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1.
In this study, different solvent extracts of skullcap (Scutellaria baicalensis) were assayed for their total phenol content (TPC), antioxidant activity [determined as DPPH radical scavenging activity, superoxide dismutase (SOD)-like activity, oxygen radical absorbance capacity (ORAC) assay, and comet assay], and α-glucosidaseinhibitory activity. The TPC of skullcap ranged from 9.06 mg/g gallic acid equivalents (GAE) for acetone extract (AE) to 91.8 mg/g GAE for methanol extract (ME). AE, which had a low TPC, exhibited the highest DPPH radical scavenging activity and SOD-like activity. TPC positively correlated with the ORAC assay (r=0.96, p<0.001). All skullcap extracts significantly reduced the hydrogen peroxide-induced DNA damage in human leukocytes. ME with a high TPC and ORAC value showed the highest α-glucosidase inhibition. The difference in the biological activities of the extracts may be due to the differences in their chemical structure or polarity. Therefore, the results obtained indicate that might be a potential source of compounds with health-protective effects. ME, in particular, might be a prospective therapeutic agent for diabetes.  相似文献   

2.
This study was designed to characterize a β-glucosidase from Oenococcus oeni 31MBR, a strain widely used in Chinese winemaking. An intracellular β-glucosidase (EC 3.2.1.21) was partially purified using a combination of ammonium sulfate precipitation and chromatographic methods. A single band was obtained in SDS-PAGE electrophoresis, indicating that the enzyme was highly purified and had an estimated molecular mass of 38.9 kDa. The enzyme exhibited highest activity at pH 4.5–5.0. The optimum temperature was 45 °C. Ethanol promoted the activity of this enzyme up to three times. Among the several metal ions assayed, only Mn2+ exhibited a partial promotion effect. The K m and V max values for p-nitrophenyl-β-d-glucopyranoside were 1.05 mmol/L and 0.957 nmol/min, respectively. Up to now, this study contains the first characterization of a native β-glucosidase purified from crude extracts of O. oeni 31MBR.  相似文献   

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Extracellular and intracellular α-galactosidases were produced by yeast Debaryomyces hansenii UFV-1 grown on different media with several carbon sources. D. hansenii grown in YP-medium (1% yeast extract and 2% peptone) presented maximum cell mass (8.45 mg/mL) after 36 h of cultivation, with lactose as carbon source, followed by sucrose, glucose, raffinose, and galactose. Higher extracellular and intracellular α-galactosidases activities were observed at 48 h of D. hansenii cultivation in YPmedium containing galactose (0.97 and 5.27 U/mL) and lactose (1.28 and 4.88 U/mL), supporting the evidence for the model of induction for the yeast GAL/MEL regulon, such as described in Sacharomyces cereviseae.  相似文献   

5.
Oilseed rape (Brassica napus L.) is an important agronomic crop used for oil, food and animal feed. Glyphosate resistant B. napus is tolerant to the herbicide glyphosate and has been widely adopted due to higher economic returns. However, a concern for growing transgenic B. napus is the potential escape of cp4 epsps transgene via cross fertilization with wild and/or weedy species including Brassica juncea, especially in China, where B. juncea is prevalent. We assessed transgene inheritance and quantification upon wild B. juncea × transgenic B. napus outcrossing from three backcross (BC) generations and their progenies using real-time PCR. Under in vitro conditions, a stable inheritance and similar cp4 epsps copy number between different generations (BC2, BC3 and BC4) and their progenies were observed. A marginally higher copy number was observed when B. juncea was used as the paternal as compared to when it was used as maternal parent. This study demonstrates stable inheritance of the glyphosate resistance trait and the production of fit out crossed offspring in cases of wild type B. juncea × transgenic B. napus.  相似文献   

6.
Growth stress is important to achieve upright growth and avoid exterior influence on living trees. However, many problems are also triggered by the release of growth stress during wood processing, such as end split of log, distortion of board and inaccurate sawing. In order to evaluate the possibility of these problems to occur in poplar clone 107, a new breeding poplar clone in China, surface longitudinal growth strain (SLGS) and internal longitudinal growth strain (ILGS) both of straight and inclined trees were measured for depicting distributing patterns of growth strain both in peripheral and radial directions. Besides that, according to one-way ANOVA analysis, individual tree and peripheral position have a significant effect on SLGS in inclined trees, whereas such effect is insignificant in straight trees. Fiber morphology and shrinkage of wood sample beneath the SLGS testing positions were determined to illustrate the relationships between these properties with SLGS. The results suggested that growth stress is a poor indicator of fiber morphology and wood shrinkage properties for straight trees but a good one for inclined trees. Both the positive SLGS and ILGS are unexpectedly found at the opposite wood side of inclined trees. It is speculated that when the reorientation of inclined trees is insufficiently supported by exerting tensile stress at tension wood side, compressive stress will be formed at the opposite wood side as a complement.  相似文献   

