0000000000653547
AUTHOR
Gloria Sánchez
Development of a real-time PCR assay for detection and quantification of enterotoxigenic members of Bacillus cereus group in food samples
A highly sensitive real-time PCR (qPCR) procedure, targeting the phosphatidylcholine-specific phospholipase C gene (pc-plc), was developed for specific detection and quantification of strains belonging to Bacillus cereus group. The target region was selected based on the enterotoxigenic profiles of 75 Bacillus strains. The inclusivity and exclusivity of the RTi-PCR assay were assessed with 59 isolates of the B. cereus group, 16 other Bacillus spp., and 4 non-Bacillus strains. The assay was also used to construct calibration curves for different food matrices, and it had a wide quantification range of 6 log units using both serial dilutions of purified DNA and calibrated cell suspensions of …
Recent developments in the use of viability dyes and quantitative PCR in the food microbiology field.
The increase in foodborne outbreaks highlights the need for rapid, sensitive and specific methods for food safety monitoring, enabling specific detection and quantification of viable foodborne pathogens. Real-time PCR (qPCR) combined with the use of viability dyes, recently introduced, fulfils all these requirements. The strategy relies on the use of DNA-binding molecules such as propidium monoazide (PMA) or ethidium monoazide (EMA) as sample pretreatment previous to the qPCR. These molecules permeate only membrane-compromised cells and have successfully been applied for different types of foodborne pathogens, including bacteria and viruses. Moreover, those dyes have been explored to monito…
Green tea extract assisted low-temperature pasteurization to inactivate enteric viruses in juices.
The current popularity of minimally processed foods is an opportunity for natural antimicrobial agents to be combined with mild heat treatments to act synergistically in reducing viral foodborne pathogens. Viral inactivation by heat-treatments (at 25, 40, 50 and 63 °C for 30 min) combined with aged green tea extract (aged-GTE) was initially evaluated in phosphate buffered saline (PBS) against murine norovirus (MNV-1) and hepatitis A virus (HAV) by cell culture, and against human norovirus by in situ capture RT-qPCR. The combination of aged-GTE and heat treatment at 50 °C for 30 min exerted strong antiviral activity, reducing by more than 5 log MNV-1 infectivity in PBS. Heating at 40 °C for …
Antiviral properties of silver nanoparticles against norovirus surrogates and their efficacy in coated polyhydroxyalkanoates systems
Silver nanoparticles (AgNP) have strong broad-spectrum antimicrobial activity and gained increased attention for the development of AgNP based products, including medical and food applications. Initially, the efficacy of AgNP and silver nitrate (AgNO3) was evaluated for inactivating norovirus surrogates, the feline calicivirus (FCV) and the murine norovirus (MNV). These norovirus surrogates were exposed to AgNO3 and AgNP solutions for 24 h at 25 °C and then analyzed by cell-culture assays. Both AgNP and silver ions significantly decreased FCV and MNV infectivity in a dose-dependent manner between concentrations of 2.1 and 21 mg/L. Furthermore, poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (…
SARS-CoV-2 RNA and antibody detection in human milk from a prospective multicenter study in Spain
Background During the COVID-19 pandemic in 2020, breastfeeding in women positive for SARS-CoV-2 was compromised due to contradictory data regarding potential viral transmission. However, growing evidence confirms the relevant role of breast milk in providing passive immunity by generating and transmitting specific antibodies against the virus. Thus, our study aimed to develop and validate a specific protocol to detect SARS-CoV-2 in breast milk matrix as well as to determine the impact of maternal SARS-CoV-2 infection on presence, concentration, and persistence of specific SARS-CoV-2 antibodies. Study design/Methods A prospective multicenter longitudinal study in Spain was carried out from A…
Processing Strategies to Inactivate Hepatitis A Virus in Food Products: A Critical Review
Hepatitis A infection, caused by hepatitis A virus (HAV), is the leading cause of human viral hepatitis throughout the world and is mainly propagated via the fecal–oral route. Transnational outbreaks of food-borne infections are reported with increasing frequency as a consequence of international food trade. Food-borne outbreaks caused by HAV are mainly associated with bivalve molluscs, produce (soft fruits and leafy greens), and ready-to-eat meals. The purpose of this paper was to conduct a structured and systematic review of the published literature on the current state of knowledge regarding the stability of HAV in foods as well as the efficacy of food processing strategies and to identi…
High pressure treatment and green tea extract synergistically control enteric virus contamination in beverages
Consumers are driving food production toward the use of natural preservatives and minimal processing technologies. Green tea extract (GTE) at low concentration could be combined with high pressure processing (HPP) for reduced treatment times and quality impact on foods in a hurdle concept for synergistic effects on foodborne viral pathogens, specifically human norovirus and hepatitis A virus (HAV). Viral inactivation by HPP (at 300, 400, and 500 MPa for 5 min) combined with 3.3 mg/mL aged-GTE was initially evaluated in buffer (PBS) against murine norovirus (MNV), a culturable human norovirus surrogate, and HAV. Furthermore, human norovirus inactivation was evaluated by the novel human intes…
On the use of Persian gum for the development of antiviral edible coatings against murine norovirus of interest in blueberries.
In the last decades, berries have been identified as important vehicles for the transmission of foodborne viruses and different strategies are being explored to eliminate or reduce viral contamination in these fruits. The aim of this work was to develop novel edible coatings with antiviral properties for inactivating and reducing murine norovirus (MNV). Firstly, the effect of gelatin (G) addition on Persian gum (PG) films was studied in terms of microstructural, mechanical, optical, and water barrier properties. The following PG:G ratios were considered: 100:0, 75:25, 50:50, 25:75, and 0:100. Microstructure analysis revealed the compatibility of both hydrocolloids since no phase separation …
Bias of library preparation for virome characterization in untreated and treated wastewaters
The use of metagenomics for virome characterization and its implementation for wastewater analyses, including wastewater-based epidemiology, has increased in the last years. However, the lack of standardized methods can led to highly different results. The aim of this work was to analyze virome profiles in upstream and downstream wastewater samples collected from four wastewater treatment plants (WWTPs) using two different library preparation kits. Viral particles were enriched from wastewater concentrates using a filtration and nuclease digestion procedure prior to total nucleic acid (NA) extraction. Sequencing was performed using the ScriptSeq v2 RNA-Seq (LS) and the NEBNext Ultra II RNA …
On the use of carrageenan matrices for the development of antiviral edible coatings of interest in berries
Different film-forming dispersions (FFD) based on κ−, ι− and λ− carrageenans and green tea extract (GTE) have been developed as an innovative strategy to guarantee the food safety of blueberries and raspberries. First, the FFD were characterized (surface tension and viscosity) and the physicochemical properties (water vapour permeability-WVP-, water sorption, contact angle, mechanical properties) of the stand-alone films were evaluated. Then, the FFD were applied to refrigerated-stored raspberries and blueberries, and the antiviral activity against murine norovirus (MNV), a cultivable norovirus surrogate, and hepatitis A virus (HAV) of coated fruits was determined at refrigerated (10 °C) an…
Epidemiological Surveillance of Norovirus and Rotavirus in Sewage (2016–2017) in Valencia (Spain)
© 2020 by the authors.
