Robert Rusinek

This study examined the effect of particle size, moisture content, mixing, and consolidation time on the flow and mechanical behaviour of bulk rice assessed using a Schulze Ring Shear Tester RST-01. Three rice fractions: 0.5–1.0 mm, >1.0 mm, and whole grains were tested at 8% and 20% moisture. Fine particles showed high flowability in dry conditions but exhibited a strong increase in cohesion and a significant drop in the flow function coefficient at the higher moisture content. Unexpectedly, whole grains showed the highest shear resistance after moistening and consolidation, which can be attributed to force chain formation and localized capillary bonding. Extended mixing and consolidation further stabilized the structure and reduced flowability. These findings indicate that larger particles can exhibit greater mechanical stability in moist conditions. The results emphasize the need to consider particle size and preparation history in the handling and storage of bulk materials.

The paper presents an analysis of the content of caffeine, tocopherols, and phenolic compounds as well as the volatile compound profile and volatile compound emission intensity in relation to the cultivation parameters of the Typica variety of Arabica coffee from Peru, Costa Rica, Guatemala, and Ethiopia. The study provides a detailed description of the cultivation and post-harvest parameters of the coffee types selected for the analyses. Special emphasis was placed on the analysis of the plantation altitude effect on instrumentally determined aromatic parameters and bioactive properties. The analyses were performed with the use of high-performance liquid chromatography, gas chromatography, and an electronic nose. The investigation results indicate a significant effect of the altitude of coffee cultivation on the most important biological and chemical properties of coffee beans, e.g. caffeine content, phenolic content, intensity of volatile compound emission, and coffee aroma. Other factors, such as shading and post-harvest processing, were also found to interact with the cultivation altitude and influence the content of these coffee attributes.

Flower petals, as byproducts, provide significant health benefits and can be used in food production. In this study, the impact of the micronization process using a ball mill on the properties of micronized powders derived from wild rose petals of the rugosa variety (Rosa rugosa Thunb.) was examined. The micronized rose powders were subjected to an investigation regarding their particle size, color, molecular characterization (FTIR), electronic nose procedure and antioxidant potential. The study found that micronization considerably reduced d50 particle dimensions from 98.6 µm to 39.9 µm. An FTIR analysis revealed the presence of characteristic (2980, 1340, and 1225 cm⁻¹) bands. The hydrolysable tannins are the most abundant polyphenolic chemicals in rose powders, followed by anthocyanins. Rose powders are an extremely valuable antioxidant raw material due to their high total phenol content (71.8 mg GAE/g), which increased by approximately 26% after micronization. The antioxidant activity, as determined by ABTS^•+, DPPH^• and FRAP, is likewise very high. The intensity of volatile chemicals decreased in powders after micronization.

This study was focused on the analysis of the emission of volatile compounds as an indicator of changes in the quality degradation of corn groats with 14% and 17% moisture content (wet basis) using an electronic nose (Agrinose) at changing vertical pressure values. The corn groats were used in this study in an unconsolidated state of 0 kPa (the upper free layer of bulk material in the silo) and under a consolidation pressure of 40 kPa (approximately 3 m from the upper layer towards the bottom of the silo) and 80 kPa (approximately 6 m from the upper layer towards the bottom of the silo). The consolidation pressures corresponded to the vertical pressures acting on the layers of the bulk material bed in medium-slender and low silos. Chromatographic determinations of volatile organic compounds were performed as reference tests. The investigations confirmed the correlation of the electronic nose response with the quality degradation of the groats as a function of storage time. An important conclusion supported by the research results is that, based on the determined levels of intensity of volatile compound emission, the electronic nose is able to distinguish the individual layers of the bulk material bed undergoing different degrees of quality degradation.

In the present study, three degrees of roasting (light, medium, and dark), which significantly differentiate the properties of coffee beans, were analyzed. Additionally, the effect of the roasting level on the profile of volatile and biologically active compounds, including chlorogenic acids,...

Satisfying the water needs of the maize crop in central-eastern Poland was assessed in the years 2001-2021 using meteorological data obtained from seven Institute of Meteorology and Water Management – National Research Institute (IMGW-PIB) stations located at Białowieża, Legionowo, Pułtusk,...

