Ultraviolet-C resistance of selected spoilage yeasts in orange juice.
This study determined the ultraviolet-C (UV-C) dose necessary to reduce 90% population (DUV-C) of 17 spoilage yeasts and their composited inoculum in orange juice (pH 3.71, 11.60 °Brix, 0.55% citric acid, 2.46% w/v insoluble solids). Growth parameters of all test yeasts were first established to standardize the growth stage of the cells prior to harvesting and eventual UV-C challenge studies. Approximately 4-5 log CFU/ml cells in the mid-stationary growth phase (30.3 t0 39.9 h, 25 °C) were suspended in 4 ml turbulent flowing juice and subjected to UV-C irradiation at an incident surface irradiance of 3.64-4.9...
Source: Food Microbiology - December 2, 2018 Category: Food Science Authors: Feliciano RJ, Estilo EEC, Nakano H, Gabriel AA Tags: Food Microbiol Source Type: research

Microbial contamination of moose (Alces alces) and white-tailed deer (Odocoileus virginianus) carcasses harvested by hunters.
Abstract Hunting is currently a very popular activity, and interest in game meat is increasing. However, only limited research is available on the bacterial quality and safety of moose (Alces alces) and white-tailed deer (Odocoileus virginianus) harvested by hunters. Poor hunting hygiene can spread bacteria onto the carcasses, and inadequate chilling of the carcasses may increase the bacterial load on the carcass surface. We studied the bacterial contamination level on carcasses of 100 moose and 100 white-tailed deer shot in southern Finland. Hunters eviscerated carcasses in the field and skinned them in small sla...
Source: Food Microbiology - December 2, 2018 Category: Food Science Authors: Sauvala M, Laaksonen S, Laukkanen-Ninios R, Jalava K, Stephan R, Fredriksson-Ahomaa M Tags: Food Microbiol Source Type: research

Phages for biocontrol in foods: What opportunities for Salmonella sp. control along the dairy food chain?
sso M Abstract Controlling the presence of pathogenic bacteria, such as Salmonella sp., in dairy products production is a burning issue since contamination with Salmonella can occur at any stage of the production chain. The use of Salmonella-phages applied as control agents has gained considerable interest. Nonetheless, Salmonella-phage applications specifically intended for ensuring the safety of dairy products are scarce. This review identifies recent advances in the use of Salmonella-phages that are or could be applied along the dairy food chain, in a farm-to-fork approach. Salmonella-phages can be promising to...
Source: Food Microbiology - December 2, 2018 Category: Food Science Authors: LeLièvre V, Besnard A, Schlusselhuber M, Desmasures N, Dalmasso M Tags: Food Microbiol Source Type: research

Test sensitivity of a commercial serine protease digestion kit for the detection of Trichinella spiralis and Trichinella pseudospiralis larvae in pig muscle.
In this study the T-AAD kit was compared to the reference method. Minced pork samples were spiked with T. spiralis muscle larvae (ML) with- and without capsule or T. pseudospiralis ML, and analysed with both tests. Test results of individually spiked test samples were analysed by generalised linear modelling. The T-AAD test kit was comparable to the reference method for the qualitative detection of T. spiralis in pigs, but not quantitatively. Overall, 94% of spiked T. spiralis were recovered using MSM against 75.2% when using T-AAD (p 
Source: Food Microbiology - December 2, 2018 Category: Food Science Authors: Franssen F, Johne A, van der Giessen J, Nöckler K, Mayer-Scholl A Tags: Food Microbiol Source Type: research

Does only the age of the hen matter in Salmonella enterica contamination of eggs?
Abstract Contamination of eggs with Salmonella enterica is a significant risk factor contributing to foodborne disease. Periods of peak egg contamination were identified by conducting longitudinal environmental and egg sampling in 7 layer flocks until they were 50 weeks of age. A total of 714 environmental samples and 8958 eggs were cultured using standard methods for the detection of salmonellae. Pooled egg contamination with Salmonella Typhimurium or Salmonella Infantis was detected at a true prevalence (TP) of 0.002 (95% CI = 0.001, 0.004) or 0.005 (95% CI = 0.004, 0.007), respectively. S. Typhimurium a...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Crabb HK, Gilkerson JR, Browning GF Tags: Food Microbiol Source Type: research