7.
The aim of this work was to carry out the physicochemical and functional characterization of the purified galactomannan obtained from mesquite seed’s endosperm (MSG). From the seeds, a MSG content of 13/100 g with a purity of 94/100 g was determined. The dispersions of MSG samples (up to 5 g/100 mL) exhibited a shear thinning non-Newtonian behavior, with 35.68 mPa.s of viscosity, and surface tension values between 43.5 and 61.06 dynes/cm. The chromatographic analysis revealed a 1.1:1 mannose/galactose ratio, with a molecular weight between 900,000 and 1,000,000 Da. The calorimetric analysis showed a specific vitreous transition temperature of 52.92 °C. The values of apparent viscosity were superior to those of commercial galactomannans, which indicates that MSG can be used too as a thickening agent. The obtained results provide information, which contribute to a better knowledge of MSG, in order to consider its sustainable exploitation in a future.  相似文献   

8.
Araça-boi (Eugenia stipitata), bacuri (Platonia insignis) and cupuaçu (Theobroma grandiflorum) are three exotic fruits typical of the Amazonian region. Their pulps are very much appreciated by the inhabitants and have been recently exported. The present paper reports on the chemical composition of these pulps: the gross composition (carbohydrates, protein, fat, ash and dietary fibre contents) has been determined, together with a more detailed analysis of sugars, amino acids, fatty acids and minerals. Altogether, the data indicate that these fruit pulps of Amazonian origin are of nutritional interest and should be promoted at least at a regional level.  相似文献   

9.
Comparative typing analysis of 25 Lactobacillus delbrueckii subsp. bulgaricus strains, isolated from traditional yoghurts in Turkey, was performed by RAPD–PCR (randomly amplified polymorphic DNA–PCR) and MLST (multilocus sequence typing). RAPD–PCR analyses were performed using two primers; M13 and 1254. Primer 1254 produced better results than primer M13. The bands produced by primer 1254 were brighter and easier to interpret, and a higher number of bands were produced. In addition, clusters produced by primer 1254 were grouped according to the source of isolation. MLST analysis was performed using three genes, β-gal, pheS and rpoA, and isolates were successfully characterized at strain level. To our knowledge, MLST analyses were used for the first time for strain level discrimination in L. delbrueckii subsp. bulgaricus. It enabled a detailed understanding of L. delbrueckii subsp. bulgaricus strains by using allele and sequence types’ analysis. Both MLST and RAPD allowed for the typing of clusters according to the isolation source, while RAPD provided an increased differentiation. However, by increasing the number of genes analyzed, the discriminatory power of MLST could be increased.  相似文献   

10.
The present study revealed that the nutritive value of grape seeds (Vitis vinifera L.) was 383.55±0.13 Kcal/100 g, with magnesium as the most abundant mineral element (70.44±0.88 mg/L). The maximum phenolic (392.58±1.70mg of GAE/g), flavonoid (256.16±1.60 mg of QE/g), and tannin (30.95±0.17mg of CE/g) contents were also found in the ethanol, dichloromethane, and hexane extracts, respectively. The major phytochemical compounds in the ethyl acetate extract were identified via gas chromatography–mass spectrometry (GC–MS) analysis. The ethanol extract has the highest antioxidant activity (IC50=140±1.20 μg/mL for DPPH, 145.28±0.45mg α-tocopherol/g for total antioxidant capacity, and EC50=80±1.41 μg/mL for ferric-reducing power assays). For β-carotene test, the highest antioxidant activity was obtained in the hexane extract. A satisfactory antimicrobial activity was found against a panel of microorganisms with the ethyl acetate extract as the best antimicrobial agent. Additionally, it was found that the bactericidal concentration required for the grape seed extract to kill Listeria monocytogenes should be less than 12.50 mg/mL (minimum inhibitory concentration=4).  相似文献   

