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关键词： Fullerene   DPPH   HSA   Cytotoxicity   Haemolysis   Photobleaching   Platelet aggregation   Genotoxicity   Molecular dynamics  

摘要： Amino acid adducts of light fullerenes have a potential of application in a variety of fields of biomedicine, that is reactive oxygen species scavenging activity, anticancer activity, viruses and bacteria inactivation etc. In this work, the water-soluble C-60 fullerene derivative with L-hydroxyproline (C-60(C5H9NO3)(2), C-60-Hyp) was studied. Extensive biomedical investigation of this compound, namely, antiradical activity in the reaction with stable diphenylpicrylhydrazyl radical, the binding to human serum albumin, photodynamic properties, cytotoxicity in glioblastoma A172 and lung carcinoma A549 cell lines, erythrocytes haemolysis, platelet aggregation, genotoxicity on human peripheral blood mononuclear cells was conducted. Moreover, the dynamic and structural characteristics of C-60-Hyp-H2O binary system were obtained using molecular dynamic (MD) method, and size distribution along with zeta-potentials of C-60-Hyp associates was measured.

关键词： gamma-PGA   Physicochemical properties   Microstructure   Frozen storage   Surimi  

摘要： The cryoprotective effects of gamma-polyglutamic acid (gamma-PGA) on grass carp surimi during frozen storage at -20 degrees C were investigated. The results showed that gamma-PGA significantly maintained the quality traits of frozen grass carp surimi. Among the different concentrations of gamma-PGA, treatment with 0.8% gamma-PGA represented highest cryoprotective effect on the grass carp surimi during frozen storage, and its cryoprotective effect was also better than that of a conventional cryoprotectant (SS treatment). During freeze-thaw process, the gel strength and Ca2+ ATPase activity treated with 0.8% gamma-PGA were 40.7% and 31% higher than those of the control group, respectively. Moreover, after 84 days frozen storage, the addition of 0.8% gamma PGA increased the gel strength, salt-soluble protein content, Ca2+-ATPase activity and the whiteness by 87.1%, 50%, 70.8% and, 11.9%, respectively, compared to the control. Meanwhile, treatment with 0.8% gamma-PGA primely maintained the gel structure and sensory score of frozen grass carp surimi as well. These results indicated that gamma-PGA was a potential cryoprotectant applying for the production, storage and transportation of surimi.

关键词： Collective dynamics   Flocking control   Functional theory   Multiagent system   Physicochemically inspired methodology  

摘要： Theoretical studies suggest that dispersion and repulsion are two important interactions that occur within non-polar particles. Enlightened by this, we propose a simple model for flocking of autonomous agents interacting by physicochemically inspired dispersion and repulsion interactions. This interdisciplinary effort provides a generic framework for design and analysis of distributed flocking by introducing virtual electrons (VEs). We innovatively utilize the functional theory to construct the energy functional with the distribution density of VEs as the basic variable and then solve the Lagrangian equation to derive the control law of multiagent flocking. Theoretical analysis reveals that the proposed protocol can ensure that autonomous agents asymptotically converge to an equilibrium configuration from chaotic movement and meanwhile all agents tend in time to a common velocity. Numerical simulations are presented to verify the effectiveness of theoretical results. We also give a comparison with the collective potential method and found that the proposed approach can realize the rapid transition of autonomous agents from disordered to ordered movement. This implies that the proposed framework can effectively avoid the limitation of constructing a complicated empirical field and thus may have broad application prospects.

