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关键词： Brown rice   Germination   Roasting   Volatile compounds   Tea infusions  

摘要： Germinated brown rice was roasted for the preparation of tea. The germination induced substantial increases in reducing sugars (from 3224.06 to 5028.80 mg/100 g), free amino acids (from 62.51 to 165.07 mg/100 g), volatile compounds, and phenolics (10.06 to 14.27 mg GAE/100 g). Roasting decreased the residual contents of free amino acids and reducing sugars, but produced the volatiles and phenolics. Browning index was slightly decreased by the germination (from 22.69 to 20.13), but significantly increased by the subsequent roasting. The germinated BR (GBR) was more susceptible to roasting than native BR. Acrylamide content in the roasted GBR was significantly lower than that in the roasted BR, because of the lower asparagine content in GBR. Sensory evaluation revealed that a mild roasting for 5 min at 230 degrees C after germination for 2 days was appropriate to produce a brown rice tea.

关键词： Solution combustion synthesis   Sodium chloride   Thermodynamics   Iron oxide   Ni2+ ion removal  

摘要： Salt-assisted solution combustion synthesis (SSCS) method is a promising technique for synthesizing various nanopowders with ultra-fine particle size and high surface area. It is known that the introduced soluble salt into the synthesis process plays a role as a particle separator which leads to the particle size reduction. However, the potential effects of soluble salts on the thermodynamic aspects of SSCS procedure and the other physical and chemical properties of the obtained nanopowders have not been investigated in detail. In this study, various amounts of sodium chloride (1-15 mol for obtaining 0.3 mol iron oxide) were introduced to the iron nitrate-glycine system to investigate effect of alkali metal salt on the thermodynamics aspects of the synthesis process and the final properties of the prepared nanoparticles. Obtained results indicated that the phase composition of the synthesized nanopowders was varied from a mixture of Fe3O4+alpha-Fe2O3 to gamma-Fe2O3+alpha-Fe2O3, and eventually to single-phase alpha-Fe2O3 by increasing the amount of sodium chloride. Such phase transformation suggested that the phase composition of multi-phase compounds prepared via SSCS method can be controlled by sodium chloride. Ultra-fine powders with 9 nm particle size and surface area of 148 m(2)/g were obtained when 11mol sodium chloride was used in the synthesis process. Magnetization of the synthesized nanoparticles were decreased from 34emu/g to 2.7emu/g due to the decrement of particle size. The combusted single-phase hematite nanopowders were submitted to the 100 mL nickel ion (Ni2+) solution with the ion concentration of 50 mg/L to explore the effect of salt on the adsorption activity of the nanoparticles. 0.4g of the synthesized powders adsorbed similar to 90% of the nickel ions within 120 min. Note that the removal percentage of the nickel ion using the synthesized hematite nanoparticle (90%) was higher than that of prepared hematite powders in the previous studies (35%)

关键词： Upper-Division Undergraduate   Physical Chemistry   Internet/Web-Based Learning   Computer-Based Learning   Curriculum   Laboratory Computing/Interfacing  

摘要： In the midst of a global pandemic in spring 2020, physical chemistry faculty gathered to share strategies and resources for teaching remotely. During this conversation, instructors created a shared document compiling the challenges they faced in spring 2020 and ways to improve teaching and learning in the physical chemistry classroom and laboratory when institutions reopened in the fall. We present a content analysis of the shared document that provides a snapshot of physical chemists' thoughts at that moment in June 2020. The themes that emerged from our analysis are assessment, choice of learning objectives, course management, opportunities, resources, student motivation, and wellbeing. We have summarized the numerous strategies, resources, and implementation ideas that were shared by participants, many of which we believe will remain in use when traditional in-person instruction resumes. Finally, the conversation connected physical chemists, strengthening our community. Continued community engagement has occurred through further synchronous conversations, asynchronous conversations on our Slack workspace, and the creation of the repository PChem Inspired Pedagogical Electronic Resource (PIPER).

关键词： Inclusion complex   Intranasal administration   Cerebrospinal fluid   beta-Cyclodextrin (beta CD)   Hydroxypropyl-beta-cyclodextrin (HP beta CD)  

摘要： Recently, many studies have shown that plant metabolites, such as geraniol (GER), may exert anti-inflammatory effects in neurodegenerative diseases and, in particular, Parkinson's disease (PD) models. Unfortunately, delivering GER to the CNS via nose-to-brain is not feasible due to its irritant effects on the mucosae. Therefore, in the present study beta-cyclodextrin (beta CD) and its hydrophilic derivative hydroxypropyl-beta-cyclodextrin (HP beta CD) were selected as potential carriers for GER nose-to-brain delivery. Inclusion complexes were formulated and the biocompatibility with nasal mucosae and drug bioavailability into cerebrospinal fluid (CSF) were studied in rats. It has been demonstrated by DTA, FT-IR and NMR analyses that both the CDs were able to form 1:1 GER-CD complexes, arising long-term stable powders after the freeze-drying process. GER-HP-beta CD-5 and GER-beta CD-2 complexes exhibited comparable results, except for morphology and solubility, as demonstrated by SEM analysis and phase solubility study, respectively. Even though both complexes were able to directly and safely deliver GER to CNS, GER-beta CD-2 displayed higher ability in releasing GER in the CSF. In conclusion, beta CD complexes can be considered a very promising tool in delivering GER into the CNS via nose-to-brain route, preventing GER release into the bloodstream and ensuring the integrity of the nasal mucosa.

