Chemistry and Chemical Engineering

Abstract

Similar to other regions, in East Central Europe, agriculture is the most vulnerable sector regarding the consequences of climate change through increasing variability in weather conditions, even on the short-term and local scales. Agricultural engineers make decisions; higher education has a crucial role in taking proper actions. Our survey aimed to get up-to-date information on the knowledge and attitude of graduating students completing agriculture-related studies at 6 universities located in Hungary, the Czech Republic, Poland, and Slovakia, with particular attention to weather projections, crop production, and soil protection issues. Analyses revealed adequate lexical knowledge of young engineers in each country. They are familiar with the agro-environmental actualities and future trends, issues to address at the right time, and the repertoire of tools and practices for taking efficient measures. A positive attitude toward proactive actions was proved. We report proof of a high level of preparedness resulting from the proper efficacy of agricultural higher education. The content of the curricula and the teaching methodologies meet well the receptiveness to learning in the V4 countries. Our findings confirm that frequent updating of the content of subjects as well as incorporating practical applications that promote active learning and engagement, are more critical today than ever, and it is possible to achieve a high level of preparedness for the challenges in the agricultural sector.

Abstract

This study analyzed the impact of storing Golden Delicious apples at 3 °C with a relative humidity of 85 ± 5% in two environments, namely a darkroom (D03) and a lightroom (L03), on the fruit quality. The research evaluated weight loss (Δm) and color metrics (a*, b*, L*, ΔE, C*, hue angle). The number of apples used for each storage was 12. Weight loss was calculated by measuring the changes in mass during storage. Color differences (ΔE), chroma (C*), and hue angle were determined based on the L*a*b* scale values. Apples stored at 3 °C in D03 experienced a minimal percentage of weight loss of 7.02%. The results indicated that compared to the D03 storage, the L03 storage had a more significant increase in Δm and color variation. The non-destructive method of measuring color characteristics facilitates the assessment of the storage conditions for Golden Delicious apples.

Abstract

Nutritional information on packaging is becoming increasingly important in the food industry. Currently, labels are seen not only on the back of the packaging but also on the front. As there are many versions of front-of-pack labels (FoPLs), the research aims to determine which helps consumers the most in making decisions about which food to include in a healthier lifestyle. Nutri-Score, Guideline Daily Amount (GDA) and Multiple Traffic Lights (MTL) FoPLs on cereals were compared using eye-tracking (ET) and choice-based conjoint analysis (CBCA). CBCA was used to assess consumer preferences and the labels and products were also ranked. Based on the results, GDA type FoPL proved to be the most useful based on conjoint analysis, ranking and the analysis of ET parameters. This label helped participants the most in choosing the product that best fits into a healthier lifestyle. The Nutri-Score label, which offers little information on a product's nutritional content, was not favourably received by the Hungarian sample, who preferred more detailed FoP labels.

Az Európát is érintő jelenlegi, napjainkban zajló éghajlatváltozás statisztikailag szignifikáns felmelegedési tendenciával jellemezhető. Az éghajlatváltozás hatása a csapadékviszonyok és az evapotranszspirációs folyamatok megváltoztatásán keresztül érinti a vízkörforgalmat, így a csapadék eloszlásának és mennyiségének várható változásai a folyamatosan emelkedő hőmérséklettel együtt a növények nagyobb vízfelhasználását eredményezhetik, ami változásokat indukálhat a talajnedvességben, a talajvízben és ennek következtében a vízmérlegben. Az emelkedő hőmérséklet hatására a jövőben a növekvő transzspirációs igény valószínűleg a növényi közösségek fokozott talajvízfelvételét eredményezi, ami a talajvízszint további csökkenését is magával vonhatja. Ha ez bekövetkezik, a talajvízfüggő erdei közösségek regenerálódása ezeken a területeken kérdésessé válik, mivel a fiatal fák gyökérzete nem fogja tudni elérni a vízforrást. Következésképpen a Kárpát-medence sík vidékein és vizes élőhelyein a nagy vízigényű erdők fennmaradása kérdésessé válhat. A fás vegetáció számára kiemelten fontos a talajvíz szerepe a vegetációs időszakban, éppen ezért a talajvízszint változását régóta, rendszeresen monitorozzák.

Konkrét megoldás lehet az árhullámok visszaduzzasztásából származó vízpótlás. A pozitív vízpótlási beavatkozásokra példa a Kaszó LIFE projekt. A projekt célja a leromlott élőhelyek rehabilitációja volt, ami a kedvező ökológiai állapot stabilizálásával teszi lehetővé a hosszú távú megőrzést. A megvalósítás eszközeként tórehabilitációt és folyó-mederbordákat alkalmaztak, biztosítva a Szentai-erdő (Nyugat-belső-somogyi kistérség) erdeinek, kis lápjainak és gyepterületeinek vízellátás javítását.

