In this paper, we have studied the essential oils chemical composition of the leaves of seven Eucalyptus species developed in Tunisia. Eucalyptus leaves were picked from trees growing in different ...arboretums in Tunisia. Choucha and Mrifeg arboretums located in Sedjnene, region of Bizerte (Choucha: E. maideni, E. astrengens et E. cinerea; Mrifeg : E. leucoxylon), Korbous arboretums located in the region of Nabeul, North East Tunisia with sub-humid bioclimate, (E. lehmani), Souiniet-Ain Drahem arboretum located in region of Jendouba (E. sideroxylon, E. bicostata). Essential oils were individually tested against a large panel of microorganisms including Staphylococcus aureus (ATCC 6539), Escherichia coli (ATCC 25922), Enterococcus faecalis (ATCC29212), Listeria ivanovii (RBL 30), Bacillus cereus (ATCC11778).
The yield of essential oils ranged from 1.2% to 3% (w/w) for the different Eucalyptus species. All essential oils contain α-pinene, 1,8-cineol and pinocarveol-trans for all Eucalyptus species studied. The 1,8-cineol was the major compound in all species (49.07 to 83.59%). Diameter of inhibition zone of essential oils of Eucalyptus species varied from 10 to 29 mm. The largest zone of inhibition was obtained for Bacillus cereus (E. astrengens) and the lowest for Staphylococcus aureus (E. cinerea). The essential oils from E. maideni, E. astrengens, E. cinerea (arboretum of Bizerte), E. bicostata (arboretum of Aindraham) showed the highest antibacterial activity against Listeria ivanovii and Bacillus cereus.
The major constituents of Eucalyptus leaves essential oils are 1,8-cineol (49.07 to 83.59%) and α-pinene (1.27 to 26.35%). The essential oils from E. maideni, E. astrengens, E. cinerea, E. bicostata showed the highest antibacterial activity against Listeria ivanovii and Bacillus cereus, they may have potential applications in food and pharmaceutical products.
•Biochemical composition of six Tunisian walnuts varieties (Juglans regia L.).•Tocopherols, alcohols, sterols, carotenoids and volatile compounds were analyzed.•Significant effect of genotype was ...observed.
The aim of this work was to study the content of tocopherols, sterols, triterpenic and aliphatic alcohols, carotenoids, and volatile compounds in the kernel oils from six walnut (Juglans regia L.) varieties. The levels of β-carotene ranged between 0.22 and 0.62mg/kg, followed by lutein (0.01–0.06mg/kg). The total content of tocopherol ranged from 186.5 to 436.2mg/kg of the extracted oil and the major isoform in all samples was γ-tocopherol. The most abundant phytosterol was β-sitosterol (974–1494mg/kg) followed by campesterol then Δ-5-avenasterol. The major triterpenic alcohol was cycloartenol (226.4–532.1mg/kg). Hexacosanol (9.71–28.15mg/kg) was the major aliphatic alcohol. The detected volatile compounds were pentanal, hexanal, nonanal, 2-decenal and hexanol. The statistical analysis showed significant differences between varieties, which are probably due to genetic factors.
Cereals constitute a major source of human and animal nutrition. In spite of the extensive production of numerous cereal species, some information is unavailable in terms of lipid composition. Due to ...the oil increasing demand by the overgrowth of the world population, oleaginous species have encountered problems in recent years. In order to find new sources of edible oil, the aim of this study was to describe the importance of seventeen varieties oil of seven cereal species. Oils were extracted by the Soxhlet method, and fatty acids were measured by gas chromatography. The present study demonstrated that the lipid content of cereal seeds ranged from 1.42% to 5.97%. In average, oat, millet, and maize had significantly higher lipid content, respectively, 5.97%, 5.06%, and 4.71%. The main fatty acid recorded in the studied cereal species, except oat, was linoleic acid C18 : 2 (ω6). Regarding the essential fatty acids linoleic acid C18 : 2 and linolenic acid C18 : 3 (ω3), the oil of all studied species, except oat, was rich in ω6 fatty acids (47.50 to 60.13%) and poor in ω3 (0.45% to 5.33%). The content of unsaturated fatty acids in all studied species ranged from 77.22 to 81.89%. Cereal oil was considered as highly unsaturated oil with the presence of the essential fatty acids necessary for human health. Therefore, cereal oils could be commercialized in small quantities in pharmacies or parapharmacies.
