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关键词： Mammalian sHSPs   Classification   Multiple sequence alignment   Protein domain analysis   Mutational analysis   Evolutionary significance  

摘要： Small heat shock proteins (sHSPs), often known as molecular chaperones, are most prevalent in nature. Under certain stress-induced conditions, these sHSPs act as an ATP-independent variation and thus prevent the inactivation of various non-native substrate proteins and their aggregation. They also assist other ATP-dependent chaperones in the refolding of these substrates. In the case of prokaryotes and lower eukaryotes, the chaperone functions of sHSPs can bind a wide range of cellular proteins but preferentially protect translation-related proteins and metabolic enzymes. Eukaryotes usually encode a larger number of sHSPs than those of prokaryotes. The chaperone functions of mammalian sHSPs are regulated by phosphorylation in cells and also by temperature. Their sHSPs have different sub-cellular compartments and cell/tissue specificity. The substrate proteins of mammalian sHSPs or eukaryotic sHSPs accordingly reflect their multi-cellular complexity. The sHSPs of animals play roles in different physiological processes as cell differentiation, apoptosis, and longevity. In this work, the characterization, location, tissue specificity, and functional diversity of sHSPs from seven different mammalian species with special emphasis on humans have been studied. Through this extensive work, a novel and significant attempt have been made to classify them based on their omnipresence, tissue specificity, localization, secondary structure, probable mutations, and evolutionary significance.

关键词： Ozone   Aflatoxin M1   beta-lactam   Tetracycline   Microbial load  

摘要： The aim of this study was to investigate the effects of the ozone treatment (OT) to milk concentrate (MC) and whey concentrate (WC) on the physicochemical and textural properties, as well as, on the microbial, antibiotic, and aflatoxin content. For that purpose, OT was applied to MC and WC samples 0 (control), 5, 10, 15, 30, or 60 min. OT (60 min) achieved 18.9 and 9.9% degradation of aflatoxin M1 in MC and WC, respectively. OT caused degradation of beta-lactam, and tetracycline in concentrates. Volume mean diameter of MC was increased by OT, those of WC was decreased. The firmness and consistency values of ozone-treated concentrates were lower than the control groups. OT decreased the cohesivity of MC. OT increased the lightness of samples, while it decreased yellowness. In MC and WC samples, OT was effective in reducing the microbial load. The degradation of antibiotics and aflatoxin, and reducing the microbial load of concentrates by OT are crucial for human health and the processing of dairy products.

关键词： AprD   Extracellular protease   Pseudomonas fragi   Meat spoilage  

摘要： Pseudomonas fragi is a common spoilage agent of aerobically stored chilled meat. Its extracellular protease contributes to the spoilage of meat. AprD is considered an important component involved in the secretion of an alkaline extracellular protease in Pseudomonas. Thus, it is very possible that aprD plays an important role in spoilage regulation in P. fragi. The objective of the present study was to investigate the effects of aprD on bacterial proteolytic activity, biological properties, and in situ spoilage potential, as well as the mode of action of the protease AprA in spoiled meat. The results showed that aprD is important for surface-associated behaviors, as an Delta aprD mutant altered autoaggregation, swimming motility, and biofilm formation. aprD also contributes to the spoilage activities of P. fragi by affecting extracellular protease activity, total volatile basic nitrogen production, pH and the sensory traits of meat samples. These results highlight the presence of aprD-mediated regulation profiles in P. fragi and may provide new perspectives on chilled meat preservation.

关键词： Corn starch   gel properties   myosin   physicochemical properties   protein–   starch interactions   structure  

摘要： Effects of corn starch on structure, physicochemical and gel properties of myosin were investigated. Particle size, turbidity, surface hydrophobicity and total sulphhydryl groups of myosin were significantly increased with the increasing of starch concentration, and the increase range of high amylose corn starch (HACS) group was the most significant. Tryptophan residue of myosin was buried, and fluorescence quenching occurred after starch was added. HACS made myosin secondary structure was changed from alpha-helix to beta-sheet. Confocal laser scanning microscopy (CLSM) photographs showed starch was encapsulated by aggregated myosin, which made the protein binding tighter and more beneficial to the formation of gel. Moreover, strength and water holding capacity of heat-induced myosin gels containing starch were significantly higher than that of pure myosin. Starch, especially HACS, could induce myosin aggregation before heating gelatinisation and promote myosin self-assembly at low temperature, which may be conducive to forming a higher quality gel after heating.

