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关键词： Drying   Ginger   Cutting orientation   Water migration   Physicochemical properties  

摘要： The combinative effects of both longitudinal cut (Lc) and transverse cut (Tc), and hot air, vacuum, freeze and catalytic infrared drying (HD, VD, FD and CID) techniques on the physicochemical properties of dried ginger was studied. The physicochemical properties determined were shrinkage, hardness, rehydration rate, color, gingerol content, total phenols and flavonoids contents (TPC and TFC), antioxidant activity and volatile components. Results showed that the Lc reduced the drying time significantly, by 15.12-29.6%, compared with Tc;and improved the physical properties (degree of shrinkage, hardness, rehydration rate) of the dried ginger. However, there was no significant difference between them on the chemical properties of the dried ginger. Among the four drying techniques, CID showed the shortest drying time (1.42-1.84 h) and retained the bioactive ingredients (gingerol content, TPC, TFC, and volatile components) better in the dried products. Overall, the study established that Lc treatment combined with CID had an excellent effect on the quality of dried ginger slices and the overall drying efficiency;and thus, were selected as the optimum treatment and drying method for drying ginger.

关键词： Physicochemical properties  

摘要： This study evaluated the effect of sago starch cross-linked phosphorylated with sodium tripolyphosphate (STPP) (4%, 8%, and 12%) in fried batter. The 12% STPP produced cross-linked starch with the highest degree of substitution (DS) at 0.017. The swelling power, amylose content, peak viscosity, breakdown viscosity, and setback were reduced as the concentration of STPP increased. The oil uptake of the fried batter added with 20% of cross-linked sago starch with the highest DS (WFCLS12) was significantly reduced from 29.16% to 19.5%. The fracturability of the fried batter added with cross-linked sago starch showed significantly higher crispness (WFCLS4-883.45 g;WFCLS8-666.61 g;WFCLS12-499.89 g) than 100% wheat flour (WF-1094.60 g). It was demonstrated that STPP (especially WFCLS12) is an effective cross-linking agent, and the addition of cross-linked sago starch into wheat flour-based batter significantly (p < .05) improved the quality of the batter. Practical applications Cross-linked phosphorylated sago starch has improved physicochemical properties than the native sago starch in terms of lower swelling characteristic, low amylose content, and acceptable results of the viscosity and pasting properties. To mitigate the issue of high oil uptake and soggy texture of fried wheat batter, the addition of cross-linked phosphorylated sago starch contributes to lower oil uptake and more crispy texture of fried batter. Hence, a healthier food product can be produced with the formulation of this cross-linked phosphorylated sago starch. At the same time, less oily and enhanced texture of fried batter can be achieved.

关键词： Quantum dots   Dendrimer   Biotin   Thermodynamics   Spectroscopy  

摘要： It is challenging to design and characterize molecular recognition pair consisting of both targeting and imaging property and it is also of particular interest to inquire into the limits of the affinity that can be achieved with designed bio-conjugate. This paper presents functionalization of luminescent quantum dots (QDs) employing multivalent dendrimer molecules conjugated with biotin as targeting moiety and photo-physical and thermodynamic behavior of this bio-conjugate in terms of highly affinic binding with avidin. It is demonstrated that fluorescence intensity of QDs remained almost unaffected when synthesized conjugate interacts with avidin and this is considered to be an important requisite for applications in imaging and sensing. The observed changes in average emission lifetime as well as values of lifetime components of avidin indicate the binding of biotin with tryptophan moiety of avidin. Calorimetric investigation reveals that binding of avidin with biotin-dendrimer conjugate is exothermic process accompanied with favorable enthalpy (Delta H = -21.6 kcal/mol) and unfavorable entropy (Delta S = -43.7 cal/mol/deg). These findings may help design of multiplexed assays where dendrimer conjugated QDs based probe molecules are immobilized via the avidin-biotin interactions which can have implications in development of immuno-histochemical techniques.

