The Influence of Freeze-Dried Alcohol-Water Extracts from Common Yarrow (Achillea millefolium L.) and German Chamomile (Matricaria chamomilla L.) on the Properties of Elastomer Vulcanizates.

This research work aimed to investigate the properties of freeze-dried extracts from Matricaria chamomilla L. and Achillea millefolium L. and to perform a characterization of their impact on the natural rubber-based vulcanizates. First, extracts were prepared in three different solvents at selected volume ratios: water (100), water-methanol (50/50), and water-ethanol (50/50). Next, the freeze-drying of extracts was established and then obtained bio-additives were introduced to the rubber mixtures. Freeze-dried extracts were investigated by UV-VIS diffuse reflectance spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Near-Infrared spectroscopy (NIR) and thermogravimetric analysis (TGA). Antioxidant activity and total phenolic content (TPC) were also defined. Rubber mixtures were examined in a rheometer and after vulcanization they were subjected to accelerated simulated aging by UV radiation and thermo-oxidative aging. To determine the resistance of vulcanizates to the degradation processes, the study of cross-linking density (equilibrium swelling method), mechanical properties (tensile strength, elongation at break) and color change were conducted. Performed studies proved the antioxidant activity of freeze-dried extracts caused by the high content of polyphenols and their beneficial influence on the properties of elastomer vulcanizates.

Antioxidant and Anti-Aging Activity of Freeze-Dried Alcohol-Water Extracts from Common Nettle (Urtica dioica L.) and Peppermint (Mentha piperita L.) in Elastomer Vulcanizates.

The research article aimed to examine the antioxidant nature of freeze-dried extracts from Urtica dioica L. and Mentha piperita L. and to present a deep characterization of their influence on the properties of natural rubber-based vulcanizates before and after simulated aging processes. Natural extracts were prepared in three solvent systems at selected volume ratios: water (100), methanol-water (50/50), ethanol-water (50/50), which were further lyophilized and used as additive to natural rubber mixtures. Freeze-dried materials were investigated by UV-VIS diffuse reflectance spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), thermal stability by thermogravimetric analysis (TGA). Antioxidant activity and total phenolic content (TPC) were also examined. Prepared samples were subjected to accelerated simulated degradation processes by using ultraviolet and thermo-oxidative aging. Vulcanizates resistance to degradation effects was determined by the study of cross-linking density (equilibrium swelling method), mechanical properties (tensile strength, elongation at break) and color change in comparison with the results of the reference samples. The research showed that analyzed extracts are characterized by a high content of polyphenols and antioxidant activity, thus have a protective influence on elastomer vulcanizates against damaging effects of aging processes, which consequently extends the lifetime of materials.

Aronia melanocarpa (Michx.) Elliot, Chaenomeles superba Lindl. and Cornus mas L. Leaf Extracts as Natural Preservatives for Pork Meat Products.

The aim of this study was to investigate the possibility of using Aronia melanocarpa, Chaenomeles superba, and Cornus mas leaf extracts as natural preservatives for pork meat products. Pork sausages were stored in modified atmosphere packaging (MAP) (80% N2 and 20% CO2) at 4 °C for 29 days. The total psychrotrophic counts (TPC) were determined during the storage period, along with the numbers of Enterobacteriaceae and lactic acid bacteria (LAB). The extracts improved the microbial quality of the meat products but to a lesser extent than sodium nitrate (III). They reduced the amounts of Enterobacteriaceae and LAB. The A.melanocarpa leaf extract showed the strongest preservative effect. The bacterial biodiversity of the meat products was investigated based on high-throughput sequencing of the 16S rRNA gene. Two predominant bacteria phyla were identified, Proteobacteria and Firmucutes, mostly consisting of genera Photobacterium, Brochothrix, and Carnobacterium. The extracts also influenced microbial community in sausages decreasing or increasing bacterial relative abundance. The extracts significantly inhibited lipid oxidation and improved the water-holding capacity of the meat, with C. superba extract showing the strongest influence. In addition, A. melanocarpa and C. superba improved the redness (a*) of the sausages. The results of this study show that A. melanocarpa, C. superba, and C. mas leaf extracts can extend the shelf life of meat products stored in MAP at 4 °C.

Antibacterial mechanisms of Aronia melanocarpa (Michx.), Chaenomeles superba Lindl. and Cornus mas L. leaf extracts.

