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关键词： Ultrasound pretreatment   Antioxidant activity   Lupin protein hydrolysate   Secondary structure   Circular dichroism   FTIR  

摘要： In our study, the effects of high-power (400 W) and low-frequency (20 kHz) ultrasound pretreatment applied for different durations (5, 10, and 20 min) and proteases (alcalase and flavourzyme) on the physicochemical, structural, and antioxidant properties of lupin protein hydrolysates (LPH) were examined. Changes in structural characteristics of the isolates and the resulting hydrolysates were measured using circular dichroism (CD), Fourier-transform infrared (FTIR), and UV-Vis spectroscopic techniques. Antioxidant activities of the LPH were assessed using 2,2-diphenyl-1picrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assays. Physicochemical properties including the yield of hydrolysate, relative crystallinity, and surface charge were also evaluated. FTIR analysis revealed that ultrasound pretreatment altered the secondary structure of the proteins as indicated by the movement of absorption peaks to higher wavelength. Also, CD studies showed a reduction in alpha-helix and increase in the beta-sheet component of LPH samples after ultrasound pre-treatment except hydrolysates prepared using flavourzyme. The particle size, zeta potential, and relative crystallinity of the hydrolysates were significantly affected by ultrasonication time and enzyme type. Also, ultrasonication had a noticeable impact on the antioxidant activity as maximum DPPH activity was recorded after 10 min sonication in hydrolysates prepared using alcalase and flavourzyme. In addition, yield of hydrolysate increased significantly (p < 0.05) after ultrasonication pretreatment. Principal component analysis also produced a two-principal component model that explained 65.33% of total data variation. It may be suggested that application of ultrasound treatment to lupin protein could enhance the various characteristics including physicochemical and antioxidant activities of its hydrolysate.

关键词： Polymers   Pit and fissure sealants   Anti-bacterial agents   Dental caries   Resins   Rynthetic  

摘要： Objectives: This study aimed to (1) formulate blend resins with 2.5 or 5 wt.% of the methacrylate monomer 1,3,5triacryloylhexahydro-1,3,5-triazine (TAT), and (2) to evaluate the blend resins regarding the physicochemical and biological properties. Methods: The base resin was formulated mixing 60 wt.% of bisphenol A glycol dimethacrylate and 40 wt.% of triethylene glycol dimethacrylate with photoinitiator/co/initiator system. TAT was added at 2.5 (G2.5%) or 5 (G5%) wt.%, and a group without TAT was used as control (Gctrl). The resins were analyzed for degree of conversion (DC), Knoop hardness (KHN), softening in solvent (Delta KHN), ultimate tensile strength (UTS), contact angle, surface free energy (SFE), antibacterial activity against Streptococcus mutans biofilm formation, and cytotoxicity against human keratinocytes. Results: There was no difference for the DC (p = 0.676). The addition of TAT at 5 wt.% induced higher KHN (p<0.001), higher resistance against softening in solvent (p<0.001), and higher UTS (p = 0.04). There were no statistically significant differences for contact angle with water (p = 0.106), alpha-bromonaphtalene (p = 0.454), and SFE (p = 0.172). The higher the TAT concentration, the higher the antibacterial activity (p<0.001). G2.5% showed no cytotoxicity compared to Gctrl (p>0.05), and G5% induced lower cell viability (p<0.05). Conclusions: The addition of 2.5 wt.% of TAT is suitable for conveying antibacterial activity for dental resins without changing the physicochemical properties or impairing the cytotoxic effect. Clinical relevance: Methacrylate monomers that decrease bacterial viability and copolymerize with the resin matrix are exciting approaches to developing therapeutic materials. TAT showed promising properties to may hamper and prevent carious lesions when incorporated into dental materials. Further evaluations with higher cariogenic challenges will be carried to analyze the formulated materials.

关键词： Poly(vinylidene fluoride)   Electrospinning   Energy   Nanogenerator   Piezoelectric  

摘要： Poly(vinylidene fluoride) (PVDF) is a versatile polymer, whose dielectric, piezoelectric and ferroelectric properties can be augmented by a range of processing routes and/or additives. We developed a flexible nanogenerator using electrospun PVDF/COOH-functionalized graphene nanosheet (FGNS)/talc nanosheet (TNS) hybrid nanocomposites. TNS loading was fixed at 0.50 wt% while FGNS loading was varied (0.05, 0.10, 0.15, and 0.20 wt %) in these nanofabrics and their structure-property relationship was explored. Incorporation of FGNS led to formation of an electrically conductive network in the polymer matrix aided by TNS and electrospinning. The uniform dispersion of the filler nanosheets led to effective enhancement of the electroactive beta-phase of the PVDF matrix. Crystallinity and polymorphism in these systems were explored by FTIR spectroscopy, X-ray diffraction and differential scanning calorimetry. A nanogenerator made of the nanofabric containing 0.5 wt% of TNS and 0.10 wt% of FGNS was mechanically impacted by pneumatic actuator (operating pressure 0.4 MPa), resulting in an output voltage of 12.9 V and a power density of 1.72 mu W/cm(2), respectively. The piezoelectric coefficient (d(33)) of this nanofiber system was 61 pm/V as revealed by piezoelectric force microscopy. These novel nanocomposites could be used in flexible energy-harvesting devices.

