Absence of Toxoplasma gondii in 100% Iberian products from experimentally infected pigs cured following a specific traditional process.
una A Abstract Infection with Toxoplasma gondii in humans has usually been related to the consumption of raw, undercooked or cured meat. Our study is based on the detection of T. gondii in cured legs and shoulders made from 100% Iberian sows fed mainly with acorn and raised as outdoor livestock in Aracena (Spain), which having been elaborated following a specific curing process (time period and location). An outdoor farm with a total of 636 animals was studied, showing a seroprevalence of 10% for the parasite T. gondii. Twenty individuals were chosen to be experimentally infected and slaughtered 60 days post-infec...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Gomez-Samblas M, Vilchez S, Ortega-Velázquez R, Fuentes MV, Osuna A Tags: Food Microbiol Source Type: research

Computational modelling of survival of Aspergillus flavus in peanut kernels during hot air-assisted radio frequency pasteurization.
In this study, a computer model based on Joule heating and thermal inactivation kinetic of A. flavus was established to predict both temperature distribution and microbial reduction among peanut kernels after RF processing. For the process validation, three 2-g peanut samples inoculated with 40 μL A. flavus were placed at three representative locations among 2.17 kg peanut kernels and subjected to various processing conditions in a 27.12 MHz, 6 kW RF heating unit together with hot air system. Results showed that the average difference of the sample temperature and microbial reduction between simulati...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Zhang S, Lan R, Zhang L, Wang S Tags: Food Microbiol Source Type: research

A dynamic and integrated in vitro/ex vivo gastrointestinal model for the evaluation of the probability and severity of infection in humans by Salmonella spp. vehiculated in different matrices.
aacute;ndez-Iturriaga M Abstract The lack of proper gastrointestinal models assessing the inter-strain virulence variability of foodborne pathogens and the effect of the vehicle (food matrix) affects the risk estimation. This research aimed to propose a dynamic and integrated in vitro/ex vivo gastrointestinal model to evaluate the probability and severity of infection of foodborne pathogens at different matrices. An everted gut sac was used to determine the adhesion and invasion of Salmonella enterica and tissue damage. S. Typhimurium ATCC 14028 was used as a representative bacterium, and two matrices (water and c...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Godínez-Oviedo A, Cuellar-Núñez ML, Luzardo-Ocampo I, Campos-Vega R, Hernández-Iturriaga M Tags: Food Microbiol Source Type: research

Evaluation of a new culture medium for the enumeration and isolation of Streptococcus salivarius  subsp. thermophilus from cheese.
We describe medium SPY9.3 for the cultivation of S. salivarius subsp. thermophilus from cheese. The medium and related incubation conditions (SPY) was compared with 2 other protocols, M17 and ST: sensitivity was assessed by parallel cultivation of 55 strains of S. salivarius subsp. thermophilus, and selectivity by (i) parallel cultivation of 60 strains belonging to 20 different non-target species and sub-species and (ii) isolating bacteria from 3 raw-milk cheeses. Colony counts were similar on SPY9.3 and M17 (mean difference 0.07 log(cfu/mL), p > 0.001) and significantly higher on ST than on M17 and SPY9.3 (me...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Shani N, Isolini D, Marzohl D, Berthoud H Tags: Food Microbiol Source Type: research

Value-added switchgrass extractives for reduction of Escherichia coli O157:H7 and Salmonella Typhimurium populations on Formica coupons.
za DH Abstract Recurring outbreaks linked to Escherichia coli O157:H7-contaminated lettuce and Salmonella enterica-contaminated sprouts highlight the need for improved food safety measures. The aim of this study was to determine the ability of a bio-based antimicrobial extract prepared from switchgrass, a dedicated energy crop, to reduce E. coli O157:H7 and S. Typhimurium populations on Formica coupons, a model food-contact surface. Overnight cultures of ~7 log CFU/mL E. coli O157:H7 and S. Typhimurium, air-dried on Formica coupons were treated with 0.625% NaClO, 70% ethanol, sterile water or different batches of ...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Choi JM, Camfield E, Bowman A, Rajan K, Labbé N, Gwinn KD, Ownley BH, Moustaid-Moussa N, D'Souza DH Tags: Food Microbiol Source Type: research

Acinetobacter spp. in food and drinking water - A review.
Abstract Acinetobacter spp. has emerged as a pathogen of major public health concern due to their increased resistance to antibiotics and their association with a wide range of nosocomial infections, community-acquired infections and war and natural disaster-related infections. It is recognized as a ubiquitous organism however, information about the prevalence of different pathogenic species of this genus in food sources and drinking water is scarce. Since the implementation of molecular techniques, the role of foods as a source of several species, including the Acinetobacter baumannii group, has been elucidated. ...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Carvalheira A, Silva J, Teixeira P Tags: Food Microbiol Source Type: research

