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关键词： Plasma activated water (PAW)   Disinfectant   Pathogens (Staphylococcus aureus and Pseudomonas aeruginosa)   Reactive oxygen and nitrogen species (RONS)  

摘要： Presently, the world is using different types of disinfectants for various applications such as disinfecting instrument surfaces in the medical field, sanitizers in airplanes, wash-rooms, etc. These disinfectants carry various harmful chemicals that harm our ecosystem. Hence in search of more eco-friendly disinfectants, our research leads us to explore plasma activated water (PAW). PAW can be produced with the help of plasma interaction with water. This interaction changes the physicochemical properties of water and makes it reactive to kill pathogens. PAW can be used for a wide variety of applications such as food preservation, fast germination, sterilization agents, etc. In the present work, PAW has been formed using non-thermal plasma and different gas or gas mixture as plasma forming gas. Its physicochemical properties have been studied to identify pH value, oxidation reduction potential, and chemical species formed after plasma interaction with a water surface. Further, the study has been carried out to determine the disinfectant ability of PAW for two types of pathogens named Staphylococcus aureus and Pseudomonas aeruginosa. Different bactericidal methods have been adopted to confirm the results. SEM, fluorescence microscopy, and release of nucleic acids and proteins from raptured cell membrane of pathogens clearly show bactericidal efficacy of PAW. The important finding of the present work is the effective killing of pathogens by PAW in a short span of interaction time (<= 10 s). The PAW has a strong possibility of using it as a disinfectant to kill a wide variety of pathogens and micro-organisms.

关键词： chalco-halide glasses   glass transition temperature   microstructure   infrared transmission  

摘要： In this paper we report the structural, thermal, microstructural and infrared transmission properties of iodine doped (Ge20Se18Te62)(100 - x)I-x (where x = 0, 8) chalco-halide glasses. The density of the specimen has been calculated experimentally. Differential thermal calorimetry shows a single glass transition temperature but two crystalline peaks. The role of annealing (503 and 593 K for 2 h) has also been taken into account to investigate the structural, microstructural, and infrared transmission properties. X-ray diffraction study has revealed that on annealing there is an origin of hexagonal Te and orthorhombic GeSe2 microcrystals which are further supported by scanning electron microscopy.

关键词： Cassava   Freezing   Functional   Pasting properties   Storage  

摘要： Cassava root spoils rapidly after harvest but can be well preserved by storing under freezing. This study investigated the functional, chemical and physicochemical properties of flour produced from frozen cassava roots. Freezing period did not significantly (p < 0.05) alter the moisture, ash, fat and fibre, but had slight effect on the carbohydrate and protein contents of the flour. Lightness, yellowness index and bulk densities of the flour samples reduced with freezing period. While freezing did not significantly (p < 0.05) change the ability of the flour samples to absorb oil, a slight but significant increase in the water absorption capacity was observed. Potassium (1.29-3.46 mg/kg), sodium (1.24-1.28 mg/kg), and calcium (0.94-1.34 mg/kg) were the major minerals in the cassava flour samples. The cyanide content (10.80-22.95 mg/kg) reduced as freezing days increased but peak, setback, breakdown and final viscosities did not follow a particular pattern. The information from this study is important to further determine the industrial potentials of flour from stored cassava roots.

关键词： gliding arc   plasma treatment   polypropylene   surface energy   X‐   ray photoelectron spectroscopy  

摘要： In this research, the polypropylene (PP) sheets used for automotive bumper surface were treated using two methods: air atmospheric gliding arc plasma and flame modifications. Atomic force microscopy was applied to study the morphology of surfaces before and after treatment processes. While calculating the surface free energy (SFE), contact angle of the surfaces was measured, and the chemical composition of the PP surface was analyzed using X-ray photoelectron spectroscopy. Surface modifications by gliding arc plasma increased the ratio of the oxygen and nitrogen atoms on the surface by 100%, indicating that polar chemical functionalities form on the surface. The surface morphology was highly affected by gliding arc plasma treatments, which triggered an impact on roughness and etching. It was also found that the SFE was drastically increased by certain modifications. Noticeable improvement was also observed in wettability by the gliding arc plasma technique. In the next stage, polyurethane paints were coated on the treated and untreated PP surfaces. Then, we examined the flame and gliding arc plasma treatments' effect on coating properties of PP bumper, adhesion analysis, water immersion resistance, and sulfuric acid resistance. Finally, high-pressure carwash test and gloss analysis were conducted on the treated and untreated coated sheets, respectively.

