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关键词： Soil quality   Conservation agriculture   Microbial biogeochemistry  

摘要： Combination of conservation agricultural practices such as reduced tillage and complex cropping systems can improve soil quality. However, the different effects of conservation practices on soil physicochemical and microbiological parameters need to be monitored, since distinct managements, crops, regions and soil types can lead to different responses. In addition, seasonality can also affect these parameters, leading to changes associated with the environmental conditions, such as temperature and moisture. To better detect differences in soil quality between agricultural practices, the most appropriate season of sampling must be identified. Therefore, the objective of this study was to assess the changes in soil physicochemical and microbiological parameters between four different agricultural practices from a 7-year experiment along two seasons with contrasting soil water content. We analyzed the differences in physicochemical and microbiological parameters, including soil organic matter (SOM), aggregates mean weight diameter (MWD), water stability of aggregates (WSA), soil pH, total nitrogen (soil N), soil C:N ratio, microbial biomass-C (MB-C), N (MB-N), and C:N ratio (MB-C:N), basal respiration, metabolic quotient (qCO(2)) and microbial quotient (MB-C:soil C), between the agricultural practices of conventional tillage with maize monoculture (CTM), no-till with maize monoculture (NTM), no-till with annual rotation of maize and soybean monoculture (NTM/S), no-till with annual rotation of maize intercropped with Brachiaria rhuziziensis and soybean monoculture (NTMB/S) compared to a long-term fallow (>40 years secondary forest) at the Brazilian coastal tablelands in both winter (rainy) and summer (dry) seasons. Results indicated that the physicochemical and mostly the microbiological variables were changed between seasons. Among the practices, NTMB/S and fallow showed higher, while NTM/S and CTM showed lower soil physicochemical quality. The differences between agri

关键词： photocatalysts   TiO2   surface modification with fluorine   photooxidation   gaseous volatile pollutants   photooxidation   intermediate products   adsorbed water   IR spectroscopy   ethanol   acetaldehyde   acetic acid   benzene   dichloroethane   chloropropane   H2S  

摘要： The influence of the modification of the TiO2 surface with F- ions on the physicochemical properties of the catalysts and efficiency in the photooxidation of gaseous molecules under atmospheric conditions and under UV irradiation was studied by IR spectroscopy. The fluorine-containing samples adsorb more water molecules than unmodified TiO2. The amount of adsorbed water increases with increasing content of surface fluoride ions. The fluorination of the TiO2 surface first leads to the substitution of the terminal OH groups by F- ions and to an increase in acidity of the bridging acidic OH groups remained on the surface. The modification also results in the structural rearrangement of the surface involving defective and surface Ti4+ sites. Fluorine modification increases the activity of TiO2 in the photocatalytic oxidation of ethanol, acetaldehyde, acetic acid, and acetone. At the same time, benzene and H2S are oxidized more rapidly on unmodified TiO2. The presence of fluorine on the TiO2 surface exerts almost no effect on the oxidation rate of chlorine-containing substrates C3H7Cl and C2H4Cl2.

关键词： Ginkgo seed   Ginkgotoxin   Ginkgolic acid   Rehydration kinetics   Antioxidants   Maillard reaction products  

摘要： Fresh Ginkgo biloba L. seeds (GBS) contain toxic compounds that are deleterious when consumed frequently, but the drying process can reduce its content. In this study, fresh GBS was rehydrated using two steps: dried using different methods (freeze-drying, infrared drying, hot-air drying, and pulse-vacuum drying) followed by rehydration by submerging into water. The influence of drying methods on rehydration kinetics and quality attributes were evaluated. Results showed the Weibull model provided the best fitting for each rehydration curve (Coefficient of determination (R-2) > 0.99, residual sum of squares (RSS), reduced chi-square (chi(2)), and root mean square error (RMSE) closer to zero). Toxic compounds (ginkgotoxin, ginkgolic acid, and cyanide) decreased significantly while total phenolic content (TPC) and total flavonoid content (TFC) increased in rehydrated products compared with fresh GBS. The sensory score was acceptable for all rehydrated products. Besides, rehydrated products showed retention of antioxidant activities and the formation of Maillard reaction products (MRP). Amongst rehydrated products, infrared drying coupled to rehydration stood out being superior with higher TPC, TFC, MRP, and antioxidant activities and lowest enzyme activities, which were again corroborated from the principal component analysis. The present findings will offer more information in selecting the best drying method for GBS's rehydration as a snack, breakfast, or others.