Synergistic bactericidal effect of hot water with citric acid against Escherichia coli O157:H7 biofilm formed on stainless steel.
This study investigated the antimicrobial effect of hot water with citric acid against Escherichia coli O157:H7 biofilm on stainless steel (SS). Hot water (50, 60, or 70 °C) with 2% citric acid exhibited a synergistic bactericidal effect on the pathogen biofilm. It was revealed that hot water and citric acid combination induced sub-lethally injured cells. Additionally, mechanisms of the synergistic bactericidal effects of hot water with citric acid were identified through several approaches. In terms of biofilm matrix, hot water removes exopolysaccharides, a major component of extracellular polymeric substances (E...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Kang JW, Lee HY, Kang DH Tags: Food Microbiol Source Type: research

Salmonella inactivation and sponge/microfiber mediated cross-contamination during papaya wash with chlorine or peracetic acid as sanitizer.
In this study, Salmonella inactivation and cross-contamination via sponges and microfiber wash mitts during simulated papaya washing and cleaning were investigated. Seven washing treatments (wash without sanitizer; wash at free chlorine 25, 50, and 100 mg/L, and at peracetic acid 20, 40, and 80 mg/L), along with unwashed control, were evaluated, using Salmonella strains with unique antibiotic markers differentially inoculated on papaya rind (serovars Typhimurium, Heidelberg, and Derby) and on wash sponge or microfiber (serovars Typhimurium, Newport, and Braenderup). Salmonella survival and transfer on papaya and ...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Gu G, Bolten S, Mendes-Oliveira G, Zhou B, Teng Z, Pearlstein D, Luo Y, Millner P, Nou X Tags: Food Microbiol Source Type: research

Prior exposure to different combinations of pH and undissociated acetic acid can affect the induced resistance of Salmonella spp. strains in mayonnaise stored under refrigeration and the regulation of acid-resistance related genes.
In conclusion, strain variations in Salmonella are extensive. The ability of the strains to adapt and induce resistant phenotypes and acid resistance-related genes is affected by the type and magnitude of the stress applied during adaptation. PMID: 33397612 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Gavriil A, Paramithiotis S, Skordaki A, Tsiripov E, Papaioannou A, Skandamis PN Tags: Food Microbiol Source Type: research

Use of Hanseniaspora guilliermondii and Hanseniaspora opuntiae to enhance the aromatic profile of beer in mixed-culture fermentation with Saccharomyces cerevisiae.
In this study, 17 non-Saccharomyces strains of 12 distinct species were isolated and submitted to a preliminary sensory evaluation to determine their potential for beer bioflavouring. Hanseniaspora guilliermondii IST315 and H. opuntiae IST408 aroma profiles presented the highest acceptability and were described as having 'fruity' and 'toffee' notes, respectively. Their presence in mixed-culture fermentations with S. cerevisiae US-05 did not influence attenuation and ethanol concentration of beer but had a significant impact in its volatile composition. Notably, while both strains reduced the total amount of ethyl esters, H...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Bourbon-Melo N, Palma M, Rocha MP, Ferreira A, Bronze MR, Elias H, Sá-Correia I Tags: Food Microbiol Source Type: research

Development and optimization of a loop-mediated isothermal amplification (LAMP) assay for the species-specific detection of Penicillium expansum.
Abstract Penicillium expansum is the main cause of Blue Mold Decay, which is the economically most significant postharvest disease on fruits. It occurs especially on pomaceous fruits such as apples and pears but also on a wide range of other fruits such as grapes or strawberries. Besides its negative economic effects on the industry, the fungus is also of health concern as it produces patulin, a mycotoxin known to provoke harmful effects in humans. A specific and rapid detection of this fungus therefore is required. In the current study, a loop-mediated isothermal amplification (LAMP) assay was developed and optim...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Frisch LM, Mann MA, Marek DN, Niessen L Tags: Food Microbiol Source Type: research

Application of bioactive glycolipids to control Listeria monocytogenes biofilms and as post-lethality contaminants in milk and cheese.
This study aimed to determine the antimicrobial activity of glycolipids to control L. monocytogenes biofilms as well as in milk and on Queso Fresco. Application of a natural glycolipid product significantly reduced biofilm-associated L. monocytogenes on both polystyrene and stainless steel at concentrations as low as 45 mg/L. When added to UHT skim milk, a concentration of 1000 mg/L inhibited L. monocytogenes growth through 7 days of storage at 7 °C, and application of 1300 and 1500 mg/L reduced counts to levels below the limit of enumeration at day 21. In contrast, 2000 mg/L were necessary to ...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Sun L, Forauer EC, Brown SRB, D'Amico DJ Tags: Food Microbiol Source Type: research

