HS-SPME Analysis of True Lavender (Lavandula angustifolia Mill.) Leaves Treated by Various Drying Methods

LaMYC7, a positive regulator of linalool and caryophyllene biosynthesis, confers plant resistance to Pseudomonas syringae

Linalool and caryophyllene are the main monoterpene and sesquiterpene compounds in lavender; however, the genes regulating their biosynthesis still remain many unknowns. Here, we identified LaMYC7, a positive regulator of linalool and caryophyllene biosynthesis, confers plant resistance to Pseudomonas syringae. LaMYC7 was highly expressed in glandular trichomes, and LaMYC7 overexpression could significantly increase the linalool and caryophyllene contents and reduce susceptibility to P. syringae in Nicotiana. In addition, the linalool possessed antimicrobial activity against P. syringae growth and acted dose-dependently. Further analysis demonstrated that LaMYC7 directly bound to the promoter region of LaTPS76, which encodes the terpene synthase (TPS) for caryophyllene biosynthesis, and that LaTPS76 was highly expressed in glandular trichomes. Notably, the LaMYC7 promoter contained hormone and stress-responsive regulatory elements and responded to various treatments, including ultraviolet, low temperature, salt, drought, methyl jasmonate, and P. syringae infection treatments. Under these treatments, the changes in the linalool and caryophyllene contents were similar to those in LaMYC7 transcript abundance. Based on the results, LaMYC7 could respond to P. syringae infection in addition to being involved in linalool and caryophyllene biosynthesis. Thus, the MYC transcription factor gene LaMYC7 can be used in the breeding of high-yielding linalool and caryophyllene lavender varieties with pathogen resistance.

Edible Herbal Medicines as an Alternative to Common Medication for Sleep Disorders: A Review Article

Insomnia is repeated difficulty in falling asleep, maintaining sleep, or experiencing lowquality sleep, resulting in some form of daytime disturbance. Sleeping disorders cause daytime fatigue, mental confusion, and over-sensitivity due to insufficient recovery from a sound sleep. There are some drugs, such as benzodiazepines and anti-histaminic agents, which help to sleep induction and insomnia cure. However, the prolonged administration is unsuitable because of tolerance and dependence. Therefore, the researchers attempt to find new medicines with lesser adverse effects. Natural products have always been good sources for developing new therapeutics for managing diseases such as cancer, cardiovascular disease, diabetes, insomnia, and liver and renal problems. Ample research has justified the acceptable reason and relevance of the use of these herbs in the treatment of insomnia. It is worth noting that in this study, we looked into various Persian herbs in a clinical trial and in vivo to treat insomnia, such as Artemisia annua, Salvia reuterana, Viola tricolor, Passiflora incarnata, lettuce, and Capparis spinose. According to research, herb extracts and fractions, particularly n-butanol fractions with non-polar agents, impact the benzodiazepine receptors and have hypnotic properties. Also, alkaloids, glycosides, flavonoids, saponins, and tannins in practically every plant are mentioned making them the popular natural compounds to help with sleep disorders and promote calmness.

Effective Improvement of the Oxidative Stability of Acer truncatum Bunge Seed Oil, a New Woody Oil Food Resource, by Rosemary Extract

Acer truncatum Bunge is a versatile, oil-producing, woody tree natively and widely distributed in northern China. In 2011, The People’s Republic of China’s Ministry of Health certified Acer truncatum seed oil (Aoil) as a new food resource. Unsaturated fatty acids account for up to 92% of the entire Aoil. When Aoil is processed or stored, it can easily oxidize. In this study, the effects of rosemary (Rosmarinus officinalis L.) extract on the oxidation stability of Aoil were analysed from multiple angles. The results of radical scavenging ability, malondialdehyde, and free fatty acid reveal that rosemary crude extract (RCE), rosmarinic acid (RA), and carnosic acid (CA) can significantly inhibit the oxidation of Aoil, and CA has the best oxidative stability for Aoil among the tested components of the crude rosemary. The delayed oxidation ability of CA for Aoil was slightly weaker than that of tert-butylhydroquinone (TBHQ), but stronger than that of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and α-tocopherol (α-T), which was confirmed by microstructures, kinematic viscosity, Aoil weight change, and functional group. Additionally, CA-enriched Aoil had the smallest content of volatile lipid oxidation products. Moreover, lecithin-CA particles were added to enhance the oxidative stability of Aoil. These findings show that CA is a potent antioxidant, capable of successfully preventing Aoil oxidation.

