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Due to societal concerns, assess the environmental impacts, address the issues and provide labelling to the consumer are growing issues for the agri-food sector. In this context, provide datasets specific to alternative systems is crucial to be able to take into account the variability between systems then address their issues and label them appropriately. This data paper compiles all the data used to produce the life cycle assessment (LCA) environmental of an organic low-input apple value chain including the cultivation of apples at farm, the transformation of a part into juice and applesauce, the retail and the consumption stages. The raw data have mostly been obtained through interviews of the farmer and complemented by literature. They have been used to build a life cycle inventory (LCI), using Agribalyse 3.0 and Ecoinvent 3.8 as background databases. The dataset also compiles the life cycle impact assessment (LCIA) using the characterization method EF3.0. As discussed in an associated scientific paper, this dataset participates in filling two gaps: integrate the variability between systems in the discussion and link upstream (at farm) and downstream (transformation, retail, consuming) impacts. This is done by (1) covering the entire value chain from cradle to grave when most papers found in literature focusses on one stage (e.g. the cultivation of apples) and (2) applying LCA to a system that present specificities not well covered by LCA literature (e.g. low-input cultivation with no fertilization up to now).
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Currently, there is renewed interest in using fatty acid soaps as surfactants. Hydroxylated fatty acids are specific fatty acids with a hydroxyl group in the alkyl chain, giving rise to chirality and specific surfactant properties. The most famous hydroxylated fatty acid is 12-hydroxystearic acid (12-HSA), which is widely used in industry and comes from castor oil. A very similar and new hydroxylated fatty acid, 10-hydroxystearic acid (10-HSA), can be easily obtained from oleic acid by using microorganisms. Here, we studied for the first time the self-assembly and foaming properties of R-10-HSA soap in an aqueous solution. A multiscale approach was used by combining microscopy techniques, small-angle neutron scattering, wide-angle X-ray scattering, rheology experiments, and surface tension measurements as a function of temperature. The behavior of R-10-HSA was systematically compared with that of 12-HSA soap. Although multilamellar micron-sized tubes were observed for both R-10-HSA and 12-HSA, the structure of the self-assemblies at the nanoscale was different, which is probably due to the fact that the 12-HSA solutions were racemic mixtures, while the 10-HSA solutions were obtained from a pure R enantiomer. We also demonstrated that stable foams based on R-10-HSA soap can be used for cleaning applications, by studying spore removal on model surfaces in static conditions via foam imbibition.
Assuntos
Descontaminação , Sabões , Sabões/química , Ácidos Graxos/química , Tensoativos/farmacologia , Tensoativos/química , EsporosRESUMO
In the food industry, the surfaces of processing equipment are considered to be major factors in the risk of food contamination. The cleaning process of solid surfaces is essential, but it requires a significant amount of water and chemicals. Herein, we report the use of foam flows based on alkyl polyglucosides (APGs) to remove spores of Bacillus subtilis on stainless-steel surfaces as the model-contaminated surface. Sodium dodecyl sulfate (SDS) was also studied as an anionic surfactant. Foams were characterized during flows by measuring the foam stability and the bubble size. The efficiency of spores' removal was assessed by enumerations. We showed that foams based on APGs could remove efficiently the spores from the surfaces, but slightly less than foams based on SDS due to an effect of SDS itself on spores removal. The destabilization of the foams at the end of the process and the recovery of surfactant solutions were also evaluated by using filtration. Following a life cycle assessment (LCA) approach, we evaluated the impact of the foam flow on the global environmental footprint of the process. We showed significant environmental impact benefits with a reduction in water and energy consumption for foam cleaning. APGs are a good choice as surfactants as they decrease further the environmental impacts.
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Mitigation of cross-contamination of fresh-cut food products at the washing step was studied by investigating how the vat design would affect the biofilm contamination surfaces. Hygienic design features such as no horizontal surfaces and only open angles exceeding 100° were proposed. The flow organization (velocity streamlines, wall shear stresses, and dynamics of the flow) was identified by means of computational fluid dynamics (CFD) calculation. Pseudomonas fluorescens PF1 biofilm growth kinetics were then mapped. The change in some geometrical features induced a better flow organization reducing "dead zones". This significantly changed the biofilm growth kinetics, delaying the detection of biofilms from 20 hr to 24 hr. Critical areas such as welds, corners, and interfaces appeared far less prone to strong bacterial development. This would mean milder or less chemicals required at the washing step and faster and easier cleaning.