Metabolic network of ammonium in cereal vinegar solid-state fermentation and its response to acid stress.
Abstract Shanxi aged vinegar (SAV), a Chinese traditional vinegar, is produced by various microorganisms. Ammonium is an important nitrogen source for microorganisms and a key intermediate for the utilization of non-ammonium nitrogen sources. In this work, an ammonium metabolic network during SAV fermentation was constructed through the meta-transcriptomic analysis of in situ samples, and the potential mechanism of acid affecting ammonium metabolism was revealed. The results showed that ammonium was enriched as the acidity increased. Meta-transcriptomic analysis showed that the conversion of glutamine to ammonia i...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Sankuan X, Cuimei Z, Bingqian F, Yu Z, Menglei X, Linna T, Jia S, Xinyi Z, Min W Tags: Food Microbiol Source Type: research

Comparative genomics of Clostridium species associated with vacuum-packed meat spoilage.
Abstract Bacterial species belonging to the genus Clostridium have been recognized as causative agents of blown pack spoilage (BPS) in vacuum packed meat products. Whole-genome sequencing of six New Zealand psychrotolerant clostridia isolates derived from three meat production animal types and their environments was performed to examine their roles in BPS. Comparative genome analyses have provided insight into the genomic diversity and physiology of these bacteria and divides clostridia into two separate species clusters. BPS-associated clostridia encode a large and diverse spectrum of degradative carbohydrate-act...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Palevich N, Palevich FP, Maclean PH, Altermann E, Gardner A, Burgess S, Mills J, Brightwell G Tags: Food Microbiol Source Type: research

The impact of key processing stages and flock variables on the prevalence and levels of Campylobacter on broiler carcasses.
This study examined the impact of key processing stages and flock variables on the prevalence of Campylobacter on broiler carcasses. Overall, the prevalence of Campylobacter was 62% in caeca, and 68%, 65% and 62% in neck skin samples collected after evisceration, final wash and carcass chilling, respectively. Campylobacter were found in 32% of caeca, and 52%, 40% and 32% of neck skin samples collected after evisceration, final wash and carcass chilling, respectively from first thin broiler batches. Final thin broiler batches were more frequently contaminated with prevalences of 83% found in caeca, 80% in neck skin samples ...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Emanowicz M, Meade J, Bolton D, Golden O, Gutierrez M, Byrne W, Egan J, Lynch H, O'Connor L, Coffey A, Lucey B, Whyte P Tags: Food Microbiol Source Type: research

Regulation of secondary metabolite biosynthesis in Monascus purpureus via cofactor metabolic engineering strategies.
This study investigated the effects of cofactor metabolism on secondary metabolite production in M. purpureus through the application of different cofactor engineering strategies. Total pigment production dramatically increased by 39.08% and 40.89%, and yellow pigment production increased by 74.62% and 114.06% after the addition of 1.0 mg/L of the exogenous cofactor reagents methyl viologen and rotenone, respectively, in submerged batch-fermentation. The extracellular red pigment tone changed to yellow with the application of electrolytic stimulation at 800 mV/cm2, but almost no citrinin production was detected. ...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Liu J, Wu J, Cai X, Zhang S, Liang Y, Lin Q Tags: Food Microbiol Source Type: research

Assessment of microbial risk during Australian industrial practices for Escherichia coli O157:H7 in fresh cut-cos lettuce: A stochastic quantitative approach.
Abstract Escherichia coli O157:H7 risk associated with the consumption of fresh cut-cos lettuce during Australian industrial practices was assessed. A probabilistic risk assessment model was developed and implemented in the @Risk software by using the Monte Carlo simulation technique with 1,000,000 iterations. Australian preharvest practices yielded predicted annual mean E. coli O157:H7 levels from 0.2 to -3.4 log CFU/g and prevalence values ranged from 2 to 6.4%. While exclusion of solar radiation from the baseline model yielded a significant increase in concentration of E. coli O157:H7 (-5.2 -log fold), drip irr...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Bozkurt H, Bell T, van Ogtrop F, Phan-Thien KY, McConchie R Tags: Food Microbiol Source Type: research

Intestinal parasites among food handlers in Iran: A systematic review and meta-analysis.
Abstract Regarding preparing and serving foods, food handlers have an influential role in the spreading of foodborne infections. Due to the great potential to cause foodborne infections, intestinal parasites (IPs) are considered a significant public health problem in today's societies. In Iran, despite several regional reports, national data on IPs prevalence in food handlers are lacking. The aim of the present study, therefore, is to estimate the pooled prevalence of IPs infections and associated pooled odds ratio of educational level among food handlers in Iran. PubMed, Web of Science, Scopus, Embase, and Google...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Teimouri A, Keshavarz H, Mohtasebi S, Goudarzi F, Mikaeili F, Borjian A, Allahmoradi M, Yimam Y, Abbaszadeh Afshar MJ Tags: Food Microbiol Source Type: research