11.
The present study evaluated physicochemical and sensory quality parameters of walnuts as a function of irradiation dose in order to determine dose levels causing minimal undesirable changes to walnuts. Physicochemical parameters including peroxide value (PV), hexanal content, fatty acid composition, volatile compounds and sensory parameters including color, texture, odor and taste were determined for unirradiated and irradiated walnuts at radiation doses of 1.0, 1.5, 3.0, 5.0 and 7.0 kGy. PV increased from 1.1 to 3.0 meq O2/kg walnut oil while the hexanal content increased from 3.80 to 34.3 mg/kg walnut after irradiation at a dose of 7.0 kGy. Of the fatty acids determined, stearic and palmitic acids concentration increased while oleic acid decreased with irradiation dose. Polyunsaturated fatty acids were unaffected by irradiation. Volatile compounds such as aldehydes, ketones, alcohols and hydrocarbons increased after irradiation indicating enhanced lipid oxidation. Color parameter L*, a* and b* remained unaffected by irradiation. Sensory analysis showed that taste was the most sensitive of all sensory attributes for the evaluation of walnut quality. Based on taste and odor scores, walnuts remained organoleptically acceptable at doses ≤3.0 kGy.  相似文献   

12.
The hydrolysis of -oryzanol, a cholesterol-lowering and antioxidative mixture of steryl ferulates (mainly 24-methylenecycloartanyl ferulate 1, cycloartenyl ferulate 2, campesteryl ferulate 3, and -sitosteryl ferulate 4) occurring in rice, by commercially available enzyme preparations was investigated. Lipase preparations from different sources did not accept -oryzanol as substrate. Cholesterol esterases, however, catalyzed a sterol-specific reaction, i.e., -sitosterol and campesterol were liberated from 3 and 4, whereas 1 and 2 remained unhydrolyzed. The same specificity profile was observed for hydrolysis of -oryzanol in artificial pancreatic juice and in reactions catalyzed by pancreatic acetone powders. The data indicate that pancreatic cholesterol esterase is involved in the hydrolysis of -oryzanol in vivo. They also provide a perspective for tailoring the composition of steryl ferulate mixtures on a large scale.  相似文献   

13.
Edible flowers, such as pansies, are becoming more popular, but they are highly perishable. So, postharvest technologies are needed, being edible coatings a good alternative. Thus, the aim of this study was to evaluate the effect of alginate coating on physico-chemical and microbiological quality of pansies during cold storage (4 °C for 0, 7, 14, 21 days). Coated pansies maintained good appearance until 14 days of storage, 7 days more than uncoated ones. Flavonoids, hydrolysable tannins and monomeric anthocyanins, as well antioxidant activity, were higher in coated pansies when compared to uncoated ones, on all assayed storage times. Furthermore, after 14 days of storage, uncoated pansies presented microorganism counts higher than coated, namely yeasts and moulds, suggesting an effective barrier protection of the alginate coating treatment. In summary, alginate coating has potential for extending shelf-life and improving physico-chemical and microbiological quality of pansies.  相似文献   

14.
This study investigated acceptability and consumer segmentation of soy sauce and famous Korean dish, bulgogi. A total of 123 participants evaluated intensity of 18 attributes and sensory liking of 4 commercial soy sauce samples and bulgogi samples made by aforementioned soy sauces. The overall results showed that appearance liking was the only significant different attribute among soy sauce samples and there were no significant differences among bulgogi samples. Furthermore, there was little correlation between overall liking of soy sauce and bulgogi samples. However, different segments of consumer groups were found by cluster analysis. Four and five subgroups of consumers were identified on evaluation of soy sauce samples and bulgogi samples, respectively. These results demonstrated that consumers’ different preference pattern. In conclusion, this study specified characteristics of commercial soy sauce perceived by consumers and consumers’ acceptability toward soy sauces and bulgogi made using soy sauces.  相似文献   

15.
Origanum × majoricum Cambess. is the most commonly grown oregano in Argentina. The aim of this work was to explore and describe its polyphenolic profile by high-performance liquid chromatography with diode array detection (HPLC-DAD) to support identification by classical microscopy. Remarkable homogeneity was found when defining the HPLC-DAD fingerprint with 17 characteristic common peaks. Eleven spectroscopically identified compounds were located. The method was successfully applied for the characterization of 22 samples from different productive regions of Argentina. The genetic inheritance from both progenitors of this hybrid oregano was evidenced by the presence of compounds coming from Origanum majorana L. and Origanum vulgare L. This method, combined with statistical multivariate analysis, was also useful to recognize two groups within the samples. Although O. × majoricum Cambess. must be considered the only hybrid between two species, two origins considering the subspecies level of O. vulgare L. have been morphologically differentiated for the hybrid, both with O. majorana L. These formulas were differentiated by their HPLC-DAD fingerprints. The Argentine hybrids studied appeared consistently grouped under these two profiles.  相似文献   