The aim of this study was to investigate the in vitro antibacterial mechanisms of Aronia melanocarpa, Chaenomeles superba, and Cornus mas leaf extracts towards meat spoilage and pathogenic bacteria. The extracts decreased bacterial viability after 24 h and 48 h of incubation. Acting as prooxidants, the extracts induced intracellular ROS (reactive oxygen species) generation in bacteria cells, with C. mas having the strongest influence. The leaf extracts increased the release of UV intracellular absorbing components, suggesting a reduction in membrane integrity. They also increased the outer-membrane permeability of the Gram-negative bacteria, with C. superba extract being the most active. Following exposure to the leaf extracts, morphological changes in the bacteria were observed, including the formation of aggregates, EPS synthesis, irregular forms, wrinkled cell surfaces, pores in the cell wall, and shriveling of cells. The leaf extracts inhibited DNA synthesis in E. coli cells by suppressing DNA gyrase activity.

Plant extracts rich in polyphenols: antibacterial agents and natural preservatives for meat and meat products.

Plant extracts contain large amounts of bioactive compounds, mainly polyphenols. Polyphenols inhibit the growth of microorganisms, especially bacteria. Their mechanism of action is still not fully understood but may be related to their chemical structure. They can cause morphological changes in microorganisms, damage bacterial cell walls and influence biofilm formation. Polyphenols also influence protein biosynthesis, change metabolic processes in bacteria cells and inhibit ATP and DNA synthesis (suppressing DNA gyrase). Due to the antioxidant and antibacterial activity of phenolic compounds, plant extracts offer an alternative to chemical preservatives used in the meat industry, especially nitrates (III). They can inhibit the growth of spoilage and pathogenic microflora, suppress oxidation of meat ingredients (lipids and proteins) and prevent discoloration. In this paper, we describe the factors that influence the content of polyphenols in plants and plant extracts. We present the antimicrobial activities of plant extracts and their mechanisms of action, and discuss the effects of plant extracts on the shelf-life of meat and meat products.

Novel Biodegradable Starch Film for Food Packaging with Antimicrobial Chicory Root Extract and Phytic Acid as a Cross-Linking Agent.

The aim of the study was to obtain and evaluate the properties of biodegradable starch film with the addition of phytic acid (0.05%) as a cross-linking agent and chicory root extract (1-5%) as an antimicrobial agent. To prepare biodegradable film, extracts from chicory root obtained with water or methanol were used. The content of bioactive compounds (sesquiterpene lactones and total polyphenols) was evaluated in chicory extracts. The antibacterial activity of the extracts was tested against Gram-negative bacteria (Pseudomonas fluorescens, Escherichia coli) and Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus) using the microculture method. The extracts acted as bacteriostatic agents, decreasing the growth rate (µmax), and extending the lag phase (tlag). The most sensitive bacterium in terms of film bacteriostatic activity was P. fluorescens; all extracts, irrespective of the solvent used, decreased its µmax value. S. aureus was the least sensitive. The obtained films were tested for their properties as food packaging (color, thickness, permeability, mechanical strength). Phytic acid improved the tensile strength and barrier properties of the films. The antimicrobial activity of the films was studied by the disk diffusion method against Gram-negative (P. fluorescens, E. coli) and Gram-positive (B. subtilis, S. aureus) bacteria, as well as fungi (Candida albicans, Aspergillus niger). The growth-inhibiting activity of each obtained film was observed for all tested microorganisms, and the most beneficial effect was observed for films with the 5% level of added extracts obtained with water. The growth-inhibiting activity for fungi, in particular for the yeast C. albicans, was low.

Anti-Oxidative Activity of Alcohol-Water Extracts from Field Horsetail (Equisteum arvense) in Elastomer Vulcanizates Subjected to Accelerated Aging Processes.