PAMPA—a drug absorption in vitro model
Parallel artificial membrane permeability assay (PAMPA) was used to measure the effective permeability, P(e), as a function of pH from 4 to 10, of 17 fluoroquinolones, including three congeneric series with systematically varied alkyl chain length at the 4'N-position of the piperazine residue. The permeability values spanned over three orders of magnitude. The intrinsic permeability, P(o), and the membrane permeability, P(m), were determined from the pH dependence of the effective permeability. The pK(a) values were determined potentiometrically. The PAMPA method employed stirring, adjusted such that the unstirred water layer (UWL) thickness matched the 30-100 microm range estimated to be i…
The effect of carvacrol on enteric viruses.
Carvacrol, a monoterpenic phenol, is said to have extensive antimicrobial activity in a wide range of food spoilage or pathogenic fungi, yeast and bacteria. The aim of this study was to assess its antiviral activity on norovirus surrogates, feline calicivirus (FCV), murine norovirus (MNV), and hepatitis A virus (HAV), as well as its potential in food applications. Initially, different concentrations of carvacrol (0.25, 0.5, 1%) were individually mixed with each virus at titers of ca. 6-7 log TCID50/ml and incubated 2h at 37°C. Carvacrol at 0.5% completely inactivated the two norovirus surrogates, whereas 1% concentration was required to achieve ca. 1 log reduction of HAV. In lettuce wash wa…
Viability RT-qPCR to Distinguish Between HEV and HAV With Intact and Altered Capsids
The hepatitis E virus (HEV) is an emerging pathogen showing a considerable increase in the number of reported cases in Europe mainly related to the ingestion of contaminated food. As with other relevant viral foodborne pathogens, real-time reverse transcriptase polymerase chain reaction (RT-qPCR) is the gold standard for HEV detection in clinical, food, and environmental samples, but these procedures cannot discriminate between inactivated and potentially infectious viruses. Thus, the aim of this study was to develop a viability PCR method to discriminate between native, heat-, and high-pressure processing (HPP)-treated HEV using the hepatitis A virus (HAV) as a cultivable surrogate. To thi…
Antiviral and antioxidant properties of active alginate edible films containing phenolic extracts
In this work, novel active edible films having antiviral activity were developed through the solvent casting method. Emulsified edible films were prepared by adding lipids into alginate films in order to improve their water vapour permeability. In addition, two natural extracts rich in phenolic compounds, specifically a green tea extract (GTE) and a grape seed extract (GSE) were used as active agents. Interestingly, incorporating GTE or GSE within the biopolymer matrix, the films exhibited significant antiviral activity against murine norovirus (MNV) and hepatitis A virus (HAV) since ∼2 log reduction were recorded for the 0.75 g extract/g alginate in the film, being GTE more efficient than …
HEV Occurrence in Waste and Drinking Water Treatment Plants
Hepatitis E virus (HEV), particularly zoonotic genotype 3, is present in environmental waters worldwide, especially in industrialized countries. Thus, monitoring the presence of HEV in wastewater treatment plants (WWTPs) is an emerging topic due to the importance of reusing water on a global level. Given the limited data, this study aimed to monitor the occurrence of HEV in influent and effluent water in waste- and drinking-water treatment plants (WWTPs and DWTPs). To this end, different procedures to concentrate HEV in influent and effluent water from WWTPs and DWTPs were initially evaluated. The evaluated procedures resulted in average HEV recoveries of 15.2, 19.9, and 16.9% in influent, …
Detection Of Genomic Variants Of SARS-CoV-2 Circulating In Wastewater By High-Throughput Sequencing
The use of SARS-CoV-2 metagenomics in wastewater can allow the detection of variants circulating at community level. After comparing with clinical databases, we identified three novel variants in the spike gene, and six new variants in the spike detected for the first time in Spain. We finally support the hypothesis that this approach allows the identification of unknown SARS-CoV-2 variants or detected at only low frequencies in clinical genomes.
SARS-CoV-2 RNA titers in wastewater anticipated COVID-19 occurrence in a low prevalence area
Postprint disponible en http://hdl.handle.net/10261/211707
Sustainable bioactive pectin-based films to improve fruit safety via a circular economy approach.
This work reports on the valorisation of persimmon (Diospyros kaki Thunb.) for the development of food-grade antiviral coatings against major viral foodborne pathogens, human noroviruses (NoVs) and hepatitis A virus (HAV). Initially, the antiviral activity of polyphenol-rich pectin extracts with abundant non-covalent interactions (PPN), pectin extracts enriched with intact pectin-polyphenol ester and O-glycosyl bonds (PPC) and hydro-ethanolic polyphenol-rich extracts (EPE) was compared. Higher viral reductions were found for the pectin extracts rich in polyphenols, mainly in those containing covalent pectin-polyphenol interactions. This specific extract was mixed with commercial citrus pect…
Evaluation of two different concentration methods for surveillance of human viruses in sewage and their effects on SARS-CoV-2 sequencing
8 páginas, 5 figuras, 1 tabla
Evaluation of viability PCR performance for assessing norovirus infectivity in fresh-cut vegetables and irrigation water
Norovirus (NoV) detection in food and water is mainly carried out by quantitative RT-PCR (RT-qPCR). The inability to differentiate between infectious and inactivated viruses and the resulting overestimation of viral targets is considered a major disadvantage of RT-qPCR. Initially, conventional photoactivatable dyes (i.e. propidium monoazide, PMA and ethidium monoazide, EMA) and newly developed ones (i.e. PMAxx and PEMAX) were evaluated for the discrimination between infectious and thermally inactivated NoV genogroup I (GI) and II (GII) suspensions. Results showed that PMAxx was the best photoactivatable dye to assess NoV infectivity. This procedure was further optimized in artificially inoc…
Survival of Enteric Viruses in the Environment and Food
Enteric viruses are those human viruses that are primarily transmitted by the fecal-oral route, either by person-to-person contact or by ingestion of contaminated food or water. The importance of viral foodborne diseases is increasingly being recognized, and several international organizations have found that there is an upward trend in their incidence. Thus, in this review, state-of-the-art information regarding virus persistence in food and the environment is compiled.
