37 research outputs found
Chemical characteristics and compositions of red pepper seed oils extracted by different methods
No full textThe present work was undertaken to study the physicochemical characteristics, fatty acid, phenolic and tocopherol compositions as well as the antioxidant activities of red pepper seed oils extracted using different methods (soxhlet, cold-pressing, supercritical-CO2 and microwave-assisted extraction process). The results showed that the red pepper seeds were (on a dry-weight basis): ash 3.05%, water 6.63%, oil 18.39%, protein 28.33%, and total carbohydrate 43.60%. In addition, the results revealed that the predominant fatty acids were linoleic, palmitic and oleic acids. The highest and lowest contents of linoleic acid (76.54%) were found in microwave-assisted (76.54%) and soxhlet (73.65%) extracted pepper seed oils, respectively. < Gamma>-tocopherol was the main tocopherol at 278.65 mg/100 g seed oil, followed by < alpha>-tocopherol and < delta>-tocopherol. Nevertheless, high content in total tocopherols was found in microwave extracted red pepper seed oils. The lowest and highest values of oxidative stability were 1.25 and 11.26 h for soxhlet and microwave-assisted extracted seed oils, respectively. Overall, the high antioxidant activities of microwave-assisted extracted seed oil suggest that it could be economically used as valuable natural products for industrial, cosmetic, and pharmaceutical utilizations
Nutritional composition of Zizyphus lotus L. seeds
No full textBACKGROUND: Zizyphus lotus seeds are an unutilized source of vegetable oil and protein and nothing has been reported on their physicochemical characteristics which would indicate the potential uses of these seeds.
RESULTS: The percentage composition of the Zizyphus lotus seeds is (on a dry-weight basis): ash 1.05%, oil 32.92%, protein 19.11%, total carbohydrate 40.87% and moisture 6.05%. Calcium, potassium and magnesium constitute the major minerals of Zizyphus lotus seeds. The seed proteins are rich in threonine, glutamic acid, leucine, arginine and aspartic acid (26.73%, 17.28%, 13.11%, 9.47% and 7.76%, respectively). The main fatty acids of the oil are oleic (61.93%), linoleic (18.31%) and palmitic (9.14%) acids. Glycerol trioleate (OOO; O: oleic acid) was the most abundant triacylglycerol, representing 26.48% of the total triacyglycerols. beta-Tocopherolwas themajor tocopherol (130.47 mg100 g(-1)). This oilwas rich in Delta 7-campestrol and beta-sitosterol (147.82 and 82.10 mg 100 g(-1) oil), respectively.
CONCLUSION: Zizyphus lotus seeds are rich in fat and protein which are of potential industrial significance. In addition, Zizyphus lotus L. seed oil contained many bioactive compounds. This fact is of great economic interest owing to several applications of Zizyphus lotus L. seeds in the food, cosmetics and medicinal industries
Physicochemical and bioactive properties of six honey samples from various floral origins from Tunisia
No full textThe present study was undertaken to determine the physicochemical, biochemical, and antioxidant activities of Tunisian honey samples. All the extracted honey samples appeared to conform to the European Legislation (EC Directive 2001/110) for all parameters. Mint honey, for instance, possesses significant pH value (p < 0.05), invertase activity, water, and protein contents. In addition, this study demonstrates that the color of the Tunisian honeys is highly variable and ranges from pale yellow to dark brown. The total phenolic, flavonoid and carotenoid contents significantly vary (. p < 0.05). The highest values were found in mint honey, which has a very dark color. Correlations between the analyzed parameters are statistically significant (p < 0.05). The DPPH radical scavenging activity of rosemary honey was determined as lower (p < 0.05) than the other analyzed honey samples. Yet, the highest activity was detected in mint honey. The results suggest that Tunisian honeys could be beneficially used as a functional or nutraceutical substance as they prevent or moderate oxidative stress-related diseases
Physicochemical, rheological, and thermal properties of six types of honey from various floral origins in Tunisia
No full textPHYSICOCHEMICAL CHARACTERISTICS AND ANTIOXIDANT ACTIVITIES OF ZIZYPHUS LOTUS L. SEED OIL
No full textThis study was designed to examine both the chemical composition as well as the antioxidant activities of the seed oil extracted from Zizyphus lotus L. The results showed that the neutral lipids were mainly composed of triacylglycerols (92.75% of total lipids). Phosphatidylcholine and digalactosyldiacylglycerol were the main phospholipid and glycolipid subclasses, respectively. Oleic, linoleic and palmitic acids were the major fatty acids in the lipids of Z. lotus seeds. In addition, b-tocopherol was the predominant tocol at 122.13 mg/100 g seed oil, which was equivalent to 60.41% of the total tocols followed by d-tocopherol (13.30%) and d-tocotrienol (8.95%). The total phenol and flavonoid contents were 18.45 mg/100 g and 2.31 QE/g oil, respectively, with ferulic acid as the main phenolic acid (1.36 mg/100 g oil). Overall, the strong antioxidant activities suggest that it could be advantageously used as a functional or nutraceutical food in order to prevent or moderate oxidative stress-related diseases
Exploring potential new galactomannan source of Retama reatam seeds for food, cosmetic and pharmaceuticals: Characterization and physical, emulsifying and antidiabetic properties
No full textIn this study, physicochemical, interfacial and emulsifying properties of Retama reatam and guar galactomannans were comparatively investigated. The results showed that Retama reatam galactomannan is mainly composed of total carbohydrates (95.52%) and lower protein contents (0.87%). The sugars identified were mannose (Man) and galactose (Gal), with a Man:Gal ratio of 1.85 compared to guar gum (1.83). The results of thermal properties indicated were transition temperature (T g ) and melting temperature (T m ) very similar to those of the guar gum. Moreover, results also revealed that there is no significant difference in terms of equilibrium interfacial tension of Retama reatam gum at 10 and 20 °C. Moreover, preliminary tests show that stable oil-in-water nanoemulsions may be formulated using Retama reatam gum. Therefore, measurement of mean oil droplet diameter d after heating at 80 °C, shows that stable nanoemulsions may be formulated using Retama reatam galactomannan. Further in vivo experiments confirmed that Retama reatam gum can reduce the glycemic index of starchy foods and inhibit the surge of postprandial blood glucose level
ANALYSE PAR ELEMENT FINI DU TRANSFERT DE CHALEUR TRIDIMENSIONNEL EN REGIMES STATIONNAIRE ET TRANSITOIRE
No full textL’objectif de cette étude est l’application de la méthode des éléments finis pour la
détermination du champ de température, en régime stationnaire et transitoire, dans un solide
tridimensionnel. En effet, la transformation de l’équation de la chaleur de la forme
différentielle à la forme dite faible a été établie en utilisant la méthode de Galerkin puis
appliquée à un élément-fini cubique à huit noeuds. Nous avons également présenté deux
solutions analytiques de l’équation de la chaleur, en régime stationnaire et transitoire, en
utilisant les séries de Fourier, une technique assez originale a été présentée permettant de
traiter un bon nombre de conditions aux limites simples. Les températures obtenues par la
MEF ont été comparées avec celles issues de la méthode analytique où nous avons constaté
une parfaite concordance des résultats
