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关键词： flaxseed oil   high load   isomaltooligosaccharide   Maillard reaction products   sodium caseinate  

摘要： High-load flaxseed oil microcapsule is prepared with the Maillard reaction products (MRPs) of sodium caseinate and isomaltooligosaccharide as wall material. It is found that the emulsifying activity index and emulsion stability index of MRPs are increased by 31.32% and 34.11% respectively at the appropriate degree of graft (26.30%) compared with the mixture of sodium caseinate and isomaltooligosaccharide. Smaller droplet size and lower polydispersity index can be achieved in the flaxseed oil emulsions coated by MRPs, due to the change of sodium caseinate molecular weight and spatial structure. The microencapsulation efficiency of the microcapsules coated by MRPs is highly improved up to 98.22% at oil load of 58.43%, compared with the control group. Furthermore, MRPs as coating material can protect flaxseed oil against lipid oxidation at 50 degrees C for 4 weeks. More importantly, the smooth, round, and compact external surface structures of microcapsule powder support its physical necessity for industrial usage. Due to its high microencapsulation efficiency and good oxidation stability, MRPs formed with sodium caseinate and isomaltooligosaccharide show great application potential in preparing high load oil microcapsule.

关键词： geochemical classification   major oxides   provenance   South India   weathering indices   Yercaud lake  

摘要： Freshwater lakes and sediments need to be monitored continuously for environmental assessment and geochemical explorations. Lake sediments are major sinks for organic matter and for all geochemical elements. In the present study, total organic matter (TOC), nitrogen (TN), and geochemical analysis of major oxides was carried out on Yercaud Lake surface sediments, located at a higher elevation in South India to infer sediment distribution pattern and source for organic matter. Particle size distribution of lake surface sediments suggests that the sediments are predominantly silty sand and sandy silt, poorly to very poorly sorted and symmetrically skewed. TOC/TN ratio (6.54-12.65) reveal that the organic matter (OM) is derived from the in situ lake sources particularly from the vascular plants and lake biota accumulation. Weathering indices that fall from [chemical index of alteration (CIA)] 88.59-93.08 values and A-CN-K plot reflects intense chemical weathering of the bedrock exposures in the source area, which was accelerated under warmer and humid climate conditions in the sub-tropical regions. Al2O3/TiO2 ratio (6.94-26.62) indicates weathering particularly of the exposed charnockite rocks around the lake basin.

关键词： Casein  

摘要： Effects of pH adjustment on physicochemical properties of microfiltration retentates of skim milk and rehydration of resulting micellar casein concentrate (MCC) powders were investigated. Aliquots of retentate (pH 6.9) were adjusted to pH 7.3, 7.6 or 7.6 followed by readjustment to pH 6.9 (6.9R) prior to powder preparation. The retentates with pH 6.9, 7.3, and 7.6 had casein micelle size of 179, 189 and 197 nm, respectively, while sample 6.9R had size of 183 nm, similar to retentate at pH 6.9. Higher retentate pH resulted in lower ionic calcium and higher conductivity, with sample 6.9R having higher values for both parameters than the pH 6.9 sample. The MCC powders displayed poorer wettability and enhanced dispersibility with increasing retentate pH. Interestingly, the 6.9R powder had the best wettability and dispersibility. This study demonstrated that pH-mediated modifications of the physicochemical properties of retentates improve the rehydration properties of resultant MCC powders. (c) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://***/licenses/by/4.0/).

关键词： Polymer stability   Chitosan   Rheology   Pyroligneous liquor   Pyroligneous acid   Fluorescence spectroscopy   Ultraviolet radiation  

摘要： Pyroligneous liquor and chitosan are natural and biodegradable products from renewable sources. Both present antimicrobial and antioxidant activities and induce resistance in plants, making these products promising to be used as raw material for agricultural inputs. Chitosan, dissolved in distilled pyroligneous liquor (DPL) from Eucalyptus grandis, produces colloidal systems with high ultraviolet absorption and it could be proposed as plant protective coating, based on their intrinsic characteristics. Chitosan undergoes degradation in an acidic environment;therefore, it is necessary to understand the stability of colloidal systems. We evaluated the systems obtained from chitosan and DPL for their physicochemical properties and structural characteristics at storage times at room temperature (20 +/- 5 degrees C) up to 30 months. The colloidal systems presented a Newtonian flow during the storage time evaluated. Posteriorly, the colloidal systems were destabilized and the precipitates (PPT) were analyzed. Phenolic compounds from DPL were attached to the chitosan chains;this result is supported by fluorescence spectroscopy performed with PPT dissolved in non-fluorescent buffer. The PPT were fluorescent with emission maxima changing to higher wavelengths with storage time. The amounts of total phenols attached to polymer chains increased over time. As a result, there is an increase in the absorption of ultraviolet radiation with storage time. The results show that colloidal systems composed by chitosan formed complexes with phenolic compounds from DPL, which are promising for application in agriculture.

