Ascorbic acid: a review of its chemistry and reactivity in relation to a wine environment

Extensive reviews of research are available on the use of ascorbic acid, and its consequent degradation pathways, in physiological conditions or food matrices. However, very little information can be found for wine-related systems. This review highlights the relevant chemistry and reactivity of ascorbic acid with a focus on its behavior and potential behavior in a wine environment. The review describes the use of ascorbic acid as a complementary antioxidant preservative to sulfur dioxide along with the metal-catalyzed and radical-dependent manner by which it achieves this role. The relevant degradation products of ascorbic acid in aerobic and anaerobic conditions are presented as well as the interaction of these degradation products with sulfur dioxide and other wine-relevant sulfur compounds. Limitations in existing knowledge, especially regarding the crossover between the antioxidant and pro-oxidant roles of ascorbic acid, are identified.     

Maximizing profit on New England organic dairy farms: an economic comparison of 4 total mixed rations for organic Holsteins and Jerseys

The objective of these experiments was to compare 4 total mixed rations fed to USDA-certified organic dairy cows in New England. Forty-eight Jersey cows from the University of New Hampshire (UNH) and 64 Holstein cows from the University of Maine (UMaine) were assigned to a 2 × 2 factorial arrangement of treatments testing the main effects of corn silage versus grass silage as the forage base and commodity concentrates versus a complete pelleted concentrate mixture. Treatment diets were fed as a total mixed ration for 8 wk during the winter and spring months of 2007, 2008, and 2009. Milk yield, component, and quality data were recorded and used to calculate the value of the milk produced for each cow. The dry matter intake (DMI) was recorded and used to calculate the average cost per cow per day of each diet. Income over feed costs were calculated for each diet using milk value and feed cost data. Feed cost and income over feed cost data were resampled using bootstrap methodology to examine potential patterns. Milk yield, milk fat and true protein concentrations, and SCC were similar among treatments. Cows at UNH fed corn silage tended to have higher DMI and lower milk urea nitrogen than did cows fed grass silage, whereas cows fed pellets had higher DMI than cows fed commodities. Cows at UNH fed commodities tended to have higher body condition scores than those fed pellets. Cows at UMaine fed commodities tended to have higher DMI than did cows fed pellets, and cows fed corn silage had lower milk urea nitrogen than did cows fed grass silage. Body weights and body condition scores were not different for cows at UMaine. Feed costs were significantly higher for corn silage diets and diets at UNH containing pellets, but not at UMaine. The calculated value of the milk and income over feed costs did not differ among treatments at either university. Bootstrap replications indicated that the corn silage with commodities diet generally had the highest feed cost at both UNH and UMaine, whereas grass silage diets containing commodities generally had the lowest cost. In contrast, the grass silage with commodities diets had the highest income over feed cost in the majority of the replications at both UNH and UMaine replications, whereas the corn silage with commodities diets had the lowest rank. Similar results were observed when forage prices were increased or decreased by 5, 10, and 25% above or below the actual feed price. Feeding a grass silage-based diet supplemented with commodity concentrates may have an economic advantage for dairy producers in New England operating under an organic system of production.     

Protease stability in bovine milk under combined thermal-high hydrostatic pressure treatment

At atmospheric pressure, inactivation of protease from B. subtilis in raw milk and pasteurized milk (with and without homogenization) was studied in a temperature range of 50–80 °C. Thermal inactivation followed a first order kinetic model in the temperature range tested. Temperature dependence of the first order inactivation rate constants could be accurately described by the Arrhenius equation, allowing Ea values to be calculated. Different milk systems did not show differences in enzyme thermo stability.The combined thermal (40, 50 and 60 °C)-high hydrostatic pressure (300–450 and 600 MPa) effect on protease activity was studied. Protease was very resistant to high pressures. Pressure stability was higher in raw milk than in pasteurized milk; homogenization appeared to have a protective effect on the enzyme. The separate effects of pressure and temperature on enzyme inactivation were related to changes in L?-values and milk appearance.A very pronounced antagonistic effect between high temperature and pressure was observed, i.e. at temperatures where thermal inactivation at atmospheric pressure occurs rapidly, application of pressure up to 600 MPa exerted a protective effect.Industrial relevanceHigh hydrostatic pressure (HHP) is an emerging technology that has been successfully applied as a minimal process for a variety of foods. Although the potential for the use of HHP treatment as an alternative method to heat treatment of milk was proposed almost a century ago, the suitability of this innovative technology to extend the shelf-life of milk hinges not only on its ability to inactivate pathogenic vegetative microorganisms but also on its effectiveness to inactivate indigenous and endogenous enzymes. This work examines the combined effects of temperature, pressure and homogenization on the protease (exogenous enzyme from B. subtilis) activity in milk. Inactivation of protease could extend the shelf life of milk.     

Diacetyl in Foods: A Review of Safety and Sensory Characteristics

Diacetyl, noted for its appealing butter‐like aroma, is present naturally in many foods, and humans have been exposed to it since the beginning of civilization. The advent of microwave (MW) cooking technology has led to the development of a significant market for MW popcorn, to which diacetyl and other flavoring compounds have been frequently added. Based upon reported associations between diacetyl inhalation and lung disease in employees of MW popcorn processing facilities, a very conservative safe level of occupational exposure to diacetyl has been proposed by the American Conference of Governmental Industrial Hygienists. Yet there is conflicting evidence that diacetyl causes lung disease in workers, and no evidence to condemn diacetyl as the cause of lung problems in MW popcorn consumers. Consumer dietary exposure to diacetyl in foods is below levels of health concern while common airborne levels of diacetyl from MW popcorn are far below the conservatively established limit to protect workers.     

