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关键词： Suspensions (fluids)  

摘要： The blackberry is characterized by its components presenting physiological activity. The objective of the research was to evaluate the influence of the composition and the homogenization time on the stability of suspensions based on blackberry concentrate (BC) and gum arabic (AG). The response surface methodology was used, considering the following independent variables: total solids provided by the BC TSBC (10%-11%), AG (0.4%-0.6%), and time (6-10 min), and the dependent variables: total suspension solids (TSS), pH, viscosity (mu), spectral absorption index (R), zeta potential (zeta), D-10, D-50, and D-90, total phenols (TPs), antioxidant activity, and anthocyanins. The suspension was optimized under criteria of better physicochemical stability and higher antioxidant activity: TSS: 10.2 +/- 0.2%, pH: 3.07 +/- 0.01, mu: 1,123.7 +/- 38.1 cP, R: 0.38 +/- 0.04, |zeta|: 14.8 +/- 0.9 mV, D-10, D-50,D- and D-90 (6.6 +/- 0.8;86.7 +/- 4.1, and 245.9 +/- 12.9 mu m, respectively), TP 473.5 +/- 61.0 mg GAE/100g, DPPH and ABTS: 843.4 +/- 66.7 and 699.9 +/- 49.7 mg trolox/100g, respectively, and anthocyanins: 21.9 +/- 1.6 mg cyd-3-glu/100g. The stability of the suspensions was favored by the synergistic effect of the mu-zeta, the low values of particle size, and R. Practical applications Processing conditions and composition in the formulation of the suspensions based on blackberry, cause a series of changes in the quality parameters. The present work determines the stability of the colloidal system and composition in bioactive components, for effective use of the suspension in a spray drying process, thus strengthening the blackberry supply chain and generate value through alternatives that improve the shelf life of this fruit, characterized by having a short shelf life when they are in a fresh stage.

关键词： Acidity constants   LSER   LFER   Monothiocarbohydrazones   TD-DFT   X-ray  

摘要： Derivatives of thiocarbohydrazone studied so far have shown great biological activity such as antioxidant, antimicrobial, and anticancer. Most of these compounds are bis-substituted derivatives, while monothiocarbohydrazones are much less investigated. Eighteen monothiocarbohydrazones were synthesized and subjected to physicochemical characterization in order to facilitate the examination of their potential biological activity and application in future studies. The structure of synthesized derivatives was confirmed with NMR and FT-IR spectroscopy, and with elemental analysis. For one of the compounds, single-crystal X-ray diffraction analysis was performed. Specific and non-specific molecular interactions were interpreted by LSER principles, using Catalan's model. For additional information about the dominance and influence of the interactions presented, correlations with Hansen's solubility parameters were calculated. Influence of the type and position of the substituent on absorption maxima was determined with LFER (linear free-energy relationship) principles, using Hammett's equation. Acidity constants of the synthesized compounds were theoretically calculated and experimentally determined. Moreover, the excitation of a molecule by a photon of UV-Vis light was interpreted by time-dependent density functional theory (TD-DFT) calculations of UV absorption bands, and intramolecular charge transfer (ICT) was quantified by calculations of the charge transfer distances (D-CT).

关键词： biological control   digestive microenvironments   nematophagous fungus  

摘要： Duddingtonia flagrans is a biological alternative to the use of anthelmintic drugs in ruminants. This fungus must be ingested by the animal, pass through the cavities of the digestive tract and reach the feces where it develops traps that capture the nematodes. The severe conditions encountered in this process negatively affect the fungus, which is reflected in the low recovery rates compared to the amount administered. The aim of this study was to evaluate independently the in vitro effect of typical physical and chemical conditions of the gastrointestinal cavities of ruminants on the concentration, viability, and the in vitro nematode predatory ability of the chlamydospores of D. flagrans. The factors evaluated individually were pH (2, 6, and 8), temperature (28 +/- 2 degrees C and 39 +/- 2 degrees C), exposure to artificial saliva, and milling. The results showed that the concentration and viability of D. flagrans were not affected by the action of pH, temperature, milling, or exposure to artificial saliva. Regarding the in vitro nematode predatory ability, a reduction was observed after the milling process and the exposure for 24 h at different pH.