Antiviral capacity of sanitizers against infectious viruses in process water from the produce industry under batch and continuous conditions
The presence of human enteric viruses in produce has extensively been reported. However, the significance of the quality of process water (PW) used by the produce industry and the viral inactivation capacity of water disinfection agents used to maintain the microbiological quality of PW has received limited attention. This study evaluates the antiviral disinfection efficacy of chlorine, chlorine dioxide (ClO2) and peracetic acid (PAA) at recommended operational limits in PW using hepatitis A virus (HAV), the cultivable norovirus surrogate, murine norovirus (MNV-1), and MS2 coliphages. Defined commodity representative crops (baby leaves, bell peppers, and the vegetable mix of tomatoes, cucum…
Comparative efficacy of Zataria multiflora Boiss., Origanum compactum and Eugenia caryophyllus essential oils against E. coli O157:H7, feline calicivirus and endogenous microbiota in commercial baby-leaf salads.
Abstract Ready-to-eat salads using baby-leaf and multi-leaf mixes are one of the most promising developments in the fresh-cut food industry. There is great interest in developing novel decontamination treatments, which are both safe for consumers and more efficient against foodborne pathogens. In this study, emulsions of essential oils (EOs) from Origanum compactum (oregano), Eugenia caryophyllus (clove), and Zataria multiflora Boiss (zataria) were applied by spray (0.8 ml) after the sanitizing washing step. The aim was to investigate their ability to control the growth of potentially cross-contaminating pathogens and endogenous microbiota in commercial baby leaves, processed in a fresh-cut…
Virus entéricos humanos en alimentos: detección y métodos de inactivación
[ES] Los principales patógenos víricos que podemos adquirir ingiriendo alimentos contaminados son los norovirus, el virus de la hepatitis A y el virus de la hepatitis E que se propagan principalmente a través de la vía fecal oral. En los últimos años, la incidencia de brotes de transmisión alimentaria causados por estos patógenos ha experimentado un aumento considerable, en parte debido al comercio globalizado y a los cambios en los hábitos de consumo. Las matrices alimentarias que mayor riesgo representan para el consumidor son los moluscos bivalvos, vegetales de IV gama, frutas tipo baya y platos listos para comer. Actualmente las técnicas moleculares son las más habituales para la detecc…
Fostering the antiviral activity of green tea extract for sanitizing purposes through controlled storage conditions
Food-contact surfaces is considered an important vehicle for the indirect transmission of foodborne viral diseases with enteric viruses, especially human norovirus (HuNoV) and hepatitis A virus (HAV). The aim of the present study was to evaluate the antiviral activity of green tea extract (GTE) at room temperature as a function of pH and storage time and to relate it with changes in composition as a consequence of degradation and epimerization reactions in the storage conditions. The obtained results revealed that freshly prepared GTE was very effective in inactivating murine norovirus (MNV) and HAV at neutral and alkaline pH but was ineffective at pH 5.5. Additionally, storage of the solut…
Sanitizing food contact surfaces by the use of essential oils
Chemical sanitizers continue to be widely used by the food industry to disinfect food contact surfaces. However, as some chemical disinfectants have been reported to produce unhealthy by-products, alternative and natural compounds need to be investigated. To this end, nine essential oils (EOs) were screened to develop a natural sanitizing solution (SAN) for disinfecting food contact surfaces. Once extracted, their antimicrobial activity and chemical composition were determined. An exploratory multivariate approach was used to investigate the relationships between the chemical and microbiological data sets. Among the tested EOs, Thymbra capitata EO, containing up to 93.31% oxygenated monoter…
Metropolitan wastewater analysis for COVID-19 epidemiological surveillance
The COVID-19 disease, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a rapidly emerging pandemic which has enforced extreme containment measures worldwide. In the absence of a vaccine or efficient treatment, cost-effective epidemiological surveillance strategies are urgently needed. Here, we have used RT-qPCR for SARS-CoV-2 detection in a series of longitudinal metropolitan wastewaters samples collected from February to April 2020, during the earliest stages of the epidemic in the Region of Valencia, Spain. We were able to consistently detect SARS-CoV-2 RNA in samples taken in late February, when communicated cases in that region were only incipient. We also find…
SARS-CoV-2 RNA in wastewater anticipated COVID-19 occurrence in a low prevalence area
Preprint disponible en http://hdl.handle.net/10261/209125
Monitoring Human Viral Pathogens Reveals Potential Hazard for Treated Wastewater Discharge or Reuse
Wastewater discharge to the environment or its reuse after sanitization poses a concern for public health given the risk of transmission of human viral diseases. However, estimating the viral infectivity along the wastewater cycle presents technical challenges and still remains underexplored. Recently, human-associated crAssphage has been investigated to serve as viral pathogen indicator to monitor fecal impacted water bodies, even though its assessment as biomarker for infectious enteric viruses has not been explored yet. To this end, the occurrence of potentially infectious norovirus genogroup I (GI), norovirus GII, hepatitis A virus (HAV), rotavirus A (RV), and human astrovirus (HAstV) a…
Experimental and CFD evaluation of ozone efficacy against coronavirus and enteric virus contamination on public transport surfaces
The limited information about the routes of the transmission of SARS-CoV-2 within the ongoing pandemic scenario mobilized the administration, industry and academy to develop sanitation and disinfection systems for public and private spaces. Ozone has been proposed as an effective disinfection method against enveloped and non-enveloped viruses, including viruses with similar morphology to SARS-CoV-2. Due to this efficacy, numerous gaseous and aqueous phase ozone applications have emerged potentially to inhibit virus persistence in aerosols, surfaces, and water. In this work, a numerical model, a RANS CFD model for ozone dispersion inside tram and underground coach has been developed includin…
Effect of (−)-epigallocatechin gallate at different pH conditions on enteric viruses.
