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Fine titanium dioxide (TiO2) particles have been used as additives (E171) to modify the optical properties of foods and beverages for many years. Commercial TiO2 additives, however, often contain a significant fraction of nanoparticles (diameter <100 nm), which has led to some concern about their potentially adverse health effects. At present, relatively little is known about how the characteristics of TiO2 particles are altered as they travel through the human gastrointestinal tract. Alterations in their electrical characteristics, surface composition, or aggregation state would be expected to alter their gastrointestinal fate. The main focus of this study was, therefore, to characterize the behavior of TiO2 particles under simulated oral conditions. Changes in the aggregation state and electrical characteristics were monitored using particle size, ζ-potential, turbidity, and electron microscopy measurements, whereas information about mucin–particle interactions were obtained using isothermal titration calorimetry and surface-enhanced Raman spectroscopy. Our results indicate that there was a strong interaction between TiO2 and mucin: mucin absorbed to the surfaces of the TiO2 particles and reduced their tendency to aggregate. The information obtained in this study is useful for better understanding the gastrointestinal fate and potential toxicity of ingested inorganic particles.

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Mosquito-borne pathogens, including malaria, Zika, dengue, and chikungunya continue to be a major public health concern globally. Based on the understanding that only older female mosquitoes are infectious and represent a risk to human health, scientists have sought to age-grade mosquitoes for decades. To date, however, no reliable, cost-effective and practical methods exist to age older mosquitoes despite the tremendous epidemiological value of this approach. This study is the first attempt to develop a surface-enhanced Raman spectroscopic (SERS) method to age mosquitoes. The water extracts of Aedes aegypti mosquitoes aged 0-22 days were mixed with silver nanoparticles. The SERS spectra, which were analysed by principal component analysis and partial least square (PLS), demonstrated the capability of this approach to predict the calendar age of mosquitoes between 0 and 22 days with the coefficient of correlation (R) = 0.994 and 0.990 for PLS model calibration and validation, respectively. Spectral analysis with both SERS and infrared spectroscopy revealed the key biological sources leading to changes in spectra allowing mosquito age-grading is adenine-containing compounds and proteins. In addition, we evaluated the impact of two arthropod-borne pathogen deactivating pre-treatments (bleach and ethanol) on the discrimination capability of the SERS approach. The result shows the ethanol treatment has the potential to enhance the discrimination capability and the safety of the approach. This study represents the first step towards developing the SERS approach as a quick, reliable and field-deployable method for mosquito age-grading, which would significantly improve the effectiveness of vector-borne disease monitoring and prevention.

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Identifying sodium reduction strategies in processed foods remains a critical need toward improving public health. In this work, sodium absorption in potatoes was studied using sodium chloride osmotic solutions. The specific aims of this study were to quantify the diffusion of sodium into a potato sample and change process variables to determine how to alter sodium concentration in the samples. Sodium adsorption was quantified using linear correlation equations, derived from simplifications of Fick's second law. A sodium mass transfer coefficient (ks) was calculated from linear regression analysis. The parameter changes investigated were temperature, concentration and presence of anion species. Among these parameters, changes in temperature ranging above and below the starch gelatinization temperature resulted in the largest effect on sodium diffusion, followed closely by introduction of anion species larger than chloride. This research indicates that simple changes in cooking conditions can lead to significant mitigating strategies to reduce the sodium content in a model food system. Practical Applications The trends presented in this work represent a reliable way to predict the quantity of sodium that will diffuse into the potato matrix under the specified processing conditions. With careful control of these process variables, a meaningful reduction in final sodium content of processed potatoes can be reproducibly accomplished.

Summary Tocotrienols are members of the vitamin E family that provide many nutritional benefits. Developing tocotrienol‐fortified functional foods introduces vitamin E into consumers diets without changing their food habits. The purpose of this study was to compare the stability of tocotrienols in bulk form and six food matrices at a fixed dose (40 mg kg−1) under accelerated and conventional storage conditions. The delta‐ and gamma‐tocotrienol content was measured using HPLC, and the sensory attributes were evaluated using triangle and hedonic tests. Tocotrienol in bulk powder was less stable under stressed conditions than in bulk oil, with the powders having approximately 40% and 80% reduction in δ‐ and γ‐ after storage and bulk oil with no significant degradation. HPLC analysis demonstrated that tocotrienol content remained unchanged in dry mix lemonade, yogurt, raw and UHT milk, and margarine over time; however, complete degradation of γ‐ and partial degradation (up to 50%) of δ‐tocotrienol was observed in bread during ambient and stressed storage conditions. A significant decrease in the δ‐tocotrienol relative concentration was also observed in HTST processed milk samples. Tocotrienol addition was not perceived, and no significant difference in the product attributes and overall liking was reported in the discrimination sensory testing.

Characterization of titanium dioxide nanoparticles (TiO 2 -NPs) is significant to ensure its quality and safety in applications and facilitate risk assessment. Surface-enhanced Raman spectroscopy (SERS) is a novel technique for characterization of the size of TiO 2 particles. Herein, we investigated the key factors in the SERS analysis of anatase TiO 2 -NPs using a variety of wellcharacterized particle reference materials (8-173 nm) and gallocyanin (GLN) as a ligand for SERS. The result shows that regardless of the particle and ligand concentrations used, the R-value obtained from the ratio of TiO 2 (144 cm À 1 ) to GLN (1639 cm À 1 ) peak intensities was able to distinguish between the nano-sized particles from the micro-particles, although no significant difference was observed between 8 to 65 nm particles. This means particle size is the primary factor that affected the R. The concentration of the NPs and the ligand, respectively, could also affect the R as secondary factors and common dispersion methods such as adjusting the pH and the sonication did not affect the R. However, this method did not work in presence of a stronger binding dispersing agent such as sodium pyrophosphate (SPP). This study fulfilled the knowledge gap regarding the key factors that impacts the SERS analysis of TiO 2 -NPs which will facilitate the further application of this technique in the analysis of TiO 2 -NPs in food products and environmental matrices.