Assessment of the non-lactic acid bacteria microbiota in fresh cucumbers and commercially fermented cucumber pickles brined with 6% NaCl.
te-Peril MA Abstract Limited documentation of the cucumber fermentation microbiome has impeded the understanding of the role of microbes on the quality of finished products. We characterized the microbiome of fresh and fermented cucumber samples using culture dependent and independent techniques, with an emphasis on the non-lactic acid bacteria (non-LAB) population. Insubstantial microbiome variations were observed among fresh cucumber types with Rhizobium (31.04%), Pseudomonas (14.08%), Pantoea (9.25%), Stenotrophomonas (6.83%), and Acinetobacter (6.5%) prevailing. The relative abundance of LAB remained below 0.4...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Pérez-Díaz IM, Hayes JS, Medina E, Webber AM, Butz N, Dickey AN, Lu Z, Azcarate-Peril MA Tags: Food Microbiol Source Type: research

Microbial characterisation of the edible grasshopper Ruspolia differens in raw condition after wild-harvesting in Uganda.
Abstract This research aimed at establishing the chemical intrinsic properties and the microbial quality of an edible grasshopper Ruspolia differens and the effect of its source (geographical area) in Uganda, trading point, swarming season and plucking on these parameters. The intrinsic properties of the grasshopper can support the growth of a wide variety of microorganisms. High counts of total aerobic microbes, Enterobacteriaceae, lactic acid bacteria, total aerobic spores, and yeasts and moulds were obtained. Metagenetic analyses yielded 1793 Operational Taxonomic Units (OTUs) belonging to 24 phyla. Actinobacte...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Ssepuuya G, Wynants E, Verreth C, Crauwels S, Lievens B, Claes J, Nakimbugwe D, Van Campenhout L Tags: Food Microbiol Source Type: research

A review of Clostridioides [Clostridium] difficile occurrence through the food chain.
z-Graciá C Abstract The epidemiology and transmission of Clostridioides difficile, particularly for community-associated infections, are not completely understood. Although there have been no confirmed cases of any foodborne disease caused by C. difficile, its occurrence in livestock and foods suggests that contaminated food products with spores could be a vehicle to spread C. difficile infection. This review proposes potential sources of C. difficile infection in the community and contamination routes of food products. Based on European research, it also summarizes the occurrence and organism characterizat...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Candel-Pérez C, Ros-Berruezo G, Martínez-Graciá C Tags: Food Microbiol Source Type: research

Sequential treatment of hydrogen peroxide, vacuum packaging, and dry heat for inactivating Salmonella Typhimurium on alfalfa seeds without detrimental effect on seeds viability.
This study suggests that sequential treatment is recommended and applicable for decontaminating alfalfa seeds for sprout production. PMID: 30297043 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Hong EJ, Park SH, Kang DH Tags: Food Microbiol Source Type: research

Evaluation of sampling methods for the detection of pathogenic bacteria on pre-harvest leafy greens.
This study indicates that while the mean detection probabilities for the three sampling methods are similar, the random or stratified random sampling are less variable, particularly when the number of contamination sites or number of samples analyzed are small. PMID: 30297044 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Xu A, Buchanan RL Tags: Food Microbiol Source Type: research

Genomic and metabolic features of the Bacillus amyloliquefaciens group- B. amyloliquefaciens, B. velezensis, and B. siamensis- revealed by pan-genome analysis.
This study therefore provides insights into the genomic and metabolic features of the B. amyloliquefaciens group. PMID: 30297045 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Chun BH, Kim KH, Jeong SE, Jeon CO Tags: Food Microbiol Source Type: research

Growth and metabolism of non-Saccharomyces yeasts isolated from Washington state vineyards in media and high sugar grape musts.
Abstract Utilization of carbohydrates and amino acids/ammonium by selected non-Saccharomyces yeasts and impacts on alcoholic fermentation was evaluated using media and high sugar grape musts (>270 g/L). Consumption patterns of single cultures were ascertained in synthetic media and a Chardonnay grape must. While the non-Saccharomyces species maintained>106 cfu/mL after>40 days, concentrations of residual sugars ranged from 103 g/L (Wickerhamomyces anomalus) to 155 g/L (Candida californica), amino acids and ammonium were generally depleted (>85%), and excessive amounts of volatile acidity (>0...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Aplin JJ, White KP, Edwards CG Tags: Food Microbiol Source Type: research

Comparative evaluation of spoilage-related bacterial diversity and metabolite profiles in chilled beef stored under air and vacuum packaging.
This study explored the evolution of spoilage and related volatile organic compounds (VOCs) in chilled beef under air and vacuum packaging (VP). The results suggested that different storage conditions affected changes in bacterial communities and metabolites in beef and consequently affected the odor properties of the stored beef, thereby leading to spoilage. Bacterial species belonging to Pseudomonadaceae (Pseudomonas spp.) and lactic acid bacteria (Lactobacillus sp.) dominated the bacterial communities in beef stored under air and VP, respectively, with several VOCs associated with off-odors of the stored beef and most l...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Mansur AR, Song EJ, Cho YS, Nam YD, Choi YS, Kim DO, Seo DH, Nam TG Tags: Food Microbiol Source Type: research