Zoonotic parasitic organisms on vegetables: Impact of production system characteristics on presence, prevalence on vegetables in northwestern Iran and washing methods for removal.
This study aimed to determine the prevalence of zoonotic parasites on vegetables freshly harvested and "ready to eat" vegetables from greengrocers and markets in northwestern Iran. In addition, the effect of cropping system and season on contamination levels were assessed as well as the efficacy of washing procedures to remove parasites from the vegetables. A total of 2757 samples composed of field (n = 1, 600) and "ready to eat" (n = 1157) vegetables were analyzed. Vegetables included leek, parsley, basil, coriander, savory, mint, lettuce, cabbage, radish, dill, spinach, mushroom, c...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Hajipour N, Soltani M, Ketzis J, Hassanzadeh P Tags: Food Microbiol Source Type: research

Impact of DNA extraction and sampling methods on bacterial communities monitored by 16S rDNA metabarcoding in cold-smoked salmon and processing plant surfaces.
This study confirmed the importance of methodology standardization and the need for analytical validation before 16S rDNA metabarcoding surveys. PMID: 33397623 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Maillet A, Bouju-Albert A, Roblin S, Vaissié P, Leuillet S, Dousset X, Jaffrès E, Combrisson J, Prévost H Tags: Food Microbiol Source Type: research

Stress resistance associated with multi-host transmission and enhanced biofilm formation at 42  °C among hyper-aerotolerant generalist Campylobacter jejuni.
Stress resistance associated with multi-host transmission and enhanced biofilm formation at 42 °C among hyper-aerotolerant generalist Campylobacter jejuni. Food Microbiol. 2021 May;95:103706 Authors: Mouftah SF, Cobo-Díaz JF, Álvarez-Ordóñez A, Mousa A, Calland JK, Pascoe B, Sheppard SK, Elhadidy M Abstract One of the emerging conundrums of Campylobacter food-borne illness is the bacterial ability to survive stressful environmental conditions. We evaluated the heterogeneity among 90 C. jejuni and 21 C. coli isolates from different sources in Egypt with respect to b...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Mouftah SF, Cobo-Díaz JF, Álvarez-Ordóñez A, Mousa A, Calland JK, Pascoe B, Sheppard SK, Elhadidy M Tags: Food Microbiol Source Type: research

Effect of water activity on inactivation of Listeria monocytogenes using gaseous chlorine dioxide - A kinetic analysis.
Abstract The aim of this study was to investigate the effect of water activity (aw) on inactivation of Listeria monocytogenes using gaseous chlorine dioxide (ClO2 (g)) under room temperature. Surface-inoculated tryptic soy agar (TSA) plates adjusted to 9 different water activity levels ranging from 0.994 to 0.429 were used as samples exposed to ClO2 (g) at 150, 250, and 350 ppm for different durations of treatment time. Results showed that the antimicrobial effect of ClO2 (g) significantly decreases as the aw level and ClO2 (g) concentration decrease. Nonlinear models, such as the modified Chick model and the...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Park HW, Chen G, Hwang CA, Huang L Tags: Food Microbiol Source Type: research

Exploring the potential of foodborne transmission of respiratory viruses.
Abstract The ongoing pandemic involving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has raised the question whether this virus, which is known to be spread primarily though respiratory droplets, could be spread through the fecal-oral route or via contaminated food. In this article, we present a critical review of the literature exploring the potential foodborne transmission of several respiratory viruses including human coronaviruses, avian influenza virus (AVI), parainfluenza viruses, human respiratory syncytial virus, adenoviruses, rhinoviruses, and Nipah virus. Multiple lines of evidence, inclu...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: O'Brien B, Goodridge L, Ronholm J, Nasheri N Tags: Food Microbiol Source Type: research

Comparative transcriptome analysis reveals the key regulatory genes for higher alcohol formation by yeast at different α-amino nitrogen concentrations.
This study provided knowledge about the metabolic pathways of higher alcohols and gave an important reference for the breeding of S. cerevisiae with low-yield higher alcohols to deal with the fermentation system with different α-AN concentrations in the brewing industry. PMID: 33397627 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Wang YP, Sun ZG, Zhang CY, Zhang QZ, Guo XW, Xiao DG Tags: Food Microbiol Source Type: research

Spoilage potential of Bacillus subtilis in a neutral-pH dairy dessert.
The objective of this study was the characterization of the microbiota associated with spoilage of vanilla cream pudding during storage at different temperatures. Commercial cream samples were stored aerobically at 4, 8, 12 and 15 °C for a maximum time period of 40 days. At appropriate time intervals, cream samples were subjected to: (i) microbiological analyses, and (ii) high-performance liquid chromatography (HPLC). Furthermore, the spoilage microbiota was identified through repetitive extragenic palindrome-PCR, while selected isolates were further characterized based on sequencing of the V1-V3 region of the 16S...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Moschonas G, Lianou A, Nychas GE, Panagou EZ Tags: Food Microbiol Source Type: research

