are disconnected from each other is overly simplistic. The ways in which actors are embedded in hierarchical structures may help to explain why coordination challenges persist, despite the presence of cross-sectoral linkages among them.
Mostrar más [+] Menos [-]Beverages containing low energy sweeteners do not differ from water in their effects on appetite, energy intake and food choices in healthy, non-obese French adults Texto completo
2018
Fantino, Marc | Fantino, Agnès | Matray, Marie | Mistretta, Frédéric
The usefulness of replacement of caloric sugars by low-calorie sweeteners (LCS) for weight management has been questioned on the grounds that the uncoupling of LCS sweet taste and dietary energy may confuse physiological mechanisms, leading potentially to higher energy and sugar intake. The aim of the present study was to determine whether LCS beverages compared to water, when consumed with meals, differ in their effects on energy and food intake in acute trials and after long-term habituation. Ad libitum food intake of 166 (80 women; 86 men) healthy non-obese adults (BMI between 19 and 28 kg/m2), infrequent consumers of LCS was measured in four 2-consecutive-day testing sessions (Day 1 in the laboratory, Day 2 free-living). During the first 3 sessions, held one-week apart, participants were required to drink either water or commercial non-carbonated LCS lemonade (330 ml) with their main meals (randomised cross-over design). On Day 1, motivational ratings were obtained using visual analogue scales and ad libitum food intakes (amounts and types of foods selected) were measured using the plate waste method. On Day 2, participants reported their ad libitum intakes using a food diary. After Session 3, participants were randomly assigned to the LCS habituation group or to the water control group. The habituation (660 ml LCS lemonade daily vs 660 ml water) lasted 5 weeks. The fourth and final test session measured food intakes and motivational ratings after habituation. Water and LCS beverage did not differ in their effects on total energy intake, macronutrient intakes or the selection of sweet foods and on motivational ratings. Similar results were obtained in both LCS-naïve and LCS-habituated individuals.
Mostrar más [+] Menos [-]Formulation and Stabilization of Concentrated Edible Oil-in-Water Emulsions Based on Electrostatic Complexes of a Food-Grade Cationic Surfactant (Ethyl Lauroyl Arginate) and Cellulose Nanocrystals Texto completo
2018
Bai, Long | Xiang, Wenchao | Huan, Siqi | Rojas, Orlando J.
We report on high-internal-phase, oil-in-water Pickering emulsions that are stable against coalescence during storage. Viscous, edible oil (sunflower) was emulsified by combining naturally derived cellulose nanocrystals (CNCs) and a food-grade, biobased cationic surfactant obtained from lauric acid and L-arginine (ethyl lauroyl arginate, LAE). The interactions between CNC and LAE were elucidated by isothermal titration calorimetry (ITC) and supplementary techniques. LAE adsorption on CNC surfaces and its effect on nanoparticle electrostatic stabilization, aggregation state, and emulsifying ability was studied and related to the properties of resultant oil-in-water emulsions. Pickering systems with tunable droplet diameter and stability against oil coalescence during long-term storage were controllably achieved depending on LAE loading. The underlying stabilization mechanism was found to depend on the type of complex formed, the LAE structures adsorbed on the cellulose nanoparticles (as unimer or as adsorbed admicelles), the presence of free LAE in the aqueous phase, and the equivalent alkane number of the oil phase (sunflower and dodecane oils were compared). The results extend the potential of CNC in the formulation of high-quality and edible Pickering emulsions. The functional properties imparted by LAE, a highly effective molecule against food pathogens and spoilage organisms, open new opportunities in food, cosmetics, and pharmaceutical applications, where the presence of CNC plays a critical role in achieving synergistic effects with LAE.
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