Justyna Walczak-Skierska

• PhD
• PhD at Nicolaus Copernicus University

The modern functional food market is developing dynamically, responding to the growing demand for products combining nutritional and health-promoting values. At the center of this evolution are natural bio-organic extracts, rich in bioactive compounds such as antioxidants, polyphenols, flavonoids, carotenoids, and vitamins, which can enrich traditi...

Macrophages, the most abundant cells that participate in tumour progression, are the subject of a number of anticancer therapy approaches. Our previous results revealed that an extract of the fungus Coriolus versicolor (CV) has anti-cancer and immunomodulatory properties. The aim of the present study was to investigate whether CV extract-treated tr...

The lipid composition of bacterial membranes is pivotal in regulating bacterial physiology, pathogenicity, and interactions with hosts. This study presents a comprehensive analysis of bacterial membrane lipid profiles across diverse Gram-positive and Gram-negative species. Utilizing matrix-assisted laser desorption/ionization (MALDI) in conjunction...

In this investigation, we detail the synthesis of silver nanoparticles (AgNPs) via a precise Chemical Vapor Deposition (CVD) methodology, aimed at augmenting the analytical performance of Laser Desorption Ionization Mass Spectrometry (LDI-MS) for the detection of low-molecular-weight analytes. Employing a precursor supply rate of 0.0014 mg/s facili...

This study analyzes the impact of physicochemical parameters on the microbiological and fatty acid profiles of cream, buttermilk, and anhydrous milk fat. Using gas chromatography coupled with mass spectrometry (GC-MS), the fatty acids present in these dairy products were qualitatively determined, highlighting the differences associated with the pro...

The current study aimed to investigate the impact of silicon (Si) supplementation in the form of Na 2 SiO 3 on the metabolome of peas under normal conditions and following exposure to cadmium (Cd) stress. Si is known for its ability to enhance stress tolerance in various plant species, including the mitigation of heavy metal toxicity. Cd, a signifi...

Understanding the changes that occur in milk during refrigeration is essential for optimizing dairy product processes and ensuring their quality and shelf life. In this study, we aimed to investigate the effects of a 7-day refrigeration period on the fatty acid (FA) profile and protein composition of milk. Our findings revealed significant alterati...

Lipidomic profiling has emerged as a powerful tool for the comprehensive characterization of bacterial species, particularly in the context of clinical diagnostics. Utilizing matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), this study aims to elucidate the lipidomic landscapes of bacterial strains isolate...

In the presented study, the effects of cadmium (Cd) stress and silicon (Si) supplementation on the pea plant (Pisum sativum L.) were investigated. The tendency to accumulate cadmium in the relevant morphological parts of the plant (roots and shoots respectively)-bioaccumulation, the transfer of this element in the plant (translocation) and the phys...

The global threat of numerous infectious diseases creates a great need to develop new diagnostic methods to facilitate the appropriate prescription of antimicrobial therapy. More recently, the possibility of using bacterial lipidome analysis via laser desorption/ionization mass spectrometry (LDI-MS) as useful diagnostic tool for microbial identific...

Enzyme-assisted extraction of plant material is widely used method for isolation of biologically active compounds. Changes in the structure of the plant material occuring during enzymatic hydrolysis and their consequences for the extraction process of biological active compounds as well functional aspects of the quality of the obtained extracts are...

The presence of certain microorganisms in dairy products or silage is highly desirable. Among them are probiotic strains of lactic acid bacteria (LAB), which show many beneficial features, including antimicrobial properties that support the development of beneficial microflora; in addition, owing to their biochemical activity, they influence the nu...

Butter is an important source of essential fatty acids, lipid-soluble vitamins, and antioxidants in the diet. However, this study showed that the presence of the Lacticaseibacillus paracasei strain has a great influence on the fatty acid profile as well as provitamin D3 and vitamin D3 content in the cream—the raw material from which the butter is o...

Mycotoxins are toxic metabolites produced by mold fungi, which commonly contaminate cereal crops. These compounds include zearalenone (ZEA), which may disturb the proper functioning of the endocrine system in mammals. The metabolism of ZEA plays a key role in its toxic properties. The type and amount of produced metabolites may contribute to both t...