Acid tolerance response of Salmonella during simulated chilled beef storage and its regulatory mechanism based on the PhoP/Q system.
Abstract To investigate the persistence of acid tolerance response (ATR) and the regulatory mechanism during chilled storage, Salmonella ATCC 14028 and the △phoP mutant were acid adapted and then incubated in meat extract at 4 °C for 24 days as simulated beef storage. The bacterial population, D values and expression of PhoP/PhoQ linked genes of both strains were determined at 6-day intervals. Although a mild suppression effect on the D values of adapted Salmonella was found during the long-time storage in meat extract at 4 °C, the D value of adapted strains was significantly higher than non-ad...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Lang C, Zhang Y, Mao Y, Yang X, Wang X, Luo X, Dong P, Zhu L Tags: Food Microbiol Source Type: research

The effect of four alternative chilling regimes on the bacterial load on beef carcasses.
The objective of this study was to compare the effect of current (10 °C for 10 h followed by 0 °C with a low fan speed) versus four alternative beef carcass chilling regimes, ranging from -6 °C to 0 °C and wind speeds between 1.5 and 6 m/s on the microbiology of beef carcasses. The temperature and relative humidity (RH) in the chillers, the carcass core and surface temperature, pH, water activity (aw) and carcass weight (drip) loss were recorded. Bacterial concentrations (total viable counts (TVC), total Enterobacteriaceae counts (TEC), Pseudomonas spp., lactic acid bacteria (L...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: McSharry S, Koolman L, Whyte P, Bolton D Tags: Food Microbiol Source Type: research

Viability of bacterial spores surviving heat-treatment is lost by further incubation at temperature and pH not suitable for growth.
ert O Abstract Spores from 21 strains from different genera were heat-treated and stored in different sets of process conditions (4 temperatures and 3 pH levels) defined to prevent growth. In these conditions, spores surviving the heat treatment progressively lost viability during storage. Different inactivation curve shapes (linear, shoulder and tailing) and different sensitivities to storage were observed. B. coagulans showed the fastest inactivation kinetics, with more than 4-log reduction of spore population within 24 h after heating and G. stearothermophilus displayed slower inactivation kinetics, wherea...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: André S, Charton A, Pons A, Vannier C, Couvert O Tags: Food Microbiol Source Type: research

High voltage atmospheric cold plasma treatment inactivates Aspergillus flavus spores and deoxynivalenol toxin.
This study demonstrates the efficiency of a high voltage atmospheric cold plasma (HVACP) technology using air to generate reactive oxygen (ROS) and nitrogen (RNS) species for the degradation of Aspergillus flavus cultures and the deoxynivalenol (DON) mycotoxin. Optical emission and absorption spectroscopy demonstrate ionization of hydroxyl groups, atomic oxygen and nitrogen, and confirm production of ROS and RNS, e.g. O3, NO2, NO3, N2O4, and N2O5. Fungal cultures show a depletion in pigmentation and an ~50% spore inactivation after 1-min treatments. Treated spores show surface ablation and membrane degradation by scanning ...
Source: Food Microbiology - January 7, 2021 Category: Food Science Authors: Ott LC, Appleton HJ, Shi H, Keener K, Mellata M Tags: Food Microbiol Source Type: research

Biovolume and spatial distribution of foodborne Gram-negative and Gram-positive pathogenic bacteria in mono- and dual-species biofilms.
The objective of this study was to characterize the biofilms formed by Salmonella enterica serotype Agona, Listeria monocytogenes, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE) after 12, 48, 72, 120 and 240 h of incubation at 10 °C. Biofilms containing a single species, together with dual-species biofilms in which S. enterica and a Gram-positive bacterium existed in combination, were formed on polystyrene and evaluated by using confocal laser scanning microscopy (CLSM). All strains were able to form biofilm. The greatest biovolume in the observation fie...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Rodríguez-Melcón C, Alonso-Hernando A, Riesco-Peláez F, García-Fernández C, Alonso-Calleja C, Capita R Tags: Food Microbiol Source Type: research

Suitability of lactic acid bacteria and deriving antibacterial preparations to enhance shelf-life and consumer safety of emulsion type sausages.
Abstract Ready-to-eat (RTE) sliced emulsion type sausages are sensitive to recontamination with Listeria (L.) monocytogenes during processing and packaging steps. Since Listeria spp. are able to grow on those products under cold storage conditions, taking steps to reduce the recontamination risk and implementing antibacterial hurdles contribute to consumer safety and increase the product quality. With this study data about the suitability of culture broth, cell-free supernatant (CFS) or concentrated bacteriocin preparations (CFSconc) of bacteriocin-producing lactic acid bacteria (LAB) obtained from fermented sausa...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Bungenstock L, Abdulmawjood A, Reich F Tags: Food Microbiol Source Type: research

Sourdough cultures as reservoirs of maltose-negative yeasts for low-alcohol beer brewing.
son B Abstract De novo sourdough cultures were here assessed for their potential as sources of yeast strains for low-alcohol beer brewing. NGS analysis revealed an abundance of ascomycete yeasts, with some influence of grain type on fungal community composition. Ten different ascomycete yeast species were isolated from different sourdough types (including wheat, rye, and barley) and seven of these were screened for a number of brewing-relevant phenotypes. All seven were maltose-negative and produced less than 1% (v/v) alcohol from a 12 °Plato wort in initial fermentation trials. Strains were further screened f...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Johansson L, Nikulin J, Juvonen R, Krogerus K, Magalhães F, Mikkelson A, Nuppunen-Puputti M, Sohlberg E, de Francesco G, Perretti G, Gibson B Tags: Food Microbiol Source Type: research

