Characterization of biochemical traits of dog rose (Rosa canina L.) ecotypes in the central part of Iran

Dog rose (Rosa canina L.) is a wild native species in Iran, with a significant genetic diversity. This plant serves as a rich source of vitamin C, anthocyanins, phenolic contents and carotenoids. Rose hips have been used in several food products, as well as perfumery and cosmetics industries. In this research, we investigate biochemical characteristics of five dog rose ecotypes (Kopehjamshid, Zarneh, Miyankish, Aghcheh and Sadeghiyeh), that were collected from the central part of Iran (Isfahan province). Amounts of vitamin C, total carotenoids, total phenolic contents, total anthocyanins, macro and micro minerals were measured. Seed oil are extracted by soxhlet method and analysed by gas chromatography. The macro and micro minerals levels in the fruit vary significantly among these regions. The results of this study demonstrate that dog rose have great diversity and can be used in breeding programmes in order to increase nutrient values as a food resource additive.     

Influence of Talc and SEBS-g-MA on PP/SEBS-g-MA/Talc Composites under Gamma Irradiation Sterilization Conditions

Among thermoplastics, polypropylene is outstanding with respect to its attractive combination of low cost, low weight, heat distortion temperature above 100°C, and extraordinary versatility in terms of properties and applications. With the appropriate modification, it is possible to improve the existing properties of the polypropylene, or even obtain the new ones. As a result of its originally superior properties, polypropylene is commonly used in medical purposes, where it has to undergo the process of sterilization beforehand. The sterilization of the polypropylene in medicine is most often being carried out with low dose of gamma irradiation, which can influence the changes of properties of both the polymeric matrix and modifiers. Therefore, the purpose of our research work was to determine the mechanical properties of unirradiated and gamma irradiated isotactic polypropylene (iPP) composites with talc filler and poly-(styrene-b-ethylene-co-butylene-b-styrene) block copolymer, grafted with maleic anhydride (SEBS-g-MA) as elastomeric modifier, as well as of corresponding binary blends. Unirradiated and gamma irradiated composites and blends were characterized by tensile measurements, measurements of notched impact strength and FTIR spectroscopy. The effects of composition and gamma irradiation on the properties of the iPP composites and blends are discussed, with emphasis on the study of the stabilizing effect of talc in irradiated iPP composites.     

Influence of Gamma Radiation on Electrical Conduction of Polyethylene Terephthalate (PET) at Ambient Temperature

The electrical conduction in polyethylene terephthalate (PET) exposed to a gamma radiation dose of 150 kGy was investigated in the applied field range from 4 to 36 kV/mm. Samples were irradiated in air at room temperature by means of a ⁶⁰Co gamma source at a dose rate of approximately 42 Gy/min. The electrical properties of virgin and irradiated materials were examined by charging and discharging current measurements. The current decays with time can be represented according to an inverse power law. The changes of dielectric behavior after irradiation were attributed to scission effects.     

Influence of the Extraction Method on the Quality and Chemical Composition of Walnut (Juglans regia L.) Oil

The present study investigated and compared the quality and chemical composition of Moroccan walnut (Juglans regia L.) oil. This study used three extraction techniques: cold pressing (CP), soxhlet extraction (SE), and ultrasonic extraction (UE). The findings showed that soxhlet extraction gave a significantly higher oil yield compared to the other techniques used in this work (65.10% with p < 0.05), while cold pressing and ultrasonic extraction gave similar yields: 54.51% and 56.66%, respectively (p > 0.05). Chemical composition analysis was carried out by GC–MS and allowed 11 compounds to be identified, of which the major compound was linoleic acid (C18:2), with a similar percentage (between 57.08% and 57.84%) for the three extractions (p > 0.05). Regarding the carotenoid pigment, the extraction technique significantly affected its content (p < 0.05) with values between 10.11 mg/kg and 14.83 mg/kg. The chlorophyll pigment presented a similar content in both oils extracted by SE and UE (p > 0.05), 0.20 mg/kg and 0.16 mg/kg, respectively, while the lowest content was recorded in the cold-pressed oil with 0.13 mg/kg. Moreover, the analysis of phytosterols in walnut oil revealed significantly different contents (p < 0.05) for the three extraction techniques (between 1168.55 mg/kg and 1306.03 mg/kg). In addition, the analyses of tocopherol composition revealed that γ-tocopherol represented the main tocopherol isomer in all studied oils and the CP technique provided the highest content of total tocopherol with 857.65 mg/kg, followed by SE and UE with contents of 454.97 mg/kg and 146.31 mg/kg, respectively, which were significantly different (p < 0.05). This study presents essential information for producers of nutritional oils and, in particular, walnut oil; this information helps to select the appropriate method to produce walnut oil with the targeted quality properties and chemical compositions for the desired purpose. It also helps to form a scientific basis for further research on this plant in order to provide a vision for the possibility of exploiting these oils in the pharmaceutical, cosmetic, and food fields.     

Influence of harvesting time on composition of the essential oil of Thymus capitatus (L.) Hoffmanns. & Link. growing wild in northern Sicily and its activity on microorganisms affecting historical art crafts

One of the main factors affecting historical art crafts material is the biodeterioration performed by bacteria and fungi, in archives, museums or private collections. Several microorganisms cause degradation to the natural organic material such as fibers, woods, and dyes as well as to stone objects. These alterations produce deterioration of physical, chemical, mechanical and esthetic properties. Consequently, in this publication, we report the high antibacterial and antifungal activities of wild thyme essential oil, oil that can be used as an alternative natural tool in the fight against microorganisms affecting historical art crafts.Essential oil of the Thymus capitatus growing wild in northern Sicily has been extracted by hydrodistillation from aerial parts collected at different growth times. The constituents of the essential oil have been characterized by gas chromatography (GC) and GC–mass spectrometry.Fifty-five compounds have been identified. Essential oils were characterized by a high content of carvacrol (81.2–14.2%), γ-terpinene (34.4–2.6%) and p-cymene (22.8–5.0%) of the total oil content. Essential oil yield and composition vary throughout the vegetation time of the plant. The best time to harvest this species of thyme, for phenol content, is during or immediately before the full bloom. The related oils (Tc2 and Tc3) showed a good antibacterial activity against Bacillus subtilis and Staphylococcus epidermidis and excellent antifungal properties against Fusarium oxysporum and Aspergillus niger.