细化搜索
结果 11-20 的 71
Physico-Chemical Properties, Fractionation and Antioxidant Activity of Some Essential Oils Utilized in Mayonnaise Preparation and Storage
2021
Mamdouh El kalyoubi | Mohamed Khalaf | Abdel-Aziz Shehata | Wafaa Abozeid | Mohamed Mansour
Two types of essential oils (thyme and Stachys) were used in this Estimation. The chemical composition, antioxidant activity (by DPPH assay) and the rancimat method were used to assess the stability effect of these essential oils. The tested oils were added to mayonnaise to evaluate its capability for inhibition of secondary oxidation products. By DPPH assay, antioxidant activity showed that thyme essential oil was the best antioxidant agent as radical scavenging agents at 450 and 500 ppm concentrations, even better than BHT at the200 ppm concentration. As a typical antioxidant, butylated hydroxytoluene was used for comparison. The mayonnaise samples prepared by adding thyme, stachys essential oils and TBHQ (control +) at concentrations of 200,400, 600 and 200 ppm into the sunflower oil free from antioxidant. At the amounts used in this study, thyme and stachys oils were significantly successful in reducing the oxidation of sunflower oil, especially, at 500 ppmwhich showed more efficient than BHT. Specifically, in the presence of thyme oil, the induction period of sunflower oil was considerably elongated. However, butylated hydroxytoluene (BHT) was more efficient than thyme and Stachys oils at the 200-ppm concentration against oxidation of oils. all concentrations of thyme and stachys essential oils had an antioxidant activity similar to synthetic antioxidant of TBHQ at a concentration of 200 ppm for inhibition of secondary oxidation products in mayonnaise in comparison with the control sample. As a conveniently available source of natural antioxidants, thyme and stachys essential oils can be used for use in fats, oils and food containing fats.
显示更多 [+] 显示较少 [-]DNA Barcoding of Commercial Three High Value Red Sea Fishes from The Egyptian Market
2021
rana gamaleldin | Mohamed Rashed | Mahmoud Magdy
Fish play an essential role in food security and are regarded as one of Egypt's primary food resources and, therefore, significantly im-pact the national economy. The three main sources of fish production in Egypt: marine (Red and Mediterranean seas), lakes and the River Nile, due to the elevated incidence of species substitution at the global level, precise identification of seafood species on the mar-kets considered a solution for food safety con-trol institutions and human consumer protec-tion. Mislabeling occurs when one species is substituted for another. Different species of red sea marine fish were collected from the Egyp-tian market. According to the Arabic name in the fish market, Samples searched for English and Latin family names in (www.fishdata-base.org). Commercial samples were success-fully extracted and confirmed with 1.5% aga-rose gel electrophoresis. The result showed that the mtDNA gene cytochrome c oxidase subunit I (COI) amplification was successful for all samples with high concentration, it was purified and sequenced for both directions and blasted using the NCBI database. Resulting in the identification of three commercially essen-tial and expensive fish samples, Baghbaghan (parrotfish), Hamour (Greasy Grouper) and kahaya (Spiny squirrelfish). One of them cor-rectly identified according to the market name, while the other two are recorded mistakenly under another name.
显示更多 [+] 显示较少 [-]Effect of Fungicide, Salicylic Acid, Henna Powder and Propolis on Silkworm Larvae Infected with Aspergillus spp.
2021
Eman Abd El-Razek | Madiha A Rizk Rizk | Youssef Abdallah | Khadiga Abou-Taleb | sawsan abdelmegeed
Mulberry silkworm, Bombyx mori L. is in-fected with many diseases. In this work, two fungi species, Aspergillus fumigatus and As-pergillus flavus, were isolated from the in-fected B. mori larvae during rearing process. The morphological symptoms were the same for both fungi and appeared from newly hatched larvae until moth formation. In larvae, black spots of both fungi species appeared eve-rywhere on the body, then these spots extended and eventually larvae died, and fragments of the fungus came out from the spots. The only one difference between the two fungi, is that symptoms of A. fumigatus appeared four days earlier than those of A. flavus. Newly hatched larvae were sprayed with spore suspension (1x106 conidia spores/ml) of A. fumigates and A. flavus separately. One and 12 hrs. after in-oculation, larvae were sprayed with different concentrations of fungicide (Actamyl), sali-cylic acid, and henna and propolis powders, in isolation. After words, mortality and survival percentages were calculated and compared to those that occurred in untreated check (larvae were inoculated with A. fumigatus and A. fla-vus separately without any control treatment). The lowest mortality and highest survival per-centage were occurred in larvae treated with salicylic acid at 10% after 12 hrs. from inocu-lation with A. fumigatus. On the other hand, the lowest mortality and highest survival percent-ages occurred in larvae treated with the fungi-cide Actamyl at 6% and henna at 15% after 12 hrs. from inoculation with A. flavus.
