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The influence of proteolytic enzymes on the change of lysozyme properties
This research examines the enzymatic modification of lysozyme, a glycosidic hydrolase that has restricted effectiveness against Gram-negative bacteria, in order to produce bioactive peptide fractions with improved antibacterial and physicochemical characteristics. Utilizing chicken egg lysozyme, modifications were performed in controlled settings with proteolytic enzymes, mainly pepsin, and experiments with a pepsin-trypsin ratio. The modification methods sought to improve the hydrophobic nature of lysozyme’s surface, create oligomeric and peptide forms, and decrease immunogenicity. Findings showed that raising pepsin concentration enhanced the creation of peptide fractions, increasing surface hydrophobicity while reducing hydrolytic and antioxidant activities. Increased hydrophobicity and reduced enzyme activity were linked to enhanced antibacterial effectiveness, particularly against Gram-negative bacteria, a characteristic absent in natural lysozyme. Additionally, the research noted a decrease in immunoreactivity as pepsin concentrations increased, achieving the lowest antibody response in optimized formulations. This enzymatic method offers an economical way to create lysozyme derivatives that hold considerable promise for wider applications, particularly in scenarios where lower immunoreactivity and a prolonged antibacterial spectrum are needed.
Assessment of Antimicrobial Properties of Phenolic Acid Extracts from Grain Infected with Fungi from the Genus Fusarium
Problems related with biological contamination of plant origin raw materials have a considerable effect on prevention systems at each stage of food production. Concerning the antimicrobial action of phenolic acids, studies were undertaken to investigate antibacterial properties against bacterial strains of Escherichia coli (EC), Pseudomonas fluorescence (PF), Micrococcus luteus (ML) and Proteus mirabilis (PM), as well as antifungal properties targeting microscopic fungi Fusarium spp., extracts of phenolic compounds coming from inoculated grain from various genotypes of cereals. This study evaluated the antimicrobial action of phenolic acids extracts obtained from both naturally infested and inoculated with microorganisms. For this purpose a total of 24 cereal cultivars were selected, including 9 winter and 15 spring cultivars. The analyses showed a bactericidal effect in the case of 4 extracts against Micrococcus luteus (ML), 14 extracts against Pseudomonas fluorescence (PF), 17 extracts against Escherichia coli (EC) as well as 16 extracts against Proteus mirabilis (PM). It was found that 3 out of the 24 extracts showed no antibacterial activity. In turn, fungicidal action was observed in the case of 17 extracts against Fusarium culmorum (FC) (NIV), 16 extracts against FC (3AcDON), 12 extracts against Fusarium graminearum (FG) (3AcDON), while 12 other extracts showed antifungal action against FG (NIV) and 19 extracts against Fusarium langsethiae (FL). Based on the conducted analyses it was found that grain of small-grained cereals exposed to fungal infection is a source of bioactive compounds exhibiting antimicrobial properties. It was observed that the qualitative and quantitative profiles of polyphenols vary depending on the cereal cultivar. This extracts may be used to develop an antimicrobial preparation applicable in organic farming.
Production of Antibacterial Compounds from Fermented Dairy Products Using Kefir Grain Microflora
Antimicrobial Activities Evaluation and Phytochemical Screening of Some Selected Plant Materials Used in Traditional Medicine
Plant extracts are a source of valuable ingredients that can be used in many industries. This paper presents research on the content of selected bioactive compounds in extracts obtained from various plant materials. Raw materials have a documented use in traditional medicine not only in Poland. The tested plants were: bitter melon (fruit), elderberry (flowers, fruit, leaves), wild rose (fruit, flesh, seeds), mountain ash (fruit), guelder rose (fruit), and sea buckthorn (fruit, leaves, pomace). The main goal of these tests is to indicate the potential raw materials that may constitute an alternative source of bioactive compounds with antimicrobial activity. The plant material was tested for the content of bioactive antioxidant compounds and possible antimicrobial activity. The content of polyphenols (phenolic acids and flavonoids) was analyzed using UPLC/PDA, sterols, organic acids, and other bioactive compounds. The minimum inhibitory concentration (MIC) was determined. The total free phenolic acids (TPC) and total free flavonoids (TFC) of all plant raw materials was varied and ranged from 0.21 (mg RUTE/1 g of extract) to 38.30 mg RUTE/1 g of extract) for TFC. The concentration of sterols was, on average, about 10 mg/1 g of extract. The value of approx. 20 mg/1 g of the extract was recorded for bitter melon and beach rose. The content of organic acids was about 1.5 mg/1 g of the extract to even 13 mg/1 g of the extract for sea buckthorn berries. The most sensitive to the extracts’ activity were the following bacteria: M. luteus, P. mirabilis, P. fragii, S. enteritidis, and E. coli. The tested plant materials can be used in various industries as a source of bioactive compounds of an antibacterial nature.