Determination of Polycyclic Aromatic Hydrocarbon Content in Garden Herbal Plants Using Liquid Chromatographic Analysis (HPLC-FL)

Polycyclic aromatic hydrocarbons (PAHs) are a group of chemical compounds generated as a result of the incomplete combustion of fossil fuels or wood. PAHs are known for their negative effect on living organisms, including teratogenic, carcinogenic and mutagenic activity. The objective of this study is to determine the contamination of three popular herbal species showing pro-health properties, i.e., lavender, parsley and mint, with polycyclic aromatic hydrocarbons, collected from three different backyard gardens in Poland. The concentration of PAHs in plant material was determined by high-performance liquid chromatography with a fluorescence detector (HPLC-FL). The concentration of eleven PAHs in plant material was determined with high-pressure liquid chromatography after extraction using the QuEChERS purification technique. Mint collected within an area of a mining and energy production complex (the city of Konin) was characterized by the highest Σ of 11 PAHs, equaled to 902.35 µg/g FW, with anthracene being the most abundant compound. However, it contained the lowest sum of PAHs, among all tested plants, with high carcinogenicity. Parsley from the city of Poznań showed the highest content of benzo[a]pyrene (BaP), showing the strongest carcinogenicity, while the highest value of BaP equivalent was calculated for mint collected in Konin. The obtained results suggest that the level and profile of plant contamination with PAHs depend on the species and the location of herb cultivation. In particular, mining and energy industry facilities are sources of PAHs, which contaminate plant material for further direct use or as bioactive herbal extracts.

The Effect of Nonthermal Pretreatment on the Drying Kinetics and Quality of Black Garlic

Black garlic is obtained from regular garlic (Allium sativum L.) through the aging process and consequently gains many health-promoting properties, including antidiabetic and antioxidant. However, the material is still prone to microbiological deterioration and requires a long time to dry due to its properties. Therefore, this study aimed to investigate the effect of various drying methods on the quality of black garlic as well as determine the influence of selected nonthermal pretreatments on the drying kinetics and quality of black garlic, which is especially important in the case of the materials that are difficult to dry. The Weibull model was chosen to describe drying kinetics. Additionally, color, water activity together with antioxidant activity, phenolic compounds, and antidiabetic potential were determined. This study found that the application of a pulsed electric field (PEF), a constant electric field (CEF) as well as a magnetic field (MF) significantly reduced the time of drying (by 32, 40, and 24 min for a PEF, a CEF, and a MF, respectively, compared to combined drying without the pretreatment), and resulted in high antidiabetic potential. However, the highest content of phenolic compounds (1123.54 and 1125.36 mg/100 g dm for VMD125 and CD3h-VMD, respectively) and antioxidant capacity (ABTS = 6.05 and 5.06 mmol Trolox/100 g dm for VMD500 and CD6h-VMD, respectively) were reported for black garlic treated by vacuum-microwave drying and combined convective pre-drying followed by vacuum-microwave drying. Overall, the nonthermal pretreatment decreased the time of drying and showed very good efficiency in maintaining the antidiabetic potential of black garlic, especially in the case of the materials pretreated by a constant electric field (IC₅₀ = 99 and 56 mg/mL, for α-amylase and α-glucosidase, respectively).

Recent advances in essential oil complex coacervation by efficient physical field technology: A review of enhancing efficient and quality attributes

Although complex coacervation could improve the water solubility, thermal stability, bioavailability, antioxidant activity and antibacterial activity of essential oils (EOs). However, some wall materials (such as proteins and polysaccharides) with water solubility and hydrophobic nature limited their application in complex coacervation. In order to improve the properties of EO complex coacervates, some efficient physical field technology was proposed. This paper summarizes the application and functional properties of EOs in complex coacervates, formation and controlled-release mechanism, as well as functions of EO complex coacervates. In particular, efficient physical field technology as innovative technology, such as high pressure, ultrasound, cold plasma, pulsed electric fields, electrohydrodynamic atomization and microwave technology improved efficient and quality attributes of EO complex coacervates are reviewed. The physical fields could modify the gelling, structural, textural, emulsifying, rheological properties, solubility of wall material (proteins and polysaccharides), which improve the properties of EO complex coacervates. Overall, EOs complex coacervates possess great potential to be used in the food industry, including high bioavailability, excellent antioxidant capacity and gut microbiota in vivo, masking the sensation of off-taste or flavor, favorable antimicrobial capacity.