关键词： Wastewater   Resource recovery   Economic benefits   Treatment technologies   Membrane separation  

摘要： An increase in urbanization and industrialization has not only contributed to an improvement in the lifestyle of people, but it has also contributed to a surge in the generation of wastewater. To date, conventional physicochemical and biological treatment methods are widely used for the treatment of wastewater. However, the efficient operation of these systems require substantial operation and maintenance costs, and the application of novel technologies for the treatment and disposal of sludge/residues. This review paper focuses on the application of different treatment options such as chemical, catalyst-based, thermochemical and biological processes for wastewater or sludge treatment and membrane-based technologies (i.e. pressure-driven and non-pressure driven) for the separation of the recovered products from wastewater and its residues. As evident from the literature, a wide variety of treatment and resource recovery options are possible, both from wastewater and its residues;however, the lack of planning and selecting the most appropriate design (treatment train) to scale up from pilot to the field scale has limited its practical application. The economic feasibility of the selected technologies was critically analyzed and the future research prospects of resource recovery from wastewater have been outlined in this review.

关键词： Apiculture   Digital monitoring system   Principal component analysis   Honey quality   Mineral elements  

摘要： This study was performed with floral honeys from an innovator and pioneer project in Brazil for the digital monitoring of beehives. Samples from six regions of the Santa Catarina state were evaluated for moisture, acidity, pH, electrical conductivity, 5-HMF, diastase activity, fructose, glucose, sucrose, and minerals (K, Ca, Na, Mg, and Mn). Furthermore, chemometric analyzes were applied to classify honeys based on these parameters. Some results did not corroborate with the current legislation for free acidity (<= 50 mEq kg(-1)) and electrical conductivity (<= 0.8 mS cm(-1)). In all samples, the minerals K (0.37 x 10(3) to 3.03 x 10(3) mg kg(-1)) and Ca (0.03 x 10(3) to 0.38 x 10(3) mg kg(-1)) were majority. Considering that the results were different (p < 0.05) for all floral honey samples, cluster and principal components analysis (PCA) were performed to group samples by similarity. Cluster analysis provided a first separation of the honeys and PCA highlighted the K, Ca, Mg, and Na as the best contributors for honeys discrimination. In this regard, the physicochemical parameters, sugar, and mineral content were important to elucidate the characteristics of honeys. They indicated that the beehives handling and the hygienic-sanitary conditions during the collection and transport of samples were also adequate. Furthermore, mineral elements were proposed to discriminate honey samples produced in different regions of Santa Catarina state, Brazil.

关键词： Beetroot   Fermentation   Wine   Yeast strains   Sensory evaluation  

摘要： The present study investigated the effect of different wine strains and inoculum size on the physicochemical, bioactive, and sensorial attributes of wine prepared from beetroot with varying TSS content (18 and 20 degrees Brix) and inoculum sizes (5% (v/v) and 10% (v/v)). The beetroot wine produced by fermenting the must for 0-14 days and standard protocols adopted to analyze the wine properties. It was noticed that the acidity of wine increased and pH was found to be decreased as the fermentation days increased. In addition, alcohol content was significantly enhanced (>10% by volume) in T5, which was higher than the other trials. In general, results of sensory and physicochemical analysis of different trials showed that T5 (TSS 18 degrees Brix and inoculum size of 5% (v/v)) produced the wine of acceptable quality using Saccharomyces cerevisiae. The color properties revealed that the L* value increased as fermentation progressed. Wine prepared from T5 possessed TSS of 6.55 degrees Brix, 3.96 pH, 0.35% titratable acidity, reducing sugar of 26.75 mu g ml(-1), 30.03% of DPPH free radical scavenging activity, phenol content (104.20 mu g ml(-1)) and betalain content of 10.85 mg 100 g(-1). There were significant differences in the taste, flavor, and overall acceptability of beetroot wines fermented for 14 days.

