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The inhibitory activity and binding characteristics of caffeic acid, -coumaric acid, quercetin and capsaicin, four phenolic compounds found in hot pepper, against porcine pancreatic lipase activity were studied and compared to hot pepper extract. Quercetin was the strongest inhibitor (IC =(6.1±2.4) µM), followed by -coumaric acid ((170.2±20.6) µM) and caffeic acid ((401.5±32.1) µM), while capsaicin and a hot pepper extract had very low inhibitory activity. All polyphenolic compounds showed a mixed-type inhibition. Fluorescence spectroscopy studies showed that polyphenolic compounds had the ability to quench the intrinsic fluorescence of pancreatic lipase by a static mechanism. The sequence of Stern-Volmer constant was quercetin, followed by caffeic and -coumaric acids. Molecular docking studies showed that caffeic acid, quercetin and -coumaric acid bound near the active site, while capsaicin bound far away from the active site. Hydrogen bonds and π-stacking hydrophobic interactions are the main pancreatic lipase-polyphenolic compound interactions observed.

Human milk is rich in bioactive molecules and beneficial bacteria that contribute to shaping the newborn's microbiota. In this study, we aim to evaluate lactic acid bacteria strains isolated from human milk of healthy Croatian women as potential functional starter cultures. In order to define novel potential probiotics for use in dairy products, eight strains of lactobacilli were analysed for their proteolytic, antimicrobial and antioxidant activity as well as their survival rate during freeze-drying. Based on the results obtained, the exopolysaccharide-producing MC1, the surface (S)-layer-producing MB2 and the plantaricin-producing MB18 strains are candidates for the production of fermented dairy products with potential functional and nutritional relevance for the host. The selected strains exerted high casein degradation capacity, a broad spectrum of antimicrobial activity and a promising 2,2-diphenyl-1-picrylhydrazyl hydrate radical scavenging activity. They also fulfilled the primary technological criterion by having a high survival rate during freeze-drying. The data presented emphasise the importance of human milk as a valuable source of lactic acid bacteria with unique technological and functional properties, which are important both as a basis for scientific research and for the development of novel starter cultures for functional products.

The identification and quantification of phenolic compounds and flavonoids in various natural food products is typically conducted using HPLC analysis. Their analysis is particularly complex since most natural food products contain a large number of different phenolic compounds, many of which have similar chemical characteristics such as polarity, which makes complete separation of all eluents extremely difficult. In this work we present and validate a method for the quantitative determination of the concentration of two compounds with similar retention times, i.e. they show overlapping peaks in a mixed solution. Two pairs of phenolic compounds were investigated: caffeic and vanillic acids and ferulic and p-coumaric acids. This technique takes advantage of the different absorbances of the two phenolic compounds in the eluent at various wavelengths and can be used for the quantitative determination of the concentration of these compounds even if they are not separated in the HPLC column. The presented method could be used to interpret the results of HPLC analysis of food products which possess a vast spectrum of phenolic compounds and flavonoids.

The objective of this work is to study the effect of the rapeseed oil content on the physical properties of whey protein emulsion films. For this purpose, whey protein films with the addition of 0, 1, 2 and 3% of rapeseed oil, and glycerol as a plasticizer were obtained by the casting method. Film-forming emulsions were evaluated and compared using light scattering granulometry. The Sauter mean diameters ( ) of lipid droplets in film-forming solutions showed an increasing trend when increasing the oil volume fractions. The inclusion of rapeseed oil enhanced the hydrophobic character of whey protein films, reducing moisture content and film solubility in water. All emulsified films showed high lightness ( ≈90). Parameter * decreased and parameter and total colour difference (∆ ) increased with the increase of the volume fractions of oil. These results were consistent with visual observations; control films were transparent and those containing oil opaque. Water vapour sorption experimental data at the full range of water activity values from 0.11 to 0.93 were well described with Peleg's equation (R ≥0.99). The tensile strength, Young's modulus and elongation at break increased with the increase of rapeseed oil volume fraction, which could be explained by interactions between lipids and the protein matrix. These results revealed that rapeseed oil has enormous potential to be incorporated into whey protein to make edible film or coating for some food products. The mechanical resistance decreased with the addition of the lipids, and the opacity and soluble matter content increased.