Evaluation of post-contamination survival and persistence of applied attenuated E. coli O157:H7 and naturally-contaminating E. coli O157:H7 on spinach under field conditions and following postharvest handling.
This study determined the variability in population uniformity of an applied mixture of attenuated E. coli O157:H7 (attEcO157) on spinach leaves as impacted by sampling mass and detection technique over spatial and temporal conditions. Opportunistically, the survival and distribution of naturally contaminating pathogenic E. coli O157:H7 (EcO157), in a single packaged lot following commercial postharvest handling and washing, was also evaluated. From the main study outcomes, differences in the applied inoculum dose of 100-fold, resulted in indistinguishable population densities of approximately Log 1.1 CFU g-1 by 14 day...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Gutiérrez-Rodríguez E, Gundersen A, Sbodio A, Koike S, Suslow TV Tags: Food Microbiol Source Type: research

Contamination of chicken meat with extended-spectrum beta-lactamase producing- Klebsiella pneumoniae and Escherichia coli during scalding and defeathering of broiler carcasses.
In conclusion, using high resolution molecular data we found evidence for the cross-contamination of carcasses with ESBL-producing Enterobacteriaceae during scalding and defeathering in the slaughterhouse. PMID: 30297049 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Projahn M, von Tippelskirch P, Semmler T, Guenther S, Alter T, Roesler U Tags: Food Microbiol Source Type: research

Global transcriptomic response of Listeria monocytogenes during growth on cantaloupe slices.
Abstract Understanding a pathogen's response to food environments is imperative to develop effective control strategies as well as to elucidate the impact of foods on virulence potential. The purpose of this study was to assess transcriptional response of Listeria monocytogenes after growth in cantaloupe, as well as its impact on survival in synthetic gastric fluid (SGF). The transcriptional profiles of L. monocytogenes grown in cantaloupe or Brain Heart Infusion (BHI) under refrigeration were compared by a custom-designed microarray. A total of 286 and 175 genes were significantly up- and down-regulated, respecti...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Kang J, Burall L, Mammel MK, Datta AR Tags: Food Microbiol Source Type: research

Survival of clinical and food Acinetobacter spp. isolates exposed to different stress conditions.
This study aimed to determine whether different Acinetobacter spp. isolated from human and food samples (lettuce, turkey meat, apple and pear) were resistant to stress conditions often applied in food processes, such as exposure to 60 °C, AMUKINA® and vinegar. Also the influence of food matrices on the behavior of isolates to these stress conditions was evaluated. Treatment with AMUKINA® and vinegar were effective against all clinical and food isolates. Exposure to 60 °C resulted in the reduction of the majority of isolates to values below the detection limit of the enumeration technique, however, it is...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Campos A, Lopes MS, Carvalheira A, Barbosa J, Teixeira P Tags: Food Microbiol Source Type: research

Modelling the effect of oxygen concentration on bacterial growth rates.
Abstract Predicting the microbial safety of food products stored in modified atmosphere packaging implies taking into account the effect of oxygen reduction on microbial growth. According to their respiratory-type, the micro-organisms are not impacted similarly by the oxygen concentration. The aim of this article was to quantify and model the oxygen effect on the growth rates of 5 bacterial species: Listeria monocytogenes and Bacillus weihenstephanensis (facultative anaerobic), Pseudomonas fluorescens (strict aerobic), Clostridium perfringens and Clostridium sporogenes (strict anaerobic). The results showed the ox...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Couvert O, Divanac'h ML, Lochardet A, Thuault D, Huchet V Tags: Food Microbiol Source Type: research

Changes in the microbial communities in vacuum-packaged smoked bacon during storage.
This study aimed to gain deeper insights into the microbiota composition and population dynamics, monitor the dominant bacterial populations and identify the specific spoilage microorganisms (SSOs) of vacuum-packed bacon during refrigerated storage using both culture-independent and dependent methods. High-throughout sequencing (HTS) showed that the microbial composition changed greatly with the prolongation of storage time. The diversity of microbiota was abundant at the initial stage then experienced a continuous decrease. Lactic acid bacteria (LAB) mainly Leuconostoc and Lactobacillus dominated the microbial population ...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Li X, Li C, Ye H, Wang Z, Wu X, Han Y, Xu B Tags: Food Microbiol Source Type: research