Characterization of bacteriophage VVP001 and its application for the inhibition of Vibrio vulnificus causing seafood-borne diseases.
In this study, we isolated and characterized a novel bacteriophage VVP001. Host range and transmission electron microscopy morphology observations revealed that VVP001 belongs to the family Siphoviridae and specifically infects V. vulnificus. Phage stability tests showed that VVP001 is stable at a broad temperature range of -20 °C to 65 °C and a pH range from 3 to 11, which are conditions for food applications (processing, distribution, and storage). In vitro challenge assays revealed that VVP001 inhibited V. vulnificus MO6-24/O (a clinical isolate) growth up to a 3.87 log reduction. In addition, complete...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Kim HJ, Kim YT, Kim HB, Choi SH, Lee JH Tags: Food Microbiol Source Type: research

Application of an innovative water-assisted ultraviolet C light technology for the inactivation of microorganisms in tomato processing industries.
Aguiló-Aguayo I Abstract We aimed to study the efficacy of a water-assisted UVC light device (WUVC) as an innovative clean technology for the disinfection of fresh sound tomatoes and processing wash water and water turbidity was evaluated as a critical parameter. First, wash waters with different turbidities (from 0.4 to 828 NTU) were inoculated with Listeria innocua and treated in the WUVC device at different dosages. Secondly, fresh tomatoes, inoculated with L. innocua and non-inoculated ones, were treated using the WUVC device containing wash water of different turbidities for different times. The reduc...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Abadias M, Colás-Medà P, Viñas I, Bobo G, Aguiló-Aguayo I Tags: Food Microbiol Source Type: research

Action mode of cranberry anthocyanin on physiological and morphological properties of Staphylococcus aureus and its application in cooked meat.
This study researched the action mode of cranberry anthocyanin (CA) against Staphylococcus aureus and the effect of CA on the counts of S. aureus and the quantity of cooked meat during storage. The antibacterial effect was assessed by minimum inhibitory concentration (MIC) and survival populations of S. aureus strains after CA treatments. The changes in intracellular adenosine 5'-triphosphate (ATP) concentration, cell membrane potential, content of bacterial protein and cell morphology were analyzed to reveal possible action mode. Application potentials of CA as antimicrobial agent were assessed during storage of cooked po...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Gong S, Fei P, Sun Q, Guo L, Jiang L, Duo K, Bi X, Yun X Tags: Food Microbiol Source Type: research

Screening for heat-resistant reference yeast isolate in orange juice.
This study details a screening process for yeast species that may be used as reference microorganisms for mild thermal processing of orange juice. In the initial step, 17 different strains of spoilage yeasts with similar initial populations (6.0-7.0 log CFU/mL) and growth stage (middle stationary phase) were subjected to equal heating process (55 °C, 5 min) in Yeast Peptone Glucose Broth (pH 6.06). The change in populations observed ranged from 3.33 log CFU/mL (Pichia fermentans BFE-38) to 6.53 log CFU/mL (Torulaspora delbrueckii BFE-37). In the second step of the screening, 6 of the most resistant strains we...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Anapi GR, Aba RPM, Gabriel AA Tags: Food Microbiol Source Type: research

Frozen-dough baking potential of psychrotolerant Saccharomyces species and derived hybrids.
Gibson B Abstract Despite Saccharomyces cerevisiae being a synonym for baker's yeast, the species does not perform well in all baking-related conditions. In particular, dough fermentation, or proofing, is compromised by the species' sensitivity to the low and freezing temperatures that are often used in modern bakeries. Here, screening trials that included representatives of all known Saccharomyces species, showed that S. cerevisiae was generally the most sensitive member of the genus with respect to cold and freezing conditions. We hypothesized therefore that the superior cold tolerance of the non-S. cerevisiae ...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Magalhães F, Calton A, Heiniö RL, Gibson B Tags: Food Microbiol Source Type: research

Novel approaches for the identification of microbial communities in kimchi: MALDI-TOF MS analysis and high-throughput sequencing.
Abstract Complex interactions occur within microbial communities during the fermentation process of kimchi. Identification of these microorganisms provides the essential information required to improve food quality and to understand their role in this process. This was the first study to compare two methods for accuracy in the identification of microbial community changes during the fermentation of kimchi by comparing a culture-dependent (MALDI-TOF MS analysis) and a culture-independent method (high-throughput sequencing) of 16S rRNA gene fragment). Members of the Lactobacillus-related genera, Leuconostoc, and Wei...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Kim E, Cho EJ, Yang SM, Kim MJ, Kim HY Tags: Food Microbiol Source Type: research