Chemical investigation on Salvia officinalis L. Affected by multiple drying techniques - The comprehensive analytical approach (HS-SPME, GC-MS, LC-MS/MS, GC-O and NMR)

In light of large scale production of Salvia officinalis L. and its complex storage and delivery chain, the efficient preservation process is required. At this moment, the most popular preservation method is drying, therefore a comprehensive experiment to evaluate the influence of multiple drying techniques on sage was conducted. Convective drying at 40, 50 and 60 °C, vacuum-microwave drying with powers 240, 360 and 480 W and combined drying consisting of convective pre-drying at 50 °C followed by vacuum-microwave finish-drying with power 360 W were applied. To evaluate the effect of particular procedures chemical analyses were performed, namely evaluation of changes in bioactive volatile constituents, odour-active compounds and various groups of non-volatile bioactive constituents of sage. The obtained results shown, that to receive the product with expected quality, it is necessary to identify the designation of the product before treatment, since particular groups of phytochemicals react differently during drying.

The transcription factor LaMYC4 from lavender regulates volatile Terpenoid biosynthesis

BACKGROUND

The basic helix-loop-helix (bHLH) transcription factors (TFs), as one of the largest families of TFs, are essential regulators of plant terpenoid biosynthesis and response to stresses. Lavender has more than 75 volatile terpenoids, yet few TFs have been identified to be involved in the terpenoid biosynthesis.

RESULTS

Based on RNA-Seq, reverse transcription-quantitative polymerase chain reaction, and transgenic technology, this study characterized the stress-responsive transcription factor LaMYC4 regulates terpenoid biosynthesis. Methyl jasmonate (MeJA) treatment increased volatile terpenoid emission, and the differentially expressed gene LaMYC4 was isolated. LaMYC4 expression level was higher in leaf than in other tissues. The expression of LaMYC4 decreased during flower development. The promoter of LaMYC4 contained hormone and stress-responsive regulatory elements and was responsive to various treatments, including UV, MeJA treatment, drought, low temperature, Pseudomonas syringae infection, and NaCl treatment. LaMYC4 overexpression increased the levels of sesquiterpenoids, including caryophyllenes, in Arabidopsis and tobacco plants. Furthermore, the expression of crucial node genes involved in terpenoid biosynthesis and glandular trichome number and size increased in transgenic tobacco.

CONCLUSIONS

We have shown that the stress-responsive MYC TF LaMYC4 from 'Jingxun 2' lavender regulates volatile terpenoid synthesis. This study is the first to describe the cloning of LaMYC4, and the results help understand the role of LaMYC4 in terpenoid biosynthesis.

Evaluation of New, Sputtered Carbon SPME Fibers with a Multi-Functional Group Test Mixture

We report the first fabrication of sputtered carbon, solid-phase microextraction (SPME) fibers. These fibers have competitive extraction capabilities compared with the commercial carbon wide range (CWR) SPME fiber. This report also includes a demonstration of a newly developed SPME test mix that includes 15 different compounds with a wide range of functional groups and chemical properties. The fiber fabrication process involves sputtering carbon onto fused silica fibers, and the effects of throw distance on the morphology of the carbon coatings were studied. Four different carbon coating thicknesses were evaluated, with PDMS added as a stationary phase. These fibers were characterized with multiple analytical techniques, including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), water contact angle (WCA) goniometry, as well as headspace (HS) and direct immersion (DI)–SPME–GC–MS. The best (11.5 µm) sputtered carbon SPME fibers, with and without PDMS, were evaluated using the new evaluation mix and compared with the commercial CWR fiber and a previously sputtered/developed silicon fiber. The new probe mix helped elucidate differences among the fibers, which would have been missed by current commercial test mixes. The sputtered carbon SPME fibers showed similar functional group selectivity as commercial CWR fibers. However, the sputtered carbon fibers showed higher responses per volume compared with the commercial CWR fiber, indicating the porous morphology of the sputtered carbon has the ability to overcome large phase thickness/volume discrepancies and increase the relative recovery for various compounds.

