排序方式： 共有17条查询结果，搜索用时 15 毫秒
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Damak N Bouaziz M Ayadi M Sayadi S Damak M 《Journal of agricultural and food chemistry》2008,56(5):1560-1566
Maturity is one of the most important factors associated with the quality evaluation of fruit and vegetables. This work aims to investigate the effect of the maturation process of the olive fruit on the phenolic fraction and fatty acid of irrigated Chétoui cultivar. The phenolic composition was studied by using reverse-phase high-performance liquid chromatography followed by LC-MS and GC-MS analyses and fatty acids by GC. Oleuropein was the major phenolic compound at all stages of ripeness. Unexpectedly, both phenolic compounds hydroxytyrosol and oleuropein exhibited the same trends during maturation. Indeed, the oleuropein levels decreased during the ripening process and were not inversely correlated with the concentrations of hydroxytyrosol. The antioxidant capacity of olive extracts was evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl and the beta-carotene linoleate model system. The IC 50 and AAC values of the olive extracts decreased from 3.68 to 1.61 microg/mL and from 645 to 431, respectively. There was a correlation between the antioxidant activity and the oleuropein concentration. The fatty acid composition was quantified in olive fruit during maturation and showed that fatty acids were characterized by the highest level of oleic acid, which reached 65.2%. 相似文献
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Aljumaah RS Almutairi FF Ayadi M Alshaikh MA Aljumaah AM Hussein MF 《Tropical animal health and production》2011,43(8):1605-1610
The purpose of this study was to determine the prevalence of subclinical mastitis in camels in Riyadh, Saudi Arabia and the
factors influencing its incidence. A total of 740 quarter milk samples were collected from 47 camel herds belonging to Majahim, Maghatir, Shu’l, and Sufer breeds. California mastitis test (CMT) was used as a screening test for subclinical mastitis. Samples giving negative or
trace CMT scores (0) were assigned to healthy quarters, while those giving positive scores of 1+ to 3+ were assigned to subclinically
affected quarters. Logistic regression was used to assess the association of breed, parity, and stage of lactation with the
prevalence of subclinical mastitis. Milk fat, protein, lactose, solid nonfat percentages and Na, Ca, and K concentrations
were compared in CMT-positive versus healthy quarters. One third (33%) of tested quarters had subclinical mastitis based on
CMT. The estimated probability of subclinical mastitis with the combined effects of breed, parity, and stage of lactation
ranged from 15.8% to 54.6%. The risk of subclinical mastitis increased significantly with parity and with the early stage
of lactation. The Shu’l breed had significantly higher prevalence of subclinical mastitis than other breeds. Significant decreases
in protein, lactose, and solid nonfat, Ca and K concentrations and increase in Na concentrations were associated with subclinical
mastitis. In conclusion, subclinical mastitis is prevalent in Saudi camels, and its incidence is influenced by breed, parity,
and stage of lactation. 相似文献
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Tasnim Ayadi Abdesslem Hammouda Ceclie Beck Thierry Boulinier Sylvie Lecollinet Slaheddine Selmi 《Zoonoses and public health》2019,66(5):495-503
Bird migration has long been hypothesized as the main mechanism for long‐distance dispersal of flaviviruses, but the role of migratory birds in flaviviruses spillover is not well documented. In this study, we investigated the eco‐epidemiology of West Nile virus (WNV) and Usutu virus (USUV) in trans‐Saharan passerines during their spring stopover in southern Tunisian oases. To do, we combined oral swab analysis and serological tools to assess whether migratory birds could be reaching these stopover sites while infectious or have been previously exposed to viruses. All sampled birds tested negative for oral swab analysis. However, anti‐WNV and anti‐USUV antibodies were detected in 32% and 1% of tested birds, respectively. Among WNV‐seropositive species, the Golden oriole (Oriolus oriolus) showed the highest anti‐WNV occurrence probability. In this species, anti‐WNV occurrence was twice larger in males than females. Inter‐specific and intraspecific morphological, physiological and behavioural differences could explain these results. Although our findings did not show evidence for passerines migrating while infectious, they did not exclude an existing enzootic WNV transmission cycle in Tunisian oases. Further investigations including larger samples of migratory birds are needed for a better understanding of this issue. 相似文献
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Ferouz Y. Ayadi Kasiviswanathan Muthukumarappan Kurt A. Rosentrater Michael L. Brown 《Cereal Chemistry》2011,88(2):179-188
This study was conducted to investigate the production of balanced diets for juvenile yellow perch (Perca flavescens) feeds. Six isocaloric (≈3.21 kcal/g), isonitrogenous (30.1 ± 0.4% db) ingredient blends were formulated with 0, 10, 20, 30, 40, and 50% distillers dried grains with solubles (DDGS), and appropriate amounts of soybean meal, fish meal, vitamins, and minerals. Extrusion cooking was performed using a laboratory‐scale single‐screw extruder at a constant barrel temperature profile of 40–90–100°C, and a constant screw speed of 230 rpm (24.1 rad/sec). The mass flow rate was determined during processing; it generally increased with progressively higher DDGS content. Additionally, moisture content, water activity, unit density, expansion ratio, compressive strength, compressive modulus, pellet durability index, water stability, and color were extensively analyzed to quantify the effects of DDGS content on the physical properties of the resulting extrudates. Significant differences (P < 0.05) between blends were observed for color and water activity for both the raw material and extrudates, respectively, and for the unit density of the extrudates. There were significant changes in brightness (L), redness (a), and yellowness (b) among the final products when increasing the DDGS content of the blends. Expansion ratio and compressive strength of the extrudates were low. On the other hand, all blends showed high pellet durability (PDI ≥ 96.18%). Overall, it was ascertained that DDGS could be successfully included at rates of <50%, and that each of the ingredient blends resulted in viable, high quality extrudates. 相似文献
