Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 112
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Foods ; 10(10)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34681307

RESUMO

The aim of this study was to evaluate the effects of γ-irradiation (IR), ultrasound (US), and combined treatments of ultrasound followed by γ-irradiation (US-IR), ultrasound followed by enzymatic hydrolysis with and without centrifugation (US-E and US-EWC, respectively), and ultrasound followed by γ-irradiation and enzymatic hydrolysis (US-IRE), on the digestibility and the nutritional value of fermented beverages containing probiotics. Results showed that US (20 min), IR (3 kGy) and US-IR (tUS = 20 min, dose = 3 kGy) treatments raised protein solubility from 11.5 to 21.5, 24.3 and 29.9%, respectively. According to our results, these treatments were accompanied by the increased amount of total sulfhydryl groups, surface hydrophobicity and changes to the secondary structure of the proteins measured by Fourier-transform infrared spectroscopy (FTIR). Fermented probiotic beverages, non-enriched (C) and enriched with untreated (Cr) or treated cricket protein with combined treatments were also evaluated for their in vitro protein digestibility. Results showed that the soluble fraction of US-IRE fermented beverage had the highest digestibility (94%) as compared to the whole fermented tested beverages. The peptides profile demonstrated that US-IRE had a low proportion of high molecular weight (MW) peptides (0.7%) and the highest proportion of low MW peptides by over 80% as compared to the other treatments.

2.
J Food Sci ; 86(9): 4172-4182, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34333773

RESUMO

The objective of this study was to develop probiotic beverages, enriched with plant proteins, with high nutritional value. A rice-based beverage fermented with a specific probiotic formulation comprised Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R and Lactobacillus rhamnosus CLR2 has been enriched with a combination of pea and rice proteins (PR) or pea and hemp proteins (PH) at 13 and 11% total protein, respectively. These protein associations have been selected because their amino acid ratio was >1, as recommended by the FAO. The beverage enriched with protein significantly increased its viscosity by more than 10 times thanks to the enrichment, while the fermentation reduced it by 50% for PR and 20% for PH. In vitro protein digestibility results showed that the protein enrichment and the fermentation treatment significantly increased digestibility values of the beverages with value of 72.7% for fermented PR beverage and 61.4% for unenriched fermented control beverage (p ≤ 0.05). Peptide profiles of PR and PH enriched beverages indicated that the fermentation led to a reduced level of high molecular weight (HMW) peptides of about 60% and an increase of low molecular weight (LMW) peptides by over 50%. Therefore, both the fermentation and the enrichment in protein increased the nutritional value of the rice-based beverages. PRACTICAL APPLICATION: Good quality of probiotics formulation and high-protein products are in increasing demand and plant proteins as an alternative of animal protein are popular. This study has permit to develop rice-based commercial probiotic beverages enriched in a combination of pea and rice or pea and hemp proteins in order to obtain a complete protein in terms of amino acids composition. The lactic acid fermentation and the enrichment with a plant protein combination led to a better protein digestibility of beverage.


Assuntos
Microbiologia de Alimentos , Alimentos Fortificados , Lactobacillales , Proteínas de Plantas , Probióticos , Animais , Alimentos e Bebidas Fermentados/análise , Alimentos Fortificados/análise , Alimentos Fortificados/microbiologia , Lactobacillales/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo
3.
J Food Sci ; 86(8): 3698-3706, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34268736

RESUMO

The aim of this study was to evaluate the effect of the fermentation of a probiotic beverage enriched with pea and rice proteins (PRF) on its protein quality. The protein quality was determined as the protein efficiency ratio (PER), net protein ratio (NPR), and the apparent (AD) and the true digestibility (TD) evaluated in vivo. The probiotic beverage was incorporated to a rat diet at a final concentration of 10% protein, for the evaluation of the PER, the NPR, the AD, and the TD. The protein digestibility amino acid score was also calculated. Results showed that the fermentation of beverage enriched with PRF had no effect on the TD but significantly increased the PER and the NPR (P ≤ 0.05) from 1.88 to 2.32 and from 1.66 to 2.30, respectively. Thus, the fermentation increased the protein quality of the PRF probiotic beverage. In addition, to determine if the beverage constitute in a good carrier matrix for the probiotics, the level of alive probiotics in the feces was evaluated and showed a concentration of 7.4 log CFU/g. PRACTICAL APPLICATION: Plant proteins are often of lower quality compared to animal proteins. Lactic acid fermentation of pea and rice protein has allowed to reach the same protein quality as casein. A plant-based fermented beverage with high protein quality and enriched with probiotics was developed.