Spoilage indicator bacteria in farmed Atlantic salmon (Salmo salar) stored on ice for 10 days.
This study investigated the growth of indicator and spoilage bacteria on whole Atlantic salmon (Salmo salar) stored aerobically at 2 °C. On days 0, 2, 3, 6, 8 and 10 microbiological analysis was carried out on inner flesh and outer skin samples as well as outer skin swabs (25 cm2 surface areas). Mesophilic total viable counts (TVCm) on skin, flesh and swab samples increased from 1.9, 1.1 and 2.7 log10 CFUcm2 to 6.0, 5.1 and 5.7 log10 CFU/cm2 after 10 days, respectively. Psychrotrophic counts (TVCp), increased from 2.2, 1.8 and 3.1 log10 CFU/cm2 to 6.2, 5.3 and 5.9 log10 CFU/cm2, for skin, flesh and swab sampl...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Fogarty C, Whyte P, Brunton N, Lyng J, Smyth C, Fagan J, Bolton D Tags: Food Microbiol Source Type: research

Metabolism of phenolic acids in whole wheat and rye malt sourdoughs.
MG Abstract This work aimed to study the phenolic acid metabolism of sourdough lactic acid bacteria (LAB) in laboratory media, and in sourdough fermentation with single cultures and in co-fermentations. Lactobacilli were selected from isolates obtained from 35 sourdough samples. Isolates (114 strains) were screened for phenolic acid decarboxylase gene pdc and EPS production. Ferulic acid metabolism of the 18 pdc positive strains was evaluated in mMRS; all pcd positive strains converted ferulic acid by decarboxylation and/or reduction. Single whole wheat and rye malt dough fermentation fermented with lactobacilli ...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Ripari V, Bai Y, Gänzle MG Tags: Food Microbiol Source Type: research

Effective inhibition of Salmonella Typhimurium in fresh produce by a phage cocktail targeting multiple host receptors.
Abstract Salmonella contamination of fresh produce is the primary bacterial cause of a significant number of foodborne outbreaks and infections. Bacteriophages can be used as natural antibacterial agents to control foodborne pathogens. However, the rapid development of bacterial resistance to phage infection is a significant barrier to practical phage application. To overcome this problem, we developed a novel phage cocktail consisting of the three phages (BSPM4, BSP101 and BSP22A) that target different host receptors, including flagella, O-antigen and BtuB, respectively. Whole genome sequence analysis of the phag...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Bai J, Jeon B, Ryu S Tags: Food Microbiol Source Type: research

In situ riboflavin fortification of different kefir-like cereal-based beverages using selected Andean LAB strains.
nar R Abstract Cereal-based functional beverages represent social, economic, and environmental sustainable opportunities to cope with emerging trends in food consumption and global nutrition. Here we report, for the first time, the polyphasic characterization of three cereal-based kefir-like riboflavin-enriched beverages, obtained from oat, maize and barley flours, and their comparison with classical milk-based kefir. The four matrices were successfully fermented with commercial starters: i) milk-kefir and ii) water-kefir, proving the potential of cereal ingredients in the formulation of dairy-like fermented bever...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Yépez A, Russo P, Spano G, Khomenko I, Biasioli F, Capozzi V, Aznar R Tags: Food Microbiol Source Type: research

Effects of Enterococcus faecalis UGRA10 and the enterocin AS-48 against the fish pathogen Lactococcus garvieae. Studies in vitro and in vivo.
Martínez-Bueno M, Valdivia E Abstract The aim of this study was to evaluate the effects of Enterococcus faecalis UGRA10 and its enterocin AS-48 against the fish pathogen Lactococcus garvieae. The minimum bactericidal concentrations of AS-48 against L. garvieae CECT 5807, 5806, and 5274 were 15.62, 15.62, and 7.81 μg/ml respectively. In broth cultures, enterocin at 100, 50, and 25 μg/ml reduced 108 CFU/ml lactococci after 2, 5, and 10 h, respectively. In co-cultures of UGRA10/L. garvieae at a 1/10 CFU/ml ratio, lactococci were eliminated after 24 h. Studies on UGRA10 biosafety and AS-48 tox...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Baños A, Ariza JJ, Nuñez C, Gil-Martínez L, García-López JD, Martínez-Bueno M, Valdivia E Tags: Food Microbiol Source Type: research

Survival of Listeria monocytogenes during in vitro gastrointestinal digestion after exposure to 5 and 0.5 % sodium chloride.
In this study, a recently developed internationally harmonized static in vitro digestion (IVD) model was used to investigate the survival of L. monocytogenes in the gastric and intestinal phases after exposure to 5 or 0.5% NaCl. Six isolates from three Scandinavian foodborne listeriosis outbreaks, all related to NaCl containing foods, the EGDe reference strain and an EGDe mutant, deleted for the major stress regulator gene, sigB, were included. A ten-fold reduction of NaCl in the cultivation media significantly reduced the survival fraction of the EGDe strain in the IVD model while one of the clinical outbreak isolates sho...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Pettersen KS, Skjerdal T, Wasteson Y, Lindbäck T, Vegarud G, Comi I, Aspholm M Tags: Food Microbiol Source Type: research