To elaborate a complete extraction protocol for the enhanced release of biologically active compounds from plant cells, this study aimed to optimize together the parameters of the supercriti-cal fluid extraction (SFE) process (temperature, pressure, and percentage of cosolvent) and enzy-matic treatment of plant material (pH, enzyme concentration, t...

The most critical group of all includes multidrug resistant bacteria that pose a particular threat in hospitals, as they can cause severe and often deadly infections. Modern medicine still faces the difficult task of developing new agents for the effective control of bacterial-based diseases. The targeted administration of nanoparticles can enhance...

The main goal of this study was to explore the phospholipid alterations associated with the development of prostate cancer (PCa) using two imaging methods: matrix-assisted laser desorption ionization with time-of-flight mass spectrometer (MALDI-TOF/MS), and electrospray ionization with triple quadrupole mass spectrometer (ESI-QqQ/MS). For this purp...

The separation of phospholipids were studied using supercritical fluid chromatography. The 2-ethylpyridine (2-EP), hybrid fluoro-phenyl (FP), C18, 2-picolylamine (2-PIC), 1-aminoanthracene (1-AA), DIOL and ethylene bridged hybrid (BEH) were used as a stationary phases. Methanol with 0.1% formic acid was used as a co-solvent. For the first time, the...

Predictive approaches on the activity of natural compounds based on the fragmentation by instrumental techniques are important for consideration of such molecules as drug candidates and defining new structures with promising properties. Since flavonoids are well‐known antioxidants, their redox properties can be related to their pharmacological acti...

Analysis by MALDI-TOF mass spectrometry and gas chromatography-mass spectrometry was used to characterize the lipid profile of 3 lactic acid bacteria strains. By gas chromatography coupled with mass spectrometry, 23 fatty acids were identified. Dominant acids were palmitic (C16:0), oleic (C18:1), and α-linoleic acid (C18:3n-3) for Lactobacillus par...

A combination of electrochemistry (EC) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (off-line EC-MALDI-TOF-MS) was applied for determination of the studied biologically active compounds (D-glucose, D-fructose, D-galactose, D-pinitol, L-chiro-inositol, and myo-inositol) and their possible electrochemical metabolit...

The application of silver nanoparticles as an antibacterial agent is becoming more common. Unfortunately, their effect on microorganisms is still not fully understood. Therefore, this paper attempts to investigate the influence of silver ions, biologically synthesized silver nanoparticles and nanoparticles functionalized with antibiotics on molecul...

The aim of this study was to develop a new comprehensive extraction protocol based on green technology for the enhanced release of polyphenolic compounds from plant cells. In this work, extracts from yerba mate and yellow lupine seed were obtained by using three different extraction techniques: maceration, supercritical fluid extraction with co-sol...

This work aimed to unravel the retention mechanisms of 30 structurally different flavonoids separated on three chromatographic columns: conventional Kinetex C18 (K-C18), Kinetex F5 (K-F5), and IAM.PC.DD2. Interactions between analytes and chromatographic phases governing the retention were analyzed and mechanistically interpreted via quantum chemic...

The separation of eleven antibiotics and ten metabolites were studied using high performance liquid chromatography. The C18-PFP octadecyl with integral PFP, C18-AR octadecyl with integral phenyl, C18-HL octadecyl and phenyl phase were used as stationary phases. Mixtures of acetontrile-0.1 % formic acid in water were investigated as mobile phases. T...

The aim of this research was to select parameters for supercritical extraction with CO2 of Medicago sativa L., considered as functional food, in quarter-technical plant, providing the highest concentration of bioactive polar constituents and simultaneously maintaining the highest efficiency of the process. For the purpose of optimization, mathemati...

The zearalenone binding and metabolization ability of probiotic microorganisms, such as lactic acid bacteria, Lactobacillus paracasei, Lactococcus lactis, and yeast Saccharomyces cerevisiae, isolated from food products, were examined. Moreover, the influence of cellular stress (induced by silver nanoparticles) and lyophilization on the effectivenes...

The article describes a possible application of Sc-CO 2 extraction for isolation of polyphenols from germinated lupin seeds. Efficiency of germination duration was valorized, and the obtained results suggest that six-day-long germination process provides samples with the highest polyphenolic yield. Optimization of extraction parameters was done by...