Modern machine learning methods were used to automate and improve the determination of an effective quality index for coffee beans. Machine learning algorithms can effectively recognize various anomalies, among others factors, occurring in a food product. The procedure for preparing the machine learning algorithm depends on the correct preparation and preprocessing of the learning set. The set contained coded information (i.e., selected quality coefficients) based on digital photos (input data) and a specific class of coffee bean (output data). Because of training and data tuning, an adequate convolutional neural network (CNN) was obtained, which was characterized by a high recognition rate of these coffee beans at the level of 0.81 for the test set. Statistical analysis was performed on the color data in the RGB color space model, which made it possible to accurately distinguish three distinct categories of coffee beans. However, using the Lab* color model, it became apparent that distinguishing between the quality categories of under-roasted and properly roasted coffee beans was a major challenge. Nevertheless, the Lab* model successfully distinguished the category of over-roasted coffee beans.

The aim of this study was to determine the emission of organic volatile compounds from maize grain as a function of granularity and packing density of bulk material in conditions imitating processes occurring in silos. The study was carried out with the use of a gas chromatograph and an electronic nose, which was designed and constructed at the Institute of Agrophysics of PAS and has a matrix of eight MOS (metal oxide semiconductor) sensors. A 20-L volume of maize grain was consolidated in the INSTRON testing machine with pressures of 40 and 80 kPa. The control samples were not compacted, and the maize bed had bulk density. The analyses were carried out at a moisture content of 14% and 17% (w.b.—wet basis). The measurement system facilitated quantitative and qualitative analyses of volatile organic compounds and the intensity of their emission during 30-day storage. The study determined the profile of volatile compounds as a function of storage time and the grain bed consolidation level. The research results indicated the degree of grain degradation induced by the storage time. The highest emission of volatile compounds was recorded on the first four days, which indicated a dynamic nature of maize quality degradation. This was confirmed by the measurements performed with electrochemical sensors. In turn, the intensity of the volatile compound emission decreased in the next stage of the experiments, which showed a decline in the quality degradation dynamics. The sensor responses to the emission intensity decreased significantly at this stage. The electronic nose data on the emission of VOCs (volatile organic compounds) as well as grain moisture and bulk volume can be helpful for the determination of the quality of stored material and its suitability for consumption.

Polyphenols have attracted tremendous attention due to their pro-health properties, including their antioxidant, anti-inflammatory, antibacterial and neuroprotective activities. Atherosclerosis is a vascular disorder underlying several CVDs. One of the main risk factors causing atherosclerosis is the type and quality of food consumed. Therefore, polyphenols represent promising agents in the prevention and treatment of atherosclerosis, as demonstrated by in vitro, animal, preclinical and clinical studies. However, most polyphenols cannot be absorbed directly by the small intestine. Gut microbiota play a crucial role in converting dietary polyphenols into absorbable bioactive substances. An increasing understanding of the field has confirmed that specific GM taxa strains mediate the gut microbiota–atherosclerosis axis. The present study explores the anti-atherosclerotic properties and associated underlying mechanisms of polyphenols. Moreover, it provides a basis for better understanding the relationship between dietary polyphenols, gut microbiota, and cardiovascular benefits.

Due to a widespread occurrence of multidrug-resistant pathogenic strains of bacteria, there is an urgent need to look for antimicrobial substances, and honey with its antimicrobial properties is a very promising substance. In this study, we examined for the first time antimicrobial properties of novel varietal honeys, i.e., plum, rapeseed, Lime, Phacelia, honeydew, sunflower, willow, and multifloral-P (Prunus spinosa L.), multifloral-AP (Acer negundo L., Prunus spinosa L.), multifloral-Sa (Salix sp.), multifloral-Br (Brassica napus L.). Their antimicrobial activity was tested against bacteria (such as Escherichia coli, Bacillus circulans, Staphylococcus aureus, Pseudomonas aeruginosa), yeasts (such as Saccharomyces cerevisiae and Candida albicans) and mold fungi (such as Aspergillus niger). In tested honeys, phenolic acids constituted one of the most important groups of compounds with antimicrobial properties. Our study found phenolic acids to occur in greatest amount in honeydew honey (808.05 µg GAE/g), with the highest antifungal activity aiming at A. niger. It was caffeic acid that was discovered in the greatest amount (in comparison with all phenolic acids tested). It was found in the highest amount in such honeys as phacelia—356.72 µg/g, multifloral (MSa) and multifloral (MBr)—318.9 µg/g. The highest bactericidal activity against S. aureus was found in multifloral honeys MSa and MBr. Additionally, the highest amount of syringic acid and cinnamic acid was identified in rapeseed honey. Multifloral honey (MAP) showed the highest bactericidal activity against E. coli, and multifloral honey (MSa) against S. aureus. Additionally, multifloral honey (MBr) was effective against E. coli and S. aureus. Compounds in honeys, such as lysozyme-like and phenolic acids, i.e., coumaric, caffeic, cinnamic and syringic acids, played key roles in the health-benefit properties of honeys tested in our study.