Research background. Hydrogenated fats are widely used to improve texture, flavor, and shelf life in processed foods, but their excessive consumption contributes to cardiovascular diseases. While Butia seed oil contains saturated fats, its potential as an alternative structuring lipid in food applications remains unexplored. This study investigates the formulation of oleogels based on Butia seed oil and their potential as a replacement for hydrogenated fats in cookies. Experimental approach. The aim of this study is to develop oleogels based on Butia seed oil and beeswax (w=1, 3 and 5 %) and use them in cookies as a substitute for hydrogenated fat. The chemical composition, thermal properties and functional groups of Butia seed oil and beeswax were analyzed. The lipid stability, oil binding capacity, gel stability, thermal properties and color parameters of the oleogels were characterized. The oleogels were then added to cookies as a substitute for hydrogenated vegetable fat. Mass loss, color, expansion factor, specific volume and texture properties of the cookies were evaluated. Results and conclusions. Butia seed oil had saturated fatty acids (22.87 mg/mL lauric and 22.45 mg/mL caprylic acid) and notably high concentrations of unsaturated fatty acids (oleic acid 33.21 mg/mL and linoleic acid 30.61 mg/mL). Oleogels containing 3 and 5 % beeswax remained stable for 90 days. Increasing the beeswax mass fraction resulted in greater hardness of the oleogels (p<0.05). Specifically, the oleogel with 5 % beeswax had the highest oil binding capacity, reaching 99.9 %. Cookies formulated with oleogel showed lower hardness and mass loss, as well as a higher specific volume than the control cookie (without oleogel). Notably, the use of oleogels did not alter the visual characteristics of the cookies, supporting their potential as a viable fat replacer in oven-baked products. Novelty and scientific contribution. These results suggest that oleogels containing Butia seed oil have the potential to replace hydrogenated vegetable fats in food products. This study shows that oleogels with Butia seed oil, particularly with beeswax mass fractions of 3–5 %, can effectively replace hydrogenated vegetable fats in cookie formulations. Unlike traditional structuring fats, these oleogels offer improved lipid profiles while maintaining desirable baking properties.

In this paper the effect of aflatoxin B1, ochratoxin A and zearalenon on morphology, growth parameters and metabolic activity of yeasts Saccharomyces cerevisiae, Saccharomyces uvarum, Candida utilis and Kluyveromyces marxianus was determined. The results showed that the three mycotoxins affected the morphology of all these yeasts, primarily the cell diameter, but not their final cell count. Fourier transform infrared spectroscopy showed that the yeast membranes bound the mycotoxins, C. utilis in particular. The cell membranes of most yeasts underwent denaturation, except S. uvarum exposed to ochratoxin A and zearalenone. In the early stage of fermentation, all mycotoxin-exposed yeasts had lower metabolic activity and biomass growth than controls, but fermentation products and biomass concentrations reached the control levels by the end of the fermentation, except for C. utilis exposed to 20 µg/mL of zearalenone. The adaptive response to mycotoxins suggests that certain yeasts could be used to control mycotoxin concentrations in the production of fermented food and beverages.In this paper the effect of aflatoxin B1, ochratoxin A and zearalenon on morphology, growth parameters and metabolic activity of yeasts Saccharomyces cerevisiae, Saccharomyces uvarum, Candida utilis and Kluyveromyces marxianus was determined. The results showed that the three mycotoxins affected the morphology of all these yeasts, primarily the cell diameter, but not their final cell count. Fourier transform infrared spectroscopy showed that the yeast membranes bound the mycotoxins, C. utilis in particular. The cell membranes of most yeasts underwent denaturation, except S. uvarum exposed to ochratoxin A and zearalenone. In the early stage of fermentation, all mycotoxin-exposed yeasts had lower metabolic activity and biomass growth than controls, but fermentation products and biomass concentrations reached the control levels by the end of the fermentation, except for C. utilis exposed to 20 µg/mL of zearalenone. The adaptive response to mycotoxins suggests that certain yeasts could be used to control mycotoxin concentrations in the production of fermented food and beverages.