关键词： Starch modification methods   Phenolics   Physicochemical property   Glycaemic control   Mechanism  

摘要： Background: Reduced postprandial blood glucose levels are beneficial for chronic diseases, such as type 2 diabetes and obesity. However, cooking native starches make them easily digestible, leading to a high peak of postprandial blood glucose level. Starch modification is widely used in reducing starch digestibility. Dietary phenolics, such as polyphenols and phenolic acids, have been reported to possess antidiabetic and anti-obesity activities. The interactions between starch and phenolics have been gradually revealed. Thus, using phenolics to modify starch and improve the quality of native starches has become increasingly popular. Scope and approach: In this review, the different methods used in starch modification with phenolics were investigated. Changes in the properties of starch structure and digestibility were also discussed. The glycaemic control effect and its mechanisms were proposed. Possible future research focusing on the improvement of the modification methods and the understanding of the health benefits of modified starch was suggested. Key findings and conclusions: Physical, chemical and enzymatic modification methods have been used in starch modification with phenolics. Physical modification methods, including pre-gelatinisation and non-thermal food processing technologies are the most commonly used methods. Phenolics usually form starch-phenolic complexes in the modified starch. Chemical and enzymatic modification methods are used to synthesise phenolic starch esters. Modified starches were reported to have decreased digestibility and altered starch aggregation structure. Moreover, they possess a slight glycaemic control effect and more in-vivo studies are needed. The potential mechanisms of this effect include inhibition of starch digestion and glucose transport, promotion of insulin secretion and sensitivity, activation of AMPK and appetite control.

关键词： Myofibrillar protein (MP)   Fluctuated low temperature combined with high-humidity thawing (FLHT)   Thermal stability   Moisture migration   Tertiary structure  

摘要： The physicochemical and structural changes in myofibrillar proteins (MPs) from porcine longissimus dorsi under low temperature combined with high-humidity thawing (4 degrees C, 90% RH, LHT) and fluctuated low temperature combined with high-humidity thawing (2 -> 6 -> 2 degrees C, 90% RH, FLHT) treatments were compared with those under refrigerator thawing (RT). The changes in the thermal stability and viscoelasticity of the MPs after FLHT treatment was insignificant (P < 0.05) compared with the corresponding properties of the fresh samples. In addition, FLHT resulted in a desirable water distribution, the highest total sulfhydryl content, and the lowest carbonyl content compared to the other treatments, suggesting that it effectively decreases protein oxidation. FLHT also led to slight changes in the aggregation and integrity of the MPs. Furthermore, a stable tertiary structure was obtained through FLHT. In contrast, the largest variations in all indicators of the MPs were observed following RT. These results confirmed that FLHT reduced the physicochemical deterioration of MPs from porcine muscle, thereby indicating the potential of FLHT for application in the thawing of meat.

关键词： Cassava foam   Foam thickness   Cyanogenic glucosides   Falling rate   Moisture diffusion   Microstructure  

摘要： Fresh cassava is highly susceptible to rapid post-harvest physiological deterioration due to the high water activity. Therefore, foam mat drying was considered as an alternative drying technique for preservation. The drying kinetics of white-fleshed cassava foam (air volume fraction = 0.26, overrun = 36.0 %) and yellow-fleshed cassava foam (air volume fraction = 0.24, overrun = 32.2 %) were studied. The influence of temperature and foam thickness on moisture removal ratio (MR), drying rate, diffusivity and some important physicochemical properties of the cassava foams (CSF) during drying were researched and compared with those of non-foamed cassava pulp (NFP). The cassava foams were dried to foam powders at temperatures of 50 degrees C, 65 degrees C and 80 degrees C and foam thicknesses of 6 mm, 8 mm and 10mm. The CSF exhibited two falling rates. The CSF powders had significantly lower totalcyanogenic glucosides content compared to the NFP powder, and a high retention of total carotenoids. The dry foam powders had higher lightness/luminosity (L*) values than dry pulp powders. Micrographs revealed interactions between starch granules and the hydrocolloids but microstructure was not affected by increasing temperatures. (C) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

