The samples of stinging nettle were collected during June in the Tuzla region. Aqueous extracts were prepared from fresh and dried leaves in order to determinate and compare content of bioactive components and antioxidant potential. Conventional soxhlet, ultrasound assisted extraction and traditional maceration extraction were used as extraction methods. Quantitative determination of phenols and flavonoids was carried out using spectrophotometric methods. Antioxidant activity of nettle aqueous extracts was determined using ferric reducing antioxidant power and DPPH free radical scavenging activity. Extracts obtained by Soxhlet extraction showed the highest total phenolic and flavonoid content and expected the highest antioxidant capacity, while extracts obtained by maceration gave the lowest results. KEYWORDS:stinging nettle extract;bioactive components;extraction;antioxidant

Potato isn’t eaten raw, it has to be thermally processed which influences the presence of the vitamin C considering its sensitivity, fast degradability, and a great loss of vitamin C is expected. Many different ways of thermal processing are used such as boiling, frying, baking and similar. The vitamin C loss depends on the different processing ways and potato preparation. This paper aims to show how much quantity of ascorbic acid that is kept in the potato after boiling it in its skin, without the skin and when cut into pieces, as well as after frying and baking in an oven and baking in a foil. The goal of thermal processing is to keep as many nutritional ingredients as possible, and this paper will show which way of processing and preparation is the most convenient for eating.

In this study, the efficacy of different extraction techniques (maceration, ultrasound-assisted and Soxhlet extraction) on the content of biologically active components in extracts from fresh and dried nettle leaves, and their antioxidant activity were analyzed. Methanol was used as the solvent. Total phenolic content and antioxidant capacity were determined by Folin-Ciocalteu, DPPH and FRAP methods, respectively. High content of total phenolic compounds and high antioxidant activity were recorded in extracts of dried nettle. Extracts obtained from fresh nettle samples showed significantly lower content of analyzed bioactive components and lower antioxidant activity. In the case of all extracts, Soxhlet extraction proved to be the most efficient, and maceration the least efficient extraction technique for isolation of bioactive components from nettle leaves.

Chemical precipitation is a useful conventional process to remove heavy metals from aqueous solutions. In this work, a waste sludge from the Solway process was used as a precipitation agent for the precipitation of Cu (II), Ni (II), Pb (II) and Zn (II) ions with an initial concentration of 50 mg/L. The results of the research showed that the waste sludge from the Solway process completely removed Pb (II) ions from the solution in the pH range of 8.39 -11.74, also good efficiency was shown in other cations. The maximum precipitation efficiency for Cu (II) is 99.890% at pH 10.98, Ni (II) 99.940% at pH 11.81, Zn (II) 99.616% at 10.1. Waste sludge is proved to be a good precipitate for cation separation.

Muesli bars is a generic term that refers to baked or cold-formed cereal-based snack bars, and may contain other ingredients such as fruit, nuts, seeds, chocolate, yoghurt, and a variety of other fillings and/or toppings. By changing the ingredients nutritional value of muesli bar can be modified. In this research, protein-rich and energy-high muesli bars have been produced, because they contain a higher amount of fat, proteins and sugar. However, fats and sugars were not added but come from specific ingredients (hazelnuts, walnuts, chia seeds, sesame, sunflower and pumpkin seeds, oat flakes, etc.). Four muesli bar formulations were developed, two with hazelnuts and two with walnuts, added in the amount of 25% and 50%, respectively. The other ingredients were added in the same amount. The product was dried at 80°C for several hours. The composition, polyphenolic compounds and antioxidant capacity were determined in the products before and after drying. Also, muesli bars were sensory evaluated.

In this paper, the influence of biological acid dough with a strain of lactic acid bacteria (Lactobacillus plantarum) on the properties of the dough and the addition of sourdough on the quality of crackers was investigated. Changes in total titratable acidity and pH were monitored during the fermentation of the sourdough (24 hours). In the dough for the production of gluten-free crackers, the influence of the addition of sourdough on the total titratable acidity and pH value was examined. The content of water, protein, fat, starch, crude fiber, pH value and total titratable acidity was determined by flour samples for the production of gluten-free crackers and gluten-free crackers. The influence of sourdough on the sensory properties of crackers was examined. The mineral composition of zinc was determined and the contribution of the daily recommended intake was assessed. In samples of crackers subjected to storage for 5, 10, 20 and 30 days, a change in water content was monitored. The length of fermentation had a significant impact on the dynamics of pH change and on the total titratable acidity during the fermentation of sourdough. The results of the study showed that the control sample has a higher pH value than the samples with sourdough. The reason for that is the development of acetic acid during fermentation. The change in water content in the crackers over 30 days was significantly higher in the control sample compared to the samples with sourdough. Crackers with sourdough contain a significantly higher percentage of protein, ash, fiber, zinc at the expense of reducing carbohydrates.

: This paper will show that adding some spices and other raw materials can increase the nutritional value of bread and provide a product that will be acceptable for consumption. Sunflower seeds, olives or turmeric are added in amounts up to 10 %, relative to the total amount of flour. Nutritional value of bread was determined, the sensory analysis was performed and the durability or preservation of freshness was monitored.