Research background. Several loop-mediated isothermal amplification (LAMP) assays with good performance characteristics have been developed for the detection of Listeria monocytogenes in food; however, there are only a few cases in which DNA extraction, amplification and sensing have been performed in a single-tube system. Experimental approach. The efficiency of DNA extraction by lysis buffers was tested using LAMP. New primer sets for LAMP assays were designed using PrimerExplorer V5 software. The sensitivity and specificity of the LAMP inner primers were determined by optimised PCR. The end-point detection involved gel electrophoresis, turbidity and eriochrome black T (EBT) colour reaction. The sensitivity, specificity and limit of detection (LOD) of the developed LAMP assays were then characterised using L. monocytogenes, non-monocytogenes Listeria and non-Listeria bacterial strains. Results and conclusions. Both the alkaline cell lysis-based sodium hydroxide and Tris-HCl (HotSHOT)+Tween buffer and the Triton X-100 and sodium azide-based TZ buffer generated amplifiable DNA templates under isothermal conditions for LAMP. However, the TZ buffer produced a significantly higher DNA yield than the HotSHOT+Tween buffer. LAMP primers were designed to target the hlyA and inlA virulence genes of L. monocytogenes. The sensitivity and specificity of the LAMP inner primers were 100 % for both genes; however, the PCR reaction targeting the inlA gene generated fewer non-specific PCR products than the hlyA-targeting PCR. The sensitivity of the InlA LAMP assay was 100 %, while its specificity was 96 %. The LOD was 500 fg per reaction, which corresponds to 157 genome copy numbers. The combination of DNA extraction, LAMP amplification, and colorimetric endpoint detection in a single tube resulted in a LAMP assay suitable for the detection of L. monocytogenes in food under laboratory conditions, with potential for further development for on-site detection with microfluidic platforms. Novelty and scientific contribution. To the best of our knowledge, this is the first report of a LAMP assay targeting the inlA gene of L. monocytogenes. The developed single-tube LAMP assay is well-suited for integration with microfluidic systems.

Bee pollen is a nutrient-rich bee product and natural food supplement that contains proteins, vitamins, minerals and bioactive compounds, offering antioxidant, anti-inflammatory, immunostimulatory and antimicrobial activity. Numerous studies have confirmed the in vitro antimicrobial activity of both polyfloral and monofloral bee pollen. Monofloral bee pollen had a more stable chemical composition and more consistent sensory and biochemical properties, making it more suitable for various applications. This has led to a growing number of studies investigating its antimicrobial potential. Antimicrobial activity of bee pollen is influenced by natural factors such as the botanical and geographical origin, seasonal variation and beekeeping practices. The outcomes of in vitro testing also depend on choices related to extract preparation, solvent type, microbial strains and the method employed to measure antimicrobial activity. Another challenge is the limited bioavailability of bioactive compounds, restricted by the degradation-resistant outer layer of bee pollen, named the exine. The wall can be partially disrupted through processing methods that break it and enhance its nutritional and functional properties. This review provides a comprehensive overview of published studies on the antimicrobial activity of monofloral bee pollen. It summarizes the most frequently investigated botanical species and bacterial strains, highlighting those with the most promising antimicrobial results. Additionally, it examines the processing methods of pollen, comparing their effectiveness and the changes in antimicrobial activity before and after processing. The review identifies the plant species, solvents and methods that yield strong antimicrobial activity, emphasizing their potential in the broader effort to standardize high quality parameters for bee pollen.