关键词： Mild processing   Protein oxidation   Response surface methodology   Color quality   Organic acid   Non-thermal hurdle technology  

摘要： This study aimed to test the effect of UV-C light (0.01-0.64 J/cm(2)) (UV) and lactic acid (0.1-12.9%) (LA) combined treatment on sliced Brazilian dry-cured loin (Socol, BDL) for (i) Salmonella Typhimurium reduction, (ii) physicochemical changes (color (a*, cured color, and Delta E), protein and lipid oxidation) and (iii) optimization using response surface methodology (RSM). Linear inactivation rate was achieved and UV was 2-fold more efficient than LA to inactivate S. Typhimurium. At the same time these combined technologies increased lipid (linear rate, R-adj(2) = 0.88), protein oxidation (quadratic rate, R-adj(2) = 0.86) and meat discoloration. Furthermore, the minimum point of the physicochemical changes was obtained using RSM, and the decontamination process was optimized. Hence, a reduction of 1.3 log cfu/g was achieved using 0.36 J/cm(2) of UV and 7.7% of LA. These combined methods represent a promising industrial intervention strategy to dry-meat safety and quality.

关键词： Photodynamic inactivation   Botrytis cinerea   Rhizopus stolonifer   Tomato preservation   Fruit spoilage molds   Fruit quality  

摘要： This study evaluated, at a meso-scale, the antifungal effect of 405 nm LED illumination against Botrytis cinerea and Rhizopus stolonifer on tomatoes, as well as its effect of on the physicochemical properties. Tomatoes were surface-inoculated with B. cinerea and R. stolonifer, and illuminated with 87 W/m(2) for twelve days. Subsequently, the antifungal effect, defined as the difference in mold populations on the control and illuminated samples, was observed to be 1.9 log CFU/g for B. cinerea and 3.2 log CFU/g for R. stolonifer. In terms of physicochemical effects, beginning from day 9, the total phenolic content, TEAC and vitamin C content of illuminated samples was significantly higher (P > 0.05) by 24.6 %, 28.2 % and 16.5 %, respectively, compared to control, but a greater reduction in mass and lycopene content was also observed. Overall, these results suggest the potential of 405 nm LEDs for controlling mold growth on tomatoes during transportation and storage, retaining their physicochemical quality.

关键词： physicochemical properties   sensory quality   stem removal   tencha beverage  

摘要： Fresh tea leaves (Camellia sinensis;Chuanxiaoye) used to make tencha tea are a combination of the stem and leaf. Tencha made from the leaf alone is considered a high-quality tencha beverage with a seaweed-like aroma, mellow taste, and a green appearance. However, no study has investigated the differences between these two variants. In this study, the effects of stem removal on physicochemical properties and sensory quality of tencha beverage were investigated. The appearance feature, taste, and aroma were evaluated, and the results indicated that stem removal improved the quality of tencha beverages. The water extract, total free amino acids, total catechin, epigallocatechin gallate, caffeine, and chlorophyll were higher in leaf-only tencha (LOT) than in leaf and stem tencha (LST), whereas the crude fiber and phenol ammonia ratios were lower in LOT than in LST. Principal component analysis and hierarchical clustering analysis further discriminated between the tencha beverages with different stem contents. This study provided a theoretical basis for quality control by adopting a stem-leaf separation process in tencha manufacturing.

关键词： White-MTAFlow   ProRoot MTA   Biodentine   Hydraulic calcium silicate cement  

摘要： Objectives To evaluate a new material containing tantalum oxide as an alternative radiopacifier, and a water-based gel for hydration, in comparison with two calcium silicate-based cement: ProRoot MTA and Biodentine. Materials and methods ProRoot MTA (Dentsply), Biodentine (Septodont), and a new hydraulic calcium silicate cement White-MTAFlow (Ultradent) (in 'thin' consistency) were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). The interaction with dentin was also assessed using SEM and EDS. Physical and chemical properties radiopacity, setting time, linear flow, volumetric central filling, and lateral flow, pH, and volume change were investigated together with the color luminosity (L) and color change (Delta E). The agar diffusion and direct contact antimicrobial activity, and methylthiazolyldiphenyl-tetrazolium-bromide (MTT) cytotoxicity using human fibroblast cells were also evaluated. Data were statistically analyzed at a 5% significance level. Results All materials were composed of tricalcium and dicalcium silicate but had different radiopacifiers, and calcium hydroxide (portlandite) deposition was detected in XRD analysis. White-MTAFlow exhibited radiopacity values in accordance with ISO standard, and the longest setting time. The water-based gel provided the highest linear flow, a comparable cavity central filling, and the highest groove-lateral flow in the volumetric flow analysis. White-MTAFlow exhibited an alkalinity reduction, and Biodentine, a progressive increase of pH values after 28 days. However, similar volume loss for White-MTAFlow was assessed in comparison to Biodentine after the 28-day immersion. White-MTAFlow showed the highest L value (91.5), and ProRoot MTA the lowest (78.1) due to dentin staining caused by bismuth migration. None of the materials exhibited inhibition halos against the tested bacteria, and similar turbidity values were obtained after 48 h in direct co

关键词： Endodontics   Biological properties   Calcium silicate   Chemical properties   Dental materials   Physical properties  