Assuntos
Oryza , Probióticos , Animais , Bebidas , Fermentação , Ervilhas , Ratos
4.
Crit Rev Food Sci Nutr ; : 1-17, 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34309444

RESUMO

Meat and meat products are highly susceptible to the growth of micro-organism and foodborne pathogens that leads to severe economic loss and health hazards. High consumption and a considerable waste of meat and meat products result in the demand for safe and efficient preservation methods. Instead of synthetic additives, the use of natural preservative materials represents an interest. Essential oils (EOs), as the all-natural and green-label trend attributing to remarkable biological potency, have been adopted for controlling the safety and quality of meat products. Some EOs, such as thyme, cinnamon, rosemary, and garlic, showed a strong antimicrobial activity individually and in combination. To eliminate or reduce the organoleptic defects of EOs in practical application, EOs encapsulation in wall materials can improve the stability and antimicrobial ability of EOs in meat products. In this review, meat deteriorations, antimicrobial capacity (components, effectiveness, and interactions), and mechanisms of EOs are reviewed, as well as the demonstration of using encapsulation for masking intense aroma and conducting control release is presented. The use of EOs individually or in combination and encapsulated applications of EOs in meat and meat products are also discussed.

5.
Int J Biol Macromol ; 185: 535-542, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34216656

RESUMO

Antimicrobial films based on polylactic acid (PLA) were developed by incorporating Thymus vulgaris essential oil (TV-EOs) with different concentrations of ethanolic extract of Mediterranean propolis (EEP) (5 wt% and 10 wt% based on PLA). The antimicrobial activities of EEP were performed by the agar disc diffusion method. The EEP exhibited high antimicrobial properties with inhibition zone diameter of 12.1 and 11.58 mm against Staphylococcus aureus and Penicillium sp., respectively. The addition of TV-EOs to films containing 5 and 10 wt% of EEP decrease the elastic modulus from 1292 MPa to 1084 MPa and 911.1 MPa to 794 MPa compared with films containing 5 and 10% of EEP alone, respectively. However, the elongation at break increased by 64% after the addition of TV-EOs to the film containing 10 wt% of EEP. Thermal stability of films improvement by the addition of TV-EOs and EEP. Antimicrobial activity of the films showed that films containing 10 wt% EEP inhibited the growth of Candida albicans and the combination of EEP and TV-EOs in the PLA matrix showed a synergistic effect against Escherichia coli. The developed PLA-based films with antimicrobial activity have a potential application in food packaging to increase the shelf life of packaged food.


Assuntos
Antibacterianos/farmacologia , Etanol/farmacologia , Óleos Voláteis/farmacologia , Poliésteres/química , Própole/química , Thymus (Planta)/química , Antibacterianos/química , Candida albicans/efeitos dos fármacos , Sinergismo Farmacológico , Escherichia coli/efeitos dos fármacos , Etanol/química , Embalagem de Alimentos , Armazenamento de Alimentos , Óleos Voláteis/química , Óleos Vegetais/química , Óleos Vegetais/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier
6.
Microb Pathog ; 158: 105047, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34129905

RESUMO

The interactions between various essential oils (EOs) were evaluated for the development of antimicrobial formulations. A full factorial design was applied for testing eight EOs (Mustard, Thyme, Garlic, Oregano, Chinese cinnamon, Cinnamon bark, Red bergamot, Winter savory) against nine bacteria (E.coli O157:H7 RM1239, E.coli O157:H7 RM 1931, E.coli O157:H7 RM 1933, E.coli O157:H7 RM 1934, E.coli O157:H7 380-94, Listeria monocytogenes LM 1045, Listeria innocua ATCC 51742, Salmonella Typhimurium SL 1344, Salmonella enterica Newport ATCC 6962) and two molds (Penicillium chrysogenum ATCC 10106, Aspergillus niger ATCC 1015). Results showed that combinations of Thyme + Oregano, Oregano + Cinnamon bark, Chinese cinnamon + Cinnamon bark have shown high interactions in Factorial design and validated to be mostly additive effects against tested bacteria. The combination of Mustard + Thyme, Mustard + Garlic, and Thyme + Garlic EOs showed high interactions and also all additive effects against tested molds. The corresponding results of Factorial design and checkerboard render the designation to demonstrate the highly efficient formulations and interactions rapidly among abundant mixtures.


