Micro and nanoparticles of native and modified cassava starches as carriers of the antimicrobial potassium sorbat

Cross-linked and/or acetylated cassava starches were synthesized and characterized. The acetylation increased the water retention capacity and the solubility in water while the higher level of cross-linking produced the opposite effect on starch. Native (NCS) and acetylated cassava starches (ACS) were used to generate starch micro- and nanoparticles by the dialysis technique.The nanoparticle fraction was around 1.8 g 100 g1 and 12 g 100 g1 (starch dry basis) for NCS and ACS, respectively. The nanoparticle sizes were around 23?255nm with zeta potential extending from 4 to 44mV, while the microscopic fractions ranged 5?87mm. In addition, the capacity of particles to support potassium sorbate (KS) was tested. NCS and ACS particles supported a similar quantity of KS (1400 ppm) and the presence of antimicrobial decreased the particle size for NCS. The precipitation in ethanol technique was also used to generate microparticles where the particles generated from acetylated starches were smaller (8?58mm) than those from native ones (30?227 mm). The KS content that these particles could incorporate was around 2020 ppm. The applied technique modulated the average dimension of the particles obtained, as well as the antimicrobial retention capacity. These innovative materials could bepotentially helpful for shelf life extension by the contribution to the KS stabilization to be incorporated in the bulk of food products.Fil: Alzate Calderón, Paola Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; ArgentinaFil: Zalduendo, María Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gerschenson, Lia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; ArgentinaFil: Flores, Silvia Karina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Universidad de Buenos Aires; Argentin

Combinational approaches for antimicrobial packaging: natamycin and nisin

Food safety is a global priority and one of the major objectives of the current food legislation. The right combination of strategies for food industrialization including the packaging step, ensures the achievement of that objective. New food products and new industrialization processes impose the need for the development of new packaging materials that assure food protection and that address the changing demands of the food industry and of the consumers. The general perception of the importance of minimizing the environmental damage has catalyzed the exploration of new bio-based packaging materials such as biodegradable and edible films because they are environmental friendly. Additionally, consumer demand for more natural foods has promoted the research about natural antimicrobials like natamycin and nisin.In this chapter, it is reviewed the available information on antimicrobial packaging containing the natural antimicrobials natamycin and nisin simultaneously and, in particular, its antimicrobial effectiveness. According to published and new results evaluated, packaging containing natamycin and nisin is a very efficient strategy to control food contamination. Additionally, the use of biodegradable materials to produce the packaging contributes to environment protection.Fil: Jagus, Rosa Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Gerschenson, Lia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Ollé Resa, Carolina Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentin

Protease and hemicellulase assisted extraction of dietary fiber from wastes of Cynara cardunculus

6057-6075The action of protease and hemicellulase for the extraction of fractions enriched in soluble fiber from bracts and stems of Cynara cardunculus was evaluated. Using a two-factor simplex design comprising protease amounts of 0-200 ?L and hemicellulase amounts of 0-200 mg for 5 g of material, we explored the effect of a 5 h enzymatic treatment at 40 °C on the chemical composition and yield of the fractions isolated. The fractions contained inulin and pectin. In general, the protein, inulin, and polyphenol contents and also the yields were higher for fractions obtained from stems. The most marked effects were observed when enzymes were used at higher concentrations, especially for hemicellulase. The inclusion of a pre-heating step increased the yield and the inulin content for fractions isolated from bracts and stems and decreased the protein and polyphenol contents, and the galacturonic acid for bracts. These fractions, in general, contained the polyphenolic compounds monocaffeoylquinic acid, apigenin, and pinoresinol

A comparative study of the structural and mechanical properties of avian eggshells among hosts of obligate brood parasitic cowbirds (genus Molothrus)