显示更多 [+] 显示较少 [-]Evaluation of Different Control Methods on the Rust Flour Beetle Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)
2021
Sara El-Deeb | Maha El-Ghannam | Pansea Azzam
The presented study aimed to evaluate the different control methods of the rusty flour beetle Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). The experi-ments were conducted to evaluate the effi-ciency of a chemical pesticide (Mala-thion), biopesticide (Tracer 24% SC), plant oil (Lemongrass oil), plant extraction (Ac-etone extracts from Rosemary), powder (Diatomaceous earth) and modified At-mosphere (argon gas). Mortality percent-age increased with increase of exposure times at all tested concentrations. The tox-icity effect of different treatments against adults of T. castaneum at the LC50 after 7 days post-treatment at 30±1°C could be ar-ranged in descending order as follows: Malathion, Tracer 24% and lemongrass oil, while, acetone extracts from Rosemary and diatomaceous earth (DE) were the least effective. The LT50 values against the adult stage of T. castaneum were 19.99, 2.33 and 4.86 hr. for Argon 100, 80 and 60%, respectively. In order to avoid the disadvantages of using chemical insecti-cides such as malathion, it is recommended to use other more safe control methods for the environment as Tracer 24% or lemongrass oil or Argon gas.
显示更多 [+] 显示较少 [-]Effect of Clinoptilolite on Humoral Immunity and Biochemical Parameters in Calves Vaccinated with Foot and Mouth Disease Vaccine
2021
Nour Elhoda Tamim | Dawlat Salama | Hani Srour | Ehab Ibrahim
The foot and mouth disease (FMD) vaccine is used to control the FMD in cloven-hoofed animals including calves. The most important step in vaccine preparation is the selection of a suitable adjuvant which plays a main role in the vaccine’s potency. The present study is an attempt to use clinoptilolite instead of Montanide oil to enhance the efficiency of the FMD vaccine and reduce its production cost. Twelve calves were split into four groups. Three groups were vaccinated with FMD vaccine with different adjuvants i.e. 100% Montanide (ISA 206), 50% of Montanide with 1.0 μg/dose of clinoptilolite (ISA 206+CLINP), and by replacing the 100% of Montanide to 1μg/dose of clinoptilolite (CLINP). The fourth group was unvaccinated. Results showed that calves vaccinated with (ISA 206+CLINP) FMD vaccine expressed the highest and the longest periods of immune response until 38 weeks. While groups vaccinated with (CLINP) or (ISA 206) vaccine showed only protection up to 26 and 34 weeks respectively. Also, our results showed that clinoptilolite improved organ functions resulting from the stress of vaccines. Finally, this study recommended the use of clinoptilolite with Montanide oil as a potential adjuvant in the FMD vaccine to give high stimulation of the immune response.
显示更多 [+] 显示较少 [-]Capabilities of Hyperspectral Remote Sensing Data to Detect Soil Salinity
2021
Abdelrahman Medhat Saleh | Mohammed Abd-Elwahed | Yasser Metwally | Sayed Arafat
The objectives of the current study were to investigate the opportunity of estimating soil salinity from hyperspectral data and identifying the most informative spectral zones for estimation. Electrical conductivity (EC) measurements of ninety topsoil samples (0–30 cm) collected from Toshka, Egypt, were used as data set. Analytical spectral device was employed to collect the reflectance spectral signatures of soil samples. Both linear regression and HSD Tukey’s analyses displayed that the SWIR1 and SWIR2 zones are the most suitable for soil salinity prediction while, blue, green and NIR were the wickedest. Moreover, EC estimation was better in case of lower soil salinity (0-2 dS m-1) than higher levels (8-1). Partial-least-squares-regression (ΡLSR) was employed to establish soil salinity prediction model using the training set of soil samples (n=75). The PLSR model was set up using the most informative wave bands (SWIR1 and SWIR2). The result showed that PLSR linear model gave a precise prediction of soil salinity (R2 = 0.93). The results revealed that employing reflectance values in SWIR in the model variables increases the precision of soil EC prediction.
显示更多 [+] 显示较少 [-]Detoxifying Enzymatic Activity and Insecticide-Resistance Gene Expression in Field Populations of Pink Bollworm, (Pectinophora gossypiella (Saund.))