Assuntos
Anti-Infecciosos , Listeria monocytogenes , Óleos Voláteis , Origanum , Anti-Infecciosos/farmacologia , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Listeria , Óleos Voláteis/farmacologia
7.
FEMS Microbiol Lett ; 368(9)2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-33970244

RESUMO

Stachys pilifera Benth is an endemic species of Stachys family found in Iran with a wide application as an herbal tea. The objective of this research was to evaluate the antimicrobial, antioxidant and cytotoxic activity of the essential oil from the aerial parts of S. pilifera. Essential oil (EO) composition analysis showed that cis-Chrysanthenyl acetate (24.9%), viridiflorol (18.3%), trans-Caryophyllene (9.8%), caryophyllene oxide (4.6%), α-terpineol (3.3%) and linalool (3.1%) were the most abundant components. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the EO showed a higher antimicrobial activity against Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) than Gram-negative organisms (Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa and Salmonella enterica subsp. Enterica). The antioxidant activity of EO was studied using DPPH, FRAP and ß-carotene/linoleic acid assays. IC50 for the DPPH, FRAP and ß-carotene/linoleic acid tests were 23.2, 28.7 and 16.1 µg/mL, respectively, that it was higher than the results for BHT (P ≤ 0.05). The cytotoxic activity of the EO was evaluated using HT29 and HUVEC cells and it was observed that by increasing in EO concentration from 0.026 to 19.4 ug/mL, the viability of the cells for HT29 and HUVEC reduced to 6.8 and 7.1%, respectively. The results from this study suggest the possibility to use the essential oils from S. pilifera Benth as a natural preservative in processed or packaged food due to its high antibacterial, antioxidant and cytotoxic activities.

8.
Methods Mol Biol ; 2227: 205-226, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33847944

RESUMO

Ficolins are innate immune recognition proteins involved in activation of the lectin complement pathway. These oligomeric lectin-like proteins are assembled from subunits consisting of a collagen-like triple helix and a trimeric fibrinogen-like recognition domain. In humans, three ficolins coexist: they differ in their ligand binding specificities, but share the capacity to associate with proteases through their collagen-like stalks and trigger complement activation. We describe methods to decipher the recognition specificities of ficolins, based on surface plasmon resonance, an optical technique allowing real-time and label-free monitoring of biomolecular interactions. This technique was mainly used to characterize and compare binding of the three recombinant full-length ficolins and of their isolated recognition domains to various immobilized BSA-glycoconjugates, acetylated BSA or biotinylated heparin. The avidity phenomenon that enhances the apparent affinity of interactions between oligomeric lectin-like proteins and the multivalent ligands is also discussed.


Assuntos
Lectinas/química , Lectinas/metabolismo , Ressonância de Plasmônio de Superfície/métodos , Animais , Sítios de Ligação , Células CHO , Células Cultivadas , Cricetulus , Drosophila , Humanos , Cinética , Lectinas/farmacologia , Ligantes , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Especificidade por Substrato
9.
Nutr. hosp ; 38(1): 152-160, ene.-feb. 2021. tab, graf
Artigo em Inglês | IBECS | ID: ibc-198852