关键词： Undergraduates   Students   Molecules   Free radicals   Lasers  

关键词： Undergraduates   Students   Molecules   Free radicals   Lasers  

关键词： Undergraduates   Students   Molecules   Free radicals   Lasers  

关键词： Titanium dioxide  

摘要： Titanium dioxide is a food additive that has raised some concerns for humans due to the presence of nanoparticles. We were interested in knowing the fate of TiO2 particles in the gastro-intestinal tract and their potential effect on digestive enzymes. For this purpose, we analysed the behaviour of two different food grade TiO2 samples (E171) and one nano-sized TiO2 sample (P25) through a standardized static in vitro digestion protocol simulating the oral, gastric and intestinal phases with appropriate juices including enzymes. Both E171 and P25 TiO2 particles remained intact in the digestive fluids but formed large agglomerates, and especially in the intestinal fluid where up to 500 mu m sized particles have been identified. The formation of these agglomerates is mediated by the adsorption of mainly alpha-amylase and divalent cations. Pepsin was also identified to adsorb onto TiO2 particles but only in the case of silica-covered E171. In the salivary conditions, TiO2 exerted an inhibitory action on the enzymatic activity of alpha-amylase. The activity was reduced by a factor dependent on enzyme concentrations (up to 34% at 1 mg mL(-1)) but this inhibitory effect was reduced to hardly 10% in the intestinal fluid. In the gastric phase, pepsin was not affected by any form of TiO2. Our results hint that food grade TiO2 has a limited impact on the global digestion of carbohydrates and proteins. However, the reduced activity specifically observed in the oral phase deserves deeper investigation to prevent any adverse health effects related to the slowdown of carbohydrate metabolism.

关键词： Proteins  

摘要： Incorporating protein emulsified droplets into protein gels as active fillers have attracted much attention. However, using animal and plant protein mixtures emulsified droplets as the filler is lacking. We investigated the effect of emulsified droplets covered by potato protein (PP) and whey protein (WP) mixtures of different ratios (10/0, 9/1, 7/3, 5/5, 3/7, 1/9, 0/10) on mechanical, microstructural characteristics and digestion of emulsion-filled WP gels (EFWG). The results showed that the particle size of emulsified droplets increased with the enhancement of PP ratio, whereas their zeta-potential value decreased. Increasing the PP ratio improved the elastic moduli (G '), fracture stress and hardness of EFWG, while lowered the water holding capacity and swelling ratios of EFWG. Confocal laser scanning microscopy revealed that a higher PP ratio leads to a thicker gel skeleton and fine network. Although the enhancement of the PP ratio decreased disulfide bond content in EFWG, it improved the hydrogen bond and total non-covalent interactions in EFWG. Increased PP in filling emulsions delayed the release rate of the free amino group and free fatty acid during digestion. Moreover, the presence of NaCl improved the gel properties and digestion of EFWG. The findings of this study may provide information for developing new WP gel products with specific digestion rates.

关键词： Nanoparticles  

摘要： Curcumin, a polyphenolic compound isolated from turmeric, exhibits various biological activities. The application of this nutraceutical in foods, however, is limited due to its extreme hydrophobicity, inferior stability, and poor bioaccessibility. The purpose of this paper is to prepare alcohol-free curcumin-loaded zein/sophorolipid nanoparticles (Cur-Z/SNPs) by one-step self-assembly to overcome the abovementioned challenges of curcumin. In detail, Cur-Z/SNPs were formed by mixing curcumin, zein, and sophorolipid under neutral conditions without any organic reagents or high energy equipment. The encapsulation efficiency and loading capacity of Cur-Z/SNPs were 94.08% and 11.50%, respectively. The spherical shape of Cur-Z/SNPs was observed by using a transmission electron microscope. The self-assembly mechanism involved hydrogen bonding, hydrophobic and electrostatic interactions, and the crystalline nature of curcumin changed to amorphous during self-assembly. Cur-Z/SNPs enhanced the zein denaturation resistance. They exhibited complete redispersibility and improved the aqueous solubility by approximately 246 times compared with free curcumin. The fresh Cur-Z/SNPs exhibited physicochemical stability at pH 5.0-8.0, ionic strength within 250 mM, and storage at 25 degrees C and 4 degrees C for 30 days. Notably, Cur-Z/SNPs could achieve excellent storage stability at room temperature as compared to those at refrigeration. Furthermore, lyophilization had a positive effect on storage stability, did not change the pH stability, and slightly reduced the ionic strength stability. Besides, Cur-Z/SNPs increased the 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH) scavenging capacity compared to free curcumin. The bioaccessibility of curcumin was increased by about 6 times by Cur-Z/SNPs. These findings provided new insight into the application of hydrophobic nutrients in alcohol-free functional foods.