Paulius Kaškonas

Bee pollen is a rich natural source of phenolic compounds and other bioactive constituents; however, the resistant pollen cell wall restricts the release of these compounds. This study investigated the effect of multi-stage bioprocessing involving bacterial fermentation, spontaneous fermentation, and enzymatic hydrolysis on the recovery of bioactive compounds from ten bee pollen collected from different regions of Lithuania. First-stage treatments included fermentation with Lactobacillus acidophilus, L. rhamnosus, L. reuteri, Bifidobacterium animalis, spontaneous fermentation, or enzymatic hydrolysis using Viscozyme^® L, cellulase, or Clara-diastase. Second-stage bioprocessing combined the initial treatment with either bacterial fermentation or enzymatic hydrolysis. Total phenolic content (TPC), total flavonoid content (TFC), radical scavenging activity (RSA), and inhibition of heat-induced bovine serum albumin (BSA) denaturation (BSA-DI) were determined using spectrophotometric assays. Statistical analysis demonstrated that multi-stage bioprocessing significantly enhanced the chemical composition and bioactivity of bee pollen compared with single-stage treatments. The greatest improvements were achieved when enzymatic hydrolysis preceded bacterial fermentation, resulting in increases of up to 5.0-, 4.2-, 6.3-, and 5.3-fold in TPC, TFC, RSA, and BSA-DI activity, respectively. These findings suggest that combining enzymatic hydrolysis with bacterial fermentation may be a promising approach for improving the recovery of bioactive compounds and selected functional properties of bee pollen.

This report analyzes the different standard methods of quantity measurement, which, when applied in the processes of receiving and transferring fuel quantities, lead to discrepancies and accounting losses. Three main factors contribute to these discrepancies: unavoidable errors of measuring devices (calibration uncertainty ranging from 0.1 to 0.5% at best), systematic errors due to non-applied corrections during transactions, and systematic errors due to different regulations, which result in inconsistent conversion rules applied throughout the entire purchase-production-sales chain. Modeling of air buoyancy effects showed that neglecting buoyancy correction can lead to measurable and economically significant discrepancies, especially in large-scale operations. The mass of light petroleum products can be underestimated by up to 0.15%, potentially resulting in approximately $3 million in annual financial losses for a medium-sized refinery processing 10,000 tonnes per day. These findings underscore the necessity of applying buoyancy corrections for conventional weighing, especially for liquid petroleum products (LPP) measured in open systems. Conversely, for LPG weighed in closed, pressurized containers, a constant correction factor (0.99985) applies, but its economic impact is negligible. Therefore, the study recommends omitting this LPG correction unless contractually required, to streamline processes and reduce complexity. Achieving result comparability throughout the entire petroleum supply chain requires implementing uniform quantity calculation provisions using calibrated instruments and standardized methods under different conditions. This necessitates that all measurement results are traceable to reference conditions (mass in vacuum, volume at +15 °C). The proposed algorithms for oil mass and volume measurement and recalculation highlight the need for unified international regulations and a robust system.

Background/Objectives: A variety of phytochemicals from different plants are collected by bees into bee pollen granules. This research focused on evaluating the effects of lactic acid fermentation and enzymatic hydrolysis on the antibacterial activity of bee pollen and its interaction with antibiotics. There is limited knowledge regarding the interactions between treated bee pollen extracts and antibiotics, and this study contributes to the field by providing new insights into the antibacterial activity of pollen subjected to eight distinct treatment methods. Methods: Bee pollen’s bacterial fermentation using a Lacticaseibacillus rhamnosus culture and spontaneous fermentation were performed. Bee pollen hydrolysis was performed using commercial enzymes, including enzyme mixtures as well as pure enzymes. The agar well diffusion assay was employed to assess the antibacterial activity against Staphylococcus aureus, Listeria monocytogenes, and Salmonella enterica serovars Enteritidis and Typhimurium, as well as their interaction with antibiotics (ceftazidime, ciprofloxacin, oxytetracycline dihydrate, and erythromycin). Results: This study showed an enhancement in bee pollen’s antibacterial activity after both fermentation and enzymatic hydrolysis. The increase varied with the pollen’s origin, treatment type, and culture used for antimicrobial tests. More than 77% of bee pollen extracts demonstrated a synergistic effect with antibiotics across all tested bacterial strains, while antagonistic interactions were comparatively rare. Conclusions: The applied treatment methods can improve the antibacterial properties of bee pollen. Bee pollen extracts, in combination with antibiotics, can enhance their effectiveness. These findings provide new insights into the potential use of bee pollen in combating bacterial infections.