Development and application of a real-time polymerase chain reaction method for quantification of Escherichia coli in oysters (Crassostrea gigas).
The objective of this study was to develop a qPCR method for quantification of E. coli in oysters. Additionally, different methods were evaluated for DNA extraction from oyster samples and the more reliable method was chosen. Primers and probe were designed targeting uidA gene of E. coli and shown to specifically amplify DNA from E. coli. Standard curves with bacterial DNA extracted from oysters samples artificially inoculated with E. coli were conducted. A good correlation was noticed when the qPCR method was compared to a culture method in oyster samples. This is the first report of a method exclusively developed for dir...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Miotto M, Fonseca AA, Barretta C, da Silva HS, Pellizzaro T, De Dea Lindner J, Vieira CRW, Parveen S, Prudencio ES Tags: Food Microbiol Source Type: research

Synthesis of prebiotic galactooligosaccharides from lactose and lactulose by dairy propionibacteria.
ate G Abstract The potential of probiotic bacteria to produce prebiotic oligosaccharides by transgalactosylation has been minimally studied. In this work, we screened the β-galactosidase (β-gal) activity of dairy propionibacteria (PAB) isolated from Argentinean foods to select strains for the synthesis of oligosaccharides from lactose (GOS) and lactulose (OsLu). PAB, when grown in a medium with lactose as a carbon source, were disrupted, and the cell-free extracts were assayed for β-gal activity. Nine strains grew on lactose and showed β-gal activities from 0.27 to 2.60 U mL-1. Propionibacteriu...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Sabater C, Fara A, Palacios J, Corzo N, Requena T, Montilla A, Zárate G Tags: Food Microbiol Source Type: research

Genomic and metatranscriptomic analyses of Weissella koreensis reveal its metabolic and fermentative features during kimchi fermentation.
Abstract The genomic and metabolic features of Weissella koreensis, one of the major lactic acid bacteria in kimchi, were investigated through genomic, metabolic, and transcriptomic analyses for the genomes of strains KCTC 3621T, KACC 15510, and WiKim0080. W. koreensis strains were intrinsically vancomycin-resistant and harbored potential hemolysin genes that were actively transcribed although no hemolysin activity was detected. KEGG and reconstructed fermentative metabolic pathways displayed that W. koreensis strains commonly employ the heterolactic pathway to produce d-lactate, ethanol, acetate, CO2, d...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Jeong SE, Chun BH, Kim KH, Park D, Roh SW, Lee SH, Jeon CO Tags: Food Microbiol Source Type: research

Control of microbes on barley grains using peroxyacetic acid and electrolysed water as antimicrobial agents.
Abstract The extent and type of microbial growth on barley grain is a key determinant of malt quality for beer production, as problematic microbial products can persist into the brewing process and impact beer quality. Microbial composition on malting barley grain are influenced by field growth, storage and malting conditions. The present study investigated the efficacy of electrolysed water (EW) with free chlorine concentrations of 5, 50, 100 and 500 ppm, as well as peroxyacetic acid (PAA) at 100 and 500 ppm, as pre-steep treatments to control microbes on grains during the malting process. The research determ...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Rood L, Koutoulis A, Bowman JP, Evans DE, Stanley RA, Kaur M Tags: Food Microbiol Source Type: research

Characterization of bacteria and yeasts isolated from traditional fermentation starter (Fen-Daqu) through a 1H NMR-based metabolomics approach.
This study highlights the specific functions of S. cerevisiae, S. fibuligera, B. licheniformis, W. anomalus and lactic acid bacteria in the production of light-flavour baijiu (fen-jiu). Our results show that all investigated species deliver an important contribution to the functionality of the fermentation starter Daqu. PMID: 30166130 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Li RY, Zheng XW, Zhang X, Yan Z, Wang XY, Han BZ Tags: Food Microbiol Source Type: research

Microbial community dynamics of Dan'er barley grain during the industrial malting process.
Abstract The microbes associated with barley grains are known to have either deleterious or beneficial effects on the malting process, thereby affecting the quality of malt and even beer. Dan'er barley is the major cultivar grown in Jiangsu Province in China, malt derived from this cultivar, however, invariably causes filtration problems. To understand the microbial community of Dan'er barley and its probable effects on malt quality and subsequent brewing process, the present study combined culture-dependent methods and culture-independent PCR denaturing gradient gel electrophoresis (PCR-DGGE) strategies. The resu...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Li X, Cai G, Wu D, Zhang M, Lin C, Lu J Tags: Food Microbiol Source Type: research

