Ce travail a pour objectif la comparaison de ¡'influence de la méthode de désamerisation sur la qualité sensorielle de deux confitures : bigarade et pamplemousse. Le sel, la chaleur et l'eau sont ...considérés comme des éléments moteurs dans l'opération de désamerisation. Dans le cadre de cette étude le facteur sel a été variable ; six taux de sel ont été fixés au cours de cette opération. Ils correspondent aux six pourcentages (0 ; 0,3125 ; 0,625 ; 1,25 ; 2,5 et 5 %) de sel pris en fonction du poids du fruit. Les résultats montrent que l'amertume a disparu totalement pour des concentrations de 2,5 % pour la bigarade et 5 % pour le pamplemousse. Les résultats montrent également que c'est la confiture de bigarade, désamérisée å la concentration en sel de 2,5 %, qui est la plus appréciée. Le test de préférence montre que c'est la confiture de bigarade qui est la plus préférée pour toutes les concentrations testées.
Joie de vivre et apaisement, voilà les impressions que procure la fragrance chaude de l’essence d’Orange douce. Cet agrume est cultivé majoritairement dans les pays méditerranéens, mais aussi en ...Amérique du Sud.
In this research, some of the physical properties of some citrus species (orange, mandarin, grapefruit, lemon and bitter orange) such as size, mass, volume, density, sphericity and projection area ...and terminal velocities of the fruits in water, hydrodynamic properties such as friction force and lift force in water were determined. To determine the dimensions and the projected area, each fruit image was obtained from the three coordinates, and then analyzed using Image Tool 3.0 image processing software. Geometric mean diameter, sphericity and surface area values were calculated based on data. The mass, volume, and density of fruit were also measured. According to the results obtained in the experiments, the terminal velocity in water was measured the highest in the bitter orange fruit (0.55 m s-1) and the lowest in the lemon fruit (0.21 m s-1). According to the results of Pearson correlation matrix analysis showing the relation of parameters to each other, the correlation between terminal velocity in water and fruit density was found to be important for all citrus species tested.
Les agrumes occupent une superficie importante de 65 000 ha en Algérie (2014), leurs fruits sont utilisés dans l’alimentation humaine sous forme fraîche ou transformée, mais les feuilles sont ...communément utilisées en phytothérapie traditionnelle. Les bienfaits constatés par la population nous ont incités à valoriser les feuilles de Citrus clementina récupérées après la taille des arbres, par l’évaluation de l’activité antimicrobienne et la caractérisation chimique de leurs extraits flavonoïdes. L’étude quantitative en composés flavonoïdes montre un rendement de 11,2 % en flavonesflavonols, de 12,36 % en anthocyanes, de 17,87 % en hétérosides et de 12,1 % en C-glycosides. L’étude par spectrophotomètre UV-visible révèle que l’extrait des feuilles renferme 2,48 ± 0,36 mg/g de flavones-flavonols, 3,33 ± 0,296 mg/g de C-glucosides, 0,34 ± 0,05 mg/g d’anthocyanes et 3,77 ± 0,20 mg/g d’hétérosides. L’analyse par HPLC de l’extrait de feuilles de clémentinier révèle sa contenance en acide gallique (35,849 %), acide ascorbique (35,849 %), acide caféique (area = 6,1803 %), acide benzoïque (6,1125 %), catéchine (23,4311 %) et rutine (6,0082 %). Ces extraits montrent une activité antimicrobienne variable à l’égard de tous les germes microbiens (Gram+, Gram– et levure) étudiés. L’extrait flavones-flavonols montre une forte activité antimicrobienne à l’égard des souches Staphylococcus aureus, Staphylococcus epdermidis, Echerichia coli, Pseudomonas aeruginosa et Schacharomyces cervisai avec un diamètre supérieur à 20 mm et une concentration minimale d’inhibition (CMI) égale à 382, 150, 382 μg/ml et 0,380 mg/ml respectivement. Les autres extraits (anthocyanes et C-glycosides) ont un effet intermédiaire, faible ou absent sur les micro-organismes testés. Le pouvoir bactériostatique (CMI) de Staphylococcus aureus en milieu liquide est de 238 μg/ml, et le pouvoir bactéricide (concentration minimale bactéricide) est de 1,845 μg/ml. Cette méthode de dilution est plus précise que celle de milieu gélosé. Citrus fruits are abundant in Algeria, their fruits are used in food, either in fresh or processed form but leaves are commonly used in traditional herbal medicine. These health facts goods found by the population, led to valorize the leaves of Citrus clementina after recovered the branches of the year after the size, by the evaluation of the antimicrobial activity of their flavonoid extracts. The quantitative study of flavonoid compounds showed a yield of 11.2% in flavones-flavonols, 12.36% in anthocyanins, 17.87% in heterosids and 12.1% in C-glycosides. Analysis in UV–Visible spectrophotometer reveals that leaf extracts contain 2.48 ± 0.36 mg/g of flavone— flavonols, 3.33 ± 0.296 mg/g of C-glucosides, 0.34 ± 0.05 mg/g of Anthocyanins and 3.77 ± 0.20 mg/g of heterosids. HPLC analysis of clementine leaves extract reveals the presence of Gallic acid (35.849%), Ascorbic acid (35.849%), Cafeic acid (area = 6.1803%), benzoïc acid (6.1125%), catechine (23.4311%) and rutin (6.0082%). Flavonoid extracts show a variable antimicrobial activity against all microbial bacteria (Gram+, Gram− and yeast) studied. The flavones-flavonols-extract showed a highest antimicrobial activity against strains of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa and Saccharomyces cerevisiae with a diameter superior to 20 mm and IMC of 382 μg/ml, 150 μg/ml, 382 μg/ml and 0.380 mg/ml respectively. Other extracts (anthocyanins and C-glycosides) have an intermediate effect or weak or absent on microorganisms tested. The bacteriostatic MIC on Staphylococcus aureus in liquid medium is 238 μg/ml and bactericidal MBC is 1.845 mg/ml. This dilution method is more precise than that of agar medium.