关键词： Acceptability   cooking   fish burger   physicochemical properties   sensory analysis   sous vide  

摘要： The effect of sous vide (SV) pretreatment on the physicochemical (texture, water holding capacity (WHC) and protein modifications) and sensory (appearance, odour, flavour and overall acceptability) properties of sturgeon fish burgers cooked by four common methods (steaming, baking, microwaving and frying) were investigated. The texture analysis results showed that SV combined with transglutaminase could make the structure of cooked fish burgers denser and increase the springiness (ranging from 3.60 to 4.97 mm) and chewiness (ranging from 4.50 to 9.57 N), especially in microwave-cooked samples. In terms of sensory quality, on the one hand, SV could effectively inhibit off-flavours from oxidation and prevents evaporative losses of flavour volatiles (nitrogen oxides, organic sulphur and aromatic compounds) during cooking. On the other hand, the overall acceptability of microwave-cooked sample pretreated with SV was higher than that of other cooking methods, especially compared with steaming (P < 0.05). The above results indicate that it is feasible to obtain common cooked fish burgers with improved physicochemical and good sensory properties using SV pretreatment.

关键词： Solanum lycopersicum   Aspergillus niger (Cu-17)   Heavy metal stress   IAA  

摘要： This study aimed to evaluate the effect of endophytic fungi isolated from Cucurbita roots on growth, physiological, biochemical and molecular attributes of Solanum lycopersicum L. under Cd and Cr stress. The initial screening experiments on Oryza sativa L. seedlings revealed a plant growth promoting endophyte (Cu-17) out of the 17 isolated strains. The strain was identified as Aspergillus niger by amplifying ITS region of 18 S rDNA. A pot experiment was set to evaluate the effect of A. niger on S. lycopersicum exposed to two different concentrations (100 ?g/g and 500 ?g/g) of Cd and Cr. A. niger alleviated Cd and Cr stress in S. lycopersicum by reducing its translocation to the aerial parts of the host plant. A. niger also enabled the S. lycopersicum to produce significant amounts of IAA, proline, flavonoids, phenols, catalase (CAT) and ascorbic acid oxidase (AAO), in addition to sugar and proteins. Moreover, A. niger facilitated the S. lycopersicum to induce stress responsive genes (SlGSH1 and SlPCS1) in order to develop tolerance against the Cd and Cr stress. Both SlGSH1 and SlPCS1 genes helped the S. lycopersicum to chelate Cd and Cr and thus mitigate their toxicity. The results, therefore, conclude that A. niger might be used as biofertilizer for healthy and safe crop production in Cd and Cr contaminated soils.

关键词： Lignin   Film   High solid content   Physicochemical characteristics   Value-added application  

摘要： Alkali lignin (AL) and polyethylene glycol (PEG) were polymerized with hexamethylene diisocyanate (HDI) to form a novel lignin-based polyurethane film (LPF) with high solid content under the condition of silica as leveling and dispersing agent. The -CNO/-OH molar ratio under the optimum lignin content condition on the effects of thermal stability, mechanical property, glass transition temperature (Tg), water contact angle (WCA), pencil hardness, and crosshatch adhesion of LPFs were systematically evaluated. Fourier transform infrared spectra confirmed that AL and PEG successfully reacted with HDI. The elasticity modulus (121.62?157.20 MPa), tensile strength (13.31?17.07 MPa), WCA (63.6?71.3?), and pencil hardness (2B?2 H) of LPFs increased simultaneously as the -CNO/-OH molar ratio increased. The elongation at break (465.53?326.74 %) of the LPFs gradually decreased. The change trends were probably related to the enhanced crosslinking density between HDI and polyols (AL and PEG). The maximum decomposition temperature (Tmax), Tg and heat capacity change (?Cp) of the LPFs showed a trend of first increasing and then decreasing as result of the superfluous -CNO. Interestingly, all the LPFs appeared strong crosshatch adhesion (5B) and excellent biodegradability. The approach with short processing time and simple operation was a potential method for preparing LPFs with high solid content. The experiment will help to promote the value-added application of technical lignin, such as layer construction of coated fertilizer.