RESUMO

INTRODUCTION: breast milk (MH) contains nutrients and bioactive compounds for child development, including probiotic bacteria, which contribute to intestinal maturation. This benefit accompanies the individual until adulthood. There are new methods such as spray drying that give this compound a good conservation without loss of microbiota. OBJECTIVE: the aim of this study was to analyze the viability of lactic acid bacteria isolated from human milk with probiotic potential after the spray drying process, as well as to evaluate the possible adhesion in the colon of mice of the Balb/C strain after feeding them powdered human milk and a commercial formula milk. METHOD: we isolated and identified the presence of lactic acid bacteria with possible probiotic potential in powdered human milk using the MALDI-TOF MS technique. Powdered human milk and a commercial formula milk were fed to mice of the Bald/C strain for 14 weeks. Glucose level and weight were measured in the mice. The feces were collected to verify the presence of lactic bacteria. The mice were sacrificed and their intestines were weighed, isolating the lactic acid bacteria both from the intestines and from the feces. The strains isolated from mice fed human milk were evaluated for their probiotic potential, analyzing their ability to inhibit pathogens, resistance to pH, temperature, adhesion, and hydrophobicity. RESULTS: the presence of Lactobacillus fermentum LH01, Lactobacillus rhamnosus LH02, Lactobacullis reuteri LH03, and Lactobacillus plantarum LH05 in powdered human milk was identified. All strains showed a possible probiotic profile due to the ability of bacteria to resist low pH, bile salts, and exposure to gastric enzymes, as well as their hydrophobicity and self-aggregation capacity, and their failure to show hemagglutination or hemolysis activity in a culture medium rich in erythrocytes. We observed that the consumption of powdered human milk prevented weight gain and constipation in mice. CONCLUSIONS: after spray drying, strains with possible probiotic potential may be preserved in human milk. The consumption of powdered human milk with probiotic bacteria prevents constipation and weight gain in mice, when compared to those fed a commercial formula milk


INTRODUCCIÓN: la leche materna (HM) contiene los nutrientes y compuestos bioactivos necesarios para el desarrollo infantil, incluidas bacterias probióticas, que contribuyen a la maduración intestinal. OBJETIVO: el objetivo de este estudio fue analizar la viabilidad de las bacterias acidolácticas aisladas de la leche humana con potencial probiótico, después del proceso de secado, así como evaluar su posible adhesión en el colón de ratones (BAlb/C) alimentados con leche humana en polvo y leche de una fórmula comercial. MÉTODO: se aislaron e identificaron mediante la técnica de Maldi-Tof-MS las bacterias acidolácticas con posible potencial probiótico en la leche humana en polvo. Se alimentó con leche humana en polvo y leche de una fórmula comercial a ratones de la cepa Bald/C durante 14 semanas. Se midieron el nivel de glucosa y el peso. Las heces se recolectaron para verificar la presencia de bacterias lácticas. Los ratones se sacrificaron y se pesaron los intestinos, aislando las bacterias lácticas tanto de los intestinos como de las heces. En las cepas aisladas de la leche humana se evaluó el potencial probiótico analizando su capacidad para inhibir patógenos, resistir distintos pH y temperaturas, adherirse y mostrar hidrofobicidad. RESULTADOS: se identificó la presencia de Lactobacillus fermentum LH01, Lactobacillus rhamnosus LH02, Lactobacullis reuteri LH03 y L. plantarum LH05 en la leche humana en polvo. Todas las cepas mostraron resistencia a los pH bajos, a las sales biliares y a la exposición a enzimas gástricas, así como una buena hidrofobicidad y capacidad de autoagregación. Además, no presentaron actividad de hemaglutinación o hemólisis en un medio de cultivo rico en eritrocitos. Observamos que el consumo de leche humana en polvo evita en los ratones el aumento de peso y el estreñimiento. CONCLUSIONES: después del secado por aspersión, las cepas con posible potencial probiótico pueden conservarse en la leche materna. El consumo de leche humana en polvo con bacterias probióticas evita el estreñimiento y el aumento de peso en los ratones, en comparación con los alimentados con leche de una formula comercial


Assuntos
Animais , Camundongos , Leite Humano/microbiologia , Probióticos , Lactobacillus fermentum/isolamento & purificação , Lactobacillus plantarum/isolamento & purificação , Obesidade/prevenção & controle , Constipação Intestinal/prevenção & controle , Lactobacillus reuteri/isolamento & purificação , Lactobacillus fermentum/fisiologia , Lactobacillus plantarum/fisiologia , Constipação Intestinal/veterinária , Obesidade/veterinária
10.
Microb Pathog ; 153: 104798, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33609647

