Influence of rosemary-tocopherol/packaging combination on meat quality and the survival of pathogens in restructured irradiated pork loins

Irradiated restructured pork loins treated with rosemary-tocopherol/double-packaging had lower TBARS values than vacuum-packaged control after 10 days of refrigerated storage. The rosemary-tocopherol combination, however, had no effect on the production of sulfur volatiles responsible for the irradiation off-odor, and color changes in irradiated pork. V7/A3 double-packaging was effective in reducing the sulfur volatiles significantly. Rosemary-tocopherol combination was highly effective in reducing the volatile hexanal in irradiated restructure pork. Irradiation was effective in reducing Listeria monocytogenes and Salmonella typhimurium inoculated on the surface of restructured pork loin in dose-dependent manner. The irradiation D(10) values for L. monocytogenes and S. typhimurium were 0.58 and 0.55kGy, respectively. During the 20 days of refrigerated storage, L. monocytogenes in both nonirradiated and irradiated samples grew gradually, but the number of S. typhimurium decreased. The added rosemary-tocopherol, however, showed little bacteriocidal effects to L. monocytogenes and S. typhimurium.     

The value of the VaNTH Engineering Research Center

This article summaries some of the project-level assessment and evaluation activities that have been used to assess the value added for innovations that incorporate learning science principles and learning technology underlying the HPL model proposed by Bransford et al. [1]. Based on a counterfactual model of causal analysis, VaNTH investigators have been encouraged to use experimental and quasi-experimental research designs to estimate the "value added" for their innovations. Although some studies have been undertaken with little difficulty, practical constraints have resulted in the need to allow quasi-experimental designs to emerge over time and institutions. By applying the logic, principles, and criteria of a counterfactual causal model, as opposed to a "cookbook" application of designs and statistical procedures, VaNTH investigators have begun to develop a firm knowledge base about the relative effectiveness of their HPL-inspired innovations. The overall effects and differences among studies are being investigated through the use of a statistical technique known as meta-analysis. This article demonstrates that it is possible to assess and evaluate, in a quantitative way, the relative effects of educational innovations in engineering courses. It also demonstrates, albeit in a preliminary fashion, that a broader assessment of the HPL model underlying VaNTH can be undertaken by systematically looking across studies within VaNTH. By implication, the knowledge gained about engineering education from A&E efforts within VaNTH should be much greater than the sum of its parts.     

Assessing Pedagogy in Bioengineering Classrooms: Quantifying Elements of the “How People Learn” Model Using the VaNTH Observation System (VOS)

One goal of the VaNTH Engineering Research Center is to estimate the effects of the “value added” to bioengineering student learning as a result of “How People Learn” (HPL) framework interventions. A necessary step in that process is to assess pedagogical differences in both lecture‐based and HPL‐oriented courses. Data from 28 bioengineering courses, over five semesters, were analyzed using a newly developed HPL Index. This index, developed from the Classroom Interaction Observation portion of the VaNTH Observation System, reports levels of HPL‐inspired pedagogy, traditional pedagogy, and classroom organization within a class using codes for different types of faculty and student interactions assigned by an observer in real time. Results confirm the HPL Index's ability to distinguish pedagogical practices based on HPL principles and pedagogical practices based on traditional, non‐HPL pedagogy.     

Smith and Glass's psychotherapy conclusions need further probing: On Landman and Dawes's reanalysis.

Critiques J. T. Landman and R. M. Dawes's (see record 1982-30838-001) reanalysis of the M. L. Smith and G. V. Glass (see record 1978-10341-001) psychotherapy outcome study. It is suggested that the Landman and Dawes study has 2 serious sampling problems. The first is the mismatch between the population sampled from and the population to which the sample, after reanalysis, is compared. Also, there is a flaw in the sampling procedure itself. It is further suggested that the conceptual shortcoming of the reanalysis turns around Landman and Dawes's definition of well-controlled studies. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Membership opinions about APA: A recent snapshot.

A 1986 survey of 2,100 American Psychological Association (APA) members, to which 78% responded, showed that members belonged to APA for varied reasons and that scientists, scientist-practitioners, and practitioners shared few common rationales for maintaining their membership. Most members belonged to other organizations in addition to APA, and less than 50% of those chose APA as their most important organizational membership. Whereas the APA Monitor and APA journals received a strong endorsement from respondents, the publication of Psychology Today was clearly controversial. The cost and size of the convention also were sources of dissatisfaction. Recommended changes in convention format included scheduling more keynote addresses and establishing area-specific conventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High temperature studies of electron-beam pumped argon-nitrogen laser characteristics

Gain and laser output power of an electron beam pumped Ar-N2mixture were measured over the temperature range 25 to 350°C. The gain is about 0.6 cm^-1at room temperature, and increases to almost 1 cm^-1at 250°C. The laser performance at elevated temperatures was determined using a specially designed high temperature resonator. The fluorescence yield and laser output are found to decrease monotonically with temperature.     

