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关键词： High voltage electrostatic field   Catfish fillets   Physicochemical properties   High-throughput sequencing  

摘要： The effects of high-voltage electrostatic field (HVEF) on the microbial communities and quality characteristics of catfish fillets were investigated. Samples with 30 kV/15 min HVEF treatment and without treatment (control) were stored at 4 degrees C for 0, 1, 3, 5 and 7 d. The total volatile basic nitrogen (TVB-N) and total viable count (TVC) of HVEF-treated sample (20.5 mg/100 g and 5.64 log CFU/g, respectively) were significantly lower than those of the control (32.4 mg/100 g and 7.42 log CFU/g, respectively) at 7 d. Therefore, the shelf life of HVEF-treated fillets was 2 days longer than the control (5 d). Besides, HVEF treated samples showed less tissue damages, lower thiobarbituric acid-reactive substances (TBARS) and higher water holding capacity throughout the chilling storage. Additionally, the high-throughput sequencing results indicated that HVEF treatment reduced the relevant abundance of Flavobacterium and Geobacillus at 0 d, and mainly inhibited the growth of Acinetobacter and Streptococcus after 7 d storage, which meant the growth of spoilage bacteria were inhibited, corresponding with the results of TVB-N and TVC. The results indicated HVEF treatment could be implemented as a new fish processing technology to delay product quality deterioration and extend the shelf life of catfish fillets.

关键词： ZnTe thin films   Buffer layer   Electron beam evaporation   Annealing   Physical properties  

摘要： The Cd-based solar cells possess rear contact problem in superstrate device architecture, which may be eliminated by inserting a suitable buffer layer of zinc telluride (ZnTe) films of appropriate thickness between CdTe absorber and Cu/Au metal contacts. The present work meticulously reports the influence of annealing on the physicochemical properties of ZnTe thin films where ZnTe films were grown employing electron beam thermal evaporation technique and subsequently annealed for 1 h in air ambient and vacuum in 100-300 degrees C temperature range with an interval of 100 degrees C. Structural analysis reveals that as-grown and air/vacuum annealed ZnTe films have (111) preferred reflection with zinc blende structure of cubic phase (except 300 degrees C air annealed films) and grain size is boosted from 22 to 40 nm with annealing. The direct optical energy band gap is estimated in range of 2.25-2.84 eV and 2.65-2.87 eV for air and vacuum annealing, respectively. The contacts between the film surface and the TCO layer showed ohmic behavior as revealed by the I-V characteristics. The EDS results confirmed ZnTe thin film deposition and FESEM micrographs of air annealed films demonstrated the grain growth. The AFM images of vacuum annealed films showed hill-like topographies where hill density and RMS surface roughness reduced with annealing. The findings warrant that 100 degrees C air annealed ZnTe thin films could be employed as an efficient buffer layer and rear contact material to the Cd-based solar cell devices.

关键词： Silica nanoparticles   Nanovenoms   Venoms   Antivenoms   Adjuvants   Crotalus durissus terrificus  

摘要： Nanoparticles (NPs) are being studied due to their potential use as therapeutic and immunomodulatory tools, including their ability to transport antigens with the aim to induce a specific immune response. The production of snake antivenoms (AV) involves several inoculations of venom (V) in the presence of adjuvants (ADJ) to improve the immune response of inoculated animals, causing a decrease in its quality and shelf life. Therefore, it is interesting to develop new strategies for reduce these side effects. For that reason, associating V to NPs to replace conventional ADJ could be a useful tool for future AV production. In this work, nanovenoms (NVs) were generated by the adsorption of Crotalus durissus terrificus (Cdt) V proteins over silica NPs (SiNPs) synthesized according to the Stober method. Microphotographies obtained under Transmission Electron Microscopy (TEM) displayed a protein crown over NPs and Fourier Transform Infrared (FT-IR) presented the expected spectra for NVs resulting from the sum of those exhibited by Cdt V and SiNPs separately. SDS PAGE and immunoblotting assays confirmed the presence of proteins over SiNPs. Furthermore, the different enzymatic activities detected demonstrated that SiNPs were capable of binding V proteins preserving its activity and therefore would keep its native structure. In the same way, the NVs conserve the potential cytotoxic effects present in the V as we observed when culturing THP-1 cells with these complexes. This evidence allows us to infer that developed NVs could be used as a new platform for the production of antisera or for immunomodulatory therapies.

