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关键词： CO oxidation   Removal of CO   Robust catalysts review   Physicochemical   Properties   Emerging catalysts  

摘要： Carbon monoxide (CO) is the most harmful pollutant in the air, causing environmental issues and adversely affecting humans and the vegetation and then raises global warming indirectly. CO oxidation is one of the most effective methods of reducing CO by converting it into carbon dioxide (CO2) using a suitable catalytic system, due to its simplicity and great value for pollution control. The CO oxidation reaction has been widely studied in various applications, including proton-exchange membrane fuel cell technology and catalytic converters. CO oxidation has also been of great academic interest over the last few decades as a model reaction. Many review studies have been produced on catalysts development for CO oxidation, emphasizing noble metal catalysts, the configuration of catalysts, process parameter influence, and the deactivation of catalysts. Nevertheless, there is still some gap in a state of the art knowledge devoted exclusively to synergistic interactions between catalytic activity and physicochemical properties. In an effort to fill this gap, this analysis updates and clarifies innovations for various latest developed catalytic CO oxidation systems with contemporary evaluation and the synergistic relationship between oxygen vacancies, strong metal-support interaction, particle size, metal dispersion, chemical composition acidity/basicity, reducibility, porosity, and surface area. This review study is useful for environmentalists, scientists, and experts working on mitigating the harmful effects of CO on both academic and commercial levels in the research and development sectors. (C) 2021 Elsevier Ltd. All rights reserved.

关键词： 化学  

ISBN: (纸本)9787030678256

摘要： 本书对实验内容采用组合式编排，即以一种或一类物质的多种物性或一种物性的多种测量方法构成系列实验，同时对每个实验提供扩展性实验设计策略。根据教学需要可对基础、设计、综合三个层次的实验灵活选择组合，以培养学生综合分析问题和解决问题的能力。全书分为绪论、组合实验系列和附录。组合实验系列包括7个系列共34个实验。附录包括6个物理化学实验技术专题和24个常用的重要物理化学数据表。

关键词： electron beam   myofibrillar protein   myosin   gamma-ray irradiation  

摘要： Myofibrillar protein (MPS) and myosin (MS) from grass carp was irradiated by gamma-ray and electron beam (EB) irradiation with different dose (2, 4, 6, 8, and 10 kGy). The changes in the physicochemical properties (solubility, Ca2+-ATPase activity, total and reactive sulfhydryl content, surface hydrophobicity [S-0-ANS]), and structure of MPS and MS were investigated in the present work. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that there were degradation and aggregation of MPS and MS caused by irradiation, and the disappearance of myosin heavy chains (MHC) irradiated by EB was earlier than that of irradiated by gamma-ray. As compared with MPS, the extracted MS was more easily destroyed. With the increase of irradiation dose, the particle size, solubility, Ca2+-ATPase activity, and SH content of MPS and MS decreased (p < .05), while the S-0-ANS first increased and then decreased. Two-way analysis of variance results suggested that the degree of protein denaturation depends on the irradiation mode and dose. Compared with gamma-ray irradiation, the EB irradiation had a greater impact on the physicochemical properties of MPS and MS.

关键词： Decontamination   Foodborne pathogen   Organic acid   Bioactive compounds   Quality parameters  

摘要： This study aimed to evaluate the effects of acetic acid, lactic acid, peracetic acid, sodium dichloroisocyanurate and hydrogen peroxide combined with ultrasound in the sanitization process of arugula, kale, cucumber, and strawberry. The natural contaminant microbiota (mesophilic aerobic bacteria and molds and yeast), physicochemical and nutritional quality (pH, titratable total acidity, soluble solids, vitamin C, phenolic compounds and antioxidant capacity), and Salmonella Enteritidis inactivation were investigated using hierarchical cluster analysis, k-means clustering method, and principal component analysis. Among the physicochemical properties, total phenolic compounds were the most sensitive to sanitization processes. Overall, decimal reductions between 0.7 and 3.3 log CFU/g were obtained for natural microbiota. Moreover, ultrasound improved the sanitizer's efficacy. Lactic acid and hydrogen peroxide combined with ultrasound significantly inactivated S. Enteritidis, as confirmed by scanning electron microscopy, with a reduction of 4 logs CFU/g. Decontamination efficiency between leafy vegetables (kale and arugula) and non-leafy vegetables (strawberry and cucumber) was the same for all treatments investigated. Sodium dichloroisocyanurate and ultrasound showed low microbial inactivation efficiency. Ultrasound combined with non-chlorinated compounds can be considered a promising strategy for the minimally processed vegetable industry to increase food safety.