Epigallocatechin gallate (EGCG), a flavonoid from green tea, is said to have extensive antimicrobial activity in a wide range of food spoilage or pathogenic fungi, yeast and bacteria. In this work, the antiviral activity of EGCG was assessed against hepatitis A virus (HAV) and murine norovirus (MNV), a human norovirus surrogate, at different temperatures, contact times and pH conditions by cell-culture methods. EGCG was effective in reducing the titers of HAV and MNV in a dose-dependent manner at neutral pH and 25 and 37 °C, while no effect was reported at 4 °C. HAV and MNV infectivity was completely removed after overnight treatment with EGCG at 2.5 mg/mL at 37 °C. Furthermore, results als…
Application of propidium monoazide quantitative PCR for selective detection of live Escherichia coli O157:H7 in vegetables after inactivation by essential oils.
The use of propidium monoazide (PMA) is enjoying increased popularity among researchers in different fields of microbiology. Its use in combination with real-time PCR (qPCR) represents one of the most successful approaches to detect viable cells. PMA-qPCR has successfully been used to evaluate the efficacy of various disinfection technologies in different microorganisms. Initially, in this study the effect of four essential oils (EOs), cumin, clove, oregano and cinnamon, was evaluated on suspensions of the enterohemorrhagic Escherichia coli O157:H7 by PMA-qPCR, LIVE/DEAD BacLight flow cytometry analysis (LIVE/DEAD-FCM), and plate count. E. coli O157:H7 cells treated with EOs at killing conc…
Bioactive extracts from persimmon waste: influence of extraction conditions and ripeness
In this work, a bioactive persimmon extract was produced from discarded fruits. A central composite design was used to evaluate the effect of different extraction parameters and ripeness stages of persimmon fruits on the total phenolic content and antioxidant activity of the resulting extracts. Significantly greater phenolic contents were obtained from immature persimmon (IP) fruits. The optimum IP extract with the conditions set by the experimental design was industrially up-scaled and its composition and functional properties were evaluated and compared with those obtained under lab-scale conditions. Both extracts contained significant protein (>20%) and phenolic contents (∼11–27 mg GA/g …
Evaluation of Zataria multiflora Boiss. essential oil activity against Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes by propidium monoazide quantitative PCR in vegetables
Essential oils (EOs) have long been applied as flavoring agents in foods, and due to their content in antimicrobial compounds, they have potential as natural agents for food preservation. Recently, real-time PCR in combination with PMA has successfully been applied to discriminate between live Escherichia coli O157:H7 and dead bacteria killed by cumin, clove, oregano and cinnamon EOs. In this study, initial experiments were performed in order to elucidate the minimum bactericidal concentration of Zataria multiflora EOs on E. coli O157:H7, Salmonella enterica and Listeria monocytogenes. Thereafter PMA-qPCR was applied in order to selectively quantify life cells within a bacterial population …
Comparing analytical methods to detect SARS-CoV-2 in wastewater
Wastewater based epidemiology (WBE) has emerged as a reliable strategy to assess the coronavirus disease 2019 (COVID-19) pandemic. Recent publications suggest that SARS-CoV-2 detection in wastewater is technically feasible; however, many different protocols are available and most of the methods applied have not been properly validated. To this end, different procedures to concentrate and extract inactivated SARS-CoV-2 and surrogates were initially evaluated. Urban wastewater seeded with gamma-irradiated SARS-CoV-2, porcine epidemic diarrhea virus (PEDV), and mengovirus (MgV) was used to test the concentration efficiency of an aluminum-based adsorption-precipitation method and a polyethylene…
Evaluation of silver-infused polylactide films for inactivation of Salmonella and feline calicivirus in vitro and on fresh-cut vegetables
There is a growing trend to develop packaging materials with an active role in guarantying that the quality and safety characteristics of packaged products will remain or improve from preparation throughout shelf-life. In the present study, 0.001-1.0 wt.% silver ions were satisfactorily incorporated into polylactide (PLA) films by a solvent casting technique. Silver migration from the films was measured by voltamperometry and then correlated with its antimicrobial efficacy against Salmonella enterica and feline calicivirus (FCV), a human norovirus surrogate, by using the Japanese industrial standard (JIS Z 2801). The PLA-silver films showed strong antibacterial and antiviral activity in vit…
A single method for recovery and concentration of enteric viruses and bacteria from fresh-cut vegetables
Fresh-cut vegetables are prone to be contaminated with foodborne pathogens during growth, harvest, transport and further processing and handling. As most of these products are generally eaten raw or mildly treated, there is an increase in the number of outbreaks caused by viruses and bacteria associated with fresh vegetables. Foodborne pathogens are usually present at very low levels and have to be concentrated (i.e. viruses) or enriched (i.e. bacteria) to enhance their detection. With this aim, a rapid concentration method has been developed for the simultaneous recovery of hepatitis A virus (HAV), norovirus (NV), murine norovirus (MNV) as a surrogate for NV, Escherichia coli O157:H7, List…
Platinum chloride-based viability RT-qPCR for SARS-CoV-2 detection in complex samples.