关键词： Pseudomonas aeruginosa   Methicillin-resistant Staphylococcus aureus (MRSA)   Cation exchange chromatography   Biofilm  

摘要： This study aimed to produce the novel bacteriocin from Pseudomonas aeruginosa 43. The bacteriocin was purified through 80% ammonium sulfate precipitation, cation exchange chromatography, and gel filtration, and the specific antimicrobial activity was 400 AU/ml of protein. The molecular weight of purified bacteriocin was 10 kDa determined by SDS-PAGE. It was shown to be heat stable at 121 degrees C for 30 min and functioned well at low pH in a range of 3-7. Reduction of activity was shown after treatment with proteinase K, trypsin, papain, and alpha-amylase that confirmed its proteinaceous nature. Bacteriocin also showed its stability against various organic solvents and chemical reagents. Scanning electron microscope analysis indicated that bacteriocin from P. aeruginosa 43 damaged the morphology of methicillin-resistant Staphylococcus aureus (MRSA). Also, the novel bacteriocin exhibited an enhanced ability to impair biofilm formation and to reduce the density of established biofilms. LC-MS analysis study showed elastase is a novel peptide produced by P. aeruginosa 43 which has broad spectrum of inhibition against MRSA. The study suggested that bacteriocin from P. aeruginosa 43 could be developed as a antimicrobial agent for skin infection.

关键词： Textures  

摘要： The coagulation of dromedary and cows' skim milk using camel chymosin was evaluated. Milk coagulation was monitored using viscosimetric and conductometric techniques. Syneresis and cheese yield were also assessed. The proximate composition, colour, texture and sensory properties of the cheeses obtained were investigated over 7 days storage. The initial viscosity value was higher for cows' skim milk than for dromedary skim milk. Dromedary skim milk had substantially longer coagulation time (about 72.3 min) than cows' skim milk (about 27.5 min). Dromedary skim milk gel had lower syneresis percentage and moisture content with higher cheese yield. pH values of white brined cheeses decreased during storage with lower values for dromedary skim milk cheeses. Hardness of cheeses increased during storage with higher values for cows' skim milk cheeses. Regardless of storage day, dromedary skim milk cheeses were more acceptable than cows' skim milk cheeses as evaluated by sensory panellists. (c) 2021 Elsevier Ltd. All rights reserved. The coagulation of dromedary and cows' skim milk using camel chymosin was evaluated. Milk coagulation was monitored using viscosimetric and conductometric techniques. Syneresis and cheese yield were also assessed. The proximate composition, colour, texture and sensory properties of the cheeses obtained were investigated over 7 days storage. The initial viscosity value was higher for cows' skim milk than for dromedary skim milk. Dromedary skim milk had substantially longer coagulation time (about 72.3 min) than cows' skim milk (about 27.5 min). Dromedary skim milk gel had lower syneresis percentage and moisture content with higher cheese yield. pH values of white brined cheeses decreased during storage with lower values for dromedary skim milk cheeses. Hardness of cheeses increased during storage with higher values for cows' skim milk cheeses. Regardless of storage day, dromedary skim milk cheeses were more acceptable than cows? skim milk cheeses

关键词： tennessin   oganesson   nichonium   astatine   radon   properties   comparative calculation method  

摘要： The method of comparative calculation, based on the correlation of some properties with others in the group of analogous elements and which has been repeatedly utilized to determine the properties of astatine, can be used to estimate number of the physicochemical properties of tennessine, oganesson, and nichonium. It was found that in the group some properties of these elements were linearly dependent on other their properties.

关键词： Agrobiodiversity   Date paste   Physico‐   chemical composition   Phenolic Profile   Antioxidant activity   Sensory evaluation  