关键词： Edible insects   Fortified muffin   Sensory profile   Microstructure   Color   Texture  

摘要： Insects are the most common animal group in the world and they constitute about 80% of the animal kingdom. Today, around 1600 insect species have been consumed by humans. The aim of this study was to explore the potential use of edible insect flours for the production of protein rich muffins. Proximate composition and sensory quality of muffins were also explored. The protein and fat content of resulting muffins were effectively improved. While grasshopper powder provided 12.91 +/- 0.40% protein content, mealworm powder enhancement obtained 36.56 +/- 1.26% fat content compared with control (p <= 0.05). Physical properties of resulting muffins were also investigated. GR-M sample presented the highest baking yield of 88.66 +/- 0.58%. On the other hand, fortification with edible insect powders led to have denser structures with the lower specific volume than the control;incorporation of 15% with mealworm powder obtained the lowest specific volume (1.14 +/- 0.02 cm(3)/g). As regard to textural parameters, inclusion of edible insect flours also affected the textural properties;muffins fortified with grasshopper powder showed a significantly (p <= 0.05) softer crumb with lower springiness, cohesiveness and chewiness while no significant differences (p > 0.05) in all textural properties except cohesiveness and adhesiveness between used insect types were observed. Sensory characteristics revealed that fortification of wheat flour by mealworm powder provided a muffin with liking score ranged from 6.70 to 8.70 for all attributes tested, therefore, indicating that mealworm powder could be an effective ingredient in increasing nutritional value of bakery products.

关键词： Whey protein   Nanoparticles   Aggregation   Powder   Physical properties  

摘要： Spray-dried whey protein isolate (WPI) powders were prepared at pilot-scale from solutions without heat (WPIUH), heated (WPIH) or heated with calcium (WPIHCa), which were analysed and compared with a control sample (WPIC). WPIC, WPIUH, WPIH and WPIHCa solutions had whey protein denaturation levels of 0.0, 3.2, 64.4 and 74.4%, respectively. Computerised tomography scanning showed that 52.6(,) 84.0, 74.5 and 41.9% of WPIC, WPIUH, WPIH and WPIHCa powder particles had diameters of <= 30 mu m. WPIHCa and WPIH powders were cohesive, while WPIC and WPIUH powders were easy flowing. Marked differences in microstructure were observed between WPIH and WPIHCa. There were no measured differences in wall friction, bulk density or colour.

关键词： Avicennia marina   Polysaccharide   Physicochemical properties   Antibiofilm   Antioxidant  

摘要： A low molecular weight polysaccharide, the AMLP was isolated from the leaves of Avicennia marina and sequentially purified using DEAE-Sepharose fast flow and size exclusion chromatography. Monosaccharide analysis suggested that AMLP is mainly composed of fucose (38.34 %), galactose (30.16 %), mannose (13.32 %), and rhamnose (18.18 %). IR spectroscopy and High-performance size-exclusion chromatography (HPSEC) analysis revealed that AMLP was a sulfated homogenous heteropolysaccharide, and their molecular weight observed was 1.31 kDa. The Spectroscopic analysis of AMLP comprised of (1,2)- alpha-L-Fucp, (1,6)-beta-D-linked galactan, alpha-rhamnose, and (1,4)-beta-D mannose residues. AMLP has a loosely arranged granular bead-like appearance present on the surface and also with the presence of some porous structures. The rheological properties of AMLP exhibited pseudoplastic properties with shear-thinning flow behavior. Congo red test and X-ray diffraction (XRD) results indicated the semi-crystalline nature of AMLP with a triple-helical structure. Thermogravimetric and Differential scanning calorimetry (TGA-DSC) analysis of AMLP found was thermally stable and its degradation temperature observed was 280 degrees C. Furthermore, AMLP exhibited potential antibacterial and antibiofilm properties against bacterial pathogens such as Listeria monocytogenes, Escherichia coli, Klebsiella pneumonia, Salmonella typhimurium, and Staphylococcus aureus. The In vitro antioxidant activities such as DPPH scavenging, Superoxide radical scavenging, OH radical scavenging, and reducing power activities of AMLP were evaluated and the results revealed that the tested antioxidant activities of AMLP were significantly (P < 0.05) increased with increasing the concentrations. Overall, these findings suggested that AMLP could be used as a potential candidate in pharmaceutical, cosmetics, and food industry applications.