Jelen kutatás célja pedig a Kaszó LIFE projekt vízpótlási beavatkozásai után, azok felszín alatti vízszintre gyakorolt hidrológiai hatásainak elemzése volt. A meteorológiai adatok és a monitoring adatok alapján elmondható, hogy a Szentai-erdőben 30 éves szárazodási tendencia volt tapasztalható, amelynek elsődleges mutatója a talajvízszint csökkenése. Kiemelendőek a 2016–2017-es vizsgálati időszak évei, amikor az alapvetően lefolyástalan vizsgálati területen nem volt elegendő csapadék a talajvíz szintjének fenntartásához. Kutatási eredményeink azonban azt mutatták, hogy a vízpótlást célzó beavatkozások (mederbordák és tározótavak) összességében a talajvízszint emelkedését biztosítják.

A két beavatkozási típus talajvízszint emelkedésére gyakorolt hatását vizsgálva arra a következtetésre jutottunk, hogy míg a tavak építése jelentősen befolyásolja a környező kutak vízszintjét, addig a mederbordák esetében kisebb mértékű a hatás.

This study explored the effects of salicylic acid on the growth and biochemical responses of peppermint (Mentha piperita L.) under different soil salinity levels, a major challenge in agricultural productivity. The experiment was conducted using a factorial design with salicylic acid applied at concentrations of 0, 5, 10, and 50 ppm, combined with sodium chloride-induced salinity at 0, 1,000, 2,000, and 3,000 mg kg^–1 soil. Results demonstrated that increasing soil salinity negatively impacted plant growth, reducing plant height, leaf number, and the dry weight of aerial parts. Salinity stress also led to reduced nutrient uptake, particularly for essential elements like calcium and potassium, while increasing sodium levels in plant tissues. However, the foliar application of salicylic acid, especially at 50 ppm, significantly improved growth parameters and mitigated the detrimental effects of salinity. Notably, at the highest salinity level (3,000 mg kg^–1), salicylic acid enhanced plant height by 11.1% and leaf number by 30.9% compared to untreated plants. Salicylic acid also boosted biochemical responses, such as increasing total phenolic and flavonoid content, which are critical for stress tolerance. This study underscores the potential of salicylic acid as a stress mitigator, promoting better growth and physiological resilience in peppermint under saline conditions, offering valuable insights for improving crop performance in salinity-affected regions.

Abstract

The simplest way to remove pesticide residues from fruits and vegetables is to wash them with tap water. However, this method is not effective enough. In this study, the effectiveness of different washing methods assisted by ultrasound on pesticide removal was investigated. For this purpose firstly, apples were soaked in a cypermethrin (CYP) and spirotetramat (SPI) solution, which are frequently used as insecticides. Subsequently, the apples were washed in solutions prepared with vinegar, lemon juice, and baking soda at different concentrations (0.5%, 1% and 2%) and assisted by ultrasound (2.5–5 min). The residues in the medicated and washed samples were analysed on an LC-MS/MS instrument after extraction using the QuEChERS extraction method. The results of the analysis showed that acidic vinegar and lemon juice were more effective than baking soda. Moreover, the application of ultrasound significantly increased this effect. When a 0.5% vinegar solution was assisted by ultrasound, 62% of the cypermethrin residue was removed and 82% of the spirotetramat residue was removed. These values were 51.5% and 49.6% higher than tap water, respectively. In conclusion, acidic solutions such as vinegar, which we can easily prepare at home, are highly effective in removing pesticide residues when assisted by ultrasound.

Abstract

The relevance of the subject under study is conditioned by numerous technological problems of providing livestock enterprises of the Republic of Kazakhstan with quality equipment for animal feeding and the associated need to develop and implement dosers for the preparation of compound feed mixture. This study introduces an innovative approach through the development and analysis of a novel dosing auger with an active return channel, which distinguishes itself from existing models by enhancing the precision and efficiency of feed preparation processes. The purpose of this study was to investigate the key parameters of the dosing auger with an active return channel for its further use in agricultural enterprises for preparation of compound feed. The findings of this study emphasise the significance of compliance of current trends in the improvement of prepared feed with the established zootechnical requirements from the standpoint of optimising the technological equipment used in this process. The key aspects of feed dosing sequence when using volumetric and mass dosing methods were considered. The main advantages of auger-in-auger dosers that distinguish them from all other types of dosers were described.