The Evaluation of Activity of Selected Lactic Acid Bacteria for Bioconversion of Milk and Whey from Goat Milk to Release Biomolecules with Antibacterial Activity
The aim of the study was to assess the antibacterial features of functional macromolecules released during the fermentation of goat milk and whey from goat milk by selected lactic acid bacteria strains that are components of kefir grain microflora. Two milk sources were used: goat milk and whey from goat milk. The lactic acid bacteria (LAB) and indicator microorganisms used were Lactobacillus plantarum PCM 1386, Lactobacillus fermentum PCM 491, Lactobacillus rhamnosus PCM 2677, Lactobacillus acidophilus PCM 2499, Escherichia coli PCM 2793, Salmonella enteritidis PCM 2548, Micrococcus luteus PCM 525, and Proteus mirabilis PCM 1361. The metabolic activity of LAB was described by the Gompertz model, and the parameters proposed for this experiment were the maximum rate of change of electrical impedance and potential biodegradability. Antibacterial activity was examined using the culture method in a liquid medium, determination of the reduction in indicator microorganisms, and optical density changes. Results show that the selective LAB produced certain active biomolecules with antibacterial activity from whey, a by-product that is sometimes troublesome for goat milk processors to manage. Lactobacillus acidophilus is a microorganism that is characterized by the highest metabolic activity in goat milk and whey from goat milk. It has the possibility to produce macromolecules with antibacterial activity.
Physicochemical Evaluation of Preparations Obtained as a Result of Enzymatic Modification of Lysozymes with Pepsin and Trypsin
Determination of chemical markers affecting the occurrence of Panolis flammea Den. & Shiff.
AbstractThe research conducted so far on the chemical mechanisms of trees' defence against foliophages has not uncovered the chemical compounds biosynthesized by plants that are essential for these mechanisms. The objective of this study was to identify a chemical indicator for the presence of the pine beauty moth in Pinus sylvestris stands. Fresh needled shoots were collected from the crowns of pine trees in stands where the pine beauty moth tends to occur in large numbers, as well as from control stands. Total phenolic contents, total flavonoids contents, total chlorophyll content, terpene compounds, phenolic compound concentration, LMWOAs, sugar content, and colour analysis were conducted. Chlorophyll content, the presence of Panolis flammea in forest stands, and the colour of pine needles were discovered to be related. Variable L* correlated positively with the concentrations of chlorophyll a and b. In pine needles that were not attacked by the pine beauty moth, significantly higher concentrations of 4‐hydroxybenzoic acid, salicylic acid, chlorogenic acid, syringic acid, quercitin, and rutin were found, with the first compound having the most significant effect (4‐hydroxybenzoic acid). Based on the study results, the connected compounds in pine needles make them susceptible to insect attack. In addition, insect repellent programmes were mentioned.
Safety Culture and Pro-Quality Awareness of Employees as Key Factors in Sustainable Management of Food Sector Enterprises
Sustainable business management in the food sector entails the systematic integration of social, environmental, and economic considerations into organizational decision-making, which has direct implications for food safety assurance systems. This study sought to evaluate how the maturity of an organization’s safety culture influences employees’ pro-quality and food-safety-related behaviors. A complementary objective was to examine employees’ understanding of pro-quality awareness in the context of the principles, goals, and operational procedures associated with sustainable management. The research was carried out in three food industry enterprises located in the Greater Poland region. The methodological framework consisted of internal audits assessing compliance with food safety and quality management standards, combined with a structured questionnaire survey. A total of 169 employees from various operational and administrative departments participated. The results indicate that employees’ professional qualifications and organizational roles significantly affect their awareness of how individual actions contribute to food safety and product quality outcomes. Moreover, the implementation of a sustainable, systems-oriented management approach supported a more comprehensive understanding of food production processes where employees recognize their impacts on public health, the socio-economic environment, natural ecosystems, and future generations. At the same time, this approach underscores the interdependence between employee well-being, organizational performance, and consumer protection.
Physical and biochemical characteristics of Japanese quail (Coturnix japonica) eggs based on shell color
Abstract Ten percent of the world’s total edible eggs come from Japanese quail. The popularity of quail eggs is attributed to their high yolk content and hypoallergenic properties. This study aimed to analyze the physical characteristics and selected biochemical parameters of Japanese quail eggs based on shell color (dotted - D group, spotted - S group, and hazy - H group). The heaviest and most elongated eggs were found in the group H. The yolk index was significantly higher in dotted eggs, which also exhibited the highest lysozyme content and activity. The thickest shell (p≤0.05) with the lowest elasticity was observed in hazy eggs. However, no differences were found between eggshell colors concerning their breaking strength. The highest Ca content in the shell was found in the spotted group (S), while hazy eggs exhibited the lowest (p≤0.05) Ca and Mg content, despite having the thickest shells. Hazy eggs were also characterized by the highest crude protein content and the smallest proportion of crude fat and ash. The dotted eggs had the highest (p≤0.05) proportions of C16:1 and C18:2 fatty acids and a higher PUFA content (p≤0.05). Nutritionally, the dotted eggs performed best in terms of fatty acid profile and were also characterized by higher Mg, Ca, Cu, Mn, K, and Na content compared to the other groups. In summary, dotted eggs may be more appealing to consumers due to their advantageous physical and biochemical characteristics.