The article aimed to highlight the antioxidant potential of natural extracts obtained from Equisteum arvense in elastomer vulcanizatec made of natural rubber. Horsetail extracts were prepared using four solvent systems at different volume ratios: methanol-water (50/50 and 70/30) and ethanol-water (50/50 and 70/30), which were then lyophilized and added to the polymer matrix. A deep characterization of the obtained bio-additives was performed. The obtained vulcanizates were subjected to various aging processes: thermo-oxidative, ultraviolet and solar. Then, the resistance and susceptibility of vulcanizates to selected processes of accelerated, simulated degradation were determined based on the changes in the spatial structure (network nodes), material strength and physical properties (color). The research showed the presence of polyphenols in the extracts of horsetail, which resulted in their high anti-oxidative activity. Moreover, the extracts were able to absorb UV radiation. As a consequence, they were active additives that protected rubber vulcanizates against the damaging effects of the aging processes, securing their functional properties. Samples containing natural extracts were characterized by better stability of: mechanical strength parameters, the increase in cross-linking density and color changes after simulating aging processes in comparison with the control sample.

Cytotoxic and DNA-Damaging Effects of Aronia melanocarpa, Cornus mas, and Chaenomeles superba Leaf Extracts on the Human Colon Adenocarcinoma Cell Line Caco-2.

Aronia melanocarpa, Cornus mas, and Chaenomeles superba leaf extracts contain large amounts of bioactive compounds-mainly polyphenols, which possess many health benefits including anti-cancer properties. Here, we investigate the biological effects of A. melanocarpa, C. mas, and C. superba leaf extracts on the human colon adenocarcinoma cell line Caco-2. The antiproliferative activity of the extracts was measured using the MTT assay. The most cytotoxic extract was C. mas (IC50 = 0.60%). The extracts caused morphological changes in the Caco-2 cells, including partial detachment of cells, necrotic cells, chromatin condensation, cytoplasmic vacuolization, cell nuclei lysis, and nucleus fragmentation. The DNA damage in the Caco-2 cells after exposure to the leaf extracts was measured using the alkaline comet assay. The extracts increased DNA damage in a concentration dependent manner. However, at lower non-cyto- and non-genotoxic (IC0) concentrations the extracts induced DNA repair in Caco-2 cells after exposure to hydrogen peroxide. In conclusion, the results of these studies suggest that A. melanocarpa, C. mas and C. superba leaf extracts can show anticancer activity. However, further research is required on the mechanisms of anti-cancer activity by these extracts, with the application of more advanced and wide-ranging techniques including in vivo experiments.

Composition and Antibacterial Activity of Aronia melanocarpa (Michx.) Elliot, Cornus mas L. and Chaenomeles superba Lindl. Leaf Extracts.

The purpose of this study was to investigate the composition of leaf extracts from Aronia melanocarpa, Chaenomeles superba, and Cornus mas, and their antimicrobial activity against typical spoilage-causing and pathogenic bacteria found in meat and meat products. The highest total phenolic content (TPC) was detected in C. superba extract, followed by C. mas and A. melanocarpa extracts. The antioxidant capacity of the extracts was measured by DPPH and ABTS assays. The lowest IC50 values were found for C. superba extract, followed by C. mas and A. melanocarpa extracts. LC-MS and HPLC analysis revealed that A. melanocarpa and C. superba extracts contained hydroxycinnamic acid derivatives and flavonoids (mainly flavonols). Hydroxycinnamic acid derivatives were detected in the C. mas extract, as well as flavonols, ellagitannins, and iridoids. The antibacterial activity of the plant extracts was tested against Gram-negative bacteria (Moraxella osloensis, Pseudomonas fragi, Acinetobacter baumanii, Escherichia coli, Enterobacter aerogenes, Salmonella enterica) and Gram-positive bacteria (Enterococcus faecium, Staphylococcus aureus, Brochothrix thermosphacta, Lactobacillus sakei, Listeria monocytogenes) using the microculture method. The extracts acted as bacteriostatic agents, decreasing the growth rate (µmax) and extending the lag phase (tlag). C. mas showed most potent antibacterial activity, as confirmed by principal component analysis (PCA).

Implementation of chemometrics in quality evaluation of food and beverages.

Conventional methods for food quality evaluation based on chemical or microbiological analysis followed by traditional univariate statistics such as ANOVA are considered insufficient for some purposes. More sophisticated instrumental methods including spectroscopy and chromatography, in combination with multivariate analysis-chemometrics, can be used to determine food authenticity, identify adulterations or mislabeling and determine food safety. The purpose of this review is to present the current state of knowledge on the use of chemometric tools for evaluating quality of food products of animal and plant origin and beverages. The article describes applications of several multivariate techniques in food and beverages research, showing their role in adulteration detection, authentication, quality control, differentiation of samples and comparing their classification and prediction ability.