Isolation, contact tracing and restrictions on social movement are being globally implemented to prevent and control onward spread of SARS-CoV-2, even though the infection risk modelled on RNA detection by RT-qPCR remains biased as viral shedding and infectivity are not discerned. Thus, we aimed to develop a rapid viability RT-qPCR procedure to infer SARS-CoV-2 infectivity in clinical specimens and environmental samples. We screened monoazide dyes and platinum compounds as viability molecular markers on five SARS-CoV-2 RNA targets. A platinum chloride-based viability RT-qPCR was then optimized using genomic RNA, and inactivated SARS-CoV-2 particles inoculated in buffer, stool, and urine. Ou…
Viability RT-PCR for SARS-CoV-2: a step forward to solve the infectivity quandary
Background Isolation, contact tracing and restrictions on social movement are being globally implemented to prevent and control onward spread of SARS-CoV-2, even though the infection risk modelled on RNA detection by RT-qPCR remains biased as viral shedding and infectivity are not discerned. Thus, we aimed to develop a rapid viability RT-qPCR procedure to infer SARS-CoV-2 infectivity in clinical specimens and environmental samples. Methods We screened monoazide dyes and platinum compounds as viability molecular markers on five SARS-CoV-2 RNA targets. A platinum chloride-based viability RT-qPCR was then optimized using genomic RNA, and inactivated SARS-CoV-2 particles inoculated in buffer, s…
Antibacterial performance of solvent cast polycaprolactone (PCL) films containing essential oils
Abstract The increase of consumer demand for higher quality and longer shelf-life in foods, while reducing the use of non-compostable packaging materials, has encouraged research on biopolymers incorporating natural antimicrobial compounds. Cinnamaldehyde (CNMA) and allyl isothiocyanate (AITC) were incorporated into polycaprolactone (PCL) films by solvent casting. The release study was carried out by means of ATR and transmission FTIR spectroscopy and showed high volatility of the essential oils during the film forming process. While only negligible quantities of AITC were retained in the polymer matrix after film curing, the release of CNMA was prolonged for at least 50 h at room temperatu…
Norovirus: The Burden of the Unknown
Human noroviruses (HNoVs) are primarily transmitted by the fecal-oral route, either by person-to-person contact, or by ingestion of contaminated food or water as well as by aerosolization. Moreover, HNoVs significantly contribute to foodborne diseases being the causative agent of one-fifth of acute gastroenteritis worldwide. As a consequence of globalization, transnational outbreaks of foodborne infections are reported with increasing frequency. Therefore, in this review, state-of-the-art information regarding molecular procedures for human norovirus detection in food as well common food processing technologies have been summarized. Besides, the purpose of this chapter is to consolidate bas…
Evaluation of yogurt and various beverages as carriers of lactic acid bacteria producing 2-branched (1,3)-β-D-glucan
8 páginas, 2 figuras, 2 tablas -- PAGS nros. 3271-3278
The effect of essential oils on norovirus surrogates
Abstract Essential oils (EOs) have long been applied as flavoring agents in foods, and due to their content in antimicrobial compounds, they have potential as natural agents for food preservation. In this study the effect of three EOs, clove, oregano and zataria, was evaluated on the infectivity of norovirus surrogates, i.e. feline calicivirus (FCV) and murine norovirus (MNV). Different concentrations of EOs were individually mixed with each virus at titers of ca. 7–8 log TCID 50 /ml and incubated for 2 h at 4 °C and 37 °C. The infectivity of the recovered viruses after triplicate treatments was evaluated by cell-culture assays. 2% of oregano EO at 37 °C decreased the FCV titers by 3.75 log…
Antiviral activity of alginate-oleic acid based coatings incorporating green tea extract on strawberries and raspberries
Foodborne illnesses caused by the consumption of berries contaminated with human enteric viruses, namely human noroviruses (NoVs) and the hepatitis A virus (HAV), remain a significant food safety concern. The objective of this research was to investigate a food-grade edible coating composed of alginate/oleic and containing green tea extract (GTE) as an antiviral agent for the preservation of fresh strawberries and raspberries. Berries were stored at ambient (25 °C) temperature and refrigerated (10 °C) conditions. Initially, the effect of the pH of the film-forming dispersions (FFD) on their antioxidant and antiviral activity was analysed. Then, the physicochemical properties of edible algin…
Early detection of SARS-CoV-2 infection cases or outbreaks at nursing homes by targeted wastewater tracking
Objectives Near-source tracking of SARS-CoV-2 RNA in the sewage drains serving particular buildings may allow rapid identification of SARS-CoV-2 infection cases or local outbreaks. In this pilot study, we investigated whether this was the case for nursing homes (NH). Methods The study involved five NH (from A to E) affiliated to the Clínico-Malvarrosa Health Department, Valencia (Spain). These were nursing or mixed nursing/care homes of different sizes, altogether providing care for 472 residents attended by a staff of 309. Near-source sewage samples were screened for presence of SARS-CoV-2 RNA by RT-qPCR at least 5 days per week during the study period. SARS-CoV-2 RNA testing in nasopharyn…
Polymers and Biopolymers with Antiviral Activity: Potential Applications for Improving Food Safety
Gastroenteritis and hepatitis, caused by human noroviruses (HuNoVs) and hepatitis A virus (HAV), respectively, are the most common illnesses resulting from the consumption of food contaminated with human enteric viruses. Food-grade polymers can be tailor designed to improve food safety, either as novel food-packaging materials imparting active antimicrobial properties, applied in food contact surfaces to avoid cross-contamination, or as edible coatings to increase fresh produce's shelf life. The incorporation of antimicrobial agents into food-grade polymers can be used to control the food microbiota and even target specific foodborne pathogens to improve microbiological food safety and to e…
Optimization of electrospraying conditions for the microencapsulation of probiotics and evaluation of their resistance during storage and in-vitro digestion
Electrospraying has recently emerged as a novel microencapsulation technique with potential for the protection of probiotics. However, research efforts are still needed to minimize the viability loss observed during the processing of sensitive strains, and to maximize productivity. The aim of the present work was the optimization of the electrospraying conditions for the microencapsulation of a model probiotic microorganism, Lactobacillus plantarum, within a whey protein concentrate matrix. In a pre-optimization step, the convenience of encapsulating fresh culture instead of freeze-dried bacteria was established. Additionally, a surface response methodology was used to study the effect of t…
Application of viability PCR to discriminate the infectivity of hepatitis A virus in food samples.
Abstract Transmitted through the fecal–oral route, the hepatitis A virus (HAV) is acquired primarily through close personal contact and foodborne transmission. HAV detection in food is mainly carried out by quantitative RT-PCR (RT-qPCR). The discrimination of infectious and inactivated viruses remains a key obstacle when using RT-qPCR to quantify enteric viruses in food samples. Initially, viability dyes, propidium monoazide (PMA) and ethidium monoazide (EMA), were evaluated for the detection and quantification of infectious HAV in lettuce wash water. Results showed that PMA combined with 0.5% Triton X-100 (Triton) was the best pretreatment to assess HAV infectivity and completely eliminate…
Hepatitis E virus in lettuce and water samples: A method-comparison study
The hepatitis E virus (HEV), which is an increasing cause of acute viral hepatitis in Europe, is a zoonotic virus that is mainly transmitted through contaminated water, consumption of raw or undercooked meat from pigs or wild boar, blood transfusion, and organ transplantation. Although the role of HEV transmission through contaminated produce has not been confirmed, the presence of HEV has been reported in irrigation waters and in vegetables. The present study used a World Health Organization (WHO) international standard and clinical samples to evaluate the performance characteristics of three RT-qPCR assays for detection and quantification of HEV. Two of the evaluated assays provided good …
Enhanced Accumulation of Betulinic Acid in Transgenic Hairy Roots of Senna obtusifolia Growing in the Sprinkle Bioreactor and Evaluation of Their Biological Properties in Various Biological Models.