Research background. Glycosyltransferases represent a large and diverse family of enzymes that catalyze the transfer of sugar residues to proteins and lipids, thereby regulating essential cellular processes such as protein quality control and cell wall biosynthesis. In yeast, protein O-mannosyltransferases and other glycosyltransferases are crucial for maintaining cell wall integrity. While the functions of many of these enzymes are well characterized, the role of some of them, such as Gmh5p, remains unknown. This study aims to elucidate the function of Gmh5p, a previously uncharacterized member of the GT34 glycosyltransferase family, in the context of protein and cell wall biosynthesis in Schizosaccharomyces pombe. Experimental approach. To identify proteins and pathways compensating for reduced O-mannosylation, we performed a genetic screening for multi-copy suppressors in a conditional lethal nmt81-oma2+ mutant background. The enzymatic activity of Gmh5p was biochemically characterized, and its functional homology to known mannosyltransferases was assessed through complementation experiments in Saccharomyces cerevisiae. In addition, the N-glycosylation status of model substrates was analyzed in gmh5Δ mutant strains. Results and conclusions. Gmh5p was identified as a suppressor of O-mannosylation defects. Contrary to its predicted function, Gmh5p did not exhibit α-1,2-galactosyltransferase activity but instead showed mannosyltransferase activity. Expression of gmh5+ in S. cerevisiae mnn10 mutants restored hygromycin tolerance to near wild-type levels. Furthermore, N-glycosylation of model substrates was reduced in gmh5Δ mutants. These results demonstrate that Gmh5p is a mannosyltransferase involved in the outer chain elongation of N-linked glycans and functions as a homologue of Mnn10p. Novelty and scientific contribution. This study provides the first functional characterization of Gmh5p as a mannosyltransferase of the GT34 family and demonstrates its role in N-glycan biosynthesis. Our findings expand the current understanding of the diversity and specificity of glycosyltransferases in eukaryotes and highlight their importance in cell wall biology.

Research background. Artichoke leaves, an important waste product of the food industry, have an important antioxidant and antimicrobial capacity. Although there are several studies in the literature to determine their antioxidant and antimicrobial activity, a comparison of green extraction technologies including microwave, ultrasound probe and ultrasound bath methods in relation to the maceration technique has not been performed. Also, several parameters such as the extraction temperature, power, extraction mode and extraction time are important parameters for obtaining targeted compounds in the highest amount. For this reason, we aimed to compare various extraction methods including microwave-assisted extraction, ultrasound-assisted extraction with probe, ultrasound-assisted extraction in a water bath and maceration in terms of extraction parameters for obtaining bioactive compounds from artichoke leaves. Experimental approach. Microwave-assisted extraction at two different power values, ultrasound-assisted extraction with probe in continuous or pulsed mode with two different extraction times each, ultrasound-assisted extraction in a water bath at two different power values with two different extraction times each and maceration with two different times were used for the extraction. The extraction temperature is an important parameter affecting the thermal degradation of bioactive compounds. We used a constant extraction temperature of 50 °C. Total phenolic and total flavonoid content, antioxidant capacity, phenolic compound profile analysis by LC-QTOF-MS and antimicrobial activity by agar diffusion and broth microdilution methods were determined. Results and conclusions. The bioactive compounds were found to be significantly affected by the parameters used in each extraction method. The microwave-assisted extraction method was more efficient than the other extraction methods at both power values. This method also required the shortest extraction time. The ultrasound-assisted probe extraction method was the second most efficient method. The type of process, continuous or pulsed, did not affect the results, but shortening the extraction time led to lower results. A longer extraction time of the ultrasound-assisted extraction in a water bath method led to better results, similar to the ultrasound-assisted probe extraction, regardless of the used power. The extracts were highly effective against many opportunistic and pathogenic microorganisms. Novelty and scientific contribution. This study provides valuable insights into the extraction parameters of different extraction methods to obtain bioactive compounds from artichoke leaves, which could have potential applications in the food and pharmaceutical industries.