关键词： glutelin   lipids   oxidation   rice   starch  

摘要： Background and objectives Starch properties are closely related to the rice quality as starch interacts with other components during rice storage. However, several studies have neglected that the changes in proteins and lipids influence the properties of starch in rice. Herein, we used an artificial climate chest to characterize the effect of glutelin and lipid oxidation on the physicochemical properties of starch during rice storage. Findings Oxidation occurs in glutelin and lipids during the rice storage stage (p < .01). The oxidation indexes of glutelin and lipids showed the same significant negative correlation in peak viscosity (PV), breakdown (BD), and setback (SB). In contrast, concerning amylose content, final viscosity (FV), and SB, the oxidation of glutelin rather than lipids was more closely related to the changes observed in starch properties (p < .01). Lipid oxidation significantly correlated with trough viscosity (TV) and amylopectin content than glutelin oxidation (p < .01). Conclusions All the oxidation indicators of glutelin and lipids were inversely correlated with BD and SB (p < .01). Carbonyl compound content and fatty acid oxidation were significantly correlated with the physicochemical properties of rice starch. Significance and novelty The physicochemical changes in starch are closely related to the oxidation of glutelin and lipids, which can be used as indicators for assessing rice quality.

关键词： Xanthan gum   Lysozyme   Nanoparticle   High pressure homogenization  

摘要： The electrostatic self-assembly between protein and polysaccharide is a widely used method to fabricate biopolymer nanoparticles (NPs). In the present study, a novel NPs material was prepared by the high pressure homogenization (HPH) electrostatic self-assembly complexes of xanthan gum and lysozyme using the same charge at pH 12. Dynamic light scattering studies showed that the HPH treatment (30 MPa, 5 min) resulted in a smaller particle size and larger surface charge. Cryo-scanning electron microscopy imaging results suggested that the HPH-NPs had a circular shape and the surface structure of HPH-NPs was compact. Circular dichroism spectrum and intrinsic fluorescence spectrum revealed that the secondary and tertiary structures of lysozyme changed due to the HPH treatment. By non-covalent binding with xanthan gum, the surface hydrophobicity of lysozyme increased. Fourier transform infrared spectroscopy results indicated that the hydrogen bonding and electrostatic interaction may be the major factors causing the formation of HPH-NPs. The HPH-NPs exhibited a good solubility, emulsification and antimicrobial activity. Therefore, our HPH-NPs material has a good potential use as the beverage ingredient for inhibiting the pathogen growth, and in turn benefiting the resultant products with a good safety.

关键词： Condensation   Imidazole derivatives   Density functional theory   Electrochemistry   Absorption and fluorescence properties  

摘要： In this study, the synthesis and physicochemical properties (thermal, electrochemical and optical) of three phenanthro[9,10-d]imidazole derivatives with N-donor substituents (PI-1 - PI-3) was presented. All compounds were obtained by condensation reactions with a yield in the range of 61-70%. Their structure was confirmed by NMR spectroscopic methods (H-1, C-13, H-H COSY, H-C HMQC and H-C HMBC). The synthesized derivatives were characterized by high thermal stability (above 300 degrees C). Two of them (PI-1 and PI-3) showed a fully reversible oxidation process, which allowed detailed spectroelectrochemical and electrochemical studies. Absorption and emission properties were tested in four solvents of different polarity. These compounds showed high quantum yields in the range from 18 to 80%. Studies on physicochemical properties have been extended to include detailed theoretical considerations.