Prevalence, distribution, and diversity of Listeria monocytogenes in retail environments, focusing on small establishments and establishments with a history of failed inspections

Despite growing concerns about cross-contamination of ready-to-eat foods with Listeria monocytogenes, our knowledge about the ecology and transmission of L. monocytogenes in retail establishments has remained limited. We conducted a cross-sectional study to characterize the prevalence, distribution, and subtype diversity of L. monocytogenes in 120 New York State retail deli establishments that were hypothesized to present an increased risk for environmental L. monocytogenes contamination (i.e., small establishments and establishments with a history of failed New York State Agriculture and Markets inspections). Analysis of these data along with previously reported data for 121 predominantly larger retail establishments in New York State identified establishment size, geographic location, and inspection history as significant predictors of L. monocytogenes presence and prevalence. The odds of an establishment being L. monocytogenes positive were approximately twice as high for large establishments, establishments located in New York City, or establishments with poor inspection history (as compared with establishments without these attributes), even though correlation between location and inspection history complicated interpretation of results. Within an establishment, L. monocytogenes was significantly more prevalent on nonfood contact surfaces than on food contact surfaces; prevalence was particularly high for floors and in floor drains, sinks, the dairy case, and milk crates. L. monocytogenes subtype diversity differed between sites, with lineage I isolates significantly associated with nonfood contact surfaces and lineage II isolates significantly associated with food contact surfaces. Isolates belonging to the same ribotype were often found dispersed across multiple sites within an operation.     

Tools to maintain postharvest fruit and vegetable quality through the inhibition of ethylene action: a review

Ethylene is a plant hormone controlling a wide range of physiological processes in plants. During postharvest storage of fruit and vegetables ethylene can induce negative effects including senescence, over-ripening, accelerated quality loss, increased fruit pathogen susceptibility, and physiological disorders, among others. Apart from the endogenous ethylene production by plant tissues, external sources of ethylene (e.g. engine exhausts, pollutants, plant, and fungi metabolism) occur along the food chain, in packages, storage chambers, during transportation, and in domestic refrigerators. Thus, it is a great goal in postharvest to avoid ethylene action. This review focuses on tools which may be used to inhibit ethylene biosynthesis/action or to remove ethylene surrounding commodities in order to avoid its detrimental effects on fruit and vegetable quality. As inhibitors of ethylene biosynthesis and action, good results have been found with polyamines and 1-methylcyclopropene (1-MCP) in terms of maintenance of fruit and vegetable quality and extension of postharvest shelf-life. As ethylene scavengers, the best results can be achieved by adsorbers combined with catalysts, either chemical or biological (biofilters).     

Apparent chemical composition of nine commercial or semi-commercial whey protein concentrates, isolates and fractions

Summary Analytical results are given for whey powders prepared on a commercial or semi-commercial scale by three companies. Altogether, five preparations enriched in β-lactoglobulin, four whey protein isolates and a fraction enriched in α-lactalbumin were analyzed for protein composition, including %β-lactoglobulin, α-lactalbumin, bovine serum albumin, casein (glyco) macropeptide and the main triglycerides. Protein composition was determined by high pressure gel permeation and reversed phase liquid chromatography and by capillary zone electrophoresis. The extent of modification of the native β-lactoglobulin structure was also measured through the degree of lactosylation and the fraction of accessible free sulphydryl groups. One significant finding was that the calculated recovery of protein following quantitation of the chromatogram or electropherogram was seldom above 90% and occasionally below 60% of that loaded onto the column or capillary, raising doubts as to the reliability of the analytical results. Extrapolation by linear regression to 100% recovery allowed estimates to be made of the true β-lactoglobulin composition of the samples. The nine samples could be placed into three distinct groups with estimated true β-lactoglobulin weight % of 70.9 ± 1.1, 62.0 ± 3.4 and 39.5 ± 4.9. Physico-chemical properties of the group of samples are reported elsewhere (Holt et al ., 1999).     

Particle Size of Whole Meal Rye Bread does not Affect the Digestibility of Macro-Nutrients and Non-Starch Polysaccharides and the Energy Value of Dietary Fibre in Humans

The effect of particle size of whole meal rye bread on the apparent digestibility of macro-nutrients, non-starch polysaccharides (NSP) and energy, the energy value of rye NSP and on faecal weight was studied in balance experiments in seven young women. The whole meal breads were prepared from one single batch of rye milled to two different particle sizes (coarse bread: 50% of particles >2 mm, 90% >1 mm; fine bread: 86% of particles <0·5 mm, 58% <0·2 mm). Two diets containing either coarse (350 g day⁻¹) or fine (377 g day⁻¹) whole meal bread and a low fibre control diet were consumed for 3 weeks each in a 3×3 cross-over design. Relative to the low fibre control diet, digestibility of protein, NSP and energy was significantly lower for the diets containing the whole meal breads. Digestibility of fat was the same for all diets. Partial digestible energy value for each g of NSP from coarse and fine whole meal rye bread was calculated to be −3±7 and 1±5 kJ, respectively. There were no differences between coarse and fine whole meal rye bread in the effects on the parameters measured with the exception on faecal wet weight, which was higher for the coarse bread diet.     

Antioxidant activity and total phenolic content of Agaricus brasiliensis (Agaricus blazei Murril) in two stages of maturity

The antioxidant capability and total phenolic contents of methanolic extracts of Agaricusbrasiliensis in two stages of maturity, young (YB) and mature (MB), were evaluated in this work. Four complementary assays, reducing power, radical scavenging capacity, inhibition of lipid peroxidation and chelating ability for ferrous ions were used to screen the antioxidant properties of extracts. Minor differences in the composition of phenolic compounds were detected, but the extracts showed similar antioxidant activities, except for the chelating ability for ferrous ions, higher in MB than in YB. Our results support the use of both young and mature fruiting bodies of Agaricus blazei as sources of antioxidant compounds.     

Individual characteristics and children's performance in open and traditional classroom settings.

Assessed the performance of 56 boys and 36 girls with different motivational and cognitive characteristics in 3 "open" and 3 "traditional" 4th-grade classrooms. Cluster analysis of factor scores representing child orientations, motives, and prior achievement produced 6 "types." Three-way analyses of variance investigated the effects of child type, classroom type (open vs traditional), sex of child, and various interactions on several outcome measures, including academic achievement, creativity, inquiry skill, social-educational attitudes, and teacher ratings of children's classroom behavior. Main effects appeared for each of the 3 independent variables, along with several Child * Class interactions. An approach using child types or clusters rather than abstracted dimensions may facilitate further Attribute * Treatment interaction research and applications. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)