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The wall teichoic acid (WTA) is the major carbohydrate found within the extracellular matrix of the Listeria monocytogenes biofilm. We first addressed the frequency of spontaneous mutations in two genes (lmo2549 and lmo2550) responsible for the GlcNAcylation in 93 serotype 1/2a strains that were mainly isolated from seafood industries. We studied the impact of mutations in lmo2549 or lmo2550 genes on biofilm formation by using one mutant carrying a natural mutation inactivating the lmo2550 gene (DSS 1130 BFA2 strain) and two EGD-e mutants that lack respective genes by in-frame deletion of lmo2549 or lmo2550 using splicing-by-overlap-extension PCR, followed by allelic exchange mutagenesis. The lmo2550 gene mutation, occurring in around 50% isolates, caused a decrease in bacterial adhesion to stainless steel compared to wild-type EGD-e strain during the adhesion step. On the other hand, bacterial population weren't significantly different after 24h-biofilm formation. The biofilm architecture was different between the wild-type strain and the two mutants inactivated for lmo2549 or lmo2550 genes respectively with the presence of bacterial micro-colonies for mutants which were not observed in the wild-type EGD-e strain biofilm. These differences might account for the stronger hydrophilic surface exhibited by the mutant cells. Upon a water flow or to a cleaning procedure at a shear stress of 0.16 Pa, the mutant biofilms showed the higher detachment rate compared to wild-type strain. Meanwhile, an increase in the amount of residual viable but non-culturable population on stainless steel was recorded in two mutants. Our data suggests that the GlcNAc residue of WTA played a role in adhesion and biofilm formation of Listeria monocyctogenes.
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Acetilglucosamina/metabolismo , Aderência Bacteriana/fisiologia , Biofilmes , Parede Celular/metabolismo , Listeria monocytogenes/fisiologia , Ácidos Teicoicos/metabolismo , Aderência Bacteriana/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Parede Celular/genética , Parede Celular/ultraestrutura , Interações Hidrofóbicas e Hidrofílicas , Listeria monocytogenes/genética , Listeria monocytogenes/ultraestrutura , Microscopia Eletrônica de Transmissão , Mutação , Fenótipo , Aço Inoxidável , Estresse Mecânico , ÁguaRESUMO
The aim of this study was to characterize the Listeria monocytogenes biofilm and particularly the nature of the carbohydrates in the biofilm extracellular matrix and culture supernatant versus to cell wall carbohydrates. Listeria monocytogenes serotype 1/2a and 4b strains were able to form complex biofilms embedded in an extracellular matrix. The soluble carbohydrates from biofilm extracellular matrix and culture supernatant were identified as teichoic acids, structurally identical to cell wall teichoic acids. In addition, the DSS 1130 BFA2 strain had a serotype 1/2a teichoic acid lacking N-acetyl glucosamine glycosylation due to a mutation in the lmo2550 gene. Consequently, we hypothesized that the extracellular teichoic acids in L. monocytogenes biofilms have the same origin as cell wall teichoic acid.
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Biofilmes , Listeria monocytogenes/metabolismo , Polissacarídeos Bacterianos/metabolismo , Ácidos Teicoicos/química , Proteínas de Bactérias/genética , Parede Celular/química , Parede Celular/genética , Parede Celular/metabolismo , Glicosilação , Listeria monocytogenes/química , Listeria monocytogenes/classificação , Listeria monocytogenes/genética , Polissacarídeos Bacterianos/química , Ácidos Teicoicos/metabolismoRESUMO
The ability of bacterial spores and vegetative cells to adhere to inert surfaces was investigated by means of the number of adherent spores (Bacillus cereus and Bacillus subtilis spores) and Escherichia coli cells and their resistance to cleaning or rinsing procedures (adhesion strength). Six materials (glass, stainless steel, polyethylene high density (PEHD), polyamide-6, polyvinyl chloride, and Teflon) were tested. Slight differences in the number of adherent spores (less than 1 log unit) were observed between materials, but a higher number of adherent E. coli cells was found on the hydrophobic materials PEHD and Teflon. Conversely, the resistance of both B. cereus and B. subtilis spores to a cleaning procedure was significantly affected by the material. Hydrophobic materials were harder to clean. The topography parameter derived from the Abbott-Firestone curve, RVK, and, to a lesser extent, the widely used roughness parameters RA (average roughness) and Rz (maximal roughness), were related to the number of adherent cells. Lastly, the soiling level as well as the adhesion strength were shown to depend largely on the microorganism. The number of adhering B. cereus hydrophobic spores and their resistance to a cleaning procedure were found to be 10 times greater than those of the B. subtilis hydrophilic spores. Escherichia coli was loosely bound to all the materials tested, even after 24 h biofilm formation.