The methyl jasmonate-responsive transcription factor DobHLH4 promotes DoTPS10, which is involved in linalool biosynthesis in Dendrobium officinale during floral development

Linalool is an aromatic monoterpene produced in the Chinese medicinal plant Dendrobium officinale, but little information is available on the regulation of linalool biosynthesis. Here, a novel basic helix-loop-helix (bHLH) transcription factor, DobHLH4 from D. officinale, was identified and functionally characterized. The expression profile of DobHLH4 was positively correlated with that of DoTPS10 (R² = 0.985, p < 0.01), which encodes linalool synthase that is responsible for linalool production, during floral development. DobHLH4 was highly expressed in petals, and was significantly induced by methyl jasmonate. Analysis of subcellular localization showed that DobHLH4 was located in the nucleus. Yeast one-hybrid and dual-luciferase assays indicated that DobHLH4 bound directly to the DoTPS10 promoter harboring the G-box element, and up-regulated DoTPS10 expression. A yeast two-hybrid screen confirmed that DobHLH4 physically interacted with DoJAZ1, suggesting that DobHLH4 might function in the jasmonic acid-mediated accumulation of linalool. Furthermore, transient overexpression of DobHLH4 in D. officinale petals significantly increased linalool production by triggering linalool biosynthetic pathway genes, especially DoTPS10. We suggest a hypothetical model that depicts how jasmonic acid signaling may regulate DoTPS10 by interacting with DobHLH4 and DoJAZ1. In doing so, the formation of linalool is controlled. Our results indicate that DobHLH4 is a positive regulator of linalool biosynthesis and may be a promising target for in vitro-based metabolic engineering to produce linalool.

Effect of Filtrated Osmotic Solution Based on Concentrated Chokeberry Juice and Mint Extract on the Drying Kinetics, Energy Consumption and Physicochemical Properties of Dried Apples

BACKGROUND

Filtration of osmotic solution affects selective penetration during osmotic dehydration (OD), and after drying is finished, this can influence the chemical composition of the material, which is also modified by OD.

METHODS

Osmotic dehydration was carried out in filtrated and non-filtrated concentrated chokeberry juice with the addition of mint infusion. Then, this underwent convective drying, vacuum-microwave drying and combined convective pre-drying, followed by vacuum-microwave finishing drying. Drying kinetics were presented and mathematical models were selected. The specific energy consumption for each drying method was calculated and the energy efficiency was determined.

RESULTS AND DISCUSSION

The study revealed that filtration of osmotic solution did not have significant effect on drying kinetics; however, it affected selective penetration during OD. The highest specific energy consumption was obtained for the samples treated by convective drying (CD) (around 170 kJ·g-1 fresh weight (fw)) and the lowest for the samples treated by vacuum-microwave drying (VMD) (around 30 kJ·g-1 fw), which is due to the differences in the time of drying and when these methods are applied.

CONCLUSIONS

Filtration of the osmotic solution can be used to obtain the desired material after drying and the VMD method is the most appropriate considering both phenolic acid content and the energy aspect of drying.

Sensory and Chemical Characteristic of Two Insect Species: Tenebrio molitor and Zophobas morio Larvae Affected by Roasting Processes

The volatile compounds from insects (Tenebrio molitor and Zophobas morio larvae) roasted at 160, 180, or 200 °C and fed with potato starch or blue corn flour were isolated by solid-phase microextraction (SPME), and identified by gas chromatography–mass spectrometry (GC-MS). In the tested material, 48 volatile compounds were determined. Among them, eight are pyrazines, aroma compounds that are formed in food products during thermal processing due to the Maillard reaction. Eleven of the identified compounds influenced the roast, bread, fat, and burnt aromas that are characteristic for traditional baked dishes (meat, potatoes, bread). Most of them are carbonyl compounds and pyrazines. To confirm the contribution of the most important odorants identified, their odor potential activity values (OAVs) and %OAV were calculated. The highest value was noted for isobuthylpyrazine, responsible for roast aroma (%OAV > 90% for samples roasted at lower temperatures), and 2,5-dimethylpyrazine, responsible for burnt aroma (%OAV > 20% for samples roasted at the highest temperature). According to the study, the type of feed did not significantly affect the results of the sensory analysis of roasted insects. The decisive influence was the roasting temperature. The highest scores were achieved for Tenebrio molitor larvae heat-treated at 160 °C.