The
(L.) (OFI) is used as a nutritional and pharmaceutical agent in various dietary and value added products. This study underlines the possible use of native prickly pear cladode powder as a ...functional ingredient for health-promoting food production. To summarise, chemical characterization of polyphenols, minerals and soluble dietary fibre was performed; furthermore, the antioxidant activity and bioaccessibility of polyphenols and minerals were assessed. Eleven compounds between phenolic acids and flavonoids were identified, with piscidic acid and isorhamnetin derivatives being the most abundant.
dietary fibre was mainly constituted of mucilage and pectin, and was composed of arabinose, galactose, glucose, mannose, rhamnose, and xylose sugars. The polyphenols' bioaccessibility was very high: piscidic acid at 200%, eucomic and ferulic acids >110% and flavonoids from 89% to 100%. The prickly pear cladode powder is also a source of minerals, as cations (calcium, sodium, potassium and magnesium) and anions (sulphate and chloride), with high magnesium bioaccessibilty (93%). OFI powder showed good capacity of radical scavenging measured by DPPH and ABTS methods, with 740 and 775 μmol Trolox/100 g OFI, respectively. Finally, the presented results allow the consideration of this natural product as a source of several essential nutrients, with a possible use in the food industry as a functional ingredient.
Millet is one of the most important cereals in the world regarding its domestic and commercial utilization. In spite of the extensive production of numerous millet species as main staple food grain ...in many developing countries in Africa and Asia, little information is available on pearl millet oil in terms of its composition of bioactive lipophilic and phenolic compounds. The aim of the present study was to describe the importance of pearl millet seeds by extracting their oil and determining its composition regarding lipids, carotenoids and phenolic compounds, and its antioxidant potential. The content of total lipids in pearl millet seeds was 5.1%, similar to that in maize grain. Several fatty acids were detected; the major fatty acid was linoleic acid (47.5%). The content of total unsaturated fatty acids in pearl millet oil was 77.2%. Pearl millet oil was rich in omega-6 (ω-6) fatty acids and it can be considered a highly unsaturated oil. This oil also has a high total phenolic content (220 mg/100 g) and antioxidant activity (79.2%). Two flavonoids (quercetin: 1.7 μg/g and catechin: 1.2 μg/g) were found in pearl millet, which are commonly recorded in other species such as sorghum, amaranth, buckwheat and quinoa. The results showed remarkably high levels of carotenoids in pearl millet (10.2 mg/kg) compared to other millet species. Pearl millet seeds may be used in future to create a new source of edible oil due to the presence of several unsaturated and essential fatty acids. Furthermore, foods manufactured from pearl millet flour will have a high content of phenolic compounds and carotenoids as well as antioxidant activity, which support human health.
This research aimed to study the influence of crop year and cultivar on the composition of phytochemicals and carbohydrates of pecan (
Carya illinoinensis
) kernels. Three pecan cultivars, Mahan, ...Moore and Burkett, grown at the same location, were analyzed for their total phenols, total flavonoids, total flavanols, total condensed tannin, total
o
-diphenols, HPLC phenolic profile, antioxidant activity, and carbohydrate composition over two harvest years. Five individual phenolic compounds were identified and quantified in pecan kernels: gallic acid, catechin, epicatechin, an ellagic acid derivative and ellagic acid. Mahan exhibited the highest content of total phenolics, flavonoids, flavanols and condensed tannins, as well as the highest antioxidant activity among the cultivars. Significant positive correlations were found between antioxidant activity and the concentration of phenolic compound in the kernels. Based on principal component analysis performed using all the measured variables, Mahan and Burkett cultivars were clearly distinguished, while Moore presented similar characteristics to both of them. The present findings showed that phytochemicals and carbohydrates varied significantly among the cultivars and harvest years. As there is little information on the phytochemical profile of pecan nuts, the information provided here will be valuable for a better understanding of their potential contribution to health promotion and disease prevention.