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17.
To investigate the influence of moisture content (MC) and steaming temperature on defects developing during steaming prior to kiln drying, mass loss, heat transfer, microstructures, extractives, and chemical transformation of Eucalyptus grandis?×?E. urophylla specimens (with moisture content of 120, 70, 60, 50, 40, 30, 20%) were observed in this study. Specimens of each experimental moisture content were steamed at 80, 100, and 120?°C for 4 h after pre-heating at atmospheric pressure, respectively. Results revealed that it was most beneficial to conduct steaming at 100?°C when the moisture content was approximately 50% after air drying when stagewise heating-up and continuous steaming schedule were adopted. Under this condition, there was a notable decrease in defects including edge bends, surface splits, and inner splits. Steaming was also a drying period characterized by various extents of mass loss. Changes in microstructures and extractive contents proved the increasing permeability of steamed wood. Deacetylation and crosslinking reactions happened in the hemicellulose of the sample materials, which contributed to the loss of hemicellulose after treatment.  相似文献   

18.
The objective of this study was to prepare and purify α-galactosidase (α-Gal) from germinating coffee beans. The molecular weight of purified α-Gal from germinating coffee beans was determined to be 38.8 kDa by SDS-PAGE. Then the purified α-Gal was applied to synthesize galactosyl β-cyclodextrin using melibiose as donor and β-cyclodextrin as acceptor. Galactosyl β-cyclodextrin was isolated by preparative high-performance liquid chromatography (HPLC) and its structure was analyzed and elucidated by HPLC, fourier transform infrared spectrometer, electro spraying ionization-mass spectrometry, and 13C nuclear magnetic resonance. Our results strongly demonstrate that the synthesized product is a mono-6-O-α-d-galactopyranosyl-β-cyclodextrin and the purified α-galactosidase could transfer one galactosyl residue directly to the β-cyclodextrin ring and synthesize the mono-6-O-α-d-galactosyl β-cyclodextrin.  相似文献   

19.
Red beets (Beta vulgaris L.) have high levels of betalains and other phytochemical compounds that are associated with antioxidant activity. They are ranked higher than other fruits and vegetables that are known for excellent health-promoting properties, such as Swiss chard. Red beet pigments have been extensively used in the food industry as a natural colorant. Although the antimicrobial activity of red beet has many potential applications in the food and consumer product industries, it has not been thoroughly investigated. In this article, we summarize the findings from recent studies quantifying phytochemical antioxidants in red beet in comparison with other natural sources and critically examine the current research where the antimicrobial potential of red beet extract has investigated, highlighting the associated challenges and limitations of these approaches. Finally, we discuss how red beets can be commercially exploited for their antimicrobial properties and future prospects for new value-added red beet products.  相似文献   

20.
The present study reports for the first time qualitative and quantitative data about flavonoids and furocoumarins distribution of unripe Citrus × myrtifolia Rafinesque homogenate, used as ingredient of the popular soft drink Chinotto. No data are available in literature about the chemical characterization of flavonoids and furocoumarins of the chinotto homogenate used to produce the industrial extract. Samples for analysis were therefore processed to better reproduce the crude materials used to obtain industrial chinotto extract: the whole fruits were cut in half, seeds removed, softly squeezed discarding part of the juice, and homogenized in small pieces. The polyphenolics separation was made by HPLC–PDA detector coupled to ESI/MS/MS in positive and negative mode. It has allowed the identification and relative quantification of 16 compounds, among which the flavone-C-glycoside lucenin-2, the 3-hydroxy-3-methylglutaryl flavanone glycoside melitidin and five polymethoxylated flavones have been detected for the first time in Citrus × myrtifolia. The flavonoids and furocoumarins distribution was compared with one of the Citrus × myrtifolia juice, and the antioxidant activity of both samples was assessed by ORAC (Oxygen Radical Absorbance Capacity)-fluorescein assay.  相似文献   

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