2021
Rabab Desouky Alam | Amgad Sobeiha | Abdel-Aziz Khdir | Naima Alsenosy
A study was conducted to assess two enzyme detoxifying activities and insecticide-resistance gene expression quantitation using real-time (PCR). Four populations of pink bollworms were compared with the baseline laboratory strain. Field populations showed higher levels of enzymatic activity, glutathione-S-transferase and β–esterases, than those of the laboratory strain. The amplification curves scored a cycle threshold (Ct) value of 25 for the ribosomal protein subunit7 (rps7). For the BtR gene, the Ct values of analyzed biological groups ranged from 20 for the laboratory strain to 24 for the Fayoum group. For Cad1, the Ct values ranged from 19 for laboratory strain to 23 for Fayoum and Qalubia populations. Therefore, the present work introduces a method for the challenge of monitoring resistance to Bt toxins in crops which requires, according to the IPM (Integrated Pest Management) program, a wise insecticide application.
显示更多 [+] 显示较少 [-]Turmeric Extracts as a Protective Natural Compound Against Hepatotoxicity Induced by Lead Nitrate in Male Albino Rat Model
2021
Abd el-Fattah Abd el-Fattah | Medhat Abozid | Kamal Mahmoud
Excessive exposure to lead may damage the liver by increasing oxidative stress, leading to many serious diseases. Dietary antioxidants may protect the liver from damage. Therefore, the effect of ethanolic and aqueous turmeric extracts against lead-induced liver damage was evaluated by estimating liver function and antioxidant/oxidative stress biomarkers. Forty rats were divided into group (A) served as the control and group (B) was treated with 93 mg/kg b.wt. lead nitrate; while group (C) and group (D) were treated as group B in addition to 400 mg/kg b.wt. of turmeric aqueous and ethanolic extracts, respectively. Group B showed a significant increase in the activities of alanine transaminase by 10 folds, aspartate transaminase by 9 folds, alkaline phosphatase by 3 folds and the level of malondialdehyde by 10 folds, while showed a significant decrease in albumin by 60%, total protein by 54.5%, and superoxide dismutase by 80.5%, catalase by 75% and glutathione by 71.6% in comparison with those of the control group. On the other hand, turmeric treatments (groups C and D) led to a readjustment of levels for such biomarkers. Collectively, these results demonstrate the potential of turmeric extracts (particularly the ethanolic extract) to improve the fatal effect of lead in a rat model.
显示更多 [+] 显示较少 [-]Preparation and Thermal Stability of α-Tocopheryl acetate and Strawberry Anthocyanins Complexed with Starch and β-Cyclodextrin
2021
Eman Rashed | Hussein Ali | Mohamed Attia | Eslam Bendary | Khaled Ramadan
In the sake of enhancing the thermal stability of α-Tocopheryl acetate (α-TA) and Strawberry Anthocyanins (AN), their encapsulation with starch or β-Cyclodextrin were prepared and characterized by UV-Vis and IR spectra in addition to thermal analysis. Thermal stability was investigated by comparing the thermographs of each host and guest with that of the prepared complex. Both hosts provided extra thermal stability to both guests where α-TA is stabilized from 230 to 291oC by complexation with starch and to 285oC by encapsulation with β-CD. AN was also stabilized from 40.02oC to 75.57 and 79.46oC by complexation with starch and β-CD respectively.
显示更多 [+] 显示较少 [-]Identification and Reconsidering Phylogeny of Some Aphid Species, (Hemiptera: Aphididae), Based on Molecular DNA Markers Using ISSRs-PCR Technique
2021
Ibrahim Adss | Reda Tabikha
Aphids are considered one of the most economically important insect pests worldwide. Successful pest management systems are based on accurate and rapid pest species identification. Traditional morphological identification of closed aphid species may be considered an inaccurate taxonomic process. To overcome the disadvantages of traditional morphological identification, molecular techniques, related to DNA markers and based on polymerase chain reaction (PCR), were approached by using nine ISSRs primers to identify and diagnose fifteen common aphid species that disperse in the Egyptian agroecosystem. The examined ISSRs primers could success-fully discriminate the tested aphid species that reflected 61.39% polymorphism among them. Moreover, four banding patterns were considered unique bands that could characterize three aphid species (Aphis gossypii, Aphis nerii and Myzus persicae). The highest genetic homology (84.9%) was observed between species Rhopalosipum padi and Schizaphis graminum. In addition, each of A. gossypii and Aphis citricola were also genetically homologous species. In contrast, species Aphis craccivora and M. persicae were analogous genetically with a low similarity percentile (59.8%). High genetic di-vergence was observed also between A. nerii and M. persicae. Two alternative molecular branching taxonomic keys were proposed by subjecting the five highest polymorphic ISSRs primers and 29 banding patterns with different molecular sizes.
显示更多 [+] 显示较少 [-]