RESUMO

Opportunistic pathogenic bacteria may cause disease after the normally protective microbiome is disrupted (typically by antibiotic exposure). Clostridioides difficile is one such pathogen having a severe impact on healthcare facilities and increasing costs of medical care. The search for new therapeutic strategies that are not reliant on additional antibiotic exposures are currently being explored. One such strategy is to disrupt the production of C. difficile virulence factors by interfering with quorum sensing (QS) systems. QS has been well studied in other bacteria, but our understanding in C. difficile is not so well understood. Some probiotic strains or combinations of strains have been shown to be effective in the treatment or primary prevention of C. difficile infections and may possess multiple mechanisms of action. One mechanism of probiotics might be the inhibition of QS, but their role has not been clearly defined yet. A literature search was conducted using standard databases (PubMed, Google Scholar) from database inception to August 2020. The objective of this paper is to update our understanding of how QS leads to toxin production by C. difficile, which is important in pathogenesis, and how QS inhibitors or probiotics may disrupt this pathway. We found two main QS systems for C. difficile (Agr and Lux systems) that are involved in C. difficile pathogenesis by regulating toxin production, motility and adherence. Probiotics and other QS inhibitors targeting QS systems may represent important new directions of therapy and prevention of CDI.


Assuntos
Clostridioides difficile , Probióticos , Clostridioides , Percepção de Quorum , Virulência
11.
Probiotics Antimicrob Proteins ; 13(4): 949-956, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33492661

RESUMO

Clostridioides difficile infections (CDI) result from antibiotic use and cause severe diarrhea which is life threatening and costly. A specific probiotic containing Lactobacillus acidophilus CL1285, Lacticaseibacillus casei LBC80R, and Lacticaseibacillus rhamnosus CLR2 has demonstrated a strong inhibitory effect on the growth of several nosocomial C. difficile strains by production of antimicrobial metabolites during fermentation. Though there are several lactobacilli shown to inhibit C. difficile growth by processes relying on acidification, this probiotic has demonstrated potency for CDI prevention among hospitalized patients. Here, we describe the acid-dependent and independent mechanisms by which these strains impair the cytotoxicity of a hypervirulent strain, C. difficile R20291 (CD). These bacteria were co-cultured in a series of experiments under anaerobic conditions in glucose-rich and no-sugar medium to inhibit or stimulate CD toxin production, respectively. In glucose-rich medium, there was low CD toxin production, but sufficient amounts to cause cytotoxic damage to human fibroblast cells. In co-culture, there was acidification by the lactobacilli resulting in growth inhibition as well as ≥ 99% reduced toxin A and B production and no observable cytotoxicity. In the absence of glucose, CD produced much more toxin. In co-culture, the lactobacilli did not acidify the medium and CD growth was unaffected; yet, the amount of detected toxin A and B was decreased by 20% and 41%, respectively. Despite the high concentration of toxin, cells exposed to the supernatant from the co-culture were able to survive. These results suggest that in addition to known acid-dependent effects, the combination of L. acidophilus CL1285, L. casei LBC80R, and L. rhamnosus CLR2 can interfere with CD pathogenesis without acidification: (1) reduced toxin A and B production and (2) toxin neutralization. This might explain the strain specificity of this probiotic in potently preventing C. difficile-associated diarrhea in antibiotic-treated patients compared with other probiotic formulae.

12.
J Food Sci ; 86(2): 420-425, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33438265

RESUMO

The edible coating has been used for covering fruits and vegetables, bringing surface protection, and extending product shelf-life. Due to the outstanding properties, nanomaterials have become a part of the packaging/coating new generation, demonstrating improvements in the barrier capacity of materials starting from construction products to the food industry. In the food industry, on the other hand, Agaricus bisporus mushrooms have a limited shelf-life from 1 to 3 days because of their high respiration rate and enzymatic browning. With the aim to reduce these two parameters and prevent rapid senescence, the objective of this study was to incorporate a natural source of nanomaterials (cellulose nanocrystals (CNCs) into a gellan gum-based coating and sprayed the surface of the mushrooms with the coating material. To evaluate the effect of CNCs, oxygen consumption, carbon dioxide production rate, and color change were recorded during the mushroom storage at 4 ± 1 °C. Results showed that all coatings were able to decrease total color change (ΔE) of mushrooms from 12 to 8 at day 10 when the coating was applied in all samples compared to control. In addition, significant differences were observed in the respiration rate when CNCs were added to the mushrooms. Oxygen consumption results exhibited a 44 mL O2 /kg · day production at day 5 with 20% CNCs compared to 269 mL O2 /kg · day observed in noncoated samples. This trend was similarly observed in the carbon dioxide production rate. PRACTICAL APPLICATION: With this research, it was remarkable to see the presence of CNCs in the coating solution reduced the respiration rate and increased the shelf-life of mushrooms. Similar applications can be industrially scaled-up to protect fruits and vegetables by CNCs-based coating or packaging materials. A variety of sustainable materials are available nowadays that serve as packaging matrix, and scientists are working on expanding the compatibility of these nanomaterials. In addition, it has been studied that CNCs enhance the degradation of polymers, an effort that many companies are making to reduce the environmental impact in their products.