Studies on the retention mechanism of lipid classes (phospholipids, sphingomyelin) were performed using three polar-embedded stationary phases for which diol, phosphate, amino, and amide moieties were incorporated into the alkyl chains of the stationary phases. Their structural descriptors were determined using the quantum-mechanical method. The re...

The aim of this study was to develop an effective Medicago sativa extraction method using enzyme-assisted supercritical fluid extraction (EA-SFE). The response surface methodology (RSM) based on Box-Behnken design was chosen to optimize the parameters of extraction process, i.e., extraction temperature, pressure and percentage of co-solvent for tot...

The aim of the study was to neutralize zearalenone by lactic acid bacteria (LAB) such as Lactococcus lactis and Bifidobacterium sp. and investigate the mechanism of zearalenone (ZEA) binding. Neutralization of ZEA by LAB was confirmed by identification of binding kinetics and spectroscopic studies such as Fourier transform infrared spectroscopy (FT...

The resistance of pathogenic bacteria to antibiotics has become a serious problem. The emphasis is placed on the development of new, effective antimicrobial strategies. One of them is the use of AgNPs in association with antibiotic drugs. The aim of this study was to obtain silver nanoparticles functionalized with ampicillin and to investigate the...

Medicago sativa L. (M. sativa) is a source of many valuable secondary metabolites. Extraction yield and the concentration of phenolics, flavonoids, and saponins, as well as antioxidant potential were determined in extracts from different parts of M. sativa obtained using extraction methods such as maceration, ultrasound-assisted extraction (UAE), a...

The paper presents the analysis of the profile composition of fatty acids in the molecules of phosphatidylcholine and phosphatidylethanolamine, by using hydrophilic interaction liquid chromatography and gas chromatography coupled with mass spectrometry. The profiles of 15 phosphatidylcholine and 8 phosphatidylethanolamine species were analyzed with...

Current studies related to lipid identification and determination, or lipidomics in biological samples, are one of the most important issues in modern bioanalytical chemistry. There are many articles dedicated to specific analytical strategies used in lipidomics in various kinds of biological samples. However, in such literature, there is a lack of...

Current studies related to lipid identification and determination, or lipidomics in biological samples, are one of the most important issues in modern bioanalytical chemistry. There are many articles dedicated to specific analytical strategies used in lipidomics in various kinds of biological samples. However, in such literature, there is lack of a...

In studies lipidomics increasingly uses advanced analytical techniques. Due to the fact that lipids are usually embedded in a matrix and is not present in free form, there is a need to properly prepare a sample. For studies of biological samples associated with medical lipidomics, very important is the issue of storage of samples. The article descr...

In our study we obtained chemically and biologically synthesized silver nanoparticles functionalized with tetracycline. First time, the kinetics of the tetracycline-binding process was investigated in batch adsorption experiments. Functionalization of silver nanoparticles was further confirmed by FTIR, TOC, DLS and zeta potential measurements. We a...

Hen's egg is a complete material needed to the development of the embryo; it is an important source of nutraceuticals compounds, such as protein, fats, vitamins, trace metals and minerals. Moreover, avian egg contains biologically active compounds, which exhibit antibacterial and antimicrobial activities as well as antitumor, antiviral, antioxidant...

Food as complex mixture of proteins, lipids, vitamins, etc. cannot be separated and identified by using in only one method. This article presents a revision on the hyphenated chromatographic techniques and methods used in food analysis and described main application in food science research, and determination of xenobiotics and their metabolites in...

A comparative study has been made of three home-made bonded silica columns for the separation of the components of bovine milk casein (a-, b- and k-casein). A gradient elution HPLC procedure is now proposed for separation of the protein components, and the tests conducted have confirmed the superiority of columns based on diol-bonded silica over oc...

Phospholipids are one of the classes of lipids, which are a major component of all cell membranes. Phosphatidylcholine (PC) is the main phospholipid present in egg yolk. The phospholipids extract from enriched egg yolk was separated using the two-dimensional high performance liquid chromatography in off-line system coupled with electrospray ionizat...

Sensitive and selective analytical procedures based on high-performance liquid chromatography with mass spectrometric detection were developed for the determination of amoxicillin in human plasma samples. Samples were prepared by applying in-house manufactured molecularly imprinted solid-phase microextraction probes. The detection of target compoun...