CHARACTERIZATION OF CLOVE OIL WITH A FT-IR ATR SPECTROSCOPIC METHOD

Clove oil possesses excellent antioxidant and antimicrobial properties, while the main components of clove oil are eugenol, acetyleugenol and caryophyllene. Two types (ground and buds) of clove were used in the analysis. The clove essential oil was obtained using a steam distillation and an ultrasonic assisted extraction method. The separation of eugenol from other components was achieved with benzoyl chloride reaction. The analysis of clove oil was with a FT-IR ATR spectroscopic method along with the use of a TLC method using mobile phases, toluene:ethyl acetate (9.3:0.7 v/v), phase A and chloroform:hexane (1:2 v/v), phase B. The UV-Vis spectrum of eugenol was with maximum at 280 nm. The obtained yield was found to be 8.79% and 12.41% for ground clove and 1.36% and 6.75% for clove buds using ultrasonic assisted extraction method, respectively. The characteristic band for the ester group C-O of eugenol acetate was observed at 1765 cm-1. The Rf value for eugenol was 0.66 with phase A, and 0.46 using phase B. The methods were easy to be handled, rapid and can be used in the routine analysis

CHARACTERIZATION OF HONEY: DETERMINATION OF METAL AND SUGAR CONTENT

In this study, five samples of honey (4 from various beekeepers and 1 from a local supermarket) were analyzed to determine the presence of Pb, Fe, Mn, Al, Cu, Cr, Zn, Cd, As, Ni and Se content using atomic absorption spectrometry. Samples were collected from the following locations: 2 from Skopje, 2 from Kumanovo and 1 from Preshevo, Srbia. HPLC was applied to determine sugars in honey samples. Acid and moisture were also determined. The average values of concentration were from 0.033 to 0.055 mg/kg, 0.610to 2.498 mg/kg, 0.052 to 0.377 mg/kg, 2.133 to 3.474 mg/kg, 0.060 to 1.034 mg/kg, 0.005to 0.019 mg/kg, and 0.067 to 0.085 mg/kg for Pb, Fe, Mn, Al, Cu, Cr, and Zn, respectively. Cadmium was determined in one sample (0.040 mg/kg), while the presence of arsenic, nickel and selenium were not observed. The total amount of reductive sugars was within the standard value of min 60 g/100 g honey. The moisture was from 16.6 to 17.6% (max 20%). The acid content was recorded from 9 to 28mEq/1 kg honey (max 50mEq/1 kg honey). The results were compared with the safety standards established from the Ministry of Agriculture, Forestry and Water Economy. In general, the analyzed parameters are within the standards and honey can serve as good dietary source

Development of thin-layer chromatographic method for determination of caffeine in black, green, and white tea

Caffeine is naturally present in tea and coffee giving the pleasant and stimulant effect. Several different types of teas, black, green, and white teas bought in market were analysis for caffeine content. The boiled sample tea was filtered through filter paper. Lead(II) acetate was used to separate tannins from caffeine followed by filtration through filter paper with a black ribbon. The liquid-liquid extraction was carried out using dichloromethane (3×5 mL) and sodium sulfate as a drying agent. The TLC method was performed on Merck precoated silica gel plates 5×10 cm (60F254, 200 μm) using either methanol or dichloromethane as solvents and the mobile phases were glacial acetic acid and ethyl acetate (95:5, v/v), while the second one was consisted of ethyl acetate and ethanol (80:20, v/v), respectfully. The Rf values were 0.36 and 0.86 for the first and the second mobile phase, respectively, in comparison to the standard caffeine. The values for pH of boiled sample teas were in the range from 4.85 to 5.80. The most abundant tea sample for caffeine was determined in green tea bought in the grocery store for health nutrition (2.04 %). The yield for tea samples from green market, white tea and two tea black samples were 0.06, 0.71, 0.07, and 0.05%, respectively. The developed TLC method can be used for determination of caffeine content in tea samples

Strengthening of biotechnological education in Macedonia as an important development component

Biotechnology is a discipline which is applied in different areas such as: food production and processing, pharmaceutical industry, diagnostics etc. By strengthening of biotechnological education in Macedonia (SBEM) can be improved and modernized this field of education in order to meet the industry needs in the country. SBEM will be coordinated by the Faculty of Technological Sciences as a part of the “Mother Teresa” University in Skopje and it will include vocational high schools dealing with biotechnology in the Republic of Macedonia and appropriate clusters in the frame of Commercial Chambers. The main objective is to improve teachers’ and trainers’competences and their ability to provide eLearning in-service vocational training courses for biotechnology secondary school teachers. Putting together of all stakeholders in biotechnological education will be done by establishment of a National Data for Biotechnological Education of Macedonia (NDBEM). Different type of training (courses, workshops, seminars) will be held at each faculty in e-learning way using active teaching/learning (ATL) approach. The trainings will be given by International and domestic experts in biotechnological education. ATL is important for university staff and vocational teachers as they had no pedagogical training during their graduate courses. University teachers will develop and implement classical and online vocational courses targeting recent advances in biotechnology for biotechnology teachers in VET schools. Previously, the market survey should be done in order to analyze the need of a real technological sector in cooperation with Commercial Chambers. NDBEM will be formed using assistance from Graz university and it will be used as a repository for online courses and teaching resources developed during trainings of university and teachers in biotechnology vocational education and training (BVET). Project deliverables will be stored and available in the NDBEM for future users. Its sustainability need to be provided by its recognition from the Ministries of Education and Science. SBEM will have the following specific objectives: improvement of quality and availability of vocational education; strengthening of professional and pedagogical competences of educators and trainers; and creation of the “open source“ repository for educators in the area of biotechnological educatio

Assessment of the impact of γ-irradiation on the piperine content and microbial quality of black pepper

The major bioactive component of black pepper (Piper nigrum) is piperine which has demonstrated beneficial therapeutic properties. The purpose of this research was to investigate the effects of different irradiation doses on the content of piperine in black pepper. Samples were irradiated with 60Co γ-rays (at absorbed doses of 0.5, 1, 3, 5, 7, 10, and 12 kGy). Thin-layer chromatography (TLC) and UV–Vis spectrophotometry methods were used for measuring the piperine content in the samples. TLC was performed using three mobile phases (1. toluene:ethyl acetate, 7:3 v/v; 2. acetone:n-hexane, 6:4 v/v; 3. toluene:methanol, 8.5:1.5 v/v) and the retention factor (R f) value for piperine was equal to 0.66, 0.94, and 0.67, respectively. The content of piperine in γ-irradiated samples of black pepper was found to be between 0.04 and 1.05% w/w from the spectrophotometry analyses. Irradiation slightly decreased the piperine content of black pepper. It was found that piperine crude yield from black pepper was from 1.10 (the unirradiated sample) to 1.69, 1.07, 0.60, 0.90, 0.30, 1.20, 0.80% for irradiated samples, respectively. Microbiological analyses were performed with standard plate count method, which resulted in a decreasing number of the total cell count of microbial cells with increasing the radiation dose. Treatment with irradiation reduced the population of bacteria by 4 logs