Turunçgil meyveleri, çeşitli fungal hastalık etmenleri tarafından neden olunan hasat sonrası hastalıklara karşı oldukça duyarlıdır. Geotrichum citri-aurantii'nin neden olduğu ekşi çürüklük, ...turunçgillerin en önemli hasat sonrası hastalıklarından biridir. Hastalıkla mücadelede genellikle sentetik fungisitler yaygın olarak kullanılsa da söz konusu uygulamaların son yıllarda etkisizliğinin yanı sıra insan sağlığı ve çevre üzerine olan zararlı etkileri birçok çalışmada bildirilmiştir. Hasat sonrası hastalıklara karşı antagonistik bakteri etmenlerinin kullanıldığı biyolojik mücadele, sentetik fungisitlere umut verici bir alternatif olduğu birçok farklı konukçu bitki patojen ilişkilerinin irdelendiği çalışmalarda araştırılmıştır. Bu çalışmada sağlıklı turunçgil ağaçlarının meyve, dal ve yapraklarından elde edilen endofitik bakteri izolatlarının biyokontrol potansiyelleri G. citri-aurantii'ye karşı petri denemeleri (in vitro) ve meyve testleri (yarı in vivo) ile araştırılmıştır. İzole edilen 24 aday bakteri izolatı arasından seçilen on altı farklı bakteri izolatı G. citri-aurantii'nin misel gelişiminin engellenmesi üzerine olan antagonistik potansiyeli in vitro çalışmalarda değerlendirilmiştir. Test edilen bakteriler arasında Bacillus spp. ait izolatlar fungal etmenin misel gelişimini % 59.5-78.6 oranında engellemiştir. En yüksek antagonistik etkinlik B. subtilis CM8 (% 78.6) izolatı tarafından neden olunmuştur. Acinetobacter johnsonii CT7, Erwinia herbicola CM5, Pseudomonas putida CL2, Pantoea agglomerans CM14, Acinetobacter lwoffii CP1 ve Stenotrophomonas maltophilia CP3 izolatları, ikili kültür denemelerinde misel gelişimini engellemede başarısız olmuştur. Bakteriyel izolatların antagonistik etkinlikleri, fungus inokulasyonundan önceki ön inkübasyon süresi ile artmıştır. Bacillus spp ait izolatlar engellenme bölgesine yakın noktalardaki hiflerde vakuolleşme, büzüşme, şişme ve erime gibi önemli morfolojik değişikliklere neden olmuştur. Yapay olarak enfekte edilen turunçgil meyveleri üzerinde hastalık çıkışı Bacillus spp. ait izolatlar tarafından % 56.7-83.3 gibi önemli oranlarda baskılanmıştır. Elde edilen sonuçlar, Bacillus spp. ait izolatların güçlü antagonistik aktivitelerinden dolayı, turunçgillerin hasat sonrası hastalık etmen(ler)i ile mücadelesinde biyofungisit olarak kullanılma potansiyeline sahip olduğunu göstermiştir.
Citrus fruits are susceptible to postharvest decays caused by various pathogenic fungal disease agents. Citrus sour rot, caused by Geotrichum citri-aurantii is one of the most important postharvest diseases of citrus fruits Although synthetic fungicides are commonly used to combat the disease, ineffectiveness of these applications as well as their harmful effects on human health and the environment have been reported in many studies recently. Biological control of postharvest diseases utilizing antagonistic bacteria has been explored in different host plant-pathogen interactions as a promising alternative to synthetic fungicides. In this study, biocontrol potentials of endophytic bacterial isolates, obtained from fruits, branch and leaves of healthy citrus trees, were investigated against Geotrichum citri-aurantii on petri plates (in vitro) and fruit tests (semi in vivo conditions). Among the 24 putative endophytic bacterial isolates isolated, sixteen different antagonist bacterial isolates were selected and assessed against mycelial growth inhibition of G. citri-aurantii in vitro studies. Among the bacterial isolates tested, Bacillus spp. isolates significantly inhibited mycelial growth of fungal agent by 59.5-78.6%. The highest mycelial growth inhibition was caused by B. subtilis CM8 (78.6%). Bacterial isolates of Acinetobacter johnsonii CT7, Erwinia herbicola CM5, Pseudomonas putida CL2, Pantoea agglomerans CM14, Acinetobacter lwoffii CP1 and Stenotrophomonas maltophilia CP3 failed to inhibit mycelial growth in dual culture assays. Antagonistic activities of bacterial isolates increased by the pre-incubation time before fungal inoculation. Bacterial isolates of Bacillus spp. caused considerably morphological changes such as vacuolation, shrivelling, swelling and lysis of hyphae close to inhibition zone. On artificially inoculated fruits, isolates of Bacillus spp. also found to suppressed disease incidence significantly by 56.7-83.3%. Due to strong antagonistic activities, isolates of Bacillus spp, tested in this study have the potential to be used as biofungicide for controlling post-harvest disease agent(s) of citrus fruits.
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