Aerobic and respirative growth of heterofermentative lactic acid bacteria: A screening study.
Abstract Heterofermentative lactic acid bacteria (76 strains) belonging to Lactobacillus, Leuconostoc and Weissella species which are important in fermentation, spoilage or as probiotics were screened in a factorial experiment for their ability to grow, produce catalase and consume oxygen in aerobiosis or in anaerobiosis, with or without supplementation with hemin and/or menaquinone in a medium containing glucose as a carbohydrate source. Aerobiosis improved growth with a few exceptions. The effect of supplementation with heme and/or menaquinone was strain specific and clear evidence of heme-boosted respiration wa...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Zotta T, Ricciardi A, Ianniello RG, Storti LV, Glibota NA, Parente E Tags: Food Microbiol Source Type: research

Polyhexamethylene guanidine as a fungicide, disinfectant and wound protector in lemons challenged with Penicillium digitatum.
Abstract Citrus green mold, a postharvest disease caused by Penicillium digitatum, provokes important economic losses on lemon production. Here, the effectiveness of polyhexamethylene guanidine (PHMG) to inhibit P. digitatum growth and to control green mold on artificially infected lemons was evaluated. At sublethal concentrations, PHMG inhibited conidia germination and infectivity (5 mg L-1), and mycelial growth (50 mg L-1). Viability of conidia was completely suppressed by treatment with 500 mg L-1 PHMG. In this condition, membrane integrity loss, cell wall disruption and ultrastructural alterat...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Olmedo GM, Cerioni L, Sepulveda M, Ramallo J, Rapisarda VA, Volentini SI Tags: Food Microbiol Source Type: research

Kluyveromyces marxianus yeast enables the production of low FODMAP whole wheat breads.
This study demonstrates the potential of inulinase-producing K. marxianus strains for the production of (whole meal) breads low in FODMAPs. PMID: 30166134 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Struyf N, Vandewiele H, Herrera-Malaver B, Verspreet J, Verstrepen KJ, Courtin CM Tags: Food Microbiol Source Type: research

Combined effect of a positively charged cinnamon leaf oil emulsion and organic acid on the inactivation of Listeria monocytogenes inoculated on fresh-cut Treviso leaves.
This study was performed to examine the inhibitory effect of combined treatments with a positively charged cinnamon leaf oil (P-CL) emulsion and various organic acids against Listeria monocytogenes inoculated on fresh-cut Treviso leaves. Combined treatments with a P-CL emulsion and an organic acid exhibited a higher inhibitory effect than treatment with each alone or NaOCl. The highest inhibitory effect was achieved by combined treatment with the P-CL emulsion and lactic acid (LA), which showed a 2.85-log reduction compared to distilled water washing. In addition, the inhibitory effect of the combined treatment was maintai...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Kang JH, Song KB Tags: Food Microbiol Source Type: research

Modelling the growth kinetics of Listeria monocytogenes in pasta salads at different storage temperatures and packaging conditions.
Abstract The aim of this study was to model Listeria monocytogenes growth kinetics in ready to eat full meal pasta salads, containing fresh and cooked ingredients. With this aim, laboratory prepared salads, representing two formulations of commercial pasta salads, were spiked with L. monocytogenes and tested under categorised packaging and storage temperature conditions. L. monocytogenes enumeration results collected in 15 different laboratory prepared salad datasets were analysed with primary and secondary models. The models showing the best fit to describe L. monocytogenes growth kinetics in the l...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: De Cesare A, Vitali S, Tessema GT, Trevisani M, Fagereng TM, Beaufort A, Manfreda G, Skjerdal T Tags: Food Microbiol Source Type: research

Performance of Leuconostoc citreum FDR241 during wheat flour sourdough type I propagation and transcriptional analysis of exopolysaccharides biosynthesis genes.
This study focused on the performance of the dextran producer Leuconostoc citreum as starter culture during 30 days of wheat flour type I sourdough propagation (back-slopping). As confirmed by RAPD-PCR analysis, the strain dominated throughout the propagation procedure, consisting of daily fermentations at 20 °C. The sourdoughs were characterized by consistent lactic acid bacteria cell density and acidification parameters, reaching pH values of 4.0 and mild titratable acidity. Carbohydrates consumption remained consistent during the propagation procedure, leading to formation of mannitol and almost equimolar amount o...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Coda R, Xu Y, Moreno DS, Mojzita D, Nionelli L, Rizzello CG, Katina K Tags: Food Microbiol Source Type: research

