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Limitations of microwave processing due to inhomogeneities of power input and energy absorption have been widely described. Over- and underheated product areas influence reproducibility, product quality, and possibly safety. Although a broad range of methods is available for temperature measurement and evaluation of time/temperature effects, none of them is sufficiently able to detect temperature differences and thermally induced effects within the product caused by inhomogeneous heating. The purpose of this review is to critically assess different methods of temperature measurement for their suitability for different microwave applications, namely metallic temperature sensors, thermal imaging, pyrometer measurement, fiber optic sensors, microwave radiometry, magnetic resonance imaging, liquid crystal thermography, thermal paper, and biological and chemical time-temperature indicators. These methods are evaluated according to their advantages and limitations, method characteristics, and potential interference with the electric field. Special attention is given to spatial resolution, accuracy, handling, and purpose of measurement, that is, development work or online production control. Differences of methods and examples of practical application and failure in microwave-assisted food processing are discussed with a special focus on microwave pasteurization and microwave-assisted drying. Based on this assessment, it is suggested that infrared cameras for measuring temperature distribution at the product surface and partially inside the product in combination with a chemical time/temperature indicator (e.g., Maillard reaction, generating heat-induced color variations, depending on local energy absorption) appear to be the most appropriate system for future practical application in microwave food process control, microwave system development, and product design. Reliable detection of inhomogeneous heating is a prerequisite to counteracte inhomogeneity by a targeted adjustment of process and product parameters in microwave applications.
Assuntos
Calefação , Micro-Ondas , Temperatura Alta , Reprodutibilidade dos Testes , TemperaturaRESUMO
Hydrocolloids are widely used in food processing because of their texture-forming abilities, which help to preserve the quality of sensitive compounds, e.g., in dried fruit foams, which have recently emerged in healthier alternative snacks. Our aim was to investigate the protective role of maltodextrin in improving the storage stability of fruit foams. This study evaluated the effect of maltodextrin concentrations on the stability of the following quality parameters: anthocyanins, ascorbic acid, color, texture, and sensory perception of dried foamed raspberry pulp during storage. This study compared three concentrations (5%, 15%, and 30% w/w) of maltodextrin in mixtures, evaluating their effect on the stability of these parameters over a 12-week storage period. The foam samples were stored at 37 °C to accelerate chemical reactions under vacuum packaging conditions which excluded oxygen. The addition of 30% maltodextrin to the raspberry pulp blend resulted in the highest retentions in all compounds tested, i.e., 74% for ascorbic acid and 87% for anthocyanins. Color and texture were similarly preserved. Adding 30% maltodextrin to the mixture did not negatively influence the acceptability of sensory perception. Maltodextrin thus represents an effective protective agent for preserving nutritional and sensory qualities for a longer storage period. Hence, using MD together with potato protein was optimal for enhancing the storage stability of fruit foam, which is important for the food industry.
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OBJECTIVE: Sleep, physical activity, and social domains of biological rhythm disruptions may have specific effects on the symptom cluster and severity of depression. However, there is a lack of structured clinical evaluation to specify the domains of biological rhythms in patients with depression. METHODS: Ninety drug-naïve subjects with depression and 91 matched healthy controls were recruited for the study. The severity of depression was examined with the Hamilton Rating Scale for Depression (HRSD), while biological rhythm was evaluated using the Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN). RESULTS: Patients with depression showed significantly greater biological rhythm disturbances than healthy controls in all domains of BRIAN (sleep, activity, social, and eating). BRIAN-Total correlated positively with HRSD-Total and HRSD-Total without sleep cluster. The sleep and activity domains correlated significantly with HRSD-Total score. Additionally, the sleep, activity, and social domains correlated significantly with HRSD-Total without the sleep cluster score. Regression analysis revealed the activity (ß = 0.476, t = 5.07, p<0.001) and sleep (ß = 0.209, t = 2.056, p = 0.043) domains may predict HRSD-Total score. CONCLUSION: Consideration of biological rhythm domains in clinical examination and focusing on the sleep and activity domains may hold promise for the management of depression.
Assuntos
Ritmo Circadiano/fisiologia , Transtorno Depressivo Maior/psicologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Estudos Transversais , Transtorno Depressivo Maior/terapia , Exercício Físico/psicologia , Terapia por Exercício , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Valores de Referência , Análise de Regressão , Sono/fisiologia , Fatores de Tempo , Adulto JovemRESUMO
Sleep may play a fundamental role in retinal regulation and the degree of retinal variables. However, no clinical study has investigated optical coherence tomography (OCT) parameters in patients with primary insomnia. All participants were evaluated with the insomnia severity index (ISI) and the Pittsburgh sleep quality index (PSQI). The retinal nerve fiber layer (RNFL), ganglion cell layer (GC), inner plexiform layer (IPL), macula and choroidal (CH) thickness were compared between 52 drug-naïve patients with primary insomnia and 45 age-gender-BMI-smoke status matched healthy controls (HC). The patients with primary insomnia differed from the HC regarding RNFL-Global (p = 0.024) and RNFL-Nasal inferior (p = 0.010); IPL-Temporal (p < 0.001), IPL-Nasal (p < 0.001); CH-Global (p < 0.001), CH-Temporal (p = 0.004), CH-Nasal (p < 0.001), and CH-Fovea (p = 0.019). ISI correlated with RNFL-Global and RNFL-Nasal inferior. The regression analysis revealed that ISI was the significant predictor for the thickness of RNFL- Nasal inferior (p = 0.020), RNFL-Global (p = 0.031), and CH-Nasal (p = 0.035) in patients with primary insomnia. Sleep disorders are seen commonly in patients with psychiatric, including ocular diseases. Adjusting the effect of insomnia can help to clarify the consistency in findings of OCT.
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Objective: Sleep, physical activity, and social domains of biological rhythm disruptions may have specific effects on the symptom cluster and severity of depression. However, there is a lack of structured clinical evaluation to specify the domains of biological rhythms in patients with depression. Methods: Ninety drug-naïve subjects with depression and 91 matched healthy controls were recruited for the study. The severity of depression was examined with the Hamilton Rating Scale for Depression (HRSD), while biological rhythm was evaluated using the Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN). Results: Patients with depression showed significantly greater biological rhythm disturbances than healthy controls in all domains of BRIAN (sleep, activity, social, and eating). BRIAN-Total correlated positively with HRSD-Total and HRSD-Total without sleep cluster. The sleep and activity domains correlated significantly with HRSD-Total score. Additionally, the sleep, activity, and social domains correlated significantly with HRSD-Total without the sleep cluster score. Regression analysis revealed the activity (β = 0.476, t = 5.07, p<0.001) and sleep (β = 0.209, t = 2.056, p = 0.043) domains may predict HRSD-Total score. Conclusion: Consideration of biological rhythm domains in clinical examination and focusing on the sleep and activity domains may hold promise for the management of depression.