Abstract

Dillenia indica is one of the important medicinal plants and is extremely popular in many systems of medicine including ayurvedic, homeopathic, and siddha. Traditionally, different parts of this plant have been used to treat cancer, wound healing, diabetes, diarrhea, bone fractures, abdominal pains, cuts and burns. In the present study, a simple, precise, accurate and validated high performance thin layer chromatographic (HPTLC) method was developed for simultaneous estimation of three pharmaceutically active compounds i.e., betulinic acid (BE), β-sitosterol (BT) and lupeol (LP) in fruits, leaves, root bark and stem bark of D. indica. Standards and plant samples were applied on TLC aluminum plate precoated with 0.2 mm layer of silica gel 60F254. The plate was run in a twin glass chamber comprising toluene:methanol:chloroform (8:1:1, v/v/v) as a mobile phase which resulted in better separation of compounds. The plates were immersed in anisaldehyde-sulfuric reagent and then heated at 105 °C for 5 min in CAMAG TLC plate heater for appearance of bands. Densitometric scanning was performed at λmax = 525 nm using tungsten light source in CAMAG TLC Scanner4 armed with WinCATS software. R _F values of BE, BT and LP standards and those of plant samples were found to be 0.38 ± 0.01, 0.54 ± 0.01 and 0.65 ± 0.02 respectively. The method was further validated by following the International Conference of Harmonization (ICH) guidelines. For BE, BT and LP, the linear regression data for the calibration plots revealed a satisfactory linear association with correlation coefficients (r ²) = 0.9736, 0.9989 and 0.9957, respectively. Linear ranges for BE, BT and LP were 2,000–6,000 ng/band, 200–1,000 ng/band, and 200–600 ng/band respectively. Accuracy of the method was assessed by recovery study conducted at three different levels with the average recovery of 99.19, 99.69 and 100.95% for BE, BT and LP, respectively. The results exhibited the highest content of BE (0.148 ± 0.01%), BT (0.031 ± 0.01%) and LP (0.047 ± 0.01%) in stem bark. The developed method will be useful for routine and quality control analysis of fruits, leaves, root bark and stem bark of D. indica species.

Abstract

Artificial sweeteners are low-calorie substances used as food additives with aim to impart a sweet taste to beverages without adding significant calories. Due to the regulatory compliance regarding the type and the amount of artificial sweetener, and due to the large consumption of beverages and the effects of artificial sweeteners on human health, their identification and quantification is of a great importance. In this research simultaneous determination of acesulfame K (ACE-K), sodium saccharin (Na-SAC) and aspartame (ASP) as the most commonly used sweeteners in beverages was performed with a reversed – phase high performance liquid chromatography (RP – HPLC) with diode array detection (DAD). The best separation of the analytes was achieved on a Poroshell 120 EC-C18 (3.0 × 50 mm, 2.7 µm) column and isocratic elution with a mobile phase consisted of acetonitrile and diluted phosphoric acid (pH = 3.8) with 7/93 volume ratio (V/V), and flow rate of 1 mL min⁻¹. The chromatographic process was followed at 195, 220 and 230 nm, under constant column temperature (25 °C). Under these chromatographic conditions, the total time of analysis was less than 5 min. The developed method was validated for linearity, precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ). The LOD under established chromatographic conditions was 0.03, 0.07 and 0.17 mg L⁻¹ for Na-SAC, ACE-K and ASP, respectively. The amount of artificial sweeteners in analyzed samples ranged from 30.32 to 148.37 mg L⁻¹ for ACE-K, from 16.10 to 93.05 for Na-SAC, and from 6.06 to 512.72 for ASP. The validated method was successfully applied for determination of analytes in different commercially available beverages.

Abstract

People are consuming increasing amounts of poultry eggs and their products, and their safety is always a public concern. However, the complex composition of poultry eggs and their products, particularly the proteins and lipids, can easily cause matrix effects, requiring the use of sorbents to remove these components to avoid affecting the detection results. Zeolitic imidazolate framework-8 (ZIF-8) is a MOF material with high specific surface area, high porosity, and high stability, making it widely used as a sorbent in pesticide residue detection. In this study, we evaluated the performance of ZIF-8 compared to classic solid phase extraction (SPE) and Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) in the pretreatment step. The results showed that ZIF-8 could better reduce the matrix effect in poultry eggs and their products. After optimizing the extraction solvents, chromatographic and mass spectrometric conditions, and pretreatment processes, we established a method using ZIF-8 as a sorbent combined with high performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS) for the detection of 80 pesticide residues in seven different types of poultry eggs and their products, yielding satisfactory results. All the target analytes showed good linearity, both with values of r ² > 0.996. The average recovery and coefficients of variation (CVs), expressed as relative standard deviations, ranges from 72.5% to 113.2% (chicken egg) (CV: 0.1%–12.9%), 72.2%–114.2% (salted duck egg) (CV: 0.1%–9.8%), 70.3%–105.6% (goose egg) (CV: 0.1%–12.0%), 70.9–120.4% (marinated egg) (RSD: 0.1%–14.8%), 70.7%–108.5% (duck egg) (CV: 0.1%–12.3%), 71.1%–105.0% (quail egg) (CV: 0.2%–5.6%), 70.7%–111.5% (century egg) (CV: 0.1%–13.4%). The values of limit of detection (LOD) and limit of quantification (LOQ) were, respectively, ranging from 0.15 to 0.85 μg kg⁻¹ and 0.34–2.6 μg kg⁻¹. When this method was applied to the detection of real samples, one chicken egg sample was found to contain 0.013 mg kg⁻¹ of fipronil, and one marinated egg sample was found to contain 0.0087 mg kg⁻¹ of thiamethoxam, indicating the necessity of stringent safety monitoring for poultry eggs and their products.