Changes in the physical properties of honey powder during storage

Honey powders produced by spray drying with the addition of Arabic gum and sodium caseinate were characterised in terms of the influence of storage time on the following physical properties: particle size, moisture content, water activity, bulk density, flowability and hygroscopicity. The storage affected those properties; after 12 weeks of storage, particle size decreased (except Arabic gum powder treated as a control sample), moisture content and water activity increased, hygroscopicity decreased. Changes in bulk density, particle size and moisture content caused the rise of Hausner ratio value; however, the powders were still characterised by a very good flow properties and low cohesiveness. The colour of reconstituted powders was also affected by storage; in most of samples, the darkening, reduction in redness and yellowness were observed. Colour parameters were the most stable in powders obtained with the addition of 2% w/w of sodium caseinate.     

EFFECT OF MICROBIAL ADSORPTION AT THE GAS/LIQUID INTERFACE ON OXYGEN ENHANCEMENT FACTORS

The adsorption of micro-organisms at the gas/liquid interface causes both an increase in the oxygen respiration rate and a decrease in the oxygen diffusion coefficient near the interface. An increase in the oxygen consumption rate increases the oxygen mass transfer rate into the bacterial broth but a decreased oxygen diffusion coefficient reduces the mass transfer rate. These two factors must be taken into account when enhancement factors are calculated.     

How valid are medical records and patient questionnaires for physician profiling and health services research? A comparison with direct observation of patients visits

OBJECTIVES: This study was designed to determine the optimal nonobservational method of measuring the delivery of outpatient medical services. METHODS: As part of a multimethod study of the content of primary care practice, research nurses directly observed consecutive patient visits to 138 practicing family physicians. Data on services delivered were collected using a direct observation checklist, medical record review, and patient exit questionnaires. For each medical service, the sensitivity, specificity, and Kappa statistic were calculated for medical record review and patient exit questionnaires compared with direct observation. Interrater reliability among eight research nurses was calculated using the Kappa statistic for a separate sample of videotaped visits and medical records. RESULTS: Visits by 4,454 patients were observed. Exit questionnaires were returned by 74% of patients. Research nurse interrater reliabilities were generally high. The specificity of both the medical record and the patient exit questionnaire was high for most services. The sensitivity of the medical record was low for measuring health habit counseling and moderate for physical examination, laboratory testing, and immunization. The patient exit questionnaire showed moderate to high sensitivity for health habit counseling and immunization and variable sensitivity for physical examination and laboratory services. CONCLUSIONS: The validity of the medical record and patient questionnaire for measuring delivery of different health services varied with the service. This report can be used to choose the optimal nonobservational method of measuring the delivery of specific ambulatory medical services for research and physician profiling and to interpret existing health services research studies using these common measures.     

The influence of sodium caseinate on the physical properties of spray‐dried honey

The aim of this work was to spray dry honey (rape and buckwheat varieties) with Arabic gum (AG) as a carrier alone or in combination with sodium caseinate (1% and 2% w/w NaCas) as a drying aid. Powder recovery ranged from 66.2 ± 0.7% to 75.8 ± 4.9%, and the values were significantly higher for samples containing NaCas. Powders were characterised by good flowability, the addition of NaCas had positive impact on this factor. However, the hygroscopicity of protein‐containing powders was higher, especially at 2% w/w of NaCas. Powders hygroscopicity was related to particle size: AG powder of the smallest particle size was the most hygroscopic, while the particle size did not affected flowability, which was strongly related to the feed solution composition. Based on the obtained results, it was concluded that the addition of 1% w/w of NaCas as a drying aid during buckwheat and rape honey spray drying with Arabic gum as a carrier is favourable, while the further increase of protein content does not give additional benefits.     

Endohedral and exohedral hybrids involving fullerenes and carbon nanotubes

Since fullerenes and carbon nanotubes (CNTs) were discovered, these materials have attracted a great deal of attention in the scientific community due to their unique structures and properties. The properties of both carbon allotropes can be modulated by chemical functionalization, and merging fullerenes and CNTs combines the electronic and optical properties of CNTs with the excellent electron acceptor characteristic of fullerenes; moreover, a synergistic effect of these hybrids can be found, as the properties of both the nanotube and the fullerene are affected by the presence of the other. In these hybrids, the fullerene can be located inside (endohedral) or outside (exohedral) the CNT and both types of hybrid have specific features. CNT-fullerene hybrids have been studied for various applications, including photovoltaics, optical limiting and flame retardancy amongst others. This review outlines the progress in research on CNT-fullerene hybrids, including endohedral and exohedral combinations, their properties, functionalization, applications and outlook.