Assuntos
Agaricus/metabolismo , Celulose , Embalagem de Alimentos/instrumentação , Nanopartículas , Polissacarídeos Bacterianos , Agaricus/química , Carboximetilcelulose Sódica , Cor , Excipientes , Armazenamento de Alimentos/métodos , Frutas , Oxigênio/metabolismo
13.
Nutr Cancer ; 73(4): 671-685, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32412316

RESUMO

The association of probiotics and fruit extracts may influence the chemopreventive effect of colorectal cancer. In this context, antiproliferative activity was evaluated to select the best extracts that would be added probiotics, after addition of Bifidobacterium or Lactobacillus in the extracts the antiradical and antioxidant activity, quinone reductase (QR) assay and apoptosis assay were evaluated. Four extracts were isolated: E1: rich in total phenolic compounds; E2: rich in water-soluble phenolic compounds; E3: rich in most apolar phenolic compounds and E4: rich in anthocyanins. The antiproliferative results showed that the best extracts for blueberry and jabuticaba were, respectively the extract E4 and E2. After addition of the probiotic bacteria in these best extracts, it was observed that E2 from jabuticaba presented significantly higher antiradical and antioxidant activity values compared to E4 from blueberry before and after addition of probiotics. There was also a 9-fold increase in activity of QR by the E2 from jabuticaba with Lactobacillus (JL). Likewise, this same extract showed a significant increase both in apoptotic and necrotic cells for both cells. In conclusion, extract rich in water-soluble phenolic compounds (E2) from jabuticaba presented a greater chemopreventive effect compared to the others.

14.
Nutr Hosp ; 38(1): 152-160, 2021 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-33319576

RESUMO

Introduction: Introduction: breast milk (MH) contains nutrients and bioactive compounds for child development, including probiotic bacteria, which contribute to intestinal maturation. This benefit accompanies the individual until adulthood. There are new methods such as spray drying that give this compound a good conservation without loss of microbiota. Objective: the aim of this study was to analyze the viability of lactic acid bacteria isolated from human milk with probiotic potential after the spray drying process, as well as to evaluate the possible adhesion in the colon of mice of the Balb/C strain after feeding them powdered human milk and a commercial formula milk. Method: we isolated and identified the presence of lactic acid bacteria with possible probiotic potential in powdered human milk using the MALDI-TOF MS technique. Powdered human milk and a commercial formula milk were fed to mice of the Bald/C strain for 14 weeks. Glucose level and weight were measured in the mice. The feces were collected to verify the presence of lactic bacteria. The mice were sacrificed and their intestines were weighed, isolating the lactic acid bacteria both from the intestines and from the feces. The strains isolated from mice fed human milk were evaluated for their probiotic potential, analyzing their ability to inhibit pathogens, resistance to pH, temperature, adhesion, and hydrophobicity. Results: the presence of Lactobacillus fermentum LH01, Lactobacillus rhamnosus LH02, Lactobacullis reuteri LH03, and Lactobacillus plantarum LH05 in powdered human milk was identified. All strains showed a possible probiotic profile due to the ability of bacteria to resist low pH, bile salts, and exposure to gastric enzymes, as well as their hydrophobicity and self-aggregation capacity, and their failure to show hemagglutination or hemolysis activity in a culture medium rich in erythrocytes. We observed that the consumption of powdered human milk prevented weight gain and constipation in mice. Conclusions: after spray drying, strains with possible probiotic potential may be preserved in human milk. The consumption of powdered human milk with probiotic bacteria prevents constipation and weight gain in mice, when compared to those fed a commercial formula milk.

