Shelf Life and Sensory Characteristics of Baby Spinach Subjected to Electron Beam Irradiation

Abstract: The use of ionizing radiation for the control of foodborne pathogens and extending the shelf life of fresh iceberg lettuce and fresh spinach has recently been approved by the U.S. Food and Drug Administration. The efficacy of electron beam irradiation for controlling foodborne pathogens has been reported. For this experiment, the effectiveness of electron beam irradiation on the microbiological and sensory characteristics of fresh spinach was studied. Total aerobic plate counts were reduced by 2.6 and 3.2 log CFU/g at 0.7 and 1.4 kGy, respectively. Lactic acid bacteria were reduced at both doses of e-beam but grew slowly over the 35 d of the experiment. Yeasts and molds were not reduced in samples exposed to 0.7 kGy whereas 1.4 kGy significantly reduced microbial counts. Gas compositions (O₂ and CO₂) were significantly different than controls. Oxygen levels inside the spinach sample bags decreased over time; however, O₂ levels did not drop below 1% that can induce anaerobic fermentation. CO₂ levels for all treatments increased through day 4; yet 7 d after irradiation, CO₂ level differences were not significant in both control and irradiated samples. Irradiation dose did not affect the basic tastes, aromatics, or mouth feels of fresh spinach, however; hardness attributes decreased as irradiated dose increased and slimy attributes of fresh spinach were higher in control samples compared to irradiated samples.     

A methodology for conducting municipal computerization studies

As urban problems become more complex and as accountability and cost minimization become more of a requirement than simply a suggestion computerization is being relied upon to handle the large amounts of data upon which public administrators base decisions. Interdisciplinary teams of faculty and staff from Texas A&M University, in the areas of urban planning, computing science, industrial engineering and accounting, have been involved in studies dealing with several aspects of computerization within municipal organizations. Experience shows that the participation and support of public administrators is vital to the success of the implementation management of computerized systems.This paper develops a staged methodology useful in conducting municipal computerization studies. Investigation of the benefits and disadvantages of computerizing existing manual systems or of a major upgrade of a present computer system is performed via a four staged process. The process highlights the role of the municipal administrator, study team, potential users of the system, and the citizens.When the administrator, the study team members and the future users have a clear understanding of the goals of the system and their goals, the study has a very high chance of being successful. The Texas A&M teams use the methodology discussed here to make a concentrated effort to ensure that all parties have a part in formulating their goals and to understand their role in the design and implementation of the system.     

Solvent fractionation of petroleum pitch for mesophase formation

Petroleum pitch (Ashland A240) has been subjected to thermal treatment and solvent fractionation to produce refined pitches to be evaluated as impregnants for C-C composites. The solvent fractions were obtained by sequential Soxhlet extraction with solvents such as hexane, benzene, and pyridine. Thermal treatment to 408 °C produced a mesophase pitch (≈50% mesophase); an appreciable portion of the mesophase was soluble in strong solvents. There were substantial differences in chemical composition and in pyrolysis behaviour of the fractions. As the depth of fraction increased, the pyrolysis yield and bloating increased, and the microstructure of the coke became finer until glassy microconstituents were formed in the deepest fractions.     

Electrochemical sulfur dioxide concentrator for flue-gas desulfurization

A small test cell has been designed to investigate the electrochemical removal and concentration of sulfur dioxide from stack gases. The cell is a high temperature molten-salt cell which uses the ternary eutectic of lithium, potassium and sodium sulfates as the electrolyte. Simulated flue-gas having a composition similar to that resulting from burning 3.5% sulfur coal is fed to the cathode, where sulfur dioxide and oxygen are converted to sulfate ion. At the anode, the reverse reaction occurs resulting in a small volume of gas containing up to 50% sulfur oxides.     

A comparison of management practices, farmer-perceived disease incidence and winter housing on organic and non-organic dairy farms in the UK

There have been increases in the number of organic dairy farms in the UK in recent years. However, there is little information on the impact of organic regulations on cow welfare. As part of a larger study, we aimed to investigate differences between organic and non-organic farms in management practices and winter housing quality. Forty organic and 40 non-organic farms throughout the UK were visited. Organic and non-organic farms were paired for housing type, and as far as possible for herd size, genetic merit and location. A detailed questionnaire covering key aspects of dairy management was carried out with each farmer. On a subset of twenty pairs, an assessment of the quality of the winter housing for both lactating and dry cows was undertaken, covering the parlour, bedding, loafing and feeding areas. Management practices and building conditions varied greatly within farm types and there was considerable overlap between organic and non-organic farms. Milk yield, level and composition of concentrate feed, management of heifers and calving, and use of 'alternative treatments' to prevent and treat mastitis differed between organic and non-organic farms. In all other respects there were no differences between farm types. Building dimensions per cow did not differ, even though organic recommendations advise greater space per cow than recommended for non-organic farms. The similarity between organic and non-organic farms in most respects indicates that cow housing and health, based on both the described management regimes and the farmers' perceptions of disease incidence, on organic dairy farms is neither compromised by the regulations, nor considerably better than on non-organic farms.     

Persistance at a liberal arts college: A replicated, five-year longitudinal study.

Analyzed data on 1,171 freshmen entering Macalester College in 1964 and 1965 to observe factors related to persistance at the college. Voluntary withdrawals (Ss who left the college in good academic standing) did not differ from the persisters (graduates of Macalester) on precollege ability and achievement measures (including the Scholastic Aptitude Test, the Omnibus Personality Inventory, and the Allport-Vernon-Lindzey Study of Values). College GPAs for the withdrawal Ss, however, revealed that these Ss did not achieve as well as the persisters. The male failures (Ss having less than a C average at time of dropping from the College) had lower achievement in high school than the withdrawals, while the female failures did less well than the withdrawals on the precollege ability tests. No generalizable differences were apparent among the groups on personality and values inventories, home proximity to the college, or participation in an experimental advising program. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personal characteristics of volunteer phone counselors.

Compared 26 volunteer telephone counselors and 34 nonvolunteer undergraduates using the Tennessee Self Concept Scale, the Personal Orientation Inventory, and the Self-Disclosure Questionnaire. Results show no differences between the groups on their self-concept except in their moral-ethical perceptions of themselves. The groups did differ on the other measures. The counselors showed a pattern of responding in the Personal Orientation Inventory suggesting that they were more self-actualizing than the college group, and they indicated a greater degree of openness on the Self-Disclosure Questionnaire. Results suggest that the volunteers are altruistic in their motivation to work in this capacity and serve as important role models for their clients. (18 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Silicon-29 solid-state nuclear magnetic resonance spectroscopy of composite interfaces

The types of structures and bonds that are formed with silicons in the composite interface were studied using ²⁹Si cross-polarization/magic angle sample spinning (CP/MAS) nuclear magnetic resonance spectroscopy (NMR). The change in mobility of silane coupling agent bonded to silica, as compared with bulk hydrolyzed silane coupling agent, can be monitored by the change in line width and the shift of resonances to higher fields, as well as by the change in the silicon-proton cross-polarization time T_SiH. In the silane coupling agent-matrix resin interface, the T_SiH values reflect the change in mobility as a function of the concentration and degree of hydrolysis of the silane coupling agent. It has been demonstrated that quantitative measurements of T_SiH can be used to investigate relative mobilities.