关键词： Exopolysaccharide   Weissella cibaria MD2   Fructan   Thermostable   Antioxidant  

摘要： In the present work, a probiotic bacteria Weissella cibaria MD2 was used for the production of exopolysaccharide (EPS), which was characterized and evaluated for several technological and biological activities. The RSM assisted optimization resulted in maximum production of EPS (12.58 g/L) when the MRS broth was supplemented with optimal carbon and nitrogen source. The EPS produced was purified using chromatography techniques and the monosaccharide analysis by HPLC showed that it was a fructan EPS. The NMR analysis suggested that the EPS MD2 is an inulin-type linear polysaccharide that consists of beta (1 -> 2) linkage. The scanning electron microscopy (SEM) images revealed that EPS MD2 has a thin sheet-like appearance with fewer fibers-like structures. The results from the thermal analysis showed that the EPS MD2 was highly thermostable and possess a degradation temperature of 279.90 degrees C. The x-ray diffraction pattern showed that the powdered EPS MD2 has a semi-crystalline nature. The EPS MD2 showed excellent antioxidant activities to scavenge free radicals. The fructan EPS showed a promising effect in increasing oxidative stress tolerance and enhancing the lifespan of C. elegans by activating the nuclear localization of DAF-16. The incredible physico-chemical and antioxidant properties (in vitro and in vivo) of this EPS can be implemented in the pharmaceutical and food industry.

关键词： Cellulose   Torrefaction   Physicochemical property   Pyrolysis   Kinetics  

摘要： Torrefaction pretreatment can upgrade biomass by reducing its oxygen content. In this study, torrefaction pretreatments with different severities (200 ?C, 230 ?C, 260 ?C, and 290 ?C) were employed to study their effects on the pyrolysis behaviors and kinetics of cellulose. Results showed that pretreatment at 290 ?C was highly effective for oxygen removal. Among the torrefied samples, the solid product of cellulose torrefied at 290 ?C had the lowest mass yield of 81.80%, lowest energy yield of 89.60%, highest carbon content of 44.91%, and highest HHV of 16.67 MJ kg-1. Pyrolysis activation energy of torrefied cellulose changed slightly at 200?260 ?C, but increased significantly at 290 ?C. According to XRD results, at the torrefaction temperature of 290 ?C, the crystal structure of cellulose changed significantly. The results of Py-GC/MS showed that the relative contents of anhydrosugars in the bio-oil were decreased by torrefaction pretreatment. The high temperature at 290 ?C has the most significant effect on the performance of bio-oil.

关键词： Chitosan   microcapsule   volatile compound   wall material   yoghurt flavour  

摘要： Yoghurt-flavoured bases have many applications in food industry, but the poor stability in the volatile compounds limits their applications. In this study, the morphology and physicochemical properties of yoghurt-flavoured base microcapsules were evaluated with four different wall materials including chitosan, beta-cyclodextrin, octenyl succinate anhydride and maltodextrin solution by spray drying. The encapsulation efficiencies of these four microcapsule formulations exceeded 93%. Microcapsules produced by chitosan possessed the best physical properties with improved encapsulation efficiency and smooth microstructure, so chitosan was selected as the encapsulating material of yoghurt-flavoured bases. Compared with those without chitosan, the encapsulated yoghurt-flavoured bases with chitosan had smaller particle size, better water solubility and moisture resistance as well as better stability. Furthermore, microencapsulation and spray drying technology can preserve many volatile compounds and the proportion of ketones, aldehydes, alcohols and other compounds increased. Hence, chitosan is a microcapsule material suitable for outputting solid yoghurt-flavoured bases.

关键词： Low-dimensional structures: growth, structure and nonelectronic properties   nanocomposites   energy-dispersive X-ray spectroscopy   mouse embryonic fibroblast cells   nanoparticles   wounds   biological characterisation   Biomedical materials   physicochemical characterisation   contact angle   contact angle tests   Structure of solid clusters, nanoparticles, nanotubes and nanostructured materials   tissue engineering   biologically produced tellurium nanoparticles   enzymes   nanofibres   in vivo wound healing properties   potential wound dressing scaffold   tensile analysis   electrospinning   biomedical materials   Physical chemistry of biomolecular solutions and condensed states   gelatin   scanning electron microscopy   Fourier-transform infrared spectroscopy   surface hydrophobicity   molecular biophysics   malondialdehyde   Fluid surface energy (surface tension, interface tension, angle of contact, etc.)   Patient care and treatment   collagen formation   elemental mapping   polymer fibres   biochemistry   Te NP-containing scaffolds   mechanical properties   nanomedicine   wound healing activity   cellular biophysics   polycaprolactone-gelatin electrospun nanofibres   Cellular biophysics   hydrophobicity   Nanotechnology applications in biomedicine   biodegradable materials   thermogravimetric analysis   Fourier transform infrared spectra   nanofabrication   X-ray chemical analysis   Electromagnetic radiation spectrometry (chemical analysis)  