Obligate avian brood parasites depend on hosts for parental care, which in turn suffer fitness losses as a result of parasitism. Mechanisms by which brood parasitic cowbirds (Molothrus spp.) reduce host breeding success include the puncture (M. rufoaxillaris and M. bonariensis) or removal (M. ater) of the eggs of the host. Our working hypothesis is that the host eggs' mechanical strength and their size and shape in species with higher frequency of parasitism covaries with the cowbird's strategy to reduce host clutch size. Our results, obtained through phylogenetic analyses based on egg 2D geometric morphometry and eggshell mechanical and ultrastructural measurements, suggest that egg-puncturer behaviour has led to an increase in the strength of the host's eggshell, which might make them more difficult to be pierced. We also characterized larger, more rounded and asymmetrical eggs in frequent hosts of M. ater, which might be more difficult to be removed. These interspecific host egg and shell traits were also positively affected by the frequency of parasitism, indicating that species-specific patterns of parasitic costs select for respective anti-parasitic defences in hosts.Fil: Lopez, Analia Veronica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Reboreda, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Fiorini, Vanina Dafne. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Gerschenson, Lia Noemi. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Hauber, Mark E.. University of Illinois. Urbana - Champaign; Estados Unido

SARS-CoV-2 and the host-immune response

The SARS-CoV-2 pandemic and the COVID-19 disease have affected everyone globally, leading to one of recorded history’s most significant research surges. As our knowledge evolves, our approaches to the virus and treatments must also evolve. The evaluation of future research approaches to SARS-CoV-2 will necessitate reviewing the host immune response and viral antagonism of that response. This review provides an overview of the current knowledge on SARS-CoV-2 by summarizing the virus and human response. The focuses are on the viral genome, replication cycle, host immune activation, response, signaling, and antagonism. To effectively fight the pandemic, efforts must focus on the current state of research to help develop treatments and prepare for future outbreaks

Development of functional pectin edible films with fillers obtained from red cabbage and beetroot

The present study aims to develop through casting, functional composite edible films based on pectin using beetroot powder and red cabbage powder as fillers obtained from by-products of plant tissue industrialisation. Physico-chemical, mechanical, thermal properties and colour stability of the films along 30 days of storage (5–45 °C; absence of light) were evaluated. The moisture and the stress at break decreased, and the intensity of red colour and the hydrophobicity increased with the presence of fillers. According to the FTIR results, there was a good compatibility between matrix and fillers in the composites. Pectin films generated an enhanced stability of red colour after 30 days of storage at 5 and 25 °C and, in general, after 16 days for 45 °C, showing their suitability to be used as colouring agents for edible food packaging applications.Fil: Otálora González, Carlos Mauricio. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Quimicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Quimicos.; ArgentinaFil: De'nobili, Maria Dolores. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Quimicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Quimicos.; ArgentinaFil: Rojas, Ana Maria Luisa. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Quimicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Quimicos.; ArgentinaFil: Basanta, Maria Florencia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Quimicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Quimicos.; ArgentinaFil: Gerschenson, Lia Noemi. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Quimicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Quimicos.; Argentin

Thermal Stability of Betalains in By-Products of the Blanching and Cutting of Beta vulgaris L. Var conditiva

The objective of this study was to evaluate the thermal stability (5°C, 25°C, and 45°C) of betalains present in by-products of the blanching and cutting of Beta vulgaris L. var conditiva, to evaluate the possibility of taking advantage of them as a source of natural colorants to be incorporated in food products. The identification of the betalain compounds present in these by-products was also performed. Blanching waters showed pigment degradation at all the temperatures evaluated. The remnant tissues were freeze dried rendering beetroot powders whose pigments only presented thermal degradation at 45°C. Sixteen betalain compounds were identified in powders by chromatography and it was concluded that a thermal treatment at 45ºC during six days affected the chemical stability of some of these compounds, producing a diversity of betalain degradation products. Results obtained allowed concluding that the red beetroot powder would have a better performance as a natural coloring additive than the blanching water at temperatures below 45°C. Probably, the low water activity of the powder and its lignin content ensured an effective protection of the pigments up to this temperature.Fil: Otálora González, Carlos Mauricio. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Químicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Químicos; ArgentinaFil: Bonifazi, Evelyn Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; ArgentinaFil: Fissore, Eliana Noemi. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Químicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Químicos; ArgentinaFil: Basanta, Maria Florencia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Químicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Químicos; ArgentinaFil: Gerschenson, Lia Noemi. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Químicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Químicos; Argentin