Bee pollen is one of the most valuable apitherapeutic products with high nutritional value. To obtain a higher diversity of compounds, higher bioactivity, and improve the release of nutrients from bee pollen, additional processing of the raw material may be applied: fermentation using microorganisms or hydrolysis using selective enzymes. This research aimed to determine the impact of enzymatic hydrolysis on the antioxidant and antibacterial activities of bee pollen. Bee pollen samples from Sweden, Spain, Netherlands, Italy, Poland, Denmark, Slovakia, Malta, and Lithuania were hydrolyzed using pure enzymes, including lipase, cellulase, protease, and amyloglucosidase, as well as enzyme mixtures such as Viscozyme^® L and Clara-diastase. Total phenolic content, total flavonoid content, and antioxidant activity were analyzed spectrophotometrically. Antibacterial activity against Staphylococcus aureus, Listeria monocytogenes, Staphylococcus enteritidis, and Salmonella typhimurium was evaluated using the agar well diffusion assay. Obtained results revealed a positive effect of enzymatic hydrolysis on biologically active compound content and activity: total phenolic content increased by 1.1 to 2.5 times, total flavonoid content by 1.1 to 3.0 times, radical scavenging activity by 1.1–3.5 times, and antibacterial activity by 1.1 to 3.3 times. K-means clustering analysis grouped samples into 5–9 clusters and was dependent on the measured characteristic used as an input—total phenolic compounds content, total flavonoid content, antioxidant activity, and antibacterial activity against four different bacteria. Chemometrics showed, that the enzyme used for the hydrolysis had a higher impact on clustering results than the geographical origin of the samples.

Reliable quantity measurements are essential to meet the needs of the public interest, health, environmental protection, and the global fair trade of petroleum products. This can only be ensured by accurate and regular calibration of the measuring instruments. The frequency of metrological supervision is differently legally regulated in different countries since there are no clear criteria for determining periodicity. This report presents an analysis of the metrological supervision of vertical and aboveground tanks (intended for oil products) in different countries and long-term data usage for supervision periodicity identification. The periodicity of metrological supervision procedures must be synchronised with technical repairs and must depend on the type and volume of the tank. Choosing the optimal periodicity frequency of different tanks can adjust the economic burden of metrological supervision considering the economic and environmental aspects that is presented in the report with suitable adaptations.

Tanks, as instruments in oil and its product’s amount measurement system chain, must be regularly maintained and metrologically inspected, as they significantly contribute to measurement uncertainty. However, when measuring a change in the amount of stored material (i.e., transfer), the measurement uncertainty becomes highly dependent not only on the mass of the transaction but also on the initial liquid level in the tank. This paper provides modeling of the uncertainties of the measuring system, which involves tanks, oil, and its product loading/unloading processes. It is shown that the accuracy of volume/mass measurement depends not only on the tank calibration table but also on the accuracy of other measuring instruments used and on the level of the liquid at the moment of measurement. The relative uncertainty of the measurement of the change in product mass depends linearly on the tank fill level present at the time of the transaction but nonlinearly on the transaction mass quantity.

Bee-collected pollen is one of the most valuable natural products. However, the pollen cell walls limit the digestibility and release of nutrients to the human body. Solid-state lactic acid fermentation can be used to ease the release of bioactive compounds from the pollen cell. The aim of this research was to determine the impact of a solid-state lactic acid fermentation process on biologically active compound composition and antioxidant activity of bee-collected pollen from various European regions (Italy, Netherlands, Lithuania, Poland, Sweden, Denmark, Malta, Slovakia, and Spain). Spontaneous fermentation and fermentation using an L. rhamnosus culture were performed. The total content of phenolic compounds, total content of flavonoids, and radical (DPPH) scavenging activity were measured by spectrophotometric tests, while UPLC was employed for quantification of phenolic compounds. The determined fermentation positive effects included an increase of total phenolic content by 1.4–2.3 times, total flavonoid content by 1.1–1.6 times, and radical scavenging activity by 1.4–2.3 times. Naringenin (21.09–135.03 µg/g), quercetin (6.62–78.86 µg/g), luteolin (29.41–88.90 µg/g), and rutin (21.40–89.93 µg/g) were the most abundant flavonoids in all samples; however, their variation level was both geographical in origin and fermentation-type dependent. Fermentation increased the content of phenolic acids with high antioxidant potentials such as ellagic, ferulic and caffeic, while reduction of chlorogenic acid was determined.

The aim of the study was to evaluate 11 cultivars of blue honeysuckle (Lonicera caerulea L.) for bioactive compounds, antioxidant capacity, and the antibacterial activity of berries. Total phenolic contents (TPCs) and total anthocyanin contents (TACs) were established by using ethanolic extracts. For contents of organic acids and saccharides, aqueous extracts were used, and vitamin C was determined by using oxalic acid solution. DPPH^• radical scavenging capacity was evaluated by using ethanolic extracts; antibacterial activity was assessed by using both ethanolic and aqueous extracts. The TPC varied from 364.02 ± 0.41 mg/100 g in ‘Vostorg’ to 784.5 ± 0.3 mg/100 g in ‘Obilnaja’, and TAC ranged from 277.8 ± 1.1 mg/100 g in ‘Čelnočnaja’ to 394.1 ± 8.4 mg/100 g in ‘Nimfa’. Anthocyanins comprised 53.8% of total phenolic contents on average. Among organic acids, citric acid was predominant, averaging 769.41 ± 5.34 mg/100 g, with malic and quinic acids amounting to 289.90 ± 2.64 and 45.00 ± 0.37 mg/100 g on average, respectively. Contents of vitamin C were 34.26 ± 0.25 mg/100 g on average. Organic acids were most effective in the inhibition of both Gram-positive and Gram-negative bacteria tested. In conclusion, berries of L. caerulea are beneficial not only for fresh consumption, but also as a raw material or ingredients of foods with high health-promoting value.