Volume 24, No. 2 (2023)

UNCATALYZED OXIDATION OF L(-)ARABINOSE BY ACIDIC MANGANESE (VII). OPTIMIZATION, STOICHIOMETRY, ACTIVATION FUNCTIONS AND MECHANISM

MUSTAFA JAIP ALLAH ABDELMAGEED ABUALREISH(1,2*)

The uncatalyzed oxidation of L(-)arabinose by manganese (VII) in acidic medium of H2SO4 and constant ionic strength (using potassium nitrate) were investigated kinetically. The change in concentration of manganese (VII) was followed using spectrophotometric method. The study showed that the reaction rate increases by raising the concentration of L(-)arabinose, manganese (VII) and H+ and is independent of salt concentration. The optimum condition of the reaction (highest rate value) found at 0.02 M of L(-)arabinose, 0.0003 M of manganese (VII), 0.5 M of H+ and 0.5 M of KNO3. Findings from stoichiometry measurements revealed that one mol of arabinose consumed two mol of manganese (VII). The temperature influence on the reaction was carried under constant experimental conditions, it was found that the rate of the reaction enhanced by raising the temperature. The activation energy of the reaction was evaluated and found to be 22.74 kJ·mol-1. Activation functions namely, frequency factor, free energy change and the entropy change of the uncatalyzed oxidation were also evaluated at various temperatures. Spot test analysis of the uncatalyzed reaction products revealed the presence of formic acid supporting the proposed mechanism. Reaction rate law was established and it was in strong agreement with the experimental results.

ASSESSMENT OF THE MICROBIOTA OF SOME MINERAL WATER FORM SLANIC MOLDOVA (ROMANIA): SEASONAL EVALUATION AND AFTER STORAGE IN DIFFERENT CONDITIONS

LAVINIA MISĂILĂ(1,2), DUMITRA RĂDUCANU(3*), NARCIS BÂRSAN(4), IRINA-CLAUDIA ALEXA(4), OANA-IRINA PATRICIU(4), LUMINIŢA GROSU(4*)

The mineral waters that come from the springs in the area of Romanian mountain resort Slanic Moldova, heterogeneous from a physical-chemical point of view, are used for external or internal therapeutic purposes. A survey of the microbiological quality of mineral waters collected from 7 springs in Slanic Moldova was conducted concerning the seasonal quantitative variation of the total number of heterotrophic bacteria (HPC) and the evolution of some representative microbiological parameters (HPC, Clostridium perfringens and Pseudomonas aeruginosa) in samples bottled and stored at (20 - 22 °C) or (4 °C). for a period of 1 - 360 days. All values for HPC determined at 22 °C were within the reference limits of 100 CFU·mL-1 for the investigated sources, in accordance with the requirements of EU and national regulations. At 37 °C, the HPC was within normal values (20 CFU/mL), for five (1 bis, 5, 10, 14 and 15) of the seven sources studied, both in the seasonal analysis and after bottling and storage in different conditions. Clostridium perfringens and Pseudomonas aeruginosa were not detected in all of the mineral water’s samples. Microbiological assessment and proper management of mineral water resources can lead to a good prediction of water quality and avoidance of health risks.

INFLUENCE OF GROUND DRY ROSE HIPS (Rosa canina L.) ON THE MAIN CHARACTERISTICS OF LACTIC ACID DRINK

IRA TANEVA(1), MARIYA KALAYDJIEVA(2), MIHAELA IVANOVA(3), ZLATIN ZLATEV(1*)

The analysis of available literature sources shows that, in most cases, when obtaining enriched lactic acid products, a fixed amount of rose hip supplement was used, and this amount was not specified. Organoleptic analysis is also missing in many of the publications. Further research is needed to establish the optimal amount of ground rosehip (Rosa canina L.) fruit in the production of lactic acid products using statistical data analysis methods. As a result of the analyzes carried out in the development, the physico-chemical, organoleptic and color characteristics of a lactic acid drink enriched with coarsely ground rose hips and rose hip flour were determined. The informativeness of these characteristics was established, using appropriate statistical methods for the type of data processed. The appropriate amounts of both additives are defined. For the lactic acid drink obtained with coarsely ground rosehip berries, the optimal amount is 2.76 %, and with the addition of rosehip flour it is 0.53 %. The proposed tools can be used in the development of methods for the valorization of waste products from food production and their addition to dairy products.