Betulinic acid, which is found in transgenic roots of Senna obtusifolia (L.) H.S.Irwin & Barneby, is a pentacyclic triterpene with distinctive pharmacological activities. In this study, we report the differences in the content of betulinic acid and selected anthraquinones in transgenic S. obtusifolia hairy roots with overexpression of the PgSS1 gene (SOPSS2 line) and in transformed hairy roots without this genetic construct (SOA41 line). Both hairy root lines grew in 10 L sprinkle bioreactor. Additionally, the extracts obtained from this plant material were used for biological tests. Our results demonstrated that the SOPSS2 hairy root cultures from the bioreactor showed an increase in the c…
Effect of green tea extract on enteric viruses and its application as natural sanitizer
In this work, the effect of green tea extract (GTE) was assessed against murine norovirus (MNV) and hepatitis A virus (HAV) at different temperatures, exposure times and pH conditions. Initially, GTE at 0.5 and 5 mg/ml were individually mixed with each virus at 5 log TCID50/ml and incubated 2 h at 37 °C at different pHs (from 5.5 to 8.5). GTE affected both viruses depending on pH with higher reductions observed in alkaline conditions. Secondly, different concentrations of GTE (0.5 and 5 mg/ml) were mixed with viral suspensions and incubated for 2 or 16 h at 4, 25 and 37 °C at pH 7.2. A concentration-, temperature- and exposure time-dependent response was showed by GTE in suspension tests, w…
Hepatitis A infections from food.
Food contaminated by hepatitis A virus (HAV) is responsible of the 2–7% of all HAV outbreaks worldwide. This review provides a description of the HAV characteristics, its infectivity and epidemiological features. In addition, this review compiles existing original papers reporting HAV prevalence, viral titres in foodstuffs and the risk associated with food contamination. The purpose of this revision is to conduct a structured and systematic review of the published molecular procedures for HAV detection in food, including the assessment of its infectivity.
In-Depth Characterization of Bioactive Extracts from Posidonia oceanica Waste Biomass
© 2019 by the authors.
Spatial and temporal distribution of SARS-CoV-2 diversity circulating in wastewater
Wastewater-based epidemiology (WBE) has proven to be an effective tool for epidemiological surveillance of SARS-CoV-2 during the current COVID-19 pandemic. Furthermore, combining WBE together with high-throughput sequencing techniques can be useful for the analysis of SARS-CoV-2 viral diversity present in a given sample. The present study focuses on the genomic analysis of SARS-CoV-2 in 76 sewage samples collected during the three epidemiological waves that occurred in Spain from 14 wastewater treatment plants distributed throughout the country. The results obtained demonstrate that the metagenomic analysis of SARS-CoV-2 in wastewater allows the detection of mutations that define the B.1.1.…
Impact of molecular weight on the formation of electrosprayed chitosan microcapsules as delivery vehicles for bioactive compounds.
The molecular weight of chitosan is one of its most determinant characteristics, which affects its processability and its performance as a biomaterial. However, information about the effect of this parameter on the formation of electrosprayed chitosan microcapsules is scarce. In this work, the impact of chitosan molecular weight on its electrosprayability was studied and correlated with its effect on the viscosity, surface tension and electrical conductivity of solutions. A Discriminant Function Analysis revealed that the morphology of the electrosprayed chitosan materials could be correctly predicted using these three parameters for almost 85% of the samples. The suitability of using elect…
Application of propidium monoazide-qPCR to evaluate the ultrasonic inactivation of Escherichia coli O157:H7 in fresh-cut vegetable wash water.
The efficacy of sanitizing technologies in produce or in vegetable wash water is generally evaluated by plate count in selective media. This procedure is time consuming and can lead to misinterpretations because environmental conditions and sanitizing processes may affect bacterial growth or culturable capability. Thus, the aim of this study was to determine the applicability of a propidium monoazide real-time PCR (PMA-qPCR) method to monitor the inactivation by ultrasound treatment of foodborne bacteria in fresh-cut vegetable wash water. To this aim, lettuce wash water was artificially inoculated with Escherichia coli O157:H7 (10⁶ CFU/mL) and treated by means of a continuous ultrasonic irr…
Microbiological and ageing performance of polyhydroxyalkanoate-based multilayer structures of interest in food packaging
Polyhydroxyalkanoates undergo crystallization during film processing and storage. In this paper, the physico–chemical ageing properties of multilayer structures based on a commercial polyhydroxybutyrate (PHB) and a polyhydroxybutyrate-co-valerate copolymer with 3% valerate content (PHBV3), containing a nanostructured zein interlayer, were analysed. The microbiological safety of the films was also evaluated by monitoring the growth of an inoculum of Listeria monocytogenes over time. Polyethyleneglycol (PEG) was added to PHBV3 films to facilitate handling as the PHBV3 mutlilayer systems (without plasticizer) cracked during film-formation. Crystallinity, thermal, mechanical, barrier and optica…
Virucidal effect of high power ultrasound combined with a chemical sanitizer containing peroxyacetic acid for water reconditioning in the fresh-cut industry
The use of chlorine-based sanitizers is widespread throughout the fresh produce industry in the process water to maintain microbial safety of produce, avoid cross-contamination and recycle water. In this study, alternative disinfection technologies were investigated due to the negative reports showing chlorine instability in the presence of organic matter and the undesirable by-product residues. Tsunami ® (15.2% peroxyacetic acid and 11.2% hydrogen peroxide) and high-power ultrasound (HPU, 0.56 kW/l, 20 kHz), alone or in combination, were evaluated in lettuce process water analyzing their ability to reduce MNV during either produce washing or water recycling. PAA concentrations of 6.4, 12.8…
Potential Antioxidant and Antiviral Activities of Hydroethanolic Extracts of Selected Lamiaceae Species
Medicinal and aromatic plants (MAPs) are potential sources of natural bioactive phytochemical compounds of an incredible worth for the food industry, such as polyphenols. Lamiaceae medicinal and aromatic plants from Granada’s high plateau, concretely Origanum bastetanum, Thymus zygis gracilis, Thymus longiflorus, Thymus membranaceus and Ziziphora hispanica, were evaluated under different conventional solid–liquid extraction conditions to obtain extracts enriched in bioactive compounds. Phenolic profile was detected by HPLC-QTOF-MS, identifying a high abundance of bioactive constituents. Furthermore, antioxidant and antiviral activities of the mentioned plants were studied as biological prop…
Quantitative detection of viable foodborne E. coli O157:H7, Listeria monocytogenes and Salmonella in fresh-cut vegetables combining propidium monoazide and real-time PCR
Abstract The increase of foodborne outbreaks associated with fresh vegetables has highlighted the importance of developing rapid and specific methods for the detection and quantification of foodborne pathogens. In this sense, real-time PCR (qPCR) fulfills these requirements although it may detect dead cells. Recently, a potential strategy to specifically detect viable cells has been proposed relying on the use of DNA binding molecules as sample pretreatment previous to the qPCR. In this study propidium monoazide (PMA) and reagent D, combined with qPCR, were evaluated for the detection and quantification of viable Escherichia coli O157:H7, Salmonella and Listeria monocytogenes. Initially, th…
Antimicrobial Bilayer Nanocomposites Based on the Incorporation of As-Synthetized Hollow Zinc Oxide Nanotubes
© 2020 by the authors.