摘要： This work is a contribution to the valorization of the Algerian date palm agrobiodiversity by studying some nutraceutical properties of date pastes from less important cultivars. A commercial date paste, prepared from Ghars variety, was compared to two date pastes prepared from the secondary cultivars Tamjouhert and Tazarzeit. Physico-chemical characteristics, phenolic profile (HPLC-DAD), and antioxidant activity were assessed for both date fruits and pastes. The sensory evaluation of date pastes was conducted through triangular, ranking, and hedonic tests. The results revealed that the transformation of date fruits into pastes caused a significant increase in phenolic content and antioxidant capacity, a decrease in sugar content in parallel with the appearance of hydroxymethylfurfural and furfural. The elaborated date pastes were characterized by a relatively low level of sugar (72.17-74.14 mg/100 g), a high amount of phenolic compounds (> 290 mg/kg DW), and a potent antioxidant activity. Seventeen phenolic compounds were identified by HPLC with global quantities for date fruits of 113 (Tamjouhert cv.) and 100 mg/kg DW (Tazarzeit cv.) and that were increased twofold after transformation to date pastes. The sensory analysis for the obtained date pastes indicated high scores of acceptability in comparison with the commercial paste. The obtained results showed clearly that these secondary cultivars possess several potentialities;this may help to valorize them by turning a part of their production into several added-value products such as date past.

关键词： FT-IR   Kappa carrageenan   Kappaphycus striatus “   sacol”   brown strain   Rhodophyta   NMR   Properties  

摘要： The red alga Kappaphycus striatus "sacol" brown strain is an economically important species and extensively cultivated at Vanphong Bay, Vietnam. To elucidate the carrageenan quality, the chemical profile of the alkali-modified carrageenan from this alga was investigated by FT-IR, H-1 and C-13 NMR spectroscopies, and methods of analysis. The structural components of the polysaccharide mainly consisted of 3,6-anhydro-alpha-D-galactose and beta-D-galactose-4-sulfate. FT-IR and H-1 and C-13 NMR spectra indicated that the polysaccharide was composed predominantly of kappa carrageenan with a small amount of iota carrageenan and 6-O-methylated carrageenan. The red alga K. striatus is good source of carrageenan for application in food or medicine.

关键词： Talc schist   Mineralogy   Clay   Geochemistry   Cameroon  

摘要： Talc schist deposits are reported in central Cameroon region, and different alteration zones were determined depending on differences related to the texture and color of the host rock. For the purpose of determining mineralogical and physicochemical characteristics of talc schist, a total of 45 samples from the sites studied were collected and analyzed using an array of physico-chemical methods. Talc schist samples are mainly composed of variable amount of talc associated with plagioclase and clay minerals. Three groups of mineral association were determined: i) talc with small amount of chlorite and traces of kaolinite, ii) talc with high amount of chlorite, iii) variable amount of talc with plagioclase and clay minerals. The talc schist samples have homogeneous grain-sizes and are classified as silty sand or sandy silt. The occurrence of Ni and Cr in the talc schists are consistent with the composition of the talc deposits formed in relation to ultramafic rocks. The genesis of talc is due to hydrothermal fluid circulation in ultramafic rocks, attested by the occurrence of S and P.

关键词： Freezing methods   Frozen unfermented dough   Starch digestibility   Ordered structure   Relative crystallinity  

摘要： Three types of freezing methods, namely, spiral tunnel freezing method (SF), cryogenic refrigerator freezing method (RF) and liquid nitrogen spray freezing method (LF), were applied to frozen unfermented dough. The particle size distribution and SEM results showed freezing methods reduced the average particle size of starch granules and destroyed the surface microstructure, especially RF, and the damaged starch content and swelling power of starch after treatment increased. Gelatinization and pasting properties of starches changed to varying degrees, indicating freezing methods caused the internal rearrangement of starch molecules. This view could also be inferred from X-ray diffraction (XRD) and Fourier Transform infrared spectroscopy (FT-IR) data. The relative crystallinity (35.51%-38.56%) and the R-1047(/1022) (0.562-0.590) were increased, compared with the control (32.44%, 0.559, respectively). Meanwhile, freezing treatment improved the digestibility of starch by promoting the combination of enzymes and starch, especially RF. Larger ice crystals formed by RF with slower freezing rate produced larger damage to starch structure, more likely to promote the binding with enzymes. LF with faster freezing rate had less effect on the starch composition than RF and SF with slower freezing rate. The data obtained clarified the influence of freezing methods on the structure and properties of starch in a yeast-free dough system, and enriched the knowledge regarding the effect of freezing technology on food components.