关键词： Fermentation  

摘要： Gari (cassava flake) is a fermented, roasted cassava product, and a major staple food in Nigeria. Yellow flesh cassava (TMS 1358) variety was processed into gari and the chemical and physicochemical properties of the gari and reconstituted paste were determined. Ash, lipid, and carbohydrate contents decreased with fermentation days while the protein and fiber contents increase with fermentation days in the gari. Starch contents decreased gradually while the sugar contents of the gari increased with fermentation days. Cyanide contents of all the gari samples were less than 1 mg/CN-1. Color of the gari samples were brighter in early fermentation periods but became darker with prolonged fermentation periods. Carotene contents decreased with storage time while pH values increased slightly at 6 months. Reconstituted gari paste fermented for 0 to 2 days was more acceptable in appearance, moldability, and in overall acceptability. Fermentation of cassava (TMS 1358) for 0-2 days and storage of gari product for up to 2 months are desirable for human consumption. Practical applications This study is about the use of improved breed cassava in making cassava flakes (gari). The biofortified cassava was used and studied over 6 months to know the effect of storage on the cassava flake. Cyanide content of the cassava variety was low and reduced with fermentation periods. Carotene contents also diminished after 2 months of storage. Utilization of biofortified cassava flakes (gari) is encouraged within 1-2 months of production and at 2nd day of fermentation. This study enables the consumers and processors to know the characteristics of this cassava variety, the best fermentation periods, and storage of the product at ambient temperature.

关键词： fermented foods   lactic acid bacteria   metabolism   microbial physiology   quality control  

摘要： Aim: The aim of this study was to study the effects of salt concentrations on the microbial communities, physicochemical properties, metabolome profiles and sensory characteristics during the fermentation of traditional northeast sauerkraut. Methods and Results: Northeast sauerkraut was spontaneously fermented under four salt concentrations (0.5, 1.5, 2.5 and 3.5%, w/w). The result of microbiological analysis showed that the population of lactic acid bacteria in 2.5%-salted sauerkraut was significantly higher than that in the other samples. Correspondingly, the speed of decrease in pH and accumulation of acids were the highest in 2.5%-salted sauerkraut. The glucose (analysed by HPLC) in 2.5%-salted sauerkraut was consumed more completely to produce higher levels of organic acids compared to those in the other samples. Principle component analysis showed clear differences in the metabolites of sauerkraut according to different salt concentrations. A higher level of volatiles (detected by HS-SPME/GC-MS) was identified in 2.5%-salted sauerkraut, and sensory evaluation demonstrated that 2.5%-salted sauerkraut had the best sensory characteristics. Conclusion: The best quality of sauerkraut was obtained from fermented under 2.5% salt concentration. Significance and Impact of the Study: This study facilitated the understanding of the effects of salt on the sauerkraut fermentation and may be useful for developing the quality of sauerkraut.

关键词： Camel milk   Spray drying   Microstructure   Freeze drying   FTIR  

摘要： This study investigated the changes in camel milk powder on spray and freeze drying by preparing spray dried whole camel milk powder (SDW), spray dried skimmed camel milk powder (SDS) and freeze-dried whole camel milk powder (FDW). All the powder variants showed significant changes (P < 0.05) in their composition, water activity and color values. Freeze dried powder (FDW) showed higher retention of calcium (15.33 g/kg) and iron (0.012 g/kg) while SDS possessed highest L* (94.83 +/- 0.74) values. FDW sample had highest interstitial air (80.84 +/- 0.66 mL/100 g), occluded air (119.47 +/- 1.08 mL/100 g) and porosity (50.59 + 0.56%) followed by SDS which was further reinforced by their SEM images. The water binding capacity was highest for FDW (5.21 g/g protein) and lowest for SDW which is attributed to highest porosity and presence of surface fat, respectively. Freeze-dried camel powder had porous sheet like structure while the spray dried samples were agglomerates of individual spherical particles. FTIR peak differences between whole camel milk powder samples (FDW and SDW) and skimmed powder sample (SDS) in wavenumber range 2850-3000 cm(-1) was due to milk fat. Fitted with BET and GAB model, the moisture sorption isotherm showed lowest monolayer moisture content for SDW, thereby highlighting its better storage stability.