关键词： low-cost material   packing material   plastic bottles   recycling   reuse   solid waste  

摘要： Water resource limitation is one of the crises facing many countries worldwide. The work aims to apply a compact unit consisting of a vertical settler (VS) followed by a self-aerated chamber (SAC) for wastewater treatment. The dimensions of the unit are 2 x 1 x 2.5 m for length, width, and height, respectively. The hydraulic retention time (HRT) is 5 h in the VS for performance study while for the kinetic study the HRT is 4, 6, 8, 10, to 12 h. The unit is packed with a non-woven fabric material produced from waste plastic. The influent organic concentrations expressed by chemical and biological oxygen demand (CODtot and BOD) are 367.7 and 254.7 mg L-1, respectively. The concentrations of CODtot and BOD in the treated effluent are 78.8 and 80.5% to 36.7 and 16.6 mg L-1, respectively. The prevailed removal kinetic for COD and nitrogen (N) concentrations is the second-order reaction kinetic. With the exception of fecal coliform (FC), the final treated effluent meet the National regulatory requirements. The disinfection step is essential to reuse the final treated effluent safely. The unit can serve 100 p.e. in rural and unserved areas in developing countries with area of 2-3 m(2).

关键词： Brine injection   LF‐   NMR   myofibrillar protein   physicochemical properties  

摘要： The aim of this study was to investigate the changes in physicochemical properties and myofibrillar protein properties of grass carp meat during brining and brine injection at 4 degrees C. The time reached equilibrium was 7 h in brining group and 5 h by injection, where the salt content was about 1.76%. The water content, water holding capacity and yield in injection group (86.59%, 9.18% and 110%, respectively) were higher than brining group (84.76%, 11.47%, and 108%, respectively) at equilibrium point significantly (P < 0.05). This was attributed to the more swollen filament lattices and disordered protein structure in injection group (P < 0.05). The myofibrillar protein structure was compared, including sulphydryl content, surface hydrophobicity, solubility, sodium dodecyl sulphate polyacrylamide gel electrophoresis pattern and secondary structure. The injection group presented the better quality of salted fish meat in shorter time.

关键词： Yoghurt   Plant extracts   Fortification   Rheological property   Textural property  

摘要： The effects of yoghurt fortification with rhubarb (RE), grape seed (GSE), thyme (TE), green tea (GTE) and mint (ME) extracts on the physicochemical, rheological, textural and sensory properties during cold storage were investigated. The syneresis value of the extract-fortified yoghurts was higher and the colour was lighter in comparison with control sample. The values of texture parameters such as firmness and consistency in RE and TE samples were higher than of CS, and all extract-fortified samples, except GSE, showed higher cohesiveness and viscosity. The ME-fortified yoghurt was found tastiest with the highest overall appreciable score. These food-agriculture wastes could be valorised for improving the nutritional and textural properties of yoghurt.

关键词： Azo dyes   Phytoremediation   Dye removal   Physicochemical parameters   Sunflower   Hairy roots  

摘要： The effect of various physicochemical parameters was investigated on the removal efficiency of azo dye reactive red 120 from wastewaters by sunflower hairy roots. The highest percentage removal of the colored dye from wastewater(s) was observed at 25 degrees C, pH 7, adsorbent dosage 12.5 g L-1, shaking speed 85 rpm and light intensity 20 mu mol m(-2) s(-1). Further, a combinatorial study with all the optimized parameters was performed in the dye concentration range of 20-110 mg L-1 to determine the synergistic effect, if any, of all the physicochemical parameters on the kinetics of the dye removal. Nearly 100% dye removal could be achieved in 32 h as opposed to only 54% under the unoptimized conditions. Similarly, the initial dye removal rate could also be enhanced (from 3.4 to 19.6 mg L-1 h(-1)) under the optimized conditions. This correlated well with the proportionate increase in the (enzymatic and non-enzymatic) antioxidant potential of the root system under the optimized process parameters. The potential degradation of reactive red 120 by sunflower hairy roots was studied by Fourier transformed infrared spectroscopy and scanning electronic microscope analysis. Interestingly, sunflower hairy root system was also able to remove other azo dyes like reactive orange 16 and reactive blue 21 from their aqueous solutions. As seen in the study with reactive red 120, the removal increased from 49.5% under unoptimized conditions to 80.7% under optimized conditions (1.6 fold) for reactive orange 16 and from 55 to 82% (1.5 fold) for reactive blue 21, suggesting that these physicochemical parameters could significantly influence the removal of azo dyes in plant cells and their optimization can lead to further enhancement in the efficiency of the phytoremediation process for azo dye removal. The effect of optimized parameters on the removal of azo dyes from other wastewater compositions (synthetic and actual with different total dissolved solids) was also investigated to che