Production and Characterization of Calcium Silica Aerogel Powder as a Food Additive.

In this study, mesoporous calcium silica aerogels were produced for use as an anticaking food additive in powdered foods. A low-cost precursor (sodium silicate) was used, and calcium silica aerogels with superior properties were obtained with different pH values (pH 7.0 and pH 9.0) by modeling and optimizing the production process. The Si/Ca molar ratio, reaction time, and aging temperature were determined as independent variables, and their effects and interactions to maximize the surface area and water vapor adsorption capacity (WVAC) were evaluated by response surface methodology and analysis of variance. Responses were fitted with a quadratic regression model to find optimal production conditions. Model results showed that the maximum surface area and WVAC of the calcium silica aerogel that was produced with pH 7.0 were achieved at a Si/Ca molar ratio of 2.42, a reaction time of 5 min, and an aging temperature of 25 °C. The surface area and WVAC of calcium silica aerogel powder produced with these parameters were found to be 198 m2/g and 17.56%, respectively. According to the results of surface area and elemental analysis, calcium silica aerogel powder produced at pH 7.0 (CSA7) had the best results compared to that produced at pH 9.0 (CSA9). Therefore, detailed characterization methods were examined for this aerogel. The morphological review of the particles was performed with scanning electron microscopy. Elemental analysis was performed via inductively coupled plasma atomic emission spectroscopy. True density was measured in a helium pycnometer, and tapped density was calculated by the tapped method. Porosity was calculated using an equation using these two density values. The rock salt was powdered with a grinder and used as a model food for this study, and CSA7 was added at a rate of 1% by weight. The results showed that adding CSA7 powder to the rock salt powder at a rate of 1% (w/w) improved the flow behavior from the cohesive region to the easy-flow region. Consequently, calcium silica aerogel powder with a high surface area and high WVAC might be considered as an anticaking agent to use in powdered foods.

Sugar beet powder production using different drying methods, characterization and influence on sensory quality of cocoa-hazelnut cream.

The sugar beet powders were produced by oven drying, freeze drying and spray drying methods. Spray-dried powder had spherical particles with smooth surfaces while powders obtained from other methods exhibited flaky shape of particles with irregular surface properties. Freeze drying led to higher porosity, higher phenolic content (466.08 ± 52.71 mmol GAE/g sample) and better flowability (lower angle of repose value) while spray-dried powder depicted better solubility and higher score in overall acceptability in sensory analyses when compared to other powder samples. Oven dried sugar beet powders exhibited the darkest color and lowest score in overall acceptability in sensory analysis. When the sensory attributes and powder properties are considered, spray-dried sugar beet powders might be more appropriate as a functional ingredient to be used in food formulations. On the other hand, more dietary fibre (12.45 ± 2.42 g/100 g powder) and more phenolics containing freeze-dried powders with better color attributes might be better choice in terms of functional properties. This study might be an attractive proposal for developing confectionery products enriched with whole sugar beet powder which have natural bio active substances to fulfill today's increasingly demanding consumer expectations.

Characterization of in vitro antifungal activities of small and American cranberry (Vaccinium oxycoccos L. and V. macrocarpon Aiton) and lingonberry (Vaccinium vitis-idaea L.) concentrates in sugar reduced fruit spreads.

In this study, cranberry and lingonberry concentrates were added to commercial sugar-reduced fruit spreads (raspberry-Aloe vera, strawberry-guava, and strawberry-lime), and tested for their antifungal activities. Selected strains of the species Absidia glauca, Penicillium brevicompactum, Saccharomyces cerevisiae and Zygosaccharomyces bailii, as well as xerophilic environmental isolates of the genera Penicillium and Eurotium were used for challenge testing. Initially, varying concentrations of synthetic antifungal agents, such as sodium benzoate, potassium sorbate and butyl 4-hydroxybenzoate were tested against these fungi on wort agar containing 31% fructose at different pH values. Subsequently, the experiments were conducted in fruit spreads containing different concentrations of cranberry and lingonberry concentrates. The results of this study demonstrate that these concentrates were able to inhibit growth of visible colonies of xerophilic and non-xerophilic fungi. Cranberry and lingonberry concentrates are interesting candidates for natural preservation against fungal growth in sugar reduced fruit spreads.