Textile applications of commercial photochromic dyes: part8. A statistical investigation of the influence of photochromic dyes on thermoplastic fibres using a UV-irradiation technique

Abstract

This research investigates the influence of the commercial photochromic dye concentration, expressed as a percentage, and polymer type and their interaction on the photocoloration properties of the as-spun and drawn fibres regarding the melt-spinning process. As-spun fibres made of polypropylene, polyethylene and polyester were spun with different percentages of the photochromic dye, drawn, tested and analysed under a factorial experimental design using appropriate experimental and statistical methods. According to the analyses and by using an independent source of ultraviolet irradiation and traditional colour measurement instrumentation of the degree of photocoloration and background colour, the most effective and significant parameter influencing the as-spun fibre’s photocoloration properties are the polymer type; the dye percentage effect was noted in the degree of photocoloration. The effects of the multi-stage hot-drawing process on the photocoloration properties of the drawn polypropylene and polyethylene fibres were characterised and statistically modelled. The dyed fibres showed reversible photochromism, developing pronounced colours from weak background colours on irradiation with ultraviolet light and returning to their original state when the ultraviolet light source was removed. The dye percentage positively affects the photocoloration of the as-spun and drawn polypropylene and polyethylene fibres. A new forecasting data source was achieved to optimise the selection of the polymer and the dye percentage and to specify the direction of increasing or decreasing of the significant process parameters. Utilising the elastic properties of manufactured fibres, they could be used in the development of chromic textiles for creative design, functional or smart purposes.     

Cognitive responses to stress: Effects of changes in demand and sex.

Replicated a previous study with female Ss by M. J. Horowitz and S. Becker (see record 1972-02452-001) testing the theory that increased intrusive and repetitive thought after exposure to stressful events is a cognitive response tendency occurring in general population groups. Reports by 1 female and 27 male students of mental contents before and after neutral and stress films were analyzed. Data contrasted for male and female Ss and for different instructional demands show that the stress film exerted a significant influence on increase in intrusive and stimulus-repetitive thought; male-female differences and demand effects were nonsignificant. Results support the hypotheses that intrusive and repetitive thinking are general cognitive responses to stress and that such changes in conscious experience can be quantified in the laboratory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developing English domestic occupancy profiles

ABSTRACT

Occupancy patterns are necessary to estimate energy demand and evaluate thermal comfort in households. Because of this, many European countries are developing representative domestic schedules to replace outdated criteria. This paper evaluates the state of knowledge of UK domestic occupancy patterns and develops new domestic occupancy profiles for England. The presented research (1) characterizes methods for collecting occupancy data and inferring patterns; (2) identifies and assesses the quality of categories of occupancy patterns used in building simulation; and (3) develops updated occupancy profiles. A systematic scoping review identified social and monitoring surveys as the most deployed data-collection methods. A systematic literature review also established that the occupancy categories most frequently used in UK building simulation are (a) a family with dependent children where the parents work full time; and (b) a retired elderly couple who spend most of their time indoors. The interview sample from the English Housing Survey 2014–15 was used to map household typologies. Results show that categories (a) and (b) combined amount to only 19% of England’s households, which suggest models are over-reliant on these groups. Considering this result, the paper develops occupancy patterns for England derived from 2015 UK Time Use Survey diaries for each household typology previously identified.     

The Influence of Ethanol on the Foaming Properties of Beer Protein Fractions: A Comparison of Rudin and Microconductivity Methods of Foam Assessment

The effect of ethanol on the foaming properties of beer protein fractions was studied using a microconductivity method and nitrogen gas to generate the foam. Increasing the ethanol concentration resulted in a decrease in foam stability. Interfacial studies including thin film drainage and dilational elasticity measurements indicated that ethanol reduced the rigidity of the adsorbed protein layer resulting in accelerated drainage from the foam lamellae and increased probability of film rupture. These results conflict with data from the Rudin method (using nitrogen gas to generate the foam) which indicate that, at low concentration, ethanol improves foam stability. These apparently conflicting results may be explained by the foam positive effects of a decline in bubble size and increase in bulk viscosity observed for the Rudin method, contrasted with the negative influence of a reduction in surface viscosity observed for the microconductivity foam assessment method.     

The microRNA-455 Null Mouse Has Memory Deficit and Increased Anxiety,Targeting Key Genes Involved in Alzheimer’s Disease

The complete molecular mechanisms underlying the pathophysiology of Alzheimer’s disease (AD) remain to be elucidated. Recently, microRNA-455-3p has been identified as a circulating biomarker of early AD, with increased expression in post-mortem brain tissue of AD patients. MicroRNA-455-3p also directly targets and down-regulates APP, with the overexpression of miR-455-3p suppressing its toxic effects. Here, we show that miR-455-3p expression decreases with age in the brains of wild-type mice. We generated a miR-455 null mouse utilising CRISPR-Cas9 to explore its function further. Loss of miR-455 resulted in increased weight gain, potentially indicative of metabolic disturbances. Furthermore, performance on the novel object recognition task diminished significantly in miR-455 null mice (p = 0.004), indicating deficits in recognition memory. A slight increase in anxiety was also captured on the open field test. BACE1 and TAU were identified as new direct targets for miR-455-3p, with overexpression of miR-455-3p leading to a reduction in the expression of APP, BACE1 and TAU in neuroblastoma cells. In the hippocampus of miR-455 null mice at 14 months of age, the levels of protein for APP, BACE1 and TAU were all increased. Such findings reinforce the involvement of miR-455 in AD progression and demonstrate its action on cognitive performance.