Sarracenia alata (Alph.Wood) Alph.Wood Microcuttings as a Source of Volatiles Potentially Responsible for Insects' Respond

Rare carnivorous plants representing the genus Sarracenia are perceived as very interesting to scientists involved in various fields of botany, ethnobotany, entomology, phytochemistry and others. Such high interest is caused mainly by the unique capacity of Sarracenia spp. to attract insects. Therefore, an attempt to develop a protocol for micropropagation of the Sarracenia alata (Alph.Wood) Alph.Wood, commonly named yellow trumpets, and to identify the specific chemical composition of volatile compounds of this plant in vitro and ex vivo was undertaken. Thus, the chemical volatile compounds excreted by the studied plant to attract insects were recognized with the application of the headspace solid-phase microextraction (HS-SPME) coupled with the GC-MS technique. As the major volatile compounds (Z)-3-hexen-1-ol (16.48% ± 0.31), (E)-3-hexen-1-ol acetate (19.99% ± 0.01) and β-caryophyllene (11.30% ± 0.27) were identified. Further, both the chemical assumed to be responsible for attracting insects, i.e., pyridine (3.10% ± 0.07), and whole plants were used in in vivo bioassays with two insect species, namely Drosophila hydei and Acyrthosiphon pisum. The obtained results bring a new perspective on the possibilities of cultivating rare carnivorous plants in vitro since they are regarded as a valuable source of bioactive volatile compounds, as including ones with repellent or attractant activity.

Coriandrum sativum L.-Effect of Multiple Drying Techniques on Volatile and Sensory Profile

Coriandrum sativum L. is a medicinal and aromatic plant spread around the world, with beneficial properties that are well recognized. Both coriander seeds and leaves are used for pharmaceutical and flavoring purposes. Even though coriander seeds tend to be more popular, the leaves are receiving a consistently growing interest, especially because of popularization of Mexican, Northern African, and Indian cuisines. This increased attention brings about the necessity for providing the product with guaranteed quality, which will retain its valuable characteristics, even after post-harvest treatment. For this reason, it is highly necessary to determine reliable protocols for cilantro preservation, which usually include drying procedures; in order to identify the optimal drying treatments, a spectrum of drying techniques-convective, vacuum-microwave, and a combination of convective and vacuum-microwave-were evaluated. Cilantro-based dried products were examined from the perspectives of volatile organic constituent composition and sensory quality. After headspace solid-phase microextraction-GC/MS analysis and sensory tests, the results demonstrate that convective drying at 70 °C for 120 min followed by vacuum-microwave drying at 360 W and convective drying at 70 °C were the optimal drying methods for preserving cilantro aroma quality, while convective drying at 70 °C for 120 min followed by convective finishing drying at 50 °C decreased cilantro aroma quality.

Volatile Composition and Sensory Properties as Quality Attributes of Fresh and Dried Hemp Flowers (Cannabis sativa L.)

Flowers of hemp (Cannabis sativa L.) are widely used in cosmetics, food, and in the pharmaceutical industry. The drying process plays a key role in retention of aroma and also in the quality of products. Seven variants of hemp flower drying, including convection drying (CD), vacuum–microwave drying (VMD), and combined drying consisting of convective pre-drying followed by vacuum–microwave finishing drying (CPD-VMFD) were checked in this study. For each process, we applied the two-term model. Dried material was submitted to color and chromatographical assessments. Analyses of obtained essential oil showed the presence of 93 volatile compounds, predominantly β-myrcene, limonene, and β-(E)-caryophyllene, as well as α-humulene. Application of 240 W during VMD and 50 °C during CD gave the highest retention of aroma compounds, amounting to 85 and 76%, respectively, but with huge color changes. Additionally, sensory analysis proved that drying with a microwave power of 240 W provides a product most similar to fresh material.

