Solvent type affects the number, distribution, and relative quantities of volatile compounds found in sweet whey powder

This study compares the performance of diethyl ether, methylene chloride, methyl formate, and pentane in the analysis of volatile flavor components in sweet whey powder. Extracts were prepared from sweet whey powder using each solvent. Volatile components were isolated by solvent extraction followed by solvent-assisted flavor evaporation. Gas chromatography-mass spectroscopy, coelution with known standards, and retention indices were used to identify the volatile compounds. Sixty total compounds were either positively or tentatively identified across all 4 solvents, but the number, distribution between the molecular classes, and relative quantities detected depended on solvent type. The highest number, widest distribution, and greatest relative quantities were found using methylene chloride and methyl formate, whereas diethyl ether and especially pentane were noticeably less effective. Results are characterized using molecular-based characteristics of solvents and solutes including dipole moment, dielectric constant, Log P (octanol-water partition coefficient), polarizability, water solubility, and Lewis acidity/basicity. Polarity and acidity/basicity were the primary factors that determined solvent performance. This work establishes a molecular-level basis for the selection of solvents in the analysis of sweet whey powder flavors.     

Ingredients and pH are Key to Clear Beverages that Contain Whey Protein

ABSTRACT:  A challenge of shelf stable beverages that contain whey protein is that a small portion of protein can be denatured and aggregated during thermal processing, resulting in a turbid solution or white precipitate that consumers perceive as a defect. In this study, 3 approaches were taken to reduce turbidity in heat-treated beverages that contain whey protein: (1) centrifugation to remove insoluble protein aggregates, (2) addition of ingredients, and (3) alteration of pH in the range from 3.0 to 4.0. At pH 3.6 and below, all samples were essentially clear both before and after heating for all ingredients. At a pH of 3.8 and above, ingredient selection was crucial to solution clarity after heat treatment. At a pH of 4.0, addition of salts at both 10 and 50 mM increased the turbidity significantly compared to the control, which contained only whey protein in water. Neither addition of sugars at 25, 50, and 100 g/L, nor addition of sugar alcohols at 25 g/L significantly affected turbidity after heat treatment compared to the control. However, sugar alcohols added at 50 or 100 g/L significantly reduced turbidity after heat treatment compared to the control. Removal of insoluble protein aggregates by centrifugation prior to heat treatment resulted in a statistically significant decrease in turbidity after heat treatment. Understanding these results at the molecular level will assist food scientists in selecting processing treatments, ingredients, and pH in the development of shelf stable clear beverages that contain whey protein.     

Morning to evening changes of intramyocellular lipid content in dependence on nutrition and physical activity during one single day: a volume selective 1H-MRS study

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Intramyocellular lipids (IMCL) were shown to be metabolically highly active. In order to get insight into short-term regulation of IMCL and to reveal related problems with standardization in metabolic studies using the common signal ratio IMCL/Cr3, relative concentration changes from morning to evening in the same day were examined under four different nutritional and exercise conditions.     

Wavelength and temperature performance of polarization-transforming fiber

We have theoretically and experimentally investigated an optical fiber with circular polarization modes on one end and linear polarization modes on the other end. We call this fiber a polarization-transforming fiber because the local modes, or polarization states they represent, are converted from linear to circular, and visa versa, in the fiber. We have developed and implemented a postdraw process for making polarization-transforming fiber samples 30 mm long with losses less than 1 dB and a polarization-mode conversion from circular to linear greater than 20 dB. Also, we have modeled and measured the dependence on wavelength and temperature of polarization-transforming fiber samples. The measured normalized wavelength dependence of a sample fiber 30 mm long was approximately 1.4 x 10(-4) nm(-1), and the measured normalized temperature dependence was approximately 6 x 10(-4) degrees C(-1). These values are better in some cases than values for conventional high-birefringent fiber quarter-wave plates.     

