Evaluation of high pressure processing (HPP) inactivation of Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes in acid and acidified juices and beverages.

Increasing consumer demand for high-quality foods has driven adoption by the food industry of non-thermal technologies such as high pressure processing (HPP). The technology is employed as a post-packaging treatment step for inactivation of vegetative microorganisms. In order to evaluate HPP inactivation of Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes in acid and acidified juices and beverages, pressure tolerance parameters were determined using log-linear and Weibull models in pH-adjusted apple juice (pH 4.

The combined effect of high pressure processing and dimethyl dicarbonate to inactivate foodborne pathogens in apple juice.

Novel processing technologies can be used to improve both the microbiological safety and quality of food products. The application of high pressure processing (HPP) in combination with dimethyl dicarbonate (DMDC) represents a promising alternative to classical thermal technologies. This research work was undertaken to investigate the combined effect of HPP and DMDC, which was aimed at reaching over 5-log reduction in the reference pathogens Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes inoculated in apple juice.

Association of fungal genera from spoiled processed foods with physicochemical food properties and processing conditions.

The processing conditions and physiochemical properties used in food manufacturing create niches which support the growth of a limited number of spoilage fungi. This study was designed to evaluate the influence of intrinsic and extrinsic food product variables on the identity of spoilage fungi genera isolated from commercially produced foods. The spoilage etiology was identified in 127 products through ITS region sequencing.

Inactivation of Salmonella enterica and spoilage microorganisms in orange juice treated with dimethyl dicarbonate (DMDC).

Salmonella enterica is the pertinent pathogen associated with orange juice products that have resulted in numerous foodborne outbreaks. Although fresh orange juice typically has a pH below 4.0, which inhibits most pathogen growth, S.

Isolation of Bacteriocin-producing Staphylococcus spp. Strains from Human Skin Wounds, Soft Tissue Infections and Bovine Mastitis.

A collection of 206 Staphylococcus spp. isolates was investigated for their ability to produce compounds exhibiting antistaphylococcal activity. This group included Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus xylosus strains recovered from bovine mastitis (n = 158) and human skin wounds and soft tissues infections (n = 48).

Effect of Water Activity on the Thermal Tolerance and Survival of Salmonella enterica Serovars Tennessee and Senftenberg in Goat's Milk Caramel.

The low thermal tolerance of Salmonella enterica in foods with intermediate moisture levels, such as caramel sauces, ensures that mild heat treatment is sufficient to achieve 5-log reductions of this pathogen. This treatment mitigates the risk posed by salmonellae in raw materials; however, recontamination might occur because of survival of the pathogen in products that are not heated before consumption. This study was conducted to evaluate the effect of water activity (a) on the thermal tolerance and survival of S.

Microbial dynamics of indicator microorganisms on fresh tomatoes in the supply chain from Mexico to the USA.

Quality and safety of fresh produce are important to public health and maintaining commerce between Mexico and USA. While preventive practices can reduce risks of contamination and are generally successful, the variable environment of the supply chain of fresh produce can be suitable for introduction or proliferation of pathogenic microorganisms. As routine surveillance of these pathogens is not practical, indicator microorganisms are used to assess the sanitary conditions of production and handling environments.

Characterization and control of Mucor circinelloides spoilage in yogurt.

Consumer confidence in the food industry is severely affected by large-scale spoilage incidents. However, relatively little research exists on spoilage potential of members of the fungal subphylum Mucormycotina (e.g.

Variable Efficacy of the Proteinaceous Antifungal YvgO in Select Fruit Juices and Teas as a Complement with UV Methods of Food Protection.

Heat-resistant fungal spores present a processing challenge for beverages and fruit juices, as thermal and UV strategies are often inadequate in reducing heat-resistant fungal burdens to acceptable levels. While effective against pathogenic or invasive bacteria, germicidal UV light treatments also fail to achieve an appreciable reduction of heat-resistant fungal spores. As an alternative, the efficacy of the antifungal protein YvgO was examined across a selection of fruit juices and teas, as well as solid model matrices.

Efficient reduction of pathogenic and spoilage microorganisms from apple cider by combining microfiltration with UV treatment.

Thermal pasteurization can achieve the U. S. Food and Drug Administration-required 5-log reduction of pathogenic Escherichia coli O157:H7 and Cryptosporidium parvum in apple juice and cider, but it can also negatively affect the nutritional and organoleptic properties of the treated products.

Determination of the validation frequency for commercial UV juice processing units.

The CiderSure 3500 is one of the most commonly used UV juice processing units in the United States for the nonthermal processing of apple cider and fulfills the 5-log performance standard established by the federal juice HACCP regulation. However, the appropriate validation frequency of this machine's quartz tubes is currently unknown by juice processors and regulatory agencies. Presently, an annual validation is recommended by the manufacturer.

Nutrient-Dependent Efficacy of the Antifungal Protein YvgO Correlates to Cellular Proliferation Rate in Candida albicans 3153A and Byssochlamys fulva H25.

YvgO is a recently characterized antifungal protein isolated from Bacillus thuringiensis SF361 that exhibits a broad spectrum of activity and pH stability. Customized colorimetric metabolic assays based on standard broth microdilution techniques were used to determine the variable tolerance of Byssochlamys fulva H25 and Candida albicans 3153A to YvgO exposure under select matrix conditions impacting cellular proliferation. Normalization of the solution pH after antifungal challenge expanded the available pH range under consideration allowing for a comprehensive in vitro assessment of YvgO efficacy.

Bactericidal thurincin H causes unique morphological changes in Bacillus cereus F4552 without affecting membrane permeability.