Antioxidant effect of fractions from chicken breast and beef loin homogenates in phospholipid liposome systems

The antioxidant effects of meat fractions from chicken breast and beef loin were compared. Five meat fractions – homogenate (H), precipitate (P), supernatant (S), high-molecular-weight (HMW) and low-molecular-weight (LMW) fractions – were prepared from chicken breast or beef loin. Each of the fractions were added to a phospholipid liposome model system containing catalysts (metmyoglobin, ferrous and ferric ion) or iron chelating agents to determine the effects of each fraction on the development of lipid oxidation during incubation at 37 °C for 120 min. All fractions from chicken breast showed stronger antioxidant effects against iron-catalyzed lipid oxidation than those from beef loin. Iron chelating capacity of water-soluble LMW and water-insoluble (P) fractions from both meats were responsible for their high antioxidant capacities. High concentration of myoglobin, which served as a source of various catalysts, was partially responsible for the high susceptibility of beef loin to lipid oxidation. Storage-stable ferric ion reducing capacity (FRC) was detected in all fractions from both meats, and was a rate-limiting factor for lipid oxidation in the presence of free ionic iron. Higher antioxidant capacity and lower myoglobin content in chicken breast were primarily responsible for its higher oxidative stability than beef loin. DTPA-unchelatable compounds, such as ferrylmyoglobin and/or hematin were the major catalysts for lipid oxidation in beef loin, but free ionic iron and storage-stable FRC also played important roles during prolonged storage.     

Investigating quality attributes and consumer acceptance of uncured, no-nitrate/nitrite-added commercial hams, bacons, and frankfurters

ABSTRACT:  Increasing demands for natural, organic, and/or preservative-free foods have resulted in the consumer availability of uncured, no-nitrate/nitrite-added processed meat and poultry products. A comprehensive understanding about the quality and sensory attributes of commercially available uncured products is unclear. The objective of this study was to determine if quality and sensory differences exist between uncured and cured meat products. Five different commercial brands (Brands A to E; 4 uncured, no-nitrate/nitrite-added, and 1 nitrite-added) of 3 product types (hams, frankfurters, and bacons) were obtained from retail supermarkets. The samples were evaluated for color, pigment content, pH, lipid oxidation, residual nitrate and nitrite content, and consumer acceptance. All brands from all product types evaluated, except for 1 bacon (Brand B), had cured color, aroma, and flavor attributes similar to the nitrite-added control (Brand E). All product types and brands contained residual nitrate and residual nitrite except for Brands B and D bacons (< 1 ppm nitrite). Lipid oxidation as measured by 2-thiobarbituric acid reactive substances revealed a large variation in the occurrence of lipid oxidation both between and within product types, with frankfurters reporting the highest levels. Color measurements indicated the majority of the brands within each product type were similar to the control. Consumer sensory ratings for surface/lean color, aroma, flavor, texture, and overall acceptance determined that variation existed. Brand E (nitrite-added control) and 1 uncured, no-nitrate/nitrite-added brand for each product type were not different ( P > 0.05) for overall acceptance and received higher scores ( P < 0.05) than all other brands within each product type.     

Effects of vegetable juice powder concentration and storage time on some chemical and sensory quality attributes of uncured, emulsified cooked sausages

ABSTRACT:  Uncured, no-nitrate/nitrite-added meat products can be manufactured with vegetable juice powder (VJP) and a starter culture containing Staphylococcus carnosus , resulting in quality and sensory attributes similar to traditional cured products. The 1st objective of this study was to determine the effects of varying concentrations of VJP and incubation times (MIN-HOLD) on quality characteristics, including lipid oxidation, color, and cured meat pigment concentrations, of emulsified-frankfurter-style-cooked (EFSC) sausages over a 90-d storage period. The 2nd objective was to compare residual nitrate and nitrite content resulting from different processing treatments and the 3rd objective was to assess sensory properties of finished products. Four EFSC sausage treatments (TRT) (TRT 1: 0.20% VJP, 30 MIN-HOLD; TRT 2: 0.20% VJP, 120 MIN-HOLD; TRT 3: 0.40% VJP, 30 MIN-HOLD; TRT 4: 0.40% VJP, 120 MIN-HOLD) and a sodium nitrite-added control (C) were used for this study. No differences for lipid oxidation (TBARS) between any TRTs and C or over time were observed. No differences ( P > 0.05) for CIE L * values were found between TRTs. CIE a * and reflectance ratio values revealed that TRTs 2, 4, and C were redder than TRTs 1 and 3 at day 0. Trained sensory intensity ratings for cured aroma, cured color, cured flavor, uniform color, and firmness determined that all but TRT 1 were similar to C. These results indicate a longer incubation time (120 compared with 30 min) was found more critical than VJP level (0.20% or 0.40%) to result in products comparable to a sodium nitrite-added control.