ASPECTS REGARDING THE EFFECTS OF THE COVID-19 PANDEMIC ON THE 10 – 11-YEAR-OLD CHILDREN'S ACTIVE MOTOR, DIETARY, AND PSYCHOLOGICAL BEHAVIOR

CĂTĂLINA ABABEI(1*), IRINA-LOREDANA IFRIM(2*), ANIȘOARA SANDOVICI(1), ALINA ABABEI(3)

Child obesity has become a phenomenon that is increasingly difficult to counteract because of their lifestyle and diet. The extra weight leads to, besides physical disorders, such as high cholesterol and diabetes, a series of psychological disorders represented by the lack of self-confidence and depression. Physical activity was strongly affected during the COVID-19 pandemic because of the imposed restrictions. The children had to study online classes a large portion of their time, which has contributed to a significant increase in the hours they have spent in front of a computer. The objective of this study was to emphasize the effects of the Coronavirus pandemic on the relation between the active motor behavior, the dietary behavior, and the psychological behavior in 10-11-year-old children of Bacau, Romania. This research is an observational study conducted by identifying, assessing, and establishing certain correlations between the aforementioned factors, based on questionnaires filled by the children's mothers. Of the main statistical markers, the following were used: the Cronbach's alpha fidelity index, and the correlation coefficients, in order to establish the validity of the questionnaires, and the significance level of the correlations between the studied aspects.

STUDY ON THE PREPARATION AND CHARACTERIZATION OF ALUMINUM-PILLARED CLAYS USING MONTMORILLONITE K10

ANA-MARIA GEORGESCU(1*), NICOLETA PLATON(1), VASILICA-ALISA ARUS(1), COSMIN JINESCU(2), FRANÇOISE NARDOU(3), ILEANA-DENISA NISTOR(1*)

Aluminum-pillared interlayered clays (Al-PILCs) were synthesized under various experimental conditions starting from commercial montmorillonite K10 (K10-Mt). The pillaring process involves several steps that are easy realized in laboratory. The effect of montmorillonite/NaCl solution mass ratio for cationic exchange, OH/Al molar ratio and the aging time of pillaring solution on physico-chemical properties and thermal stability of Al-PILCs were examined in this paper. The synthesized nanomaterials were characterized by textural analysis: specific surface area (using Brunauer-Emmett-Teller (BET) and Langmuir methods), micropore volume and micropore area by t-plot method. X-ray diffraction (XRD) analysis was used to determine the basal distance and mineralogy of the materials. The modified clays were characterized by thermal analysis using thermogravimetric (TGA) and differential thermal (DTA) analysis. The specific surface area values, the basal spacing and the thermal stability of the Al-PILCs were affected by the synthesis parameters. The modified products are intended to be used for the adsorption of organic pollutants from wastewater.

ASSESSMENT OF MICROPLASTICS IN PERSONAL CARE PRODUCTS BY MICROSCOPIC METHODS AND VIBRATIONAL SPECTROSCOPY

ANDREEA LAURA BANICA(1,2*), RALUCA MARIA BUCUR (POPA)(1*), IOANA DANIELA DULAMA(2), IOAN ALIN BUCURICA(2), RALUCA MARIA STIRBESCU(2), CRISTIANA RADULESCU(1,2,3)

Primary microplastics, known as microbeads (μBs), are found in personal care and cosmetic products (PCCPs) being used as an ingredient for physical abrasion on human body surface. Due to the fact that μBs has sizes less than 0.8 mm, sometimes even less than 0.1 mm, they can be ingested by many organisms, being transmitted in the food chain. The development of a method for isolating the microplastics from the matrix of branded PCCPs samples (i.e., shower gel, body spray) using ultrasound technique at constant temperature and pressure, high-performance vacuum filtration method with various high-purity filtration membranes (e.g., cellulose) was the first objective of this study. The second objective was to combine vibrational spectroscopy techniques (i.e., Fourier-transform infrared μ-spectroscopy) with optical microscopy, to investigate the morphology and chemical composition of MPs. Microplastics were identified in all five brands of analyzed products. Thus, an average value of 420 μBs/100 g in shower gel and 200 μBs/100 mL in body sprays was determined; the identified colors were black (mostly), blue, yellow, brown, green, and red. The observed sizes varied from tens of micrometers to a few centimeters in some cases and the thickness reached 10 μm. From visual (microscopy) and chemical (μ-FTIR spectroscopy) point of view the structure was mostly like polypropylene fibers, smaller and having glossy mate appearance.

URTICA DIOICA AND ZINGIBER OFFICINALE EXTRACTS WITH AGRO-FOOD AND PHARMACEUTICAL APPLICATIONS

IOANA-ADRIANA ȘTEFĂNESCU(*), IRINA-LOREDANA IFRIM

The present work is an attempt to highlight the effect of aqueous extracts of Urtica dioica (nettle) and Zingiber officinale (ginger) in in vitro studies. The insights from current research would be helpful to have an overview of the antioxidant potential of nettle and ginger and provide direction for optimization and development of these extracts for phytosanitary applications against vegetable diseases as well as preservation role in the agri-food industry. The antioxidant activities of nettle and ginger are found to be protective for vegetables diseases with Alternaria solani. The study also highlighted the potential of a green corrosion inhibitor for metal food packaging.