Fatty acid composition of peanut seed oil in four varieties cultivated in Tunisia showed that linoleic (C18:2), oleic (C18:1) and palmitic (C16) acids account for more than 84% for Chounfakhi and ...Massriya and for more than 85% of the total fatty acids of Trabilsia and Sinya seed oil respectively. Seed oil contents were significantly different (P ≤ 0.05) and did not exceed 48%. The study of total phenolics revealed that Chounfakhi contained more total phenolics (2.1 mg GAE/g DW), followed by the Massriya and Sinya cultivars (1.35 mg GAE/g DW for each); Trabilsia presented the lowest total phenolic content with 1 mg GAE/g DW. Considerable antiradical ability was found, especially in the Trabilsia peanut seed cultivar (IC50 = 1550 μg/ml), the Massriya and Sinya cultivars had, respectively, 720 and 820 mg/ml IC50. In the Massriya variety the sterol fraction showed antibacterial activity against Listeria ivanovii, Listeria inocua, Pseudomonas aeruginosa, Staphylococus aureus, Enterococcus hirae and Bacillus cereus.
Background:
Here, we report the frequency of capsulated ampicillin-resistant
Haemophilus influenzae
strains isolated from children in Tunisia, particularly capsular serotype b, by polymerase chain ...reaction (PCR) to determine the molecular mechanisms underlying ampicillin resistance.
Methods:
We considered 22 capsulated
H influenzae
strains selected from a series of 91 ampicillin-resistant
H influenzae
strains isolated from children between 2010 and 2011 in Tunisia. The capsular serotypes of these strains were identified by slide agglutination and PCR.
Results:
By PCR, 19 (20.88%) serotype b, 1 (1.1%) serotype a, 2 (2.2%) serotypes d and f and 69 (75.82%) non-typeable strains were found among the 91 ampicillin-resistant
H influenzae
strains. 100% of the assumption between the consequences of antigenic examinations and PCR was found. The serotype b strains showed biotypes I, II, III, IV, VI, and VIII. The other capsulated strains showed biotypes IV and VIII. Thirteen of the serotype b strains created β-lactamase (14.28%). The 19 serotype b ampicillin-resistant
H influenzae
strains were subdivided into 3 bunches as indicated: The gathering of the β-lactamase positive, ampicillin-resistant where 11 strains (57.89%) were β-lactamase positive
bla
TEM-1
(+) and
fts
I (+). The second gathering of the β-lactamase negative, ampicillin-resistant strains, where 6 isolates (31.58%) were β-lactamase negative
bla
TEM-1
(−) and
fts
I (−), and lastly, the gathering of the β-lactamase positive, amoxicillin-clavulanate resistant where 2 isolates (10.52%) were β-lactamase positive
bla
TEM-1
(+) and
fts
I (−).
Conclusion:
PCR should be used in our country because it may contribute to decreasing the probability of transmission of these strains, especially those showing the two mechanisms of resistance among children in Tunisia.
Pecan nuts (Carya illinoinensis) provide a wide range of bioactive compounds (particularly polyphenols) that improve the nutritional quality of diets. This study aimed to monitor the evolution of ...polyphenolic compounds (total phenols, total flavonoids, total flavanols, total condensed tannins, and total o-diphenols), the phenolic profile, the antioxidant activity, and the sugar concentration during pecan nut development in three Tunisian cultivars. Condensed tannins (41.98–221.13 mg catechin assay equivalents g−1 FW) were the dominant class of phenolics at all maturity stages, followed by total phenols (12.25–57.92 mg gallic acid equivalents g−1 FW). Ellagic acid and catechin were the most abundant phenolics at all maturity stages. The highest phenolic content and antioxidant activity were found at an early stage of ripening but as maturity progressed, a decreasing trend was observed. Sucrose (6.09–30.79 mg g−1 FW) was the predominant sugar followed by fructose and then glucose. A decreasing and later increasing trend of total carbohydrate concentration was detected during nut development. A Canonical Discriminant Analysis of the data succeeded in separating the three pecan cultivars due to their unique characteristics. Overall, the cultivar and the degree of maturity are the major factors controlling the chemical composition and antioxidant capacity of pecan nuts. This study provides more information on the optimal period when the maximum concentration of these health-enhancing compounds is found for use in food, nutraceutical, cosmetic, and pharmaceutical applications.
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