Dispersion of the temperature dependence of the retardance in SiO(2) and MgF(2)

We have directly measured the retardance versus temperature for single-crystal quartz (SiO(2)) and magnesium fluoride (MgF(2)) at wavelengths of 633, 788, 1318, and 1539 nm and over a temperature range of 24-80 degrees C. To our knowledge, the temperature dependence of retardance for these two materials has not been directly measured. We compared our direct measurements of the normalized temperature derivative of the retardance gamma with derived values from previously reported indirect measurements and found our results to be in agreement and our measurement uncertainties to be typically a factor of 4 smaller. Our overall mean value for gamma(SiO(2)) is -1.23 x 10(-4) with a combined standard uncertainty of 0.02 x 10(-4) and little wavelength dependence over the 633-1539-nm range. Our overall mean value for gamma(MgF(2)) is -5.37 x 10(-5) with a combined standard uncertainty of 0.17 x 10(-5) and with a small wavelength dependence over the 633-1539-nm range.     

Evaluation of Dissociation Throughout the Lifespan.

In the past 20 years, the study of dissociation has flourished partly because of the research on the links between traumatic events and dissociation. Epidemiological studies have shown that dissociative symptoms and disorders are not uncommon. The nonspecialist in this area needs a guide to the extensive literature on the evaluation of dissociation across the lifespan to choose the most appropriate form of evaluation. The authors provide summaries of various types of assessment for dissociation in infants, children, teens, and adults. The techniques they review include structured interviews, specialized questionnaires, and scales on more general instruments, along with their psychometric properties. A good evaluation of dissociation can guide diagnosis, help focus treatment, and provide a measure of treatment efficacy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of alternative follow-up procedures on mail survey response rates.

Compared the effects on response rate by 700 consumers included in a large-scale mail survey of (a) not sending a follow-up letter, (b) sending a follow-up letter with a duplicate questionnaire and return envelope, and (c) sending a follow-up letter without duplicates. Results suggest that the best method is a follow-up without duplicates. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Annealing of linear birefringence in single-mode fiber coils:application to optical fiber current sensors

Annealing procedures that greatly reduce linear birefringence in single-mode fiber coils are described. These procedures have been successfully applied to coils ranging from 5 mm to 10 cm in diameter and up to 200 or more turns. They involve temperature cycles that last 3-4 days and reach maximum temperatures of about 850°C. The residual birefringence and induced loss, are minimized by proper selection of fiber. The primary application of these coils is optical fiber current sensors, where they yield small sensors that are more stable than those achieved by other techniques. A current sensor with a temperature stability of +8.4×10^-5/K over the range from -75 to +145°C has been demonstrated. This is approximately 20% greater than the temperature dependence of the Verdet constant. Packaging degrades the stability, but a packaged sensor coil with a temperature stability of about +1.6+10^-4/K over the range from -20 to +120°C has also been demonstrated     

Environmental tobacco smoke exposure and health effects in children: results from the 1991 National Health Interview Survey

OBJECTIVE: To determine the effect of environmental tobacco smoke exposure on the health of children in the United States. DESIGN AND SETTING: Cross-sectional study of children who participated in the 1991 National Health Interview Survey. PARTICIPANTS: 17448 children residing in the United States. MAIN OUTCOME MEASURES: Rates of respiratory illnesses and all illnesses, and the morbidity due to these illnesses, in children exposed to environmental tobacco smoke in the home daily compared with those in children not exposed in the home. Our analyses controlled for age, socioeconomic status, race, family size, sex, season, and region of the country. RESULTS: Children who were exposed to environmental tobacco smoke had a higher incidence of acute respiratory illnesses (relative risk (RR) = 1.10, 95% confidence interval (CI) 0.95 to 1.26) and all chronic respiratory diseases (RR = 1.28, 95% CI 0.99 to 1.65) than children who were not exposed, although both CIs included unity, and chance cannot be ruled out as being responsible for these findings. Children who were exposed to environmental tobacco smoke had, on average, 1.87 more days of restricted activity (95% CI 0.20 to 3.54), 1.06 more days of bed confinement (95% CI 0.20 to 1.92), and 1.45 more days of school absence (95% CI 0.40 to 2.50) per year than children who were not exposed. CONCLUSIONS: Environmental tobacco smoke exposure in the home, which is completely preventable, is an important predictor of increased morbidity in children.