Assessment of ISO Method 15216 to Quantify Hepatitis E Virus in Bottled Water
Hepatitis E virus (HEV) is one of the causative agents of water-borne human viral hepatitis and considered in Europe an emerging zoonotic pathogen. Analysis of bottled water through a standard method validated for HEV can contribute towards the risk management of this hazard. Putting some recent reports by the European Food Safety Authority in place, this study aimed to assess the performance of the concentration and extraction procedures described in ISO 15216-1:2017 for norovirus and hepatitis A virus on HEV detection. Following the ISO recommendation, the bottled water samples were spiked using serially diluted HEV fecal suspensions together with mengovirus as process control and concent…
Rapid Selective Detection of Potentially Infectious Porcine Epidemic Diarrhea Coronavirus Exposed to Heat Treatments Using Viability RT-qPCR
Coronaviruses (CoVs) cause severe respiratory, enteric, and systemic infections in a wide range of hosts, including humans and animals. Porcine epidemic diarrhea virus (PEDV), a member of the Coronaviridae family, is the etiological agent of porcine epidemic diarrhea (PED), a highly contagious intestinal disease affecting pigs of all ages. In this study, we optimized a viability real-time reverse transcriptase polymerase chain reaction (RT-qPCR) for the selective detection of infectious and heat-inactivated PEDV. PEMAX™, EMA™, and PMAxx™ photoactivable dyes along with PtCl4 and CDDP platinum compounds were screened as viability markers using two RT-qPCR assays: firstly, on PEDV purified RNA…
Optimization of PMAxx pretreatment to distinguish between human norovirus with intact and altered capsids in shellfish and sewage samples
Shellfish contamination by human noroviruses (HuNoVs) is a serious health and economic problem. Recently an ISO procedure based on RT-qPCR for the quantitative detection of HuNoVs in shellfish has been issued, but these procedures cannot discriminate between inactivated and potentially infectious viruses. The aim of the present study was to optimize a pretreatment using PMAxx to better discriminate between intact and heat-treated HuNoVs in shellfish and sewage. To this end, the optimal conditions (30 min incubation with 100 μM of PMAxx and 0.5% of Triton, and double photoactivation) were applied to mussels, oysters and cockles artificially inoculated with thermally-inactivated (99 °C for 5 …
Effect of ultrasound technology combined with binary mixtures of ethanol and water on antibacterial and antiviral activities of Erodium glaucophyllum extracts
Abstract Erodium glaucophyllum is a common Mediterranean herb known for its health benefits. In this study, Erodium extracts obtained from different extraction methods (conventional vs ultrasound-assisted extraction) and extraction solvents (aqueous and hydroethanolic) were evaluated in microbiological media to determine their effects on bacteria (Salmonella enterica, Staphylococcus aureus, Listeria innocua, Bifidobacterium lactis and Lactobacillus casei) and antiviral activity (hepatitis A virus and murine norovirus). Both, the extraction method and solvent were found to be important contributing factors. Ultrasound-assisted extraction yielded the highest level of desirable Erodium-extract…
Antiviral activity of aged green tea extract in model food systems and under gastric conditions.
Aged-green tea extract (GTE) is known to reduce the infectivity of hepatitis A virus (HAV) and murine norovirus (MNV), a human norovirus surrogate, in vitro and in washing solutions. Initially, the effect of aged-GTE was evaluated on virus like particles (VLPs) of human norovirus (HuNoV) genogroup I (GI) by a porcine gastric mucine (PGM)-enzyme-linked immunosorbent assay (ELISA) and transmission electron microscopy (TEM), and on HuNoV GI suspensions by an in situ capture-RT-qPCR method, suggesting that HuNoVs are very sensitive to aged-GTE treatment at 37 °C. Moreover, the potential application of aged-GTE was evaluated using model foods and simulated gastric conditions. Then, aged-GTE samp…
Recovering coronavirus from large volumes of water
The need for monitoring tools to better control the ongoing coronavirus disease (COVID-19) pandemic is extremely urgent and the contamination of water resources by excreted viral particles poses alarming questions to be answered. As a first step to overcome technical limitations in monitoring SARS-CoV-2 along the water cycle, we assessed the analytical performance of a dead end hollow fiber ultrafiltration coupled to different options for secondary concentrations to concentrate viral particles from large volume of spiked tap water, seawater and surface water together with two quantitative RT-qPCR detection kits. Spiking the porcine epidemic diarrhea virus (PEDV), an enveloped virus surrogat…
Discrimination of non-infectious SARS-CoV-2 particles from fomites by viability RT-qPCR.