关键词： Poly (vinyl alcohol)   Chitosan   Rutin   Bioactive films   Food packaging  

摘要： Rutin induced Chitosan/Poly (vinyl alcohol) bioactive films were developed by using solvent casting technique. The effect of various concentrations (0.2, 0.4 and 0.6%) of rutin on physico-chemical and functional properties of bioactive films were studied and analysis results indicated that presence of rutin improved the barrier to UV-light, WVP, OTR, water resistance, water solubility and thermal properties. The results of water contact angle, FTIR and SEM showed that addition of rutin increased the network compactness of the bioactive films which resulted from strong intermolecular interactions through hydrogen bonding. Stress-strain curves demonstrated that the incorporation of 0.6% of rutin gives maximum values of TS, %EB and YM as 54 +/- 1 MPa, 51 +/- 1.5% and 1423 +/- 13.2 MPa, respectively. Bioactive films showed strong antimicrobial activity against E. coli and S. aureus bacteria. The overall migration of components of bioactive films in different food simulants were within the permitted limits of 10 mg/dm(2). Hence, rutin induced CS/PVA bioactive films have potential to be used for improving food quality and extending the shelf life of food.

关键词： acid-modified maize starch   dynamic light scattering   emulsifying ability   HPLC-SEC   hydrochloric acid   phosphoric acid   tartaric acid  

摘要： Native maize starch (NS) dispersions treated with hydrochloric (HA;1M, 2M), phosphoric (PA;1M, 2M) and tartaric acid (TA;0.67M, 1.33M) were investigated in terms of their morphological, structural and physicochemical properties, including emulsification capacity. The molecular weight of starch was affected by both factors (acid type and concentration). The mean molecular weight (Mw) was decreased by 89% and 11% after treatment with HA (1M) and PA (1M), respectively. TA-treated starch resulted into three distinct size distributions, one of which showed larger Mw as compared to the NS. Dynamic light scattering measurements revealed that the modified starches in aqueous environment were spread in at least two distributions, one of them showing particle sizes higher than 200 nm, whereas the other lower than 200 nm. Clarity of treated starch pastes decreased in the following order: HA > TA > PA > NS. Generally, O/W emulsification and stability properties deteriorated with starch modification. tau Alpha yielded the most stable emulsion among the modified starches.

关键词： Physicochemical properties  

摘要： Salting is important to maintain the food quality. This study aimed to evaluate the physicochemical properties and microstructure of Russian sturgeon fillets under vacuum impregnation and find out appropriate salting conditions. The treatments varied in salt concentration (5%, 10%, 15%, and 20%) and time (1, 2, 3, 4, and 5 hr);samples treated under atmospheric pressure with 10% were included as controls. In our study, vacuum impregnation improved the salting efficiency and helped to maintain a complete microstructure to enhance the water-holding capacity, especially after salting for 2 hr, the maximum value was 32.4%. Moreover, it increased the values of hardness and springiness and reduced L* and a*. In addition, the fillets under vacuum impregnation had lower TVB-N and Carbonyl content, which were 15.91 mg/100 g and 311.38 nmol/L after salting for 5 hr, respectively. Consequently, vacuum impregnation was a better way of salting for its higher salting efficiency and better physicochemical properties. Practical applications The results of this study provide information to food industry about the effects of different salt concentration and time under vacuum impregnation on the Russian sturgeon fillets. It can be seen from the results that vacuum impregnation can improve the salting efficiency and protect the original organizational structure as completely as possible. As a result, vacuum impregnation is a better way of salting.

关键词： biological cell response   ionizing radiation   physicochemical damage   prostate cancer   Raman spectroscopy   X-rays  

摘要： Exposure to ionizing radiation significantly affects biochemistry of cancer cells. The effect of irradiation can be divided into two stages, that is, the physicochemical stage and the biological response. Both effects induce different biochemical changes in the cells and should be analyzed as two separate phenomena. Thus, in the current study, Raman spectroscopy of prostate cancer cells fixed before (the physicochemical damage model) and just after (the biological response model) irradiation was undertaken to compare biochemical composition of irradiated cancer cells at both stages. Spectroscopic analysis of the cells was performed separately for cytoplasmic and nuclear regions. Biochemical changes of irradiated cells were analyzed using partial least squares regression (PLSR) method on the basis of the collected Raman spectra. Regression coefficients were therefore used to describe differences and similarities between biochemical composition of cancer cells undergoing the physicochemical stage and biological response. Additionally, PLSR models of both phenomena were compared for linear dose-dependence and a cross prediction.