Utilizing the IFS Standard for the Implementation of Sustainable Development Practices in Juice Production
The aim of this study was to identify the most common threats and non-compliances occurring during the production of unpasteurized fruit juices in relation to the requirements of the IFS standard. Additionally, this study aimed to demonstrate how the IFS standard supports the introduction of sustainable practices in the production of fruit juices. The research material was data from internal audits conducted in three plants producing unpasteurized fruit juices and final product microbial assessment and swabs from the production environment taken from the three plants. These plants are located in western Poland. Based on the assessment carried out, it was found that most non-compliances were identified in the areas covered by prerequisite programs, but the final product and production environment met product and production safety requirements. It was also stated that the corrective actions proposed and approved by the auditors correct the existing non-compliance without the aspect of continuous improvement. The research and audits carried out as part of this work allowed us to conclude that international standards, such as the IFS, are an excellent tool for introducing the principles of a sustainable approach to production plants.
New Insights into Bioactive Compounds of Wild-Growing Medicinal Plants
Plants contain bioactive substances and secondary metabolites that have a variety of functions, including antibacterial, antioxidant, anti-inflammatory, and anticancer activities. In this study, the content of bioactive compounds in five medicinal plants was determined, i.e., Plantago major L., Armoracia rusticana, Hypericum perforatum L., Rumex acetosa L., and Urtica dioica L., from 38 locations. Additionally, the antimicrobial effect of extracts of bioactive compounds from the above-mentioned plants was checked. The experiment used an original method of extracting bioactive compounds. Purpose of the research: the assessment of antimicrobial activity and chemical characterization of extracts obtained using our own method of isolating bioactive compounds from green parts of medical plants in Poland. Based on the research, the presence of bioactive compounds, i.e., phenolic acids and flavonoids, was found in the tested plant extracts. The results of this study suggest that the geographic parameters of the locations where these plants grow have different effects on their biochemical composition and biological activity. The results showed that all tested plants had significant antibacterial activities. Rumex acetose L. showed the highest antimicrobial activity against Escherichia coli and Salmonella enteritidis. These studies supplement the existing literature on the subject with information about the antimicrobial properties of the tested plant extracts that can be used in herbal medicine. The results have significant implications for the pharmaceutical, nutraceutical, and cosmetic sectors, establishing a foundation for future research in this area.
Comprehensive Assessment of Environmental Pollution in a Poultry Farm Depending on the Season and the Laying Hen Breeding System
The odors and dust emitted from hen houses affect human health and the condition of crops. The source of fumes is an element of the poultry house environment that affects the level of dust (litter and feed), the concentration of volatile compounds and the composition of the microflora (litter, dust and fodder). The research carried out as part of this study is a comprehensive assessment of the microbiological contamination (Pseudomonas, Enterobacteriaceae, and microscopic fungi) of all the elements that make up the environment of the poultry house (feed, litter, dust pollution and the atmosphere of the poultry house) in an annual cycle. The air from both types of farms is tested in terms of the quantity and quality of volatile compounds. Two types of laying hens reared on litter were compared: commercial and backyard farms. It was found that the seasons of the year and the system of keeping hens have a significant impact on the microbiological contamination with volatile compounds of the environment and the atmosphere of the hen houses. The obtained results of chemical, microbiological and questionnaire tests show that commercial farms carry a lower microbiological risk to the environment than backyard farm.
Influence of the genotype of the hen (Gallus gallus domesticus) on main parameters of egg quality, chemical composition of the eggs under uniform environmental conditions
Lysozyme Modification Using Proteolytic Enzymes
The lysozyme in the chicken egg white consists of various bioactive amino acids. However, these compounds are inactive when they are in the sequence of parent proteins. They become active only when isolated from these proteins. The aim of this study was to modify lysozyme with proteolytic enzymes under specific conditions of the reaction environment so as to obtain active biopeptides. The physicochemical properties of the resulting preparations were also assessed. Our study showed that the modification of lysozyme with hydrolytic enzymes (pepsin and trypsin) under strictly specified conditions resulted in obtaining biopeptide preparations with new and valuable properties, as compared with native lysozyme. After the enzymatic modification of lysozyme, two structural fractions were distinguished in the composition of the resulting preparations—the monomeric fraction and the peptide fraction. The modified lysozyme exhibited high surface hydrophobicity and high total antibacterial activity despite the decrease in the hydrolytic activity. Modification of lysozyme with hydrolytic enzymes, especially pepsin, resulted in preparations with very good antioxidative properties.