15.
Sci Rep ; 10(1): 21729, 2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-33303771

RESUMO

Listeria monocytogenes is a foodborne pathogen responsible for human listeriosis. The increasing incidence of listeriosis induced governments and food manufacturing enterprises to act to diminish the problem. Several methods for the detection of Listeria monocytogenes in food industries were developed. However, they are time-consuming and require the use of specialized equipment. To reduce the detection time of Listeria monocytogenes in food, in this work we developed a fluorescence sandwich immunoassay based on the use of an innovative chitosan-cellulose nanocrystal (CNC) membrane that improves the antigen capture during bacterial growth. The combined use of CNC film for the capture of p60 protein-specific antigen together with the use of fluorescence detection reduced the time of analysis from 24 to 12 h with a limit of detection (LOD) of the assay of 102 CFU/mL (2 Log). In addition, the use of monoclonal anti-PepD covalently immobilized to a CNC membrane assured a high specificity of the assay. Interestingly, the obtained results show no cross-reactivity with the five most diffused pathogen bacteria strains tested.


Assuntos
Técnicas Bacteriológicas/métodos , Imunofluorescência/métodos , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Listeria monocytogenes/isolamento & purificação , Antígenos de Bactérias/análise , Celulose , Quitosana , Indústria Alimentícia , Listeria monocytogenes/crescimento & desenvolvimento , Listeria monocytogenes/patogenicidade , Listeriose/microbiologia , Listeriose/prevenção & controle , Nanopartículas , Sensibilidade e Especificidade , Fatores de Tempo
16.
Crit Rev Food Sci Nutr ; : 1-16, 2020 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-33249886

RESUMO

Fresh foods like fruits, vegetables and shellfish are potential sources for viral infections such as human norovirus (NoV). Chemical treatment like chlorination is a well-known process for food pathogens and virus elimination. However, with the increase of the consumer demand for less toxic treatment, the use of natural antimicrobials like essential oils from spice or plants, fruit extracts, and cold pasteurization treatments (fermentation, irradiation, ozonation and high pressure) could be considered. The aim of this review is to discuss these technologies and their efficacy to eliminate NoV on the surface of fresh food.

17.
Foods ; 9(10)2020 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-33080854

RESUMO

Despite its benefits as biological insecticide, Bacillus thuringiensis bears enterotoxins, which can be responsible for a diarrhoeal type of food poisoning. Thus, all 24 isolates from foodstuffs, animals, soil and commercially used biopesticides tested in this study showed the genetic prerequisites necessary to provoke the disease. Moreover, though highly strain-specific, various isolates were able to germinate and also to actively move, which are further requirements for the onset of the disease. Most importantly, all isolates could grow under simulated intestinal conditions and produce significant amounts of enterotoxins. Cytotoxicity assays classified 14 isolates as highly, eight as medium and only two as low toxic. Additionally, growth inhibition by essential oils (EOs) was investigated as preventive measure against putatively enteropathogenic B. thuringiensis. Cinnamon Chinese cassia showed the highest antimicrobial activity, followed by citral, oregano and winter savory. In all tests, high strain-specific variations appeared and must be taken into account when evaluating the hazardous potential of B. thuringiensis and using EOs as antimicrobials. Altogether, the present study shows a non-negligible pathogenic potential of B. thuringiensis, independently from the origin of isolation. Generally, biopesticide strains were indistinguishable from other isolates. Thus, the use of these pesticides might indeed increase the risk for consumers' health. Until complete information about the safety of the applied strains and formulations is available, consumers or manufacturers might benefit from the antimicrobial activity of EOs to reduce the level of contamination.

