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Content of proteins and minerals (Mg, Ca, Cu, Zn, Mn and Co) in leaves, stem and root of stinging nettle collected from different localities from the Republic of Macedonia were determined. Generally, the higher content of proteins and minerals were determined in leaves, followed by the content in stem and root. In the quantity of proteins significant differences were determined depending to the organ of stinging nettle. The highest determined values for the protein content in leaves expressed to the dry mass were 26.89% in leaves, 14.54% in stem and 10.89% in root. The values for the calcium content in stinging nettle were higher in comparison to the magnesium values. Zink content in the leaves was two and fi ve times higher than the content of copper and manganese, respectively. In leaves, stem and root non signifi cant differences in cobalt content were determined.

Tobacco (Nicotiana tabacum L.) belongs to the group of plants that produce agricultural raw material. Besides leaves, which are used to satisfy the passion for smoking, tobacco can be used for producing oil and biodiesel, because it contains 30-40% of vegetable oil. Because of its content of citric acid, tobacco can be used for production of dyes and varnishes. Seed cake contains high percentage of proteins (35-44%) and can be used as livestock feed. Because of the high contents of lignin (40-45%) and cellulose (28-40%), tobacco stems can be used for production of energy briquettes, which makes tobacco obtain a new usability value. The aim of the experimental researches presented in this paper is to define the possibilities for production of briquettes from tobacco stems and wood raw material and to evaluate the impact of this kind of raw material on briquettes properties. For this purpose five models were made: O-control model: 100% wood raw material (BW); model T-I - 25% tobacco stems (TS) : 75% BW; model T-II - 50% TS : 50% BW; model T-III - 75% TS : 25% BW and model T-IV - 100% TS. The results of the research show that density of the briquettes is within the limits of 526.61 kg/m3 for model T-IV, to 782.73 kg/m3 for control model-O. The ash content is a little lower than the standard values and it ranges from 0.32% for O-control model, to 2.17% for model T-IV. The sulphur content is much below permissible content (0.08%), and it ranges from 0.003 to 0.008%. These briquettes, according to the low calorific value are classified in II and I class. In the smoke of the burned briquettes, minimal quantity (0.005%) of nicotine is identified

Chemical composition of seeds of C. maxima D. and C. pepo L. cultivated in the Republic of Macedonia and physico-chemical characteristics, fatty acid profiles, and sterol and tocopherol contents in pumpkin seed extracts were determined. Higher kernel yield and content of moisture, ash, total nitrogen, proteins and carbohydrates were measured in the C. pepo than in C. maxima seed. The highest extract yield of 487.4 g/kg dry matter was obtained from C. pepo kernel, while 388.2 g/kg dry matter was extracted from C. maxima kernel, when n-hexane was used as solvent. In all extracts, the palmitic, stearic, oleic and linoleic acids were predominant. The linoleic/oleic acid ratio was higher in C. maxima extracts. D7-Sterols were predominant in all extracts, while D5-sterols content was higher in the whole seed than in the kernel extracts. Higher tocopherol content was determined in the extracts of C. pepo whole seed and kernel (153.79 mg/kg and 117.81 mg/kg, respectively), than in those of C. maxima (121.24 mg/kg and 117.55 mg/kg, respectively). In all extracts γ-tocopherol content was higher than α-tocopherol.

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