Applicability of Enterobacteriaceae and coliforms tests as indicators for Cronobacter in milk powder factory environments.
This study was performed to assess the suitability of qualitative and quantitative Enterobacteriaceae and coliforms indicator tests for the presence and prevalence of Cronobacter. Environmental swabs (205) from five milk powder factories were examined. The qualitative indicator tests had good sensitivity but they lacked specificity for reliable routine use. Logistic regression analyses revealed a significant relationship between the quantitative indicator tests and Cronobacter prevalence, where the Enterobacteriaceae count was a slightly stronger predictor for Cronobacter than the coliforms count. The optimum test sensitiv...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Craven H, McAuley C, Hannah M, Duffy L, Fegan N, Forsythe S Tags: Food Microbiol Source Type: research

High-throughput sequencing-based characterization of the predominant microbial community associated with characteristic flavor formation in Jinhua Ham.
Abstract Our purpose was to investigate the main bacterial microbiota and volatile profiles in the Chinese traditional dry-cured product-Jinhua ham during different processing stages and to analyze the role of the main microbiota in the formation of characteristic flavor. We determined the microbiota of Jinhua ham by using 16 S high throughput sequencing, and found that Staphylococcus constituted the predominant microbiota throughout the flavor formation process. Based on the volatile profiles of Jinhua dry-cured products from 11 different processing via SPME-GC-MS analysis, Aldehydes were the main groups of ...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Wang Y, Li F, Chen J, Sun Z, Wang F, Wang C, Fu L Tags: Food Microbiol Source Type: research

Antimicrobial activity of copper surfaces against biofilm formation by Salmonella Enteritidis and its potential application in the poultry industry.
Abstract As a consequence of developing antimicrobial resistance to disinfectants, copper, which exhibits antimicrobial activity, has been studied as a possible alternative to the use of stainless steel surfaces. The aim was to evaluate the antimicrobial activity of copper surfaces in preventing biofilm formation by Salmonella Enteritidis and to determine their corrosive capacity. Strains of S. Enteritidis were incubated at 4 °C, 12 °C, and 25 °C with 1 cm2 coupons of electrolytic copper (99.9% Cu), brass (70% Cu), copper coated with tin, and stainless steel (control). A planktonic ...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Pontin KP, Borges KA, Furian TQ, Carvalho D, Wilsmann DE, Cardoso HRP, Alves AK, Chitolina GZ, Salle CTP, Moraes HLS, do Nascimento VP Tags: Food Microbiol Source Type: research

Bacterial diversity in six species of fresh edible seaweeds submitted to high pressure processing and long-term refrigerated storage.
;ez M Abstract Seaweeds are highly perishable foods due to their richness in nutrients. High pressure processing (HPP) has been applied for extending the shelf life of fresh seaweeds but there is no information on the effect of HPP on the bacterial diversity of seaweeds. The culturable bacteria of six species of fresh edible seaweeds (green seaweeds Codium fragile and Ulva lactuca, brown seaweeds Himanthalia elongata, Laminaria ochroleuca and Undaria pinnatifida, and red seaweed Chondrus crispus) were investigated and compared to those of HPP-treated (400 and 600 MPa for 5 min) seaweeds, at the start and...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Picon A, Del Olmo A, Nuñez M Tags: Food Microbiol Source Type: research

Efficacy of novel phages for control of multi-drug resistant Escherichia coli O177 on artificially contaminated beef and their potential to disrupt biofilm formation.
Abstract Contaminated beef is a prominent source of foodborne pathogens such as Escherichia coli O177. Susceptibility of nine multi-drug resistant E. coli O177 strains against eight individual phages and six phage cocktails was assessed using polystyrene microplate titer plate. Further, 180 beef samples were independently inoculated with E. coli O177 cells in triplicates and treated with eight individual phages and six phage cocktails to determine their efficacy in inhibiting bacteria growth at 4 °C over a 7-day incubation period. Results revealed that all E. coli O177 strains were susceptible to the...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Montso PK, Mlambo V, Ateba CN Tags: Food Microbiol Source Type: research

Effect of abattoir, livestock species and storage temperature on bacterial community dynamics and sensory properties of vacuum packaged red meat.
Abstract Shelf life of red meat is influenced by a number of intrinsic and extrinsic factors making its prediction challenging. Here we investigated the influence of geographically distant abattoir facilities and storage temperature relevant to commercial supply chain on the shelf lives of vacuum packaged (VP) beef and lamb meat. Samples of VP beef and lamb were analysed for surface pH, total viable counts, lactic acid bacterial counts, sensory properties, and associated bacterial community using Illumina MiSeq based 16S rRNA gene amplicon sequencing over a period of>200 days. The consistent 0.41 pH unit differ...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Kaur M, Williams M, Bissett A, Ross T, Bowman JP Tags: Food Microbiol Source Type: research