18.
J Food Prot ; 83(12): 2134-2146, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32692357

RESUMO

ABSTRACT: The surface of iceberg lettuce (Lactuca sativa L.) is favorable to the survival of pathogens such as bacteria, parasites, and viruses such as norovirus. The present study was conducted to investigate the antiviral properties of treatment with cranberry juice (CJ), ozone (O3), and γ-radiation alone or in combination against feline calicivirus (FCV) F9 present on the surface of iceberg lettuce. The lettuce leaves were inoculated with virus suspensions at ∼6 log TCID50 (50% tissue culture infective dose)/mL and treated with CJ, O3, and γ-radiation alone and in combination during storage at 4°C. The D10-values of 1.21 kGy, 2.23% CJ, and 14.93 ppm of O3 were obtained when samples were treated with various radiation doses, CJ, and O3, respectively. Relative radiosensitization of FCV-F9 virus on lettuce was 1.20, 1.50, 1.09, and 1.00 after combined CJ treatments of 0.1, 0.25, 0.50, and 1.50%, respectively. Optimum treatments were 5 ppm for 7.5 min for O3, 0.25% CJ, and γ-radiation at 1.5 kGy when each treatment was used alone. The combination of the three treatments produced the highest reduction of 2.15 log TCID50/mL (from initial inoculation of ∼7 log TCID50/mL) during 10 days of storage at 4°C. Antibacterial properties of treatments and physicochemical quality of lettuce were investigated during 13 days of storage at 4°C. The treatment of lettuce with γ-radiation alone (1.5 kGy) reduced the total flora by 3 log CFU/g; however, the combination of CJ (0.25%) with irradiation (1.5 kGy) reduced it by ∼5 log CFU/g after 13 days of storage at 4°C. The texture and color of the lettuce treated with the combined treatments changed slightly during storage, and chlorophyll increased by 3.81 µg/mL after 10 days of storage at 4°C. Significant differences in taste and color were observed in lettuce without treatments after 5 days of storage, whereas no difference was observed after the 0.25% CJ or the combined treatments.


Assuntos
Anti-Infecciosos , Calicivirus Felino , Norovirus , Animais , Gatos , Alface , Tolerância a Radiação
19.
Microb Pathog ; 149: 104342, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32534179

RESUMO

Shiga toxin-producing Escherichia coli O157:H7, one of the most severe human foodborne pathogens, can withstand several stresses, including some levels of γ-irradiation. In this study, the response of E. coli O157:H7 to a sensitization irradiation dose of 0.4 kGy was assessed using RNA-seq transcriptomic at 10 (t10) and 60 (t60) min post-irradiation, combined with an isobaric tags for relative and absolute quantitation (iTRAQ) proteomic analysis at 60 min post-irradiation. Several functions were induced by the treatment, such as base excision repair and nucleotide excision repair pathways; sulfur and histidine metabolism, and virulence mechanisms. Additionally, the sulA gene, coding for the cell division repressor, together with other genes involved in SOS response and repair mechanism (including recA, recN, recJ, recQ, mutM and uvrB) were up-regulated at t60. As the early response to irradiation stress (t10), dnaK, groEL, ibpA, sulfur metabolism genes, as well as those related to oxidative stress were up-regulated, while histidine biosynthesis genes were down-regulated. Acid stress, heat shock, UV resistance and several virulence genes, especially stx2A/stx2b which code for the Shiga toxins characteristic of O157:H7, were upregulated at 60 min post-irradiation. The treatment was also found to increase the levels of CysN, MutM, DinG and DnaC in the cells, proteins involved respectively in sulfur metabolism, base excision repair, recombinational DNA repair and chromosome replication. Our results provide insights into the resistance response of E. coli O157:H7 to a non-lethal irradiation dose. Our findings indicate that E. coli O157:H7 can resist to γ-irradiation through important modifications in genes expression and proteins profiles.


Assuntos
Escherichia coli O157 , Proteínas de Escherichia coli , Reparo do DNA , Escherichia coli O157/genética , Proteínas de Escherichia coli/genética , Humanos , Nucleotídeos , Proteômica
20.
Carbohydr Polym ; 240: 116211, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32475544

RESUMO

A printable nanocomposite hydrogel was fabricated with intercalation of alginate into clay galleries followed by irradiation crosslinking graft copolymerization acrylic acid to remove inorganic micropollutants from wastewater. In this regard, nanocomposite-based ink was treated by electron beam irradiation (5-60 kGy), and then irradiated inks were printed using an extrusion-based printer. Structural investigates showed that ink suspension formed a crosslinked network upon irradiation, which could preserve its shape during printing and maintain 3D printed architecture. No additional post-print crosslinking was required due to the formation of free radical and remaining in printed hydrogels as shown by electron spin resonance. Printed hydrogels treated with 5 and 60 kGy irradiation experienced instrumental changes, while functional properties of 15-45 kGy irradiated samples were unaffected upon printing. Losing crystallinity and thermal instability of hydrogels after printing were inhibited through irradiation crosslinking. Metal ion adsorption capacity showed that crosslinked printed hydrogels effectively removed heavy metal ions with high-capacity and fast-responsive. Moreover, metal ions adsorption by printed hydrogels was not selective, thus they can be used to remove various metal ion pollutants from wastewater.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...