关键词： Gluten free   Biscuits   Starch digestibility   Predicted glycaemic index   CATA  

摘要： The type and the amount of starch present in bakery products affect their glycaemic index. The control of glycaemic index in our diet can be relevant to reduce the risk of type 2 diabetes and heart diseases. The use of alternative flours to rice, maize, and their starches may improve the nutritional quality of gluten-free baked goods by reducing the glycaemic index. This work aimed at the formulation of satisfactory gluten-free biscuits by using underexploited flour mixes (from cereals, pseudocereals, and legumes), at the evaluation of their physical properties, starch digestibility and subsequent estimation of the glycaemic index. The presence of chickpea flour increased biscuit hardness and gluten-free flours darkened biscuit surface. The greatest differences in starch composition and its digestion were found between gluten-free samples and wheat-containing control. Experimental biscuits had also a lower predicted glycaemic index compared to commercial products, whereas experimental formulations presented similar values between each other. Consumers' acceptance and sensory profiling by Check All That Apply questionnaire were carried out. All formulations but one were above the acceptance threshold (50);crumbliness and easiness to swallow were drivers of acceptance, whereas sandiness exerted a negative impact on liking score.

关键词： Conjugation   emulsifying properties   Maillard reaction   polydextrose   whey protein isolate  

摘要： In this study, whey protein isolate (WPI) and polydextrose (PDX) were used to produce WPI-PDX covalent conjugates via dry-heating Maillard reaction, and their characteristics and functional properties including abilities to emulsify and stabilise the corn germ oil/water emulsions were measured. Compared with WPI alone, the WPI-PDX conjugates had higher water solubility and DPPH radical scavenging ability, and the derived emulsions exhibited good storage stability over 60 days prepared under these conditions: reaction time 24 h, conjugate concentration 4-6%, oil fraction ratio 0.6 and emulsion system pH 3-8. Further, we found that the emulsion possessed the best storage stability under the condition of 4% WPI-PDX conjugates and 0.6% oil fraction. These results provide a potent to prepare a beneficial Maillard conjugation following an optimised reaction condition and highlight the potential use of WPI-PDX conjugates as the emulsifier in food industry.

关键词： Nanostructured lipids carriers   Solid lipid   Liquid lipid   Ratio of solid to liquid lipid   Particle size   Zeta potential   Liposomes   Entrapment efficiency  

摘要： The aim of this work was to identify from a review of current literature the effects of lipids used in the development of Nanostructured Lipid Carriers (NLCs) on the physicochemical properties of the resulting formulation. The size of the solid lipid, affected by the molecular weight and the complexity of the structure, tends to affect the particle size of the final formulation proportionally;the higher the molecular weight and the more complex the molecular structure, the bigger the particle size of the NLCs. However, there is no straight correlation between the size and the structure of the liquid lipid and the particle size. Moreover, there seems to be a correlation of the solid to liquid lipid ratio which affects the particle size;there has been a trend of increasing particle size when more solid lipid was used. Regarding the entrapment efficiency, it is highly affected by the drug and its interaction with the lipids, as its solubility in the lipids needs to be high so the drug can stay entrapped within the lipid core. There was no direct correlation between the type of lipid used or the ratio and the zeta potential, which affects the stability of the NLCs. (c) 2021 American Pharmacists Association. Published by Elsevier Inc. All rights reserved.