摘要： The biologically synthesised tellurium nanoparticles (Te NPs) were applied in the fabrication of Te NP-embedded polycaprolactone/gelatin (PCL/GEL) electrospun nanofibres and their antioxidant and in vivo wound healing properties were determined. The as-synthesised nanofibres were characterised using scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy and elemental mapping, thermogravimetric analysis (TGA), and Fourier-transform infrared (FTIR) spectroscopy. The mechanical properties and surface hydrophobicity of scaffolds were investigated using tensile analysis and contact angle tests, respectively. The biocompatibility of the produced scaffolds on mouse embryonic fibroblast cells (3T3) was evaluated using MTT assay. The highest wound healing activity (score 15/19) was achieved for scaffolds containing Te NPs. The wounds treated with PCL/GEL/Te NPs had inflammation state equal to the positive control. Also, the mentioned scaffold represented positive effects on collagen formation and collagen fibre's horizontalisation in a dose-dependent manner. The antioxidative potency of Te NP-containing scaffolds was demonstrated with lower levels of malondialdehyde (MDA) and catalase (similar to 3 times) and a higher level of glutathione (GSH) (similar to 2 times) in PCL/GEL/Te NP-treated samples than the negative control. The obtained results strongly demonstrated the healing activity of the produced nanofibres, and it can be inferred that scaffolds containing Te NPs are suitable for wound dressing.

关键词： pH   Long-term field experiment   Soil organic matter transformation   Bacterial community   Fungal community   Tropical soil   No-till system  

摘要： Unsustainable agricultural management practices such as non-conservationist tillage and overuse of fertilizers result in soil acidity and, in turn, soil degradation due to reduced carbon (C) concentrations and nutrient availability and increased aluminum toxicity. Application of lime (L) and phosphogypsum (PG) can overcome these constraints and improve soil quality, but the long-term effects of these amendments on both abiotic and biotic soil properties are not known, particularly when applied in combination. Here, we evaluated the effects of L (acidity corrective), PG (soil conditioner), and their combination (LPG) on soil organic matter (SOM) transformations, soil chemical and physical properties, and microbiome assembly in a long-term experiment under a no-till crop rotation system in a tropical soil. The Ca-based soil amendments increased C concentrations (labile and stable fractions), improved soil physicochemical properties, and changed the associations between several bacterial and fungal groups. Contrary to expectations, the acidic soil amended with PG exhibited greater number of significant shifts in the bacterial community than soil amended with L or LPG, as well as higher soil bulk density. By contrast, the fungal community underwent greater shifts in soil amended with L or LPG, which had higher macroporosity. L and LPG amendment shaped the fungal community and rearranged the SOM fractions at similar rates, suggesting an essential role of the altered fungi in SOM transformation. In addition, combining L with PG increased the relevance of many low-abundance microorganisms, especially fungi, compared with the control, indicating an increase in their ecological role in the soil. Finally, by applying general joint attribute modeling and sensitivity analysis, we determined that soil fertility increased most in LPG-amended soil, as the ensuing changes in the bacterial and fungal communities resulted in improved SOM fractions, soil physical characteristics and,

关键词： Wet glycation   D-allulose   Soy protein   TD-NMR  

摘要： On a lab-scale, glycation is generally a lengthy process that would be costly if replicated on an industrial scale. In this study, a simplified method for glycating soy protein isolate has been developed. Soy proteins were glycated with allulose, fructose, and glucose in the presence of water. Free amino group content, protein solubility, browning index, and reducing sugar concentration were measured for the glycated proteins. Fourier Transform Infrared (FT-IR) spectroscopy was used to examine structural changes, and hydration behavior was evaluated using Time Domain Nuclear Magnetic Resonance (TD-NMR) relaxometry through T-2 relaxation time measurements. The results showed that proteins could be glycated under these austere conditions and with minimal control. It was found that high temperatures were not favorable for glycation, and lower temperatures could be preferred. At high temperatures, proteins become more denatured and less soluble, as shown through the Lowry method for protein solubility and TD-NMR results. Higher browning was observed at a higher temperature, primarily when allulose and fructose were used for glycation. The highest glycation was obtained with glucose, while allulose and fructose showed the lowest reactivity under the proposed conditions. Proteins with low solubility had longer T-2 relaxation times, indicating more free water and weaker water-binding capability.