Quantifying the bioprotective effect of Lactobacillus sakei CTC494 against Listeria monocytogenes on vacuum packaged hot-smoked sea bream.
In this study, the bioprotective potential of Lactobacillus sakei CTC494 against Listeria monocytogenes CTC1034 was evaluated on vacuum packaged hot-smoked sea bream at 5 °C and dynamic temperatures ranging from 3 to 12 °C. The capacity of three microbial competition interaction models to describe the inhibitory effect of L. sakei CTC494 on L. monocytogenes was assessed based on the Jameson effect and Lotka-Volterra approaches. A sensory analysis was performed to evaluate the spoiling capacity of L. sakei CTC494 on the smoked fish product at 5 °C. Based on the sensory results, the bioprotection s...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Bolívar A, Correia Peres Costa JC, Posada-Izquierdo GD, Bover-Cid S, Zurera G, Pérez-Rodríguez F Tags: Food Microbiol Source Type: research

Nitrogen metabolism in three non-conventional wine yeast species: A tool to modulate wine aroma profiles.
In this study, we further explored the impact of different nitrogen nutrition strategies on the production of carbon and sulphur volatile compounds of three non-Saccharomyces strains, namely Pichia burtonii, Kluyveromyces marxianus, Zygoascus meyerae sequentially inoculated with S. cerevisiae in Sauvignon blanc and Shiraz grape musts. Nitrogen additions were implemented according the specific requirement of each species. At the end of fermentation, we observed specific metabolic signatures for each strain in response to the nature of the nitrogen source suggesting strain-specific metabolic fluxes present. Overall, these re...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Rollero S, Bloem A, Brand J, Ortiz-Julien A, Camarasa C, Divol B Tags: Food Microbiol Source Type: research

Acetate kinase and peptidases are associated with the proteolytic activity of Lactobacillus helveticus isolated from fermented food.
This study sequenced the genomes of 60 fermented food-originated L. helveticus and systemically examined the proteolytic activity-determining factors. Our analyses found that the strength of proteolytic activity in L. helveticus was independent of the isolation source, geographic location, phylogenetic closeness between isolates, and distribution of cell envelope proteinases (CEPs). Genome-wide association study (GWAS) identified two genes, the acetate kinase (ackA) and a hypothetical protein, and 15 single nucleotide polymorphisms (SNPs) that were associated with the strength of the proteolytic activity. Further investiga...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Zhong Z, Hu R, Zhao J, Liu W, Kwok LY, Sun Z, Zhang H, Chen Y Tags: Food Microbiol Source Type: research

Genotypic and phenotypic diversity among Lactobacillus plantarum and Lactobacillus pentosus isolated from industrial scale cucumber fermentations.
odríguez F, Arroyo-López FN Abstract The Lactobacillus plantarum and Lactobacillus pentosus genotypes existing in industrial-scale cucumber fermentations were defined using rep-PCR-(GTG)5. The ability of each genotype to ferment cucumbers under various conditions was evaluated. Rep-PCR-(GTG)5 was the technique capable of illustrating the most intraspecies discrimination compared to the sequencing of housekeeping genes (recA, dnaK, pheS and rpoA), MLST and RAPD with primers LP1, OPL5, M14 and COC. Ten genotypic clusters were defined for the 199 L. pentosus tested and three for the 17 L. plantarum clon...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Pérez-Díaz IM, Johanningsmeier SD, Anekella K, Pagán-Medina CG, Méndez-Sandoval L, Arellano C, Price R, Daughtry KV, Borges M, Bream C, Connelly L, Dieck SE, Levi MT, McMurtrie EK, Smith RE, Theora JC, Wendland P, Gómez-Rodríguez F, Arroyo-López FN Tags: Food Microbiol Source Type: research

One-step duplex RT-droplet digital PCR assay for the detection of norovirus GI and GII in lettuce and strawberry.
In conclusion, one-step RT-ddPCR method developed in this study is pertinent in detecting foodborne virus such as NoV. PMID: 33279078 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Sun C, Chen J, Li H, Fang L, Wu S, Jayavanth P, Tang S, Sanchez G, Wu X Tags: Food Microbiol Source Type: research

A survey of a blown pack spoilage produced by Clostridium perfringens in vacuum-packaged wurstel.
Abstract Three hundred Clostridium strains were isolated from spoiled wurstels and were identified by traditional and molecular methods as Clostridium perfringens. The phenotypic characteristics of the strains were studied. All the strains produced acetic and butyric acids and enterotoxin. C. perfringens grew in the spoiled wurstels because it was present in raw meat (Lot 150) at a level of 3.2 log CFU/g due to an unchecked cooling phase that took 28 h to decrease the temperature of the wurstels from 60 to 9-10 °C, which is the lower limit for C. perfringens growth. During the 28 h of cooling, t...
Source: Food Microbiology - December 8, 2020 Category: Food Science Authors: Iacumin L, Comi G Tags: Food Microbiol Source Type: research