Volatile Compounds Content, Physicochemical Parameters, and Antioxidant Activity of Beers with Addition of Mango Fruit (Mangifera Indica)

This study was performed to determine the possibility of using mango fruit (Mangifera indica) in brewing technology. The aim of using the SPME-HS-GC-MS technique was to assess what changes occurred in the volatile composition of mango beers brewed in this study. Mango fruit was added to the beer in five different forms to ascertain what kind of preparation should be used to improve beer aroma. Analysis of the volatile components in mango beer showed that beer without mango addition was characterized by the lowest content of volatile compounds (1787.84 µg/100 mL). The addition of mango fruit increased the concentration of compounds, such as α-pinene, β-myrcene, terpinolene, α-terpineol, cis-β-ocimene, caryophyllene, and humulene, in beer. Beer prepared with mango pulp addition was characterized by the highest concentration of volatile components from mango beers (2112.15 µg/100 mL). Furthermore, beers with mango addition were characterized by a higher polyphenol content (up to 44% higher than control beer) and antioxidant activity than control beer and were evaluated by a trained panel as having a better taste and aroma than beer without fruit addition.

Mentha piperita L. Micropropagation and the Potential Influence of Plant Growth Regulators on Volatile Organic Compound Composition

Due to the industrial use of Mentha piperita L. (peppermint), it is important to develop an optimal method to obtain standardized plant material with specific quality parameters. In vitro cultures may allow the production of desirable odor-active compounds (OACs) and improve their share in the plant aroma profile. There are two types of explants that are commonly used, apical meristems and nodal segments. In this study, the best overall effects were shown to be produced by the combination of MS medium with the addition of 0.5 mg·dm⁻³ indolyl-3-butyric acid. In this case, a very high degree of rooting was found (97% for apical meristems, 100% for nodal meristems), lateral shoots were induced in 83% of both types of explant, and the content of OACs in the plant aroma profile increased significantly, especially menthofurolactone and cis-carvone oxide, responsible in this case for a characteristic mint-like aroma. The comparison of the volatile organic compounds (VOCs) obtained from plants of different origin by GC-MS showed no significant differences in their qualitative composition. Moreover, in-vitro-cultivated peppermint on a medium containing 0.5 mg·dm⁻³ 2-isopentinloadenine and 0.1 mg·dm⁻³ indolyl-3-acetic acid showed significant amounts of menthofurolactone in its VOC composition.

Effect of Different Drying Techniques on Dehydration Kinetics, Physical Properties, and Chemical Composition of Lemon Thyme

Lemon thyme contains several bioactive health-promoting compounds of high antioxidant capacity—such as polyphenols, carotenoids, and chlorophyll—which may undergo degradation during drying in incorrect processing conditions. This work is aimed at evaluating the impacts of different drying techniques and parameters on the chemical and physical properties of lemon thyme. In the experiment, lemon thyme leaves are dried using two traditional hot-air methods, convective drying (temperature 70°C or 80°C, air velocity 2 m/s), and fluidized bed drying (temperature 70°C or 80°C, air velocity 5–10 m/s); as well as two innovative drying methods, microwave-assisted fluidized bed (MFB) drying (microwaves at a power of 240 or 440 W, air temperature 40°C, air velocity 5–10 m/s) and microwave-vacuum (MV) drying (microwaves at a power of 240 or 440 W, under vacuum at 4–6 kPa). The kinetics of water delivery are described using the Page Model. After drying, the nutritional composition of the material is analyzed: polyphenol (total content and polyphenols profile by ultra-performance liquid chromatography), carotenoid, and chlorophyll total content, as well as antioxidant capacity (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt [ABTS+] and ferric reducing antioxidant power [FRAP]). Color changes ( L*, a*, b*, ΔE) are also analyzed using the visible effects of lemon thyme pigment disintegration. It is found that the MV drying method is the best for lemon thyme preservation, as it has the shortest process time and the highest retention of polyphenols (78.90%-82.14%), chlorophylls (51.54%-52.68%), antioxidant capacity (47.83%-48.63% of ABTS+ and 20.85%-45.45% of FRAP), and presented the least color change ( ΔE = 25.57-28.32). For preserving carotenoids, the most protective method is MFB (retention 68.46%-70.61 %).