关键词： Orange seed protein hydrolysate (OSPH)   Nano-liposome   Coating   Chitosan  

摘要： In the present study the enzymatic production of orange seed protein hydrolysate (OSPH) from orange (Siavaraze, Citrus sinensis) seed protein using alcalase and pepsin enzymes under optimal conditions was evaluated. Then, the effect of OSPH type and chitosan concentration (0, 0.1, 0.2, and 0.4% w/v) on physicochemical characteristics, release rate, stability, antioxidant activity, and morphology of the loaded nanoliposomes was assessed. The results revealed that the particle size, polydispersity index (PDI), and encapsulation efficiency (EE) were influenced by the type of loaded OSPH and chitosan concentration. The zeta potential value in the nanoliposomes after loading with OSPH obtained from alcalase and pepsin changed from -8.87 mV to -9.45 mV and +4.41 mV, respectively. In addition, this index shifted toward positive values after coating with chitosan. The freeze-thaw stress and storing at 4 degrees C (for 4 weeks) led to the highest (about 10-fold) and lowest (about 2-fold) changes in the nanoparticles size, respectively. Among different treatments, the nanoliposome coated by 0.2% W/V chitosan showed decreased peptide release rate, retention of EE, and physical stability under different conditions. Evaluation of the chemical structure using FTIR indicated the positioning of the peptides inside the polar regions, bilayer-membrane, and their ionic complexation with liposome phosphate groups. Moreover, the evaluation of the nanoparticles' morphology indicated spherical particles with smooth surfaces, confirming the dynamic light scattering (DLS) results. The results of this study indicate the efficacy of coated liposomes in protection, control of release and maintaining the antioxidant activity of peptides.

关键词： Eggshell   Wet ball milling   Nanoparticle   Calcium release   Physicochemical properties  

摘要： Nano eggshell calcium (NEC) powder was prepared from biowaste chicken eggshells using wet ball milling. The characteristics of the NEC, including the zeta potential, micromorphology, elemental composition, particle size distribution, Ca2+ concentration, and chemical structure, were investigated. According to the results, the optimum process parameters were determined to be as follows: a milling time of 13 h, rotation speed of 400 rpm, ball-to-powder ratio of 5:1, solid-to-liquid ratio of 1:2 and filling ratio of 20%. Under these conditions, the eggshell particles were reached a minimum median particle size (D-50) of 500 nm after 13 h of milling. NEC particles were negatively charged and the zeta potential notably reduced as the particle size decreased. Homogeneous, aggregated and polyhedron crystals morphology of NEC particles were observed through scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Furthermore, the selected area electron diffraction (SAED) analysis performed during TEM showed that the NEC particles were polycrystalline in nature. The FT-IR and XRD analysis revealed that the milling process did not cause significant changes to the chemical structure of the NEC. The Ca2+ concentration in the NEC suspension increased after milling, suggesting that calcium was steadily released from the particles to the suspension during milling.

关键词： Proteins  

摘要： In this study, the physicochemical properties of pumpkin seed kernel (PSK) flour were assayed and used as a fat replacer and functional ingredient in meatballs. Five different meatball formulations were prepared with 0%, 3%, 6%, 9%, and 12% replacement of beef fat with PSK flour. The PSK flour had high protein, oil, and oleic and linoleic acids, but low dietary fiber content. The treatment of PSK flour altered the proximate composition of the meatballs and reduced the fat content by about 9%-27%. The addition of PSK flour improved the cooking loss, hardness, fatty acid profile, polyunsaturated fatty acids/saturated fatty acids ratio, and thrombogenic and atherogenic indexes of meatballs, but negatively affected redness andn-6/n-3 ratio. Also, the addition of PSK flour decreased sensory scores, but the overall acceptability scores of meatballs with 3% PSK flour were close to the control. In conclusion, the inclusion of 3% PSK flour could be recommended with minimal compositional and sensory changes as a fat replacer and functional ingredient in beef meatballs. Practical applications Pumpkin seed kernel (PSK) flour can be considered as a potential source of important nutrients for food enrichment due to its high protein (31.96%), oil (49.87%), oleic (44.78%), and linoleic acid (39.40%) content. The addition of PSK flour to beef meatballs improves the cooking loss, hardness, fatty acid profile, polyunsaturated fatty acids/saturated fatty acids ratio, and thrombogenic and atherogenic indexes and reduces the fat content of the products. PSK flour can be used up to 3% for the production of beef meatballs.

