40 research outputs found

    Human milk from tandem feeding dyads does not differ in metabolite and metataxonomic features when compared to single nursling dyads under six months of age

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    Given the long-term advantages of exclusive breastfeeding to infants and their mothers, there is both an individual and public health benefit to its promotion and support. Data on the composition of human milk over the course of a full period of lactation for a single nursling is sparse, but data on human milk composition during tandem feeding (feeding children of different ages from different pregnancies) is almost entirely absent. This leaves an important knowledge gap that potentially endangers the ability of parents to make a fully informed choice on infant feeding. We compared the metataxonomic and metabolite fingerprints of human milk samples from 15 tandem feeding dyads to that collected from ten exclusively breastfeeding single nursling dyads where the nursling is under six months of age. Uniquely, our cohort also included three tandem feeding nursling dyads where each child showed a preferential side for feeding—allowing a direct comparison between human milk compositions for different aged nurslings. Across our analysis of volume, total fat, estimation of total microbial load, metabolite fingerprinting, and metataxonomics, we showed no statistically significant differences between tandem feeding and single nursling dyads. This included comparisons of preferential side nurslings of different ages. Together, our findings support the practice of tandem feeding of nurslings, even when feeding an infant under six months

    Metabolic phenotyping and strain characterisation of pseudomonas aeruginosa Isolates from cystic fibrosis patients using rapid evaporative ionisation mass spectrometry

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    Rapid evaporative ionisation mass spectrometry (REIMS) is a novel technique for the real-time analysis of biological material. It works by conducting an electrical current through a sample, causing it to rapidly heat and evaporate, with the analyte containing vapour channelled to a mass spectrometer. It was used to characterise the metabolome of 45 Pseudomonas aeruginosa (P. aeruginosa) isolates from cystic fibrosis (CF) patients and compared to 80 non-CF P. aeruginosa. Phospholipids gave the highest signal intensity; 17 rhamnolipids and 18 quorum sensing molecules were detected, demonstrating that REIMS has potential for the study of virulence-related metabolites. P. aeruginosa isolates obtained from respiratory samples showed a higher diversity, which was attributed to the chronic nature of most respiratory infections. The analytical sensitivity of REIMS allowed the detection of a metabolome that could be used to classify individual P. aeruginosa isolates after repeated culturing with 81% accuracy, and an average 83% concordance with multilocus sequence typing. This study underpins the capacities of REIMS as a tool with clinical applications, such as metabolic phenotyping of the important CF pathogen P. aeruginosa, and highlights the potential of metabolic fingerprinting for fine scale characterisation at a sub-species level

    Enhancement of PLA-PVA surface adhesion in bilayer assemblies by PLA aminolisation

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    Data Availability: The raw/processed data required to reproduce these findings cannot be shared at this time due to legal or ethical reasons.Poly(lactic acid) (PLA) and poly(vinyl alcohol) (PVA) present complementary barrier properties, and their combination in multilayer assemblies (laminates) could provide materials with more effective barrier capacity for food packaging purposes. However, their low chemical affinity compromises adequate polymer adhesion. Surface free energy modification of thermo-processed PLA films through treatment with 1,6-hexanediamine was used to enhance adhesion with polar PVA aqueous solutions. Treatments of 1 and 3 min increased the polar component of the solid surface tension, while treatments above 10 min provoked a corrosive effect in the films structure. Extensibility analyses of PVA solutions loaded with carvacrol (15 wt.%) and different Tween 85 ratios on PLA-activated surfaces allowed the selection of the 1-min aminolysed surface for obtaining PLA-PVA bilayers, by casting PVA solutions on the PLA films. This study revealed that despite aminolisation enhancing the PLA surface affinity for aqueous PVA solutions, casting-obtained bilayers presented limited oxygen barrier effectiveness due to heterogeneous thickness of PVA layer in the laminates.The authors acknowledge the financial support provided by the Ministerio de Economia y Competitividad (MINECO) of Spain (project AGL2016-76699-R). The author A. Tampau thanks MINECO for the pre-doctoral research grant #BES-2014-068100.info:eu-repo/semantics/publishedVersio

    Active Whey Protein Edible Films and Coatings Incorporating Lactobacillus buchneri for Penicillium nordicum Control in Cheese