Effectiveness of polymeric coated films containing bacteriocin-producer living bacteria for Listeria monocytogenes control under simulated cold chain break.
i R Abstract Nisin, enterocin 416K1 and living bacteriocin-producer Enterococcus casseliflavus IM 416K1 have been entrapped in polyvinyl alcohol (PVOH) based coatings applied to poly (ethylene terephthalate) (PET) films, and their effectiveness in the control of the growth of Listeria monocytogenes ATCC 19117 has been tested. The anti-listerial activity of the doped coated films was evaluated by both a modified agar diffusion assay and a direct contact with artificially contaminated precooked chicken fillets stored at 4 °C, 22 °C and under simulated cold chain break conditions (1 day at 30 °C...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Degli Esposti M, Toselli M, Sabia C, Messi P, de Niederhäusern S, Bondi M, Iseppi R Tags: Food Microbiol Source Type: research

Effect of temperature and pH on the community dynamics of coagulase-negative staphylococci during spontaneous meat fermentation in a model system.
Abstract Coagulase-negative staphylococci (CNS) contribute to the product quality of fermented meats. In spontaneously fermented meats, CNS communities are variable and difficult to predict, as their compositions depend on a superposed combination of different processing factors. To partially disentangle this superposition, a meat model system was used to study the influence of temperature and pH on the CNS community dynamics. Therefore, cured pork mince was prepared that was divided into three batches of different initial acidity levels, namely pH 5.7, pH 5.5, and pH 5.3. These three batches were incubated at thr...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Stavropoulou DA, Filippou P, De Smet S, De Vuyst L, Leroy F Tags: Food Microbiol Source Type: research

Use of biochemical miniaturized galleries, rRNA based lateral flow assay and Real Time PCR for Cronobacter spp. confirmation.
Abstract Identification of Cronobacter represent a major challenge for laboratories testing powdered infant formula (PIF). In the present study, two biochemical galleries and three molecular methods have been applied to confirm 276 Cronobacter spp. and non-Cronobacter isolates from different sources. Using the latest database of API 20 E and ID 32 E biochemical miniaturized kits, 53% and 78% of the isolates were identified respectively. From the available results, total accuracy for Cronobacter detection was in 97% (API 20 E) and 99% (ID 32 E). The three molecular methods were based on rRNA based lateral f...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Tomas D, Fan M, Zhu S, Klijn A Tags: Food Microbiol Source Type: research

High prevalence of Bacillus subtilis-infecting bacteriophages in soybean-based fermented foods and its detrimental effects on the process and quality of Cheonggukjang.
In conclusion, B. subtilis phages are widespread in Korean soybean-based fermented foods and it should be of great concern as phages may hamper the bacterial growth during fermentation and yield poor quality products. PMID: 30166141 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Ghosh K, Kang HS, Hyun WB, Kim KP Tags: Food Microbiol Source Type: research

Fog, phenolic acids and UV-A light irradiation: A new antimicrobial treatment for decontamination of fresh produce.
This study evaluates synergistic interactions of food grade phenolic acids (gallic and ferulic acid) and UV-A light to achieve decontamination of fresh produce using a fog to improve dispersion of the phenolic acids on produce surface. Nonvirulent strains of Escherichia coli O157:H7 and Listeria innocua were used as model bacteria and spinach was selected as a model fresh produce. Synergistic combination of a fog deposited phenolic acid and a UV-A light treatment achieved reduction in bacterial plate count up to 2 log CFU/cm2 independently of the initial load of the bacteria (104 or 106 CFU/cm2). Following the treatment,...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Cossu A, Huang K, Cossu M, Tikekar RV, Nitin N Tags: Food Microbiol Source Type: research

Evaluation of the efficacy of multiple physical, biological and natural antimicrobial interventions for control of pathogenic Escherichia coli on beef.
Abstract Antimicrobial effects of multiple physical, biological and natural interventions on pathogenic Escherichia coli in raw beef were assessed. A cocktail of E. coli strains was inoculated onto gamma-irradiated beef and enumerated immediately after each intervention and during storage at 4 °C for 7 days. Of the physical interventions, silver-containing antimicrobial packaging and ozone gas treatment did not show significant antimicrobial effects, however cold plasma treatment reduced E. coli levels by 0.9 and 1.82 log10 CFU/cm2 after 2 and 5 min treatments, respectively. A phage cocktail reduced E. c...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Stratakos AC, Grant IR Tags: Food Microbiol Source Type: research

Survival of Listeria innocua on Fuji apples under commercial cold storage with or without low dose continuous ozone gaseous.
This study evaluated the fate of Listeria innocua, a non-pathogenic species closely related to Listeria monocytogenes, on Fuji apple fruit surfaces during commercial cold storage with and without continuous low doses of gaseous ozone. Unwaxed Fuji apples of commercially acceptable maturity were inoculated with 6.0-7.0 Log10 CFU L. innocua/apple, and subjected to refrigerated air (RA, 33 °F), controlled atmosphere (CA, 33 °F, 2% O2, 1% CO2), or CA with low doses of ozone gas (50.0 -87.0 ppb ) storage in a commercial facility for 30 weeks. A set of uninoculated apples was simultaneously subjected to ...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Sheng L, Hanrahan I, Sun X, Taylor MH, Mendoza M, Zhu MJ Tags: Food Microbiol Source Type: research