关键词： crystal structure   DNA cleavage   enzyme inhibition   photochemistry   water‐   soluble phthalocyanine  

摘要： In this work, we have presented on the synthesis and characterization of novel 3-(1-methyl-1H-imidazole-2-thiol)phthalonitrile (1) as a ligand and its nonperipherally (M = 2H (2), Zn(II) (3), and GaCl(III) (4)) phthalocyanines and their highly water-soluble hydrochloride derivatives (2a-4a), containing 1-methyl-1H-imidazole-2-thiol substituents. All compounds were supported by FT-IR, UV-Vis, H-1-NMR, C-13-NMR, and MALDI-TOF mass spectra. The molecular structure of the novel compound (1) and its intermolecular interactions have been elucidated by analyzing the results of X-ray diffraction measurements. In order to determine the supercoiled pBR322 plasmid DNA nuclease properties of compounds (2a-4a), agarose gel electrophoresis was used. The plasmid DNA nuclease did not observe without light irradiation on increasing concentrations (2a-4a). When irradiated at 10 and 20 J/cm(2), the band intensities changed on agarose gel, displaying photonuclease activity on supercoiled pBR322 plasmid DNA of compounds (2a-4a);4a had the highest photonuclease activities in a concentration-dependent manner at 10 and 20 J/cm(2). The in vitro alpha-glucosidase inhibitory effects of compounds (2a-4a) were investigated to determine whether they can be used in potential agents for diabetes mellitus. Compounds (2a-4a) showed higher inhibitory effects than acarbose (63.03 +/- 2.14 mu M) against alpha-glucosidase enzyme. Lineweaver-Burk analysis showed that K-m increased and V-max remained the same on increasing concentrations of compounds (2a-4a). The finding results claimed that the compounds inhibited alpha-glucosidase enzyme via competitive manner. Dixon plots showed that K-i values of compounds (2a-4a) were 14.70 +/- 0.70, 11.20 +/- 0.50, and 12.60 +/- 0.20 mu M, respectively. Besides, the effect of including metal ion on photochemical and photophysical features of the compounds was studied in DMSO and water, comparatively. The compounds gave high singlet oxygen quantum yields (phi(Delta)

关键词： Cost effectiveness  

摘要： The physicochemical properties of peanut protein-stabilized emulsions and emulsion gels prepared by high-intensity ultrasound (HIU) and high-pressure homogenization (HPH) were compared. The effects of different ultrasound emulsification conditions (ultrasonic time and power, protein concentration, and oil phase percentage) on the initial particle size and stability of peanut protein-stabilized emulsions were investigated. It was observed that the optimal HIU emulsification conditions consisted of a concentration of 4% (w/v) proteins, a volume percentage of 30% (v/v) oil, and an ultrasonic treatment at 300 W for 20 min. Compared with the two emulsions prepared by HPH at 300 and 500 bar, respectively, the HIU-prepared fresh emulsion showed a larger particle size, similar zeta potential but higher interfacial protein concentration and apparent viscosity. Additionally, the HIU-prepared emulsion had lower flocculation and coalescence indices and was more resistant to gravitation separation during storage. The cold-set gel strength of the HIU-prepared emulsion was stronger than that of the HPH-prepared emulsion (300 bar), but weaker than that of the emulsion (500 bar). The non-adsorbed proteins from the HIU-prepared emulsion had unique structural characteristics, such as higher molecular weight, more unordered secondary structures, and stronger surface hydrophobicity, which likely explained why the HIU-prepared emulsion possessed better physical stability and gelling ability. Practical Applications High-pressure homogenization (HPH) is currently the most frequently used method in the food industry to produce emulsions. However, a high-pressure homogenizer is expensive and not easy to operate. In contrast, high-intensity ultrasound (HIU) emulsification is considered a cost-effective technique. In this study, a peanut protein-stabilized emulsion was successfully produced by HIU emulsification method. Its physical stability was significantly better than that of the emulsions

关键词： Paraprobiotic   Probiotic   Yogurt   FTIR   Microstructure  

摘要： Paraprobiotic yogurts were produced using killed cells of Lactobacillus acidophilus ATCCSD 5221 and Bifidobacterium lactis BB-12. Fourier-Transform Infrared Spectroscopy (FTIR-ATR), as an important and sensitive method for detecting chemical bonds in dairy product, was used to specify the FTIR-ATR spectra and detect suitable spectral regions for probiotics as well as paraprobiotics (0-day). Principal Component Analysis (PCA) was employed to specify the spectra. In PCA, two principal components (PC1 with 37.07%, PC2 with 23/40%) were found with cumulative variance greater than 90%. The microstructure was tested using field emission scanning electron microscopy. Samples containing paraprobiotics, added before fermentation, showed a different structure compared to probiotic samples with more open and larger size of pores. Treatments containing probiotics and paraprobiotics added after fermentation revealed an open and loose structure as well as a more compact structure. In yogurt samples without probiotics and paraprobiotics, an open and spongy structure was observed. The sample containing killed cells of L. acidophilus ATCCSD 5221 and B. lactis BB-12 added before fermentation exhibited the lowest syneresis, highest water holding capacity, and highest apparent viscosity due to the presence of exopolysaccharides and cell components.