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    Fungal contamination of food is responsible for health issues and food waste. In this work, the incorporation of a lactic acid bacteria (LAB) with antifungal properties (Lactobacillus buchneri UTAD104) into whey protein-based films and coatings was tested for the control of an ochratoxigenic fungi (Penicillium nordicum) in a cheese matrix. The incorporation of L. buchneri cells resulted in thicker films with less luminosity than control films and colour alteration. Nevertheless, cells inclusion did not alter moisture content, water vapour permeability, mechanical properties, hydrophobicity and chemical structure of the films. Whey protein films were able to maintain the viability of L. buchneri UTAD104 cells in 105 CFU/mL after 30 days of storage at 25 \textdegreeC. When applied in cheese, films and coatings containing L. buchneri cells prevented fungal contamination for at least 30 days, while control cheeses with films and coatings either without LAB or with Lactobacillus casei UM3 (a strain without antifungal ability) showed fungal contamination during that period. Ochratoxin A was not found in cheeses treated with films and coatings containing L. buchneri UTAD104. Results showed that the inclusion of a LAB with antifungal properties in edible films and coatings can help to reduce or eliminate P. nordicum contamination in cheeses.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Ana Guimarães received support through grant SFRH/BD/103245/2014 from the Portuguese FCT.info:eu-repo/semantics/publishedVersio

    Perspectives on utilization of edible coatings and nano-laminate coatings for extension of postharvest storage of fruits and vegetables

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    It is known that in developing countries, a large quantity of fruit and vegetable losses results at postharvest and processing stages due to poor or scarce storage technology and mishandling during harvest. The use of new and innovative technologies for reducing postharvest losses is a requirement that has not been fully covered. The use of edible coatings (mainly based on biopolymers) as a postharvest technique for agricultural commodities has offered biodegradable alternatives in order to solve problems (e.g., microbiological growth) during produce storage. However, biopolymer-based coatings can present some disadvantages such as: poor mechanical properties (e.g., lipids) or poor water vapor barrier properties (e.g., polysaccharides), thus requiring the development of new alternatives to solve these drawbacks. Recently, nanotechnology has emerged as a promising tool in the food processing industry, providing new insights about postharvest technologies on produce storage. Nanotechnological approaches can contribute through the design of functional packing materials with lower amounts of bioactive ingredients, better gas and mechanical properties and with reduced impact on the sensorial qualities of the fruits and vegetables. This work reviews some of the main factors involved in postharvest losses and new technologies for extension of postharvest storage of fruits and vegetables, focused on perspective uses of edible coatings and nano-laminate coatings.María L. Flores-López thanks Mexican Science and Technology Council (CONACYT, Mexico) for PhD fellowship support (CONACYT Grant Number: 215499/310847). Miguel A. Cerqueira (SFRH/BPD/72753/2010) is recipient of a fellowship from the Fundação para a Ciência e Tecnologia (FCT, POPH-QREN and FSE Portugal). The authors also thank the FCT Strategic Project of UID/ BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the project ‘‘BioInd Biotechnology and Bioengineering for improved Industrial and AgroFood processes,’’ REF. NORTE-07-0124-FEDER-000028 Co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER. Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico – FUNCAP, CE Brazil (CI10080-00055.01.00/13)

    Effect of different coating-forming agents on the efficacy of the biocontrol agent Candida sake CPA-1 for control of Botrytis cinerea on grapes

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    [EN] Multiple formulations of known biocontrol agent (BCA) Candida sake, containing different coatingforming polymers and surfactants were tested at different polymer:BCA ratios, in order to improve control of Botrytis cinerea on grapes. The BCA cell viability on the grape surface was analyzed and reduction in disease incidence and severity was determined. Coating-forming solids improved the survival and effi- cacy of C. sake as a BCA against B. cinerea, depending on the polymer type and ratio. The incorporation of surfactants did not improve survival or disease control, although they promoted a better cell dispersion on the grape surface. Cell growth of the antagonist during incubation led to the formation of aggregates, even when surfactants were present. Sodium caseinate and starch were the most suitable polymers to formulate C. sake preparations to obtain coating-forming systems with this BCA and to increase its survival and efficacy at the minimum economic cost of the ingredients. 2016 Elsevier Inc. All rights reservedThe authors are grateful to the Spanish Government for the financial support from the national project RTA2012-00067-C02 (Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria, Spain and FEDER founds) and to the Conselleria d'Educacio of the Generalitat Valenciana, (Spain) for A. Marin's PhD grant.Marín-Gozalbo, A.; Cháfer Nácher, MT.; Atarés Huerta, LM.; Chiralt, A.; Torres, R.; Usall, J.; Teixidó, N. (2016). Effect of different coating-forming agents on the efficacy of the biocontrol agent Candida sake CPA-1 for control of Botrytis cinerea on grapes. Biological Control. 96:108-119. https://doi.org/10.1016/j.biocontrol.2016.02.012S1081199

    Properties of film forming dispersions and films based on chitosan containing basil and thyme essential oils