Application of Pontentilla anserine, Polygonum aviculare and Rumex crispus Mixture Extracts in a Rabbit Model with Experimentally Induced E. coli Infection

The study evaluated the anti-colibacteriosis efficacy of herbs in experimental infection by rabbit pathogenic strain of E. coli O103 eae+. It also studied the effects of herbal mixture added to feed or water on blood parameters. This animal model was used since some E. coli strains pathogenic for rabbits are similar to the strains that are pathogenic to humans. The components of herbal extracts were Rumex crispus, Pontentilla anserine, and Polygonum aviculare. Supplementation was carried out in water (ExpW group) or feed (ExpF group), and four weeks later the animals were infected with the E. coli O103 eae+ strain. The administration of herbs increased the mean concentration of total protein and serum albumin (p < 0.01) without causing disturbances of electrolyte and acid-base balance. The highest total antioxidant capacity (TAS) value (p < 0.01) was observed in the ExpF group. The administration of a mixture of herbs and feed caused more reduction in the number of E. coli in cecum than supplementation into water after an experimental infection. The herbs applied in rabbits did not harm the secretory functions of liver, electrolyte, and acid-base balance of the blood. The application of the tested herbal mixtures can control the activity of the intestinal microbial community.

Determination of Various Drying Methods' Impact on Odour Quality of True Lavender (Lavandula angustifolia Mill.) Flowers

True lavender flowers (Lavandula angustifolia Mill.) is a critical source of essential oils and a flavouring agent used in numerous industries like foods, cosmetics and pharmaceuticals. Its main volatile constituents are linalool and linalyl acetate, which are commonly considered as main odour-active constituents (OACs). Nevertheless, the quality of true lavender flowers is highly dependent on its post-harvest treatment, mainly the preservation method. Recognising that drying is the most frequently used preservation method, the influence of various drying methods, including convective drying (CD) at 50, 60 and 70 °C, vacuum-microwave drying (VMD) with powers 240, 360 and 480 W and combined convective pre-drying at 60 °C followed by vacuum-microwave finish-drying with power 480 W (CPD-VMFD), on the quality of true lavender flowers was verified. The evaluation of influence was carried out by HS-SPME(HS, solid-phase microextraction), GC-MS, GC-MS-O (gas chromatography–mass spectrometry–olfactometry) techniques. Moreover, the sensory panel has assessed the sample odour quality. As a result, the optimal drying methods regarding the requirements for products were established. Overall, for total essential oil recovery, CD at 50 °C is the optimal drying method, while for odour quality concerning the sensory panel evaluation, VMD with power 360 W combined CPD-VMFD and CD at 50 °C is the optimal drying method.

The Proof-of-the-Concept of Application of Pelletization for Mitigation of Volatile Organic Compounds Emissions from Carbonized Refuse-Derived Fuel

Waste can be effectively reused through the production of carbonized refuse-derived fuel (CRDF) that enables further energy recovery. Developing cleaner production of CRDF requires consideration of practical issues of storage and handling. Thus, it needs to be ensured that CRDF does not pose an excessive risk to humans and the ecosystem. Very few studies indicate a wide variety of volatile organic compounds (VOCs) are present in CRDF, some of which are toxic. During handling, storage, transportation, and use of VOC-rich CRDF, workers and end-users could be exposed to emissions that could pose a health and safety hazard. Our recent study shows that CRDF densification via pelletization can increase the efficiency of storage and transportation. Thus, the following research question was identified: can pelletization mitigate VOCs emissions from CRDF during storage? Preliminary research aiming at the determination of the influence of CRDF pelletization on VOCs emission during storage was completed to address this question. The VOCs emissions from two types of CRDF: ground (loose, torrefied refuse-derived fuel (RDF)) and pelletized, were measured. Pelletization reduced the VOCs emissions potential during the four-day storage by ~86%, in comparison with ground CRDF. Mitigation of VOCs emissions from densified CRDF is feasible, and research is warranted to understand the influence of structural modification on VOCs emission kinetics, and possibilities of scaling up this solution into the practice of cleaner storage and transportation of CRDF.