Long-term stability of compression-molded soybean protein concentrate films stored under specific conditions.

Post-processing evolution of the functional properties of soybean protein concentrate (SPC) films, plasticized with varying levels of glycerol and processed by compression molding, was examined over a period of 90days. Films stored in the glassy state (25±2°C and 65±2% relative humidity) lost glycerol and water over time, as determined by gas chromatography and the decline in moisture content. SPC films plasticized with 40-50% glycerol showed a time-dependent increment of the elastic modulus and the tensile strength. In turn, the elongation, barrier properties, soluble mass and opacity of these films varied marginally with time. By contrast, films with 30% glycerol lost the most moisture and their elongation was reduced significantly, while water vapor permeability slightly increased with aging. The performance of aged films resulted from the balance between plasticizer and water loss, and the progressive replacement of unordered structures by intermolecular hydrogen bonded ß-sheets and aggregates.

Chronic Pain and Telomere Length in Community-Dwelling Adults: Findings From the 1999 to 2002 National Health and Nutrition Examination Survey.

Chronic pain is a common condition associated with psychological distress, functional impairments, and age-associated comorbidity. Preliminary studies, on the basis of relatively small sample sizes, suggest that the combination of chronic pain and stress is associated with telomere shortening, a widely recognized marker of cellular aging. We sought to determine the cross-sectional association of chronic pain with telomere length in 7,816 community-dwelling adults ages 20 years and older who participated in the 1999 to 2002 National Health and Nutrition Examination Survey. Consistent with previous studies, leukocyte telomere length was assessed using the quantitative polymerase chain reaction method and compared with a DNA reference standard to compute a telomere to single copy gene ratio. Standardized, in-person interviews were used to identify chronic regional pain and chronic widespread pain in 784 (10.0%) and 266 (3.4%) participants, respectively. Older age, male sex, obesity, and less physical activity were associated with shorter telomere length (P <.05 for all comparisons); however, there was no association of chronic pain with telomere length. The age-adjusted means (standard error) of telomere length telomere to single copy gene ratios were 1.04 (.02), 1.03 (.02), and 1.02 (.02) in participants with no chronic pain, chronic regional pain, and chronic widespread pain, respectively (P = .69). In addition, chronic pain did not modify the effects of age, sex, race/ethnicity, education, or psychological distress on telomere length. In summary, chronic regional and widespread pain were not associated with telomere length in this nationally representative study; however, we could not determine associations of pain duration and severity with telomere length because of limitations in pain assessment data. PERSPECTIVE: The findings from the current study do not support the hypothesis that chronic pain accelerates cellular aging measured according to leukocyte telomere length. Additional population-based studies with more detailed assessments of pain and stress are needed to further investigate potential interactive effects on telomere length and other biomarkers of aging.