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    [EN] Film-forming emulsions and films of chitosan containing basil or thyme essential oil, with and without oleic acid were characterised as to the emulsion stability (particle size, z-potential and rheological behaviour) and barrier, mechanical and optical properties of the films. The losses of the essential oil during the film formation were also quantified as well as the antifungal effect of the films against Aspergillus niger, Botrytis cinerea and Rhizopus stolonifer. The retention of essential oil in the films was greatly dependent on the stability of the film-forming emulsion. The addition of oleic acid (OA) to the chitosan-essential oil formulations enhanced the emulsion stability and oil retention in the film, at the same time that it improved the water vapour barrier properties of the film. Lipids reduced the film stretchability but when OA was present in the formulation, this reduction was mitigated, as well as the changes in colour provoked by the essential oils, whereas OA reduced the film transparency. Chitosan films with thyme or basil essential oil did not inhibit the growth of the tested fungi.The authors acknowledge the financial support provided by the Universitat Politecnica de Valencia (UPPTE/2012/183) and the Ministerio de Ciencia e Innovacion (AGL2010-20694). Author A. Perdones thanks the Universitat Politecnica de Valencia for an FPIgrant.Perdones Montero, Á.; Chiralt, A.; Vargas, M. (2016). Properties of film forming dispersions and films based on chitosan containing basil and thyme essential oils. Food Hydrocolloids. 57:271-279. https://doi.org/10.1016/j.foodhyd.2016.02.006S2712795

    Effect of chitosan lemon essential oil coatings on storage-keeping quality of strawberry

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    [EN] Film-forming dispersions (FFD) were prepared with 1% high molecular weight chitosan and 3% lemon essential oil and were submitted to two different homogenization treatments. The particle size and viscosity of the FFD were evaluated and stand-alone coatings were characterized in terms of water vapour permeability (WVP) and antimicrobial activity. The FFD were applied to cold-stored strawberries, cv. Camarosa, and the physicochemical properties, fungal decay and respiration rate of strawberries were determined throughout cold storage at 5 degrees C. The use of microfluidization to prepare chitosan-based FFD led to a significant reduction in the particle size and apparent viscosity of the dispersions, with no significant effect on the decrease in the WVP of the stand-alone coatings. Chitosan coatings did not show a significant effect in terms of the acidity, pH and soluble solid content of strawberries throughout storage. In contrast, coatings slowed down the respiration rate of samples when lemon essential oil was added to the FFD. Adding lemon essential oil enhanced the chitosan antifungal activity both in in vitro tests and during cold storage in strawberries inoculated with a spore suspension of Botrytis cinerea.The authors acknowledge the financial support provided by Conselleria de Empresa, Universidad y Ciencia (project GV/2010/082), Universitat Politecnica de Valencia (project PAID-06-09-2834) and Ministerio de Economia y Competitividad (project AGL2010-20694). Author A. Perdones is grateful to Universitat Politecnia de Valencia for a FPI grant.Perdones Montero, A.; Sánchez González, L.; Chiralt, A.; Vargas, M. (2012). Effect of chitosan lemon essential oil coatings on storage-keeping quality of strawberry. Postharvest Biology and Technology. 70:32-41. doi:10.1016/j.postharvbio.2012.04.002S32417

    Effect of chitosan lemon essential oil coatings on volatile profile of strawberries during storage

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    [EN] Chitosan coatings containing lemon essential oils were described as effective at controlling fruit fungal decay at 20 C during 7 days. In this work, GC MS was used to characterise the volatile compounds of strawberries during cold storage in order to analyse the influence of fruit coatings with chitosan, containing or not containing lemon essential oil, on the volatile profile of the fruits. The coatings affected the metabolic pathways and volatile profile of the fruits. Pure chitosan promoted the formation of esters and dimethyl furfural in very short time after coating, while coatings containing lemon essential oil incorporated terpenes (limonene, c-terpinene, p-cymene and alpha-citral) to the fruit volatiles and enhanced the fermentative process, modifying the typical fruit aroma composition. No effect of chitosan coatings was sensorially perceived, the changes induced by lemon essential oil were notably appreciated.The authors acknowledge the financial support provided by Ministerio de Economia y Competividad (AGL2013-42989-R). Angela Perdones also thanks the Universidad Politecnica de Valencia for the FPI Grant.Perdones Montero, Á.; Escriche Roberto, MI.; Chiralt, A.; Vargas, M. (2016). Effect of chitosan lemon essential oil coatings on volatile profile of strawberries during storage. Food Chemistry. 197:979-986. https://doi.org/10.1016/j.foodchem.2015.11.054S97998619
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