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A study of the molluscicidal and larvicidal activities of Citrullus colocynthis (L.) leaf extract and its main cucurbitacins against the mollusc Galba truncatula,intermediate host of Fasciola hepatica 
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Jannet Elloumi Wassim Guermazi Habib Ayadi Abderrahmen Bouaïn Lotfi Aleya 《Water, air, and soil pollution》2008,187(1-4):157-171
We investigated the coupling of abundance of bacteria, phytoplankton and ciliates with hydrocarbons in the surface water and sediments of five interconnected ponds in the arid Sfax solar salterns. This study aimed at determining the potential sources of hydrocarbons and the effects of salinity gradients on microorganism metabolism. Hydrocarbon analysis was performed by gas chromatography (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). The GC-FID allowed the detection of aliphatic hydrocarbons and n-alkanes ranging from n-C13 to n-C30. Total aliphatic hydrocarbon concentrations varied from 92.5 mg. l?1 in the first pond (having marine characteristics) to 661.1 mg. l?1 in the last pond (crystallizer) (316.8?±?120.1 mg. l?1) for water samples and from 26.7 to 127.8 μg. g?1 dry weight for sediment samples. The GC-MS enabled us to detect halogenated hydrocarbons (bromoalkanes and chloroalkanes) and n-alkenes. The distribution of n-alkanes indices coupled to several environmental factors suggests that a major fraction of hydrocarbons resulted from both prokaryotic (bacteria) and eukaryotic (protists) developments. A low hydrocarbon fraction might be petrogenic. 相似文献
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Dhouha Tangour Nizar Yeddes Amel Jrad Malika Trabelsi‐Ayadi 《Compost science & utilization》2019,27(1):1-10
In Tunisia, on‐site co‐composting of oil mill waste would overcome environmental issues and valorize renewable resources. The authors' goal was to determine the physic‐chemical and microbiological properties and nutrient supply characteristics of mixed oil mill waste and green waste compost. Two piles of the same raw materials (2/3 oil mill waste–1/3 green waste, w/w) were moistened with two kinds of water: treated urban wastewater (A1) and tap water (A2). Results showed the following: (i) produced compost decreased in C/N from 32 to 12.30?±?0.89 (A1) and 11?±?0.89 (A2); (ii) major elements (P and K) were within acceptable limits; (iii) A1 and A2 had potentially lower heavy metal contents than the limits established by the second draft of the Biological Treatment of Biowaste of the European Commission and microbial load values below the limit N FU 44‐051 values; (iv) A1 and A2 had, respectively, 93 and 89.67% as germination index Gl values, which confirmed the composts' maturity and safety; (v) for both composts, A1 and A2, culture potting made up of half compost and half soil revealed the highest bean leaves' number; and (vi) the less richness in minerals and organic compounds of A2 compared to A1 gave better germination results for white wheat and bean leaves' number for A2. Even moistened with treated urban waste water, oil mill wastes proved to be very interesting for co‐composting with green waste. 相似文献
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Ferouz Y. Ayadi K. Muthukumarappan Kurt A. Rosentrater Michael L. Brown 《Cereal Chemistry》2011,88(4):363-374
Increasing demand for seafood products and rising demand for fish meal for commercial fish feeds is driving the search for effective alternative protein sources. Twin‐screw extrusion trials were conducted to study the production of nutritionally balanced feeds for rainbow trout fingerlings (Oncorhynchus mykiss). Six isocaloric (≈4.61 kcal/g) ingredient blends with a target protein content of >45% db were formulated with 0, 10, 20, 30, 40, and 50% distillers dried grains with solubles (DDGS) and other feed ingredients. The moisture contents of the diets were initially adjusted to 5–7% db, and then extruded at 250 rpm using dual 1.9 mm dies with varying amounts of steam (7.2–7.7 kg/hr) injected into the conditioner and water (4.3–6.5 kg/hr) into the extruder. Mass flow rates, moisture contents, and temperatures were measured during processing and moisture content, water activity, unit density, bulk density, expansion ratio, compressive strength, compressive modulus, pellet durability index, water stability, and color were analyzed to quantify the effects of varying DDGS content on the extrudate physical properties. Significant differences (P < 0.05) among the blends were observed for color and bulk density for both the raw and extruded materials, respectively, and for the unit density and pellet durability index of the extruded products. There were also significant changes in redness and yellowness, but only minor changes in brightness, among the final products with increasing DDGS content. The compressive strength of the extrudates increased significantly with increasing DDGS. Expansion ratio of all pellets was low. All extruded diets achieved very good water stability. 相似文献