The ongoing coronavirus 2019 (COVID-19) pandemic constitutes a concerning global threat to public health and economy. In the midst of this pandemic scenario, the role of environment-to-human COVID-19 spread is still a matter of debate because mixed results have been reported concerning SARS-CoV-2 stability on high-touch surfaces in real-life scenarios. Up to now, no alternative and accessible procedures for cell culture have been applied to evaluate SARS-CoV-2 infectivity on fomites. Several strategies based on viral capsid integrity have latterly been developed using viability markers to selectively remove false-positive qPCR signals resulting from free nucleic acids and damaged viruses. T…
Chitosan films for the microbiological preservation of refrigerated sole and hake fillets
The effect of chitosan films for shelf-life extension of fresh fillets of hake (Merluccius merluccius) and sole (Solea solea) was evaluated over a 15-day storage at 4 ± 1 °C. Fish fillets wrapped in a chitosan matrix were individually packaged in air (AP) and under vacuum (VP). Microbiological analyses (total aerobic mesophilic bacteria, Pseudomonas, H2S-producing bacteria, lactic acid bacteria, Enterobacteriaceae and Listeria monocytogenes were carried out during the shelf-life. The microbial species were inhibited (p < 0.05) by the presence of chitosan films, especially under VP conditions. A significant (p < 0.05) increase of the lag phase and a reduction of the final microbial populatio…
Secondary Education Students’ Questions on Experimental Devices
Las preguntas forman parte esencial del trabajo que desarrollan los científicos para construir nuevo conocimiento. Sin embargo, los alumnos formulan un número muy escaso de preguntas en las situaciones usuales de aula. En este trabajo se realiza una revisión de las investigaciones realizadas sobre génesis de preguntas y se describen tres estudios empíricos realizados con estudiantes de diferentes niveles educativos ante dispositivos experimentales. Los objetivos fueron: 1) Estimular y analizar las preguntas de los estudiantes cuando intentan comprender los dispositivos; 2) Contrastar la idea de que la mayoría de preguntas destinadas a obtener información tienen su origen en inferencias fall…
On the different growth conditions affecting silver antimicrobial efficacy on Listeria monocytogenes and Salmonella enterica.
Abstract Silver is known to inhibit microorganisms and therefore it is an ideal candidate for its incorporation in a wide variety of materials for food applications. However, there is still a need for understanding how silver prolonged exposure to bacterial contamination affects the bioavailability of the active silver species. In the present study, growth curves of Listeria monocytogenes and Salmonella enterica were performed for 3–5 days in Tryptic Soy Broth (TSB) and M9 minimal medium (M9) in the presence of silver ions and silver solutions previously in contact with the growth media. The cultivability of the bacteria under these conditions was correlated with the viability of the bacter…
Improving efficiency of viability-qPCR for selective detection of infectious HAV in food and water samples.
Aim: To improve the efficacy of intercalating dyes to distinguishing between infectious and inactivated hepatitis A virus (HAV) in food. Methods and Results: Different intercalating dyes were evaluated for the discrimination between infectious and thermally inactivated HAV suspensions combining with the RT‐qPCR proposed in the ISO 15216. Among them, PMAxx was the best dye in removing the RT‐qPCR signal from inactivated HAV. Applied to lettuce and spinach, PMAxx–Triton pretreatment resulted in complete removal of the RT‐qPCR signal from inactivated HAV. Likewise, this study demonstrates that this pretreatment is suitable for the discrimination of inactivated HAV in shellfish without further …
Evaluation of a Real-Time PCR Assay for the Detection and Quantification of Group Spores in Food
A procedure based on quantitative real-time PCR was evaluated for the detection and quantification of Bacillus cereus spores. Several methods for DNA isolation, such as various heat treatments and germination solutions, were evaluated on spore suspensions of representative strains of the B. cereus group. Overall, the commercially available DNeasy tissue kit yielded the maximum amount of DNA. The procedure also was used to construct calibration curves for different food matrices, with a wide spore quantification range of 5 log units using serial dilutions of spore suspensions of B. cereus CECT 148T. The detection limit for B. cereus in artificially contaminated liquid egg and reconstituted i…
Occurrence of enteric viruses in reclaimed and surface irrigation water: relationship with microbiological and physicochemical indicators.
Aims To assess the prevalence of enteric viruses in different irrigation water sources and in the irrigated produce, and the possible links with microbiological and physicochemical water characteristics. Methods and results The prevalence and levels of Escherichia coli, Norovirus (NoV) genogroup I (GI) and II (GII), as well as Hepatitis A virus were assessed in three types of water: surface water (surface-W), reclaimed water subjected to secondary treatment (secondary-W) and reclaimed water subjected to tertiary treatment (tertiary-W), as well as in zucchini irrigated with these irrigation water sources. Chemical oxygen demand (COD), turbidity, total suspended solids, alkalinity, and maximu…
Ligands affecting silver antimicrobial efficacy on Listeria monocytogenes and Salmonella enterica
Although silver is being extensively used in food or other applications as the key component to control microbial proliferation, many factors affecting its real potential are still unknown. In the present work, the presence of specific ligands or the contents in organic matter was correlated with silver speciation and its antibacterial performance. Silver was found to be only active in form of free silver ions (FSI). The presence of chloride ions produced an equilibrium of stable silver chloride complexes which were void of antimicrobial efficacy. However, even at relatively high concentrations of chlorides, a small fraction of FSI may still be present, producing a bactericidal effect with …
Viability RT-qPCR to detect potentially infectious enteric viruses on heat-processed berries
Berries have frequently been cited as causing gastroenteritis and acute hepatitis outbreaks due to enteric virus contamination, including human norovirus and hepatitis A virus (HAV). Model experiments were performed to evaluate the potential use of viability RT-qPCR to assess the thermal inactivation of norovirus genotype I (GI), GII, and HAV on raspberries, blueberries and strawberries. Initially, two viability markers, platinum chloride and propidium monoazide (PMAxx™), were compared using thermally inactivated norovirus GI and GII suspensions. The results showed better performance of PMAxx™ pretreatment in discriminating native and inactivated viruses. Thus, the pretreatment was optimize…
Nanostructuring Biopolymers for Improved Food Quality and Safety
Abstract Food-grade biopolymers, apart from their inherent nutritional properties, can be tailored designed for improving food quality and safety, either serving as delivery vehicles for bioactive molecules, or as novel packaging components, not only improving the transport properties of biobased packaging structures, but also imparting active antibacterial and antiviral properties. In this chapter, the potential of different food-grade biopolymers (mainly proteins and carbohydrates but also some biopolyesters) to serve as encapsulating matrices for the protection of sensitive bioactives or as nanostructured packaging layers to improve transport properties and control the growth of pathogen…
Active properties of edible marine polysaccharide-based coatings containing Larrea nitida polyphenols enriched extract.
The aim of this work was to develop active edible coatings based on marine polysaccharide matrices and polyphenols-enriched native plant extracts from arid and semiarid regions of Argentina. Initially, five plant extracts were characterized in terms of antioxidant, antibacterial and antiviral activity and the one with better biological properties and no toxicity or genotoxicity, Larrea nitida (Ln) extract, was incorporated into agar, alginate or agar/alginate matrices. The Ln extract-containing films were characterized in terms of physicochemical and polyphenols release performance in food simulants. The incorporation of Ln extract provided darker films, with a more saturated orange-brownis…