Inactivation of Listeria monocytogenes and Salmonella spp. on cantaloupe rinds by blue light emitting diodes (LEDs).
This study evaluated the potential of blue light-emitting diodes (LED) of wavelength 405 and 460 nm in combination with sodium chlorophyllin to inactivate Listeria monocytogenes and Salmonella spp. on cantaloupe rind. A cocktail culture of L. monocytogenes or Salmonella spp. strains was surface inoculated onto cantaloupe rinds to reach a final concentration of 4 log CFU/cm2 and dip-treated in a 100 μM sodium copper chlorophyllin solution. The cantaloupe samples were then exposed to 405 or 460 nm LEDs at a total dose of 1210 J/cm2 and 5356 J/cm2, respectively, at 4 and 20 °C. Results showed that the antib...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Josewin SW, Kim MJ, Yuk HG Tags: Food Microbiol Source Type: research

Evaluation of biocontrol capacity of Pseudomonas graminis CPA-7 against foodborne pathogens on fresh-cut pear and its effect on fruit volatile compounds.
aire L, Abadias M Abstract The application of microorganisms to control the growth of foodborne pathogens is an alternative to the use of chemical additives. In this work, Pseudomonas graminis CPA-7 was tested as a biocontrol agent against Salmonella enterica and Listeria monocytogenes on fresh-cut pear under conditions that simulate its commercial application at 5 ± 1 °C (under a modified atmosphere and antioxidant solution). The quality of the fresh-cut fruit, including the ethanol and acetaldehyde contents and the volatile profile, was determined. After the storage period, the L. monocytog...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Iglesias MB, López ML, Echeverría G, Viñas I, Zudaire L, Abadias M Tags: Food Microbiol Source Type: research

Thermal inactivation of Aspergillus flavus in peanut kernels as influenced by temperature, water activity and heating rate.
In this study, thermal inactivation kinetics of Aspergillus flavus in peanut kernel flour at four water activity (aw) levels (0.720, 0.783, 0.846, and 0.921) with three temperatures for each aw was studied using a thermal-death-time heating block system and fitted with first-order kinetic and Weibull models. The influence of heating rates on thermotolerance of Aspergillus flavus was also investigated. The results showed that the Weibull distribution model had better coefficient of determination from 0.954 to 0.996, as compared to that (from 0.866 to 0.980) of the first-order kinetic model. An upward concavity was found wit...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Zhang S, Zhang L, Lan R, Zhou X, Kou X, Wang S Tags: Food Microbiol Source Type: research

Adherence factors of enterohemorrhagic Escherichia coli O157:H7 strain Sakai influence its uptake into the roots of Valerianella locusta grown in soil.
This study identified intrinsic bacterial factors that play a crucial role during the internalization of EHEC O157:H7 strain Sakai into the roots of Valerianella locusta grown under the growth conditions in a greenhouse. PMID: 30166148 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Eißenberger K, Moench D, Drissner D, Weiss A, Schmidt H Tags: Food Microbiol Source Type: research

Monitoring bacterial communities in ε-Polylysine-treated bighead carp (Aristichthys nobilis) fillets using culture-dependent and culture-independent techniques.
In conclusion, ε-Polylysine altered the bacterial communities and delayed quality deterioration of bighead carp fillets during chilled storage. PMID: 30166149 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Liu X, Li D, Li K, Luo Y Tags: Food Microbiol Source Type: research

Occurrence of lactic acid bacteria and yeasts at species and strain level during spontaneous fermentation of maw è, a cereal dough produced in West Africa.
Occurrence of lactic acid bacteria and yeasts at species and strain level during spontaneous fermentation of mawè, a cereal dough produced in West Africa. Food Microbiol. 2018 Dec;76:267-278 Authors: Houngbédji M, Johansen P, Padonou SW, Akissoé N, Arneborg N, Nielsen DS, Hounhouigan DJ, Jespersen L Abstract Mawè is a West African spontaneous fermented cereal-based dough. Different types of mawè exist varying in type of cereal and/or production condition, with fermentations lasting 24-48 h. With the aim of obtaining a comprehensive understanding of the microbial ec...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Houngbédji M, Johansen P, Padonou SW, Akissoé N, Arneborg N, Nielsen DS, Hounhouigan DJ, Jespersen L Tags: Food Microbiol Source Type: research