摘要： Objective. To evaluate tricalcium silicate-based (TCS) experimental materials, associated with zirconium oxide (ZrO2), calcium tungstate (CaWO4) or niobium oxide (Nb2O5) radiopacifiers, in comparison with MTA Repair HP (Angelus). Methods. Physicochemical tests: setting time, radiopacity, pH and solubility. In vitro assays: cytotoxicity: MTT and Neutral Red - NR;cell bioactivity: alkaline phosphatase activity (ALP), Alzarin red staining (ARS) and real time PCR (qPCR). Antibacterial activity: direct contact on Enterococcus faecalis in the planktonic form. Physicochemical and ARS data were submitted to ANOVA/Tukey tests;antibacterial activity, to Kruskall-Wallis and Dunn tests;MTT, NR, ALP and qPCR were analyzed by ANOVA/Bonferroni tests (alpha = 0.05). Results. TCS + CaWO4 presented the longest setting time and MTA HP the shortest. Except for TCS, all the materials presented radiopacity above 3 mmAl. The cements had alkaline pH, antibacterial activity, low solubility and no cytotoxic effects. The highest ALP activity occurred in 14 days, especially to TCS, TCS + ZrO2 and TCS + CaWO4. TCS + ZrO2, TCS + Nb2O5 and MTAHP had higher mineralized nodule formation than those of the negative control (NC). After 7 days, there was no difference in mRNA expression for ALP, when compared to NC. However, after 14 days there was no overexpressed ALP mRNA, especially TCS + Nb2O5, in relation to the CN. All the materials presented antimicrobial action. Significance. The pure tricalcium silicate associated with ZrO2, CaWO4 or Nb2O5 had appropriate physicochemical properties, antibacterial activity, cytocompatibility and induced mineralization in Saos-2, indicating their use as reparative materials. (c) 2020 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

关键词： cholesterol reduction   reduced-cholesterol butter   reduced-cholesterol cream   beta-sitosteryl oleate (BSO)  

摘要： Beta-cyclodextrin (beta-CD) has been shown to successfully lower the cholesterol content of dairy products, such as butter, but the process tends to negatively impact the overall quality and consistency. In this study, beta-sitosterol, which is similar in structure as cholesterol, was reacted with oleic acid to form beta-sitosteryl oleate (BSO), and this was used to improve the consistency of reduced-cholesterol butter. The reaction was catalyzed by sodium bisulfate (2%, w/w) at 140 degrees C, and the highest degree of esterification (94.3%) was obtained after 9 hr of reaction using a beta-sitosterol-oleic acid molar ratio of 1:5. Ultra-pasteurized cream was then treated with 15% (w/v) beta-CD at 40 degrees C with stirring (100 rpm), for 30 min. Results indicated a 95.4% reduction in cholesterol content. Finally, the reduced-cholesterol cream was constituted to contain 3, 5, and 10% (w/w) BSO, after which fat was extracted from the three formulations and their melting profiles compared to that of milk fat. The cream containing 3% BSO showed a profile similar to milk fat and was, therefore, used to formulate BSO-incorporated reduced-cholesterol butter (BSOB). Instrumental analyses showed that BSOB was comparable to the control butter with respect to physical properties, such as hardness/firmness and adhesiveness. Practical Application A modified plant sterol, beta-sitosteryl oleate, was incorporated into a reduced-cholesterol butter to improve its physicochemical properties. The reduced-cholesterol butter was comparable to regular butter with respect to its consistency and melting properties and could be made into sticks. In addition to the reduced-cholesterol butter, this product could provide the foundation for new products blending butter and oils to create other low-cholesterol, reduced saturated-fat products, possibly in stick form.

关键词： Insoluble soybean fiber (ISF)   Alkaline treatment   Emulsification   Stability   Environmental sensitivity  

摘要： Cellulose derived from agricultural by-products as a promising stabilizer for novel food emulsions has been attracting numerous interests. In this work, defatted okara was used to extract insoluble soybean fiber (ISF) under alkaline pH (7.0-12.0). The physicochemical properties of ISF, as well as the formation and stability properties of O/W emulsions (10% w/w of oil) prepared by ISF, were characterized. The results exhibited a lower residual protein content (p < 0.05), as well as a stronger electronegativity and hydrophilicity of ISF, as indicated by -potential and water-in-air three-phase contact angles (theta(wa)) measurements, respectively, as the treating pH increased. ISF extracted at lower pH (<= 10.0) could quickly form O/W emulsions, whereas with little stability. For the emulsions with better stability prepared using ISF extracted at pH 12.0, the storage ability (30 d), and sensitivity regarding pH and NaCl were evaluated. The results revealed that the gel-like network, electrostatic repulsion, and steric hindrance played dominant roles in stabilizing ISF-emulsions. These results will contribute to the development of efficient ISF-based emulsifiers/stabilizers, which may greatly improve the valorisation of soybean by-products.