关键词： Proteins  

摘要： The current investigation was undertaken to evaluate and optimize the effects of incorporation of Sesame (Sesamum indicumL.) protein and transglutaminase on physico-chemical and sensory properties of rice flour-based gluten-free cakes. Moreover, some characteristics of prepared products such as moisture content and texture specifications were measured. According to findings, all treatments had a significant effect on the sensory, texture, and color properties of the products. The strongest effect on the brightness index was observed in the sample containing 6%S. indicumprotein isolate and 0.6% transglutaminase on a backing day, the lowest effect was associated with the sample containing 5.12%S. indicumprotein isolate and 1.02% transglutaminase on the 5th day on the shelf life. The results showed that producing a gluten-free rice flour cake byS. indicumprotein and transglutaminase is possible and applying enzymes for improving the quality of gluten-free products is a promising technology. Practical applications TheS. indicumseed is a rich source of lipid, methionine, and tryptophan and protein. Also, rice has desirable specifications like good protein content, easy digestion, pleasant taste, low sodium, lipid, and fiber content, high carbohydrate content, and hypoallergenic properties. This study aimed to incorporate theS. indicumprotein in gluten-free rice-based cake formulation. Producing gluten-free products for consumers with gluten intolerance is a promising attempt. Transglutaminase was also used as an auxiliary connector to improve the properties of the final product. Given the satisfactory sensory and texture specifications, the use ofS. indicumprotein isolate and transglutaminase in gluten-free formulation is recommended. Improving color specification in terms of color stability of the outside and whiteness of the texture and better adhesiveness and hardness characteristics are some of the advantages of the proposed formulation.

关键词： Bioconversion   Enzymatic acylation   Palmitic acid   Lipase   In vitrodigestibility  

摘要： Quercetin was acylated with palmitic acid, catalyzed by eitherCandida antarcticalipase B (CAL-B) orPseudomonas cepacialipase C (PCL-C) to produce quercetin palmitate esters. The effects of various operating factors including incubation temperature, reaction duration, and molar ratio of substrates on the bioconversion yield, initial rate of reaction, and regioselectivity of the reactions were investigated. Three new esters were identified: quercetin 4 '-palmitate (C31H40O8, 540 g mol(-1)), quercetin 3 ',4 '-dipalmitate (C47H70O9, 778 g mol(-1)), and quercetin 7,3 ',4 '-tripalmitate (C63H100O10, 1016 g mol(-1)). The effects of incubation temperature, reaction duration, and molar ratio of substrates on bioconversion yields varied across the conditions. However, the highest bioconversion yield of 27.72 +/- 1.64% was obtained with PCL-C, at day 7, incubation temperature of 60 degrees C, quercetin:palmitic acid molar ratio of 1:20. The initial rate of reaction was significantly higher with PCL-C. However, regioselectivity was similar for both PCL-C- and CAL-B-catalyzed reactions with acylation occurred successively at 4 '-OH, 3 '-OH, and 7-OH. Thin-layer chromatography analysis showed that the three quercetin palmitate esters possessed enhanced lipophilicity (134% higher than quercetin). Besides, in silico investigation showed that quercetin 4 '-palmitate had a higher partition coefficient (logP) value than the parent compounds, indicating improved solubility. During gastrointestinal tract simulation, quercetin palmitate esters were recovered in the range of 71.03% to 79.36% after digestion, which were significantly higher than quercetin at 40.43 +/- 8.71%. Quercetin 4 '-palmitate was also found stable over 28 days of storage. Due to improved lipophilicity, solubility, and stability, quercetin 4 '-palmitate has the potential to be used in topical applications.

关键词： Physicochemical properties  

摘要： This study aimed to evaluate the effect of the addition of different concentrations of turmeric powder to a dairy product with plantain syrup. The dairy product was supplemented with 50% plantain syrup (w:w) and six concentrations of turmeric powder. During 28 days of storage, the color parameters (L*, a*, b*, H, and C*), water activity, oxidation, titratable acidity, pH, syneresis, water retention capacity (WRC), total soluble solids, carotenoids, antioxidant activity (DPPH), total phenolic compounds (TPC), centesimal composition, mineral contents (Ca, Na, and K), and microbiological quality were evaluated. Dairy products supplemented with turmeric were found to be more yellow (b*) and showed a saturated color (C*), lower syneresis rate, lower oxidation value, and greater antioxidant activity using DPPH, TPC, and WRC (at 28th day). The addition of turmeric to a dairy product improves the physicochemical properties, including increased calcium content, color enhancement, and improved antioxidant activity, during the product shelf life.

关键词： Wastewater treatment   Physico-chemical   Biological treatment   Advanced oxidation processes   Membrane filtration   Nanocatalysts  

摘要： The utilization of dyes in textile industries has enormously increased in recent years and has created several environmental problems. Currently, several methods are in practice to treat wastewaters. Effective and efficient treatment techniques before the discharge of used water in the environment are the need of the hour. This short review covers the research and recent developments in advanced wastewater treatment techniques such as nanophotocatalysis, ceramic nanofiltration membranes, and biofilms. The primary intent of this review article is to contribute the ready-made references for the active researchers and scientists working in the field of wastewater treatment. This review has mainly focused on advanced physico-chemical and biological techniques for the treatment of textile dye wastewaters. Further, the influence of various operating factors on the treatment, advantages, and disadvantages of various techniques was also discussed. The recently developed materials for wastewater treatment are also summarized based on the latest available literature.