Department of Chemistry, Institute of Chemistry, Technology and Metallurgy, National Institute of the Republic of Serbia, University of Belgrade, Studentski trg 12-16, 11158 Belgrade, Serbia
Dr. Miroslav M. Novaković
Department of Chemistry, Institute of Chemistry, Technology and Metallurgy, National Institute of the Republic of Serbia, University of Belgrade, Studentski trg 12-16, 11158 Belgrade, Serbia
The present study evaluates natural composition of Serbian roasted hazelnut skins (HS) with potential role in application as functional nutrient of various food products. Total phenols (TPC) and flavonoids contents (TFC) in HS extracts obtained with different ethanol concentrations (10%—I, 50%—II and 96%—III) and their antioxidant activities were investigated. The highest total phenols content (706.0 ± 9.7 mgGAE/gextract) was observed in 96% ethanol HS extract. Ethanol HS extracts showed very high antioxidant activity with effective concentrations (EC50) ranged between 0.052 and 0.066 mg/mL. The phenol and flavonoid content of roasted HS extracts I–III was determined by HPLC-ESI-MS/MS analyses. Contents of lipids, proteins, carbohydrates, metals, and C, H, N, S elements in roasted HS were also determined. Relatively high C/N, C/P and C/N/P ratios, rich metal contents and fatty acids composition indicated that hazelnut skin might be a good candidate for use as either human or fungal functional nutrient. In addition, possible application of phenolic HS extracts as UV booster was studied by recording UV spectra (220–440 nm) of 10 mg/L of HS extracts I–III combined with 10 mg/L of chemical sunscreen agent benzophenone-3 and in vitro sun protection factor (SPF) was calculated.
1 January 2007 in Journal of the Serbian Chemical Society
Essential oils from leaves with young branches of Cotinus coggygria Scop. from two localities in Serbia (Deliblatska pescara and Zemun), obtained by hydrodistillation, were analyzed by GC-MS. Thirty-one component were identified from both oils and among them monoterpenic hydrocarbons were the dominant class (87.4 and 93.1 %). The dominant constituent in both essential oils was limonene (47.0 and 39.2 %). Both oils were also tested for antibacterial and antifungal activities. In comparison to streptomycin, both oils showed slightly higher activity (against most Gram-positive bacteria) in the disc diffusion method and slightly lower activity when the microdilution method was employed. They also exhibited antifungal potential higher than that of the commercial fungicide bifonazole.
Pumpkin fruit is used in a diet since ancient times especially in rural communities. The major contributory factors of nutritional and medicinal value of pumpkins are carotenoids, polysaccharides, vitamins, minerals, and phenolic compounds. Due to a very large fruit that it is not easy to consume a whole as well as short shelf-life of fresh-cut pumpkin, different ways of conserving and processing are performed. In our study, total carotenoids, total phenolics and individual phenolics in fresh pumpkin and pumpkin traditional products such as sweet in wine, jam and juice, which are typical for northern parts of Serbia, were studied. Total carotenoids ranged from 27.6 ?g/g of pumpkin sweet in wine to 86.3 ?g/g of fresh fruit, while the amount of total phenolics varied between 93.0 ?g GAE/g of pumpkin juice and 905.9 ?g GAE/g of fresh fruit. Eight phenolic compounds were identified in the investigated samples and among them phenolic acids dominated. Among flavonoids, flavanon glycoside hesperidin was detected.