关键词： Crucifer   Electrophile   Glucosinolate   Natural food preservative   Quantitative structure-activity relationship  

摘要： Isothiocyanates (ITCs) derived from Brassicaceae are potential food preservatives. Their antimicrobial ac-tivity is strongly influenced by their subclass and side chain. This is the first quantitative structure-activity relationships (QSAR) study of ITCs as antibacterials. Twenty-six ITCs covering 9 subclasses were tested against Escherichia coli and Bacillus cereus. Minimum inhibitory concentration (MIC) and growth inhibitory response (GIR) were determined and used to develop QSAR models. MIC of the most active ITCs was 6.3-9.4 mu g/mL. The QSAR models were validated with leave-one-out cross validation. The proposed models had a good fit (R-adj(2) 0.86-0.93) and high internal predictive power (Q(adj)(2) 0.80-0.89). Partial charge, polarity, reactivity, and shape of ITCs were key physicochemical properties underlying antibacterial activity of ITCs. Furthermore, ITC compositions and antibacterial activity of Sinapis alba, Brassica napus, B. juncea, B. oleracea, and Camelina sativa extracts were determined, after myrosinase treatment. B. oleracea ITC-rich extract showed promising activity (MIC 750-1000 mu g/mL) against both bacteria. C. sativa ITC-rich extract showed promising activity (MIC 188 mu g/mL) against B. cereus. The QSAR models successfully predicted activity of the extracts based on ITC compositions. The models are useful to predict antibacterial activity of new ITCs and ITC-rich mixtures. Brassicaceae ITC-rich extracts are promising natural food preservatives.

关键词： Ultrasonic treatment   Maillard reaction   Whey protein   Structure   Emulsion gel   Astaxanthin  

摘要： In order to evaluate the effect of ultrasound and Maillard reaction on the physicochemical properties and gastrointestinal fate of astaxanthin-loaded emulsion gels, the Maillard reaction products (MRPs) of whey protein and flaxseed gum (FG) were prepared by traditional or ultrasonic assisted wet-heating. The MRPs obtained by ultrasonic assisted wet-heating had higher grafting degree and more expanded structures evidenced by the browning intensity, fluorescence intensity and circular dichroism (CD) analysis, thus enhancing its functional properties like solubility and emulsifying capacity. The MRPs improved the water holding capacity, encapsulation efficiency, stability of emulsion gels, in which astaxanthin was wrapped as a model bioactive compound. During the simulated digestion process, the bioaccessibility of loaded astaxanthin reached 72.08% for the emulsion gels stabilized by MRPs. The results highlighted the potential of MRPs in improving functionality of protein and as a delivery carrier of bioactive compounds in food industry.

关键词： Apios fortunei   Extrusion   Starch crystallinity   Amylase   Fermentation efficiency  

摘要： A novel material (Apios fortunei), which has a high starch content and potential healthcare functions, was used for yellow wine fermentation. To determine how the tuber's composition would be modified by thermal treatments and how those modifications would affect fermentation, the changes in the physicochemical properties of the A. fortunei tuber after steam cooking, traditional extrusion (extrusion without enzyme) and enzymatic extrusion (introduce the amylase into the extrusion) were investigated. The results showed a low degree of gelatinization (70.56%) in the steam-cooked sample, and the fermentation broth of the traditionally extruded sample was dense. However, the enzymatically extruded sample was almost completely gelatinized (99.09%) with an amorphous starch structure measured via X-ray diffraction and Fourier-transform infrared spectroscopy. The high water solubility index (61.66%), low water absorption index (1.68 g/g) and viscosity (<60 cP), indicated that the broth of enzymatically extruded sample had a fine fluidity. The results of the final wines indicated that enzymatic extrusion significantly increased the fermentation efficiency, from 62.22% (steam cooking) and 63.87% (traditional extrusion) to 73.47%. Meanwhile, enzymatic extrusion improved the quality characteristics of the final wines, including total amino acid (4559.20 mg/L), soluble solid content (7.35 g/100 g) and total acid (10.66 g/L).

关键词： coordination compounds of germanium with bioligands   synthesis   analysis   physicochemical and biological properties   mechanism of action   preclinical and toxicological studies   complex formation  

摘要： A promising area of modern coordination and supramolecular chemistry is the synthesis of biologically active compounds of germanium and creation of effective drugs, biomaterials, and enzyme modulators based thereon. The present review deals with biologically active compounds of germanium(IV) and contributes to the solution of problems of synthesis, physicochemical analysis, and prediction of biological activity of germanium complexes with a wide spectrum of action. Some features of coordination and chemical properties of organic acids and amino acids in the complexation with germanium dioxide and chloride have been demonstrated. The literature data on the complexation conditions, crystal and supramolecular structures of germanium(IV) complexes, geometry of germanium coordination polyhedra, types of hydrogen bonds, topology of coordination shells, and pharmacological and biological properties of a number of compounds are considered.

