Manuela Panić

Antimicrobial, cytotoxic and antioxidative evaluation of natural deep eutectic solvents

Natural deep eutectic solvents (NADES) are a new generation of green solvents. They are mixtures of two or three compounds such as choline chloride as a cationic salt and alcohols, acids, amides, amines or sugars as hydrogen-bond donors. Although the majority of NADES’ components are of natural origin and therefore NADES are often presumed to be non-toxic, the evaluation of their toxicity and biodegradability must accompany the research on their synthesis and application. Therefore, the aim of this work was to investigate the effect of ten synthesised NADES towards bacteria (i.e., Escherichia coli, Proteus mirabilis, Salmonella typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus), yeast (i.e., Candida albicans) and human cell lines (i.e., HeLa, MCF-7 and HEK293T). In addition, oxygen radical absorbance capacity (ORAC) method was used to determine the antioxidative activity of the tested NADES. Differences in toxicity response between microorganisms and cell lines were observed, and only NADES that contained organic acid showed toxicity towards the test systems. Furthermore, the NADES containing compounds that possess antioxidative activity also showed antioxidative activity. However, research whose primary purpose is the synthesis and application of NADES must be followed by an evaluation of their biological properties (e.g., antimicrobial activity, toxicity towards animal cells and antioxidative or other biological activity) to find the solvent with the best profile for wider industrial applications.

Green solvents for green extraction of biologically active compounds

I this study, decontamination and detoxification effects of non-thermal atmospheric pressure and low-pressure plasma systems were investigated on hazelnuts artificially contaminated with 7.9±0.06 log (CFU/mL) of Aspergillus parasiticus (A. parasiticus) and 7.8±0.06 log (CFU/mL) of Aspergillus flavus (A. flavus) spores. Different plasma parameters for atmospheric plasma (plasma frequency: 16-20-25 kHz, reference voltage: 40-100, plasma jet velocity: 50-100 m/min, gas flow rate: 3000-5000 L/h, raster offset: 3-5 mm, cycle time: 5, temperature, gases: high purity air or nitrogen) and low-pressure plasma (treatment time, gases: high purity oxygen, air or nitrogen) were tested for decontamination purposes. Optimum parameters for both plasma systems were determined according to remained viable spores counted after plasma treatments. Additionally, the effects of optimum plasma conditions on different concentration of aflatoxin B1(1-1000 ppb) and total aflatoxins (B1+B2, 1-1000.39 ppb) were also determined and compared with the effect of gamma radiation (10 kGY Cobalt-60 for 10 min). Improved spore inactivation of 5.6 and 4.7 log (CFU/mL) in A. paraciticus and A. flavus, respectively were achieved after 100 W-30 min of low pressure plasma treatment by using air as the plasma forming gas. Similarly, 5.5 and 5.4 log (CFU/mL) in A. paraciticus and A. flavus, respectively, were achieved after atmospheric pressure air plasma at 100 voltages, 25 kHz frequency, 3000 L/h flow rate, 60 m/min plasma jet velocity, 3 mm raster off set and 5 cycle time. 89-90% of AFB1 reduction was achieved when 10-50 ppm of pure AFB1 was treated with low-pressure air plasma at optimum conditions. On the other hand, highest AFB1 reduction of 75 % was achieved when 50 ppb of AFB1 was treated atmospheric pressure air plasma at optimum conditions.A common problem encountered in the use of grain sorghum is the milling process before the seeds can be used as food, feed or others. Milling aims to remove layers of sorghum pericarp and testa layer contains tannin from the endosperm. The layer can reduce protein digestibility in the stomach and the feeling of constipation. Institute for Agricultural Technology (BPTP East Java in cooperation with Indonesian Center for Agricultural Engineering Research and Development (ICAERD) Serpong, Banten) have developed a simple sorghum polishing machine with a diesel engine and abrasive stones type with a working capacity of 50-100 kg/hour. The purpose of this activity is to design the prototype machine polishing grain sorghum with the main objectives, namely: (i) Develop a milling system with a stone abrasive; (ii) Produce sorghum with the appearance of an intact form and bright colors. The design of sorghum polishing machine is done with the method and stage activities are divided into: the preparation stage, the stage of fabrication, testing, and reporting stage. The test results showed that the optimum milling capacity (2 × milling) is 100 kg/hour with tannin content of 0.09% and 3-5% broken grains and whiteness reached 44.66% (whole bean and bright appearance).S and their properties are playing an increasingly significant role in the industrial application. In general, materials are used according to their property requirements such as elasticity, strength, heat resistance or to meet other requirements such as corrosion resistance. However, traditional surfaces are often not able to meet the ever-increasing demands of today ́s applications in automotive, textile, medical and food industry. Thus, in recent years, advances have been made using functional coatings to exceed limitations of material to make surfaces more attractive for specific industry applications. Hygienic and efficient automation technologies are key aspects of a successful production process for example in the food and beverage industry. Requirements regarding the clean ability and durability of surfaces that are in food contact are key factors. The approach of this study was to design functional surfaces with easy to clean and/ or self-cleaning coatings that enable automation components to be easily or less cleaned. For coating procedure, physical vapor deposition was carried out to facilitate separation of the vaporized coating material to the substrate. Substrates used are aluminum, stainless steel, and plastics, for example, polyamide or polyethylene. Analytical descriptions of surface characteristics were performed using scanning electron microscopy, contact angle, and roughness. Different surfaces were successfully coated with easy to clean coatings and characterized analytically. In addition, a coating of automation components consisting of varied materials was realized and coating adhesion was improved. First application tests showed a clear improvement of material properties relating to chemical resistance and clean ability compared to today’s standard materials used.