Thurincin H is an antilisterial bacteriocin produced by Bacillus thuringiensis SF361. It exhibits inhibitory activity against a wide range of Gram-positive foodborne pathogens and spoilage bacteria including Listeria monocytogenes, B. cereus, and B.

Large-Scale Purification, Characterization, and Spore Outgrowth Inhibitory Effect of Thurincin H, a Bacteriocin Produced by Bacillus thuringiensis SF361.

Large-scale purification of the highly hydrophobic bacteriocin thurincin H was accomplished via a novel and simple two-step method: ammonia sulfate precipitation and C18 solid-phase extraction. The inhibition spectrum and stability of thurincin H as well as its antagonistic activity against Bacillus cereus F4552 spores were further characterized. In the purification method, secreted proteins contained in the supernatant of a 40 h incubated culture of B.

Development of a homologous expression system for and systematic site-directed mutagenesis analysis of thurincin H, a bacteriocin produced by Bacillus thuringiensis SF361.

Thurincin H is an antimicrobial peptide produced by Bacillus thuringiensis SF361. With a helical back bone, the 31 amino acids of thurincin H form a hairpin structure maintained by four pairs of very unique sulfur-to-α-carbon thioether bonds. The production of thurincin H depends on a putative gene cluster containing 10 open reading frames.

Pickled egg production: inactivation rate of Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus during acidification step.

Based on current U.S. Food and Drug Administration acidified foods guidelines, regulatory approval of commercial pickled egg production without a final heat treatment requires challenge studies.

Efficacy of UV, acidified sodium hypochlorite, and mild heat for decontamination of surface and infiltrated Escherichia coli O157:H7 on green onions and baby spinach.

Produce-associated foodborne illnesses outbreaks have highlighted the need for more effective decontamination methods to ensure the safety of fresh produce. The main objective of this study was to evaluate the individual and combined efficacies of germicidal UV light (12.5 to 500 mJ/cm(2)), acidified sodium hypochlorite (ASC 10 to 200 ppm), and mild heat (40 to 50°C) for decontaminating green onions and baby spinach infected with Escherichia coli O157:H7.

Decontamination of green onions and baby spinach by vaporized ethyl pyruvate.

Foodborne illnesses associated with fresh produce continue to be a major concern as consumer demand for healthier and nonthermally processed food increases. The objective of this study was to evaluate vaporized ethyl pyruvate (EP; CAS 617-35-6) as a safe alternative antimicrobial agent for the decontamination of Escherichia coli O157:H7 on green onions and spinach. Baby spinach leaves and green onions were inoculated with a five-strain cocktail of E.

Patulin reduction in apple juice from concentrate by UV radiation and comparison of kinetic degradation models between apple juice and apple cider.

Patulin, a mycotoxin produced by several genera of fungi, including Byssochlamys, Aspergillus, and Penicillium, has been an important concern in apple cider and apple juice due to its toxicity and health consequences. In this study, the effects of UV on the patulin level, physical and chemical properties, and sensory attributes in apple juice from concentrate were investigated. Kinetic modeling of patulin reduction by UV radiation in apple juice from concentrate was calculated and compared with the degradation rate observed previously in apple cider.

Functional assignment of YvgO, a novel set of purified and chemically characterized proteinaceous antifungal variants produced by Bacillus thuringiensis SF361.

This study reports a novel class of antifungal protein derived from bacterial origin. Bacillus thuringiensis SF361, the strain also responsible for producing the novel bacteriocin thurincin H, exhibits broad antifungal activity against select members of several fungal genera, including Aspergillus, Byssochlamys, and Penicillium, as well as the pathogenic yeast Candida albicans. Optimal antifungal production and secretion were observed after-log phase growth when incubated at 37°C in a carbohydrate-free growth medium.

Growth inhibition of foodborne pathogens by Oenococcus oeni.

Unlabelled: To explore the possibility of using Oenococcus oeni to inhibit foodborne pathogens, and to characterize antimicrobial compounds produced by O. oeni, 24 strains of O. oeni were tested for their ability to inhibit growth of foodborne pathogens, Escherichia coli O157:H7, Salmonella enteritidis, and Listeria monocytogenes by using the spot-on-lawn method.

Thermoaciduric Clostridium pasteurianum spoilage of shelf-stable apple juice.

Clostridium pasteurianum BB, a saccharolytic and spore-forming obligate anaerobe, was isolated and identified from shelf-stable apple juice that was responsible for multiple large spoilage outbreaks. The growth and sporulation conditions of C. pasteurianum were atypical compared with those previously published.

Identification and haplotype distribution of Alicyclobacillus spp. from different juices and beverages.

Alicyclobacillus spp. is an important thermoacidophilic, spore-forming spoilage bacterium that is a major concern for beverage and juice industries. In order to develop effective control strategies and adequately address the prevalence of contamination sources, it is necessary to characterize Alicyclobacillus' ecology in fruit, juice and beverage production and processing environments.

Reduction of patulin in apple cider by UV radiation.

The presence of the mycotoxin patulin in processed apple juice and cider presents a continual challenge to the food industry as both consumer health and product quality issues. Although several methods for control and/or elimination of patulin have been proposed, no unifying method has been commercially successful for reducing patulin burdens while maintaining product quality. In the present study, exposure to germicidal UV radiation was evaluated as a possible commercially viable alternative for the reduction and possible elimination of the patulin mycotoxin in fresh apple cider.

Modeling Penicillium expansum resistance to thermal and chlorine treatments.

Apples and apple products are excellent substrates for Penicillium expansum to produce patulin. In an attempt to avoid excessive levels of patulin, limiting or reducing P. expansum contamination levels on apples designated for storage in packinghouses and/or during apple juice processing is critical.