关键词： Lactic acid  

摘要： The quality parameters of the optimized symbiotic ultrafiltrated white cheese (OC;containing demineralized whey powder and inulin) treated with microbial transglutaminase enzyme (MTE) was compared with two commercial probiotic (PC) and non-probiotic (NC) cheeses. The counts of probiotic (Lactobacillus acidophilus LA5) and total lactic acid bacteria, and pH were significantly decreased during the 60-day cold storage period. Fat and protein contents, stress levels at the rupture point, and Young's modulus were meaningfully increased until the 30th day of storage, and thereafter were decreased. The amount of free amino acids in OC, PC, and NC cheeses were 1,440.25, 829.02, and 616.43 mu mol/L, respectively. The total amount of free fatty acids in OC, PC, and NC cheeses were 100.06, 96.79, and 90.77 mg/100 g, respectively. Results showed that OC cheese had a more compact and less porous protein structure and maintained its superior texture score until the end of the storage period. Practical applications This research article deals with improving the texture of a synbiotic ultrafiltrated Iranian white cheese using whey powder and inulin (as prebiotics) and enzymatic treatment by microbial transglutaminase. In this investigation, an optimized synbiotic cheese was produced and compared with two commercial (non-probiotic and probiotic) cheeses based on physicochemical, rheological, microstructural, and microbial characteristics of the product. We found that the optimized cheese had superior texture as compare to control cheeses. The count of probiotic bacteria in both probiotic and synbiotic cheeses throughout the storage period was more than standard (>10(7)). Therefore, our findings may likely to be of great interest to the vision of scientists, dairy technologists, and cheese-making industries.

关键词： UV-C light   Fruit juice   Microbial inactivation   Antioxidant activity   Colour   Sensory evaluation  

摘要： A laboratory-scale ultraviolet (UV-C) reactor based on Dean vortex technology was designed and tested for its capability to inactivate microorganisms in apple and red grape juices in relatively low doses of UV-C. Experiments were carried out with freshly squeezed apple juice (AJ) and freshly squeezed grape juice (GJ) inoculated with Lactobacillus plantarum NRIC1749 and Saccharomyces cerevisiae NCIB4932. Furthermore, physicochemical properties, antioxidant activity, total phenolic content, 5-HMF and colour analysis were performed in freshly squeezed apple (AJ) and grape juices (GJ). A UV-C treatment with 1668 mJ cm(-2) led to an approximately 4.07-log inactivation of Lactobacillus plantarum NRIC1749 and 1.79-log inactivation of Saccharomyces cerevisiae NCIB4932 in AJ. A 0.69-log and 0.46-log reduction could be achieved for the inactivation of L. plantarum and S. cerevisiae in GJ at 1232 mJ cm(-2), respectively. DPPH radical scavenging activity and total phenolic content of UV-C treated apple juice significantly increased, whereas total phenolic content remained constant in GJ. However, UV-C treatment had no significant effect on 5-HMF content of both juices. An effect of the treatment on the colour of both juices was observed. No significant change in the quality attributes (appearance, colour, odour, taste) was determined in the both UV-C treated juices.

关键词： Peptide emulsifiers   Synchrotron radiation circular dichroism   Dilatational surface theology   Physical stability   Lipid oxidation   Omega-3  

摘要： We investigated the role of the interfacial properties of ten synthetic potato peptides (previously identified by bioinformatics) to physically and oxidatively stabilize 5 wt% fish oil-in-water emulsions (pH 7). Peptides alpha 10, alpha 12, gamma 1, gamma 75 and gamma 76 adopted a predominantly a-helical conformation (48-57%) at the interface leading to poor inter-peptides interactions as well as weak and stretchable interfaces (E-d* < 12mN/m). Peptides beta 22, beta 27, gamma 36 and gamma 38 displayed a significantly higher degree of interfacial inter-peptide interaction, resulting in stiff and solid-like interfaces (E-d*, = 35 - 45 mN/m). beta 22 and gamma 36 peptides re-arranged at the interface adopting a highly beta-strand structure (63-65%). Emulsions stabilized with all peptides showed high physical stability during one week (D-3,D-2 at day 1 = 0.134-0.175 mu m), except from the ones stabilized with beta 27 that had creaming after day 1, or beta 22 that destabilized during storage. Emulsions stabilized with peptides exhibiting negative surface charge at pH 7 (alpha 12, beta 22, gamma 1, 775, gamma 76, gamma 36 and 740) (zeta potential: -50.9 to -69.5 mV) showed the lowest oxidative stability due to the attraction of cationic metal ions that catalyzed lipid oxidation. In contrast, emulsions stabilized with peptides having positive surface charge at pH 7 (alpha 10, beta 27 and gamma 38) (zeta potential: 11.6-42.8 mV) showed high oxidative stability (i.e., by repulsion of cationic metal ions), independently of the peptide length, secondary structure at the interface, or viscoelasticity of the interfacial layer. Hence, this work advances our understanding of the relation between interfacial properties of peptide layers and the physicochemical stability of emulsions.