Explore the vast range of titles available.

An hydrolate (also known as hydrosol, floral water, aromatic water, or herbal water) is a distillate which is a product of condensation obtained after an essential oil distillation isolation procedure. Hydrolates are colloidal suspensions composed of a continuous phase, the distilled water, and a dispersed phase, the emulsion of essential oil droplets and water-soluble components, namely oxygen-containing compounds. The movement towards a circular economy, has increased the interest in the essential oil industry co-products, such as hydrolates. Hydrolates composition were mostly studied based on their volatile constituents. Moreover, they showed a diverse range of biological properties, with potential application in food, beverages, cosmetic and pharmaceutical industries, as well as in the agroforest sector. Nevertheless, the information is fragmented and dispersed under the different hydrolates designations. In the present review, the main volatile components of 362 hydrolates obtained from 194 species from 50 families is described, and the information on the corresponding essential oil main components is detailed. Additionally, the methodologies of extraction and analysis are surveyed, as well as hydrolates characteristics and traditional uses. This review also describes the different biological properties attributed to hydrolates and, according with these properties, their potential uses.

In this work, laminated ammonium perchlorate-based composite (LAPC) with high thermal decomposition performance was prepared by ice-template freezing-induced assembly strategy. Cobalt-Konjac glucomannan (Co 2+ -KGM) hydrosol with rich AP embedded was designed and used as a frozen precursor. LAPC was obtained from the ice-template freezing of the hydrosol precursor and crystallization of AP molecules. The structure and morphology of as-obtained composite were characterized, and the thermal decomposition performances were investigated. The results showed that LAPC materials have micro-/nano-lamellar structures with the thickness size of 20 μm, which are composed of AP micro-/nanoparticles formed in the freezing crystalline progress and uniformly dispersed Co 2+ -KGM coated on the surface and inside of the micro-/nanoparticles. Thermal analysis results show that LAPC-2 has a lower decomposition temperature than raw AP, which have decreased by 114.3 °C. The activation energy of LAPC-2 thermal decomposition was reduced by 87 kJ/mol from 200 kJ/mol of AP to 113 kJ/mol of LAPC-2. A possible catalytic mechanism of thermal decomposition of LAPC is proposed. Under heating condition, the Co 2+ -KGM molecules firstly decomposed, and Co-based oxides can be in situ generated on the surface and inside of AP particles, resulting in enhancing the catalytic contact areas. Abundant distributed nanoscale Co-based oxides boosted the thermal decomposition of AP and exhibited excellent catalytic performances. Graphic abstract

The global demand for sustainable and non-toxic alternatives across various industries is driving the exploration of naturally derived solutions. Hydrosols, also known as hydrolates, represent a promising yet underutilised byproduct of the extraction process of essential oils (EOs). These aqueous solutions contain a complex mixture of EO traces and water-soluble compounds and exhibit significant biological activity. To fully use these new solutions, it is necessary to understand how factors, such as distillation time and plant-to-water ratio, affect their chemical composition and biological activity. Such insights are crucial for the standardisation and quality control of hydrosols. Hydrosols have demonstrated noteworthy properties as natural antimicrobials, capable of preventing biofilm formation, and as antioxidants, mitigating oxidative stress. These characteristics position hydrosols as versatile ingredients for various applications, including biopesticides, preservatives, food additives, anti-browning agents, pharmaceutical antibiotics, cosmetic bioactives, and even anti-tumour agents in medical treatments. Understanding the underlying mechanisms of these activities is also essential for advancing their use. In this context, this review compiles and analyses the current literature on hydrosols’ chemical and biological properties, highlighting their potential applications and envisioning future research directions. These developments are consistent with a circular bio-based economy, where an industrial byproduct derived from biological sources is repurposed for new applications.

Main conclusionNew findings are presented for Chaerophyllum coloratum L. on the volatile composition of the essential oil, based on data of hydrosol and fresh plant material, light and electron microscopy of leaves, and cytotoxic and antiviral activity.The widespread Apiaceae family includes many well-known and economically important plants that are cultivated as food or spices. Many produce essential oils and are generally a source of secondary metabolites and compounds that have numerous applications in daily life. In this study, the chemical composition of volatile organic compounds (VOCs), ultrastructure and biological activity of the Mediterranean endemic species Cheaerophyllum coloratum L. are investigated, as literature data for this plant species are generally very scarce. The essential oil and hydrosol were extracted from the air-dried leaves by hydrodistillation and the chemical composition of both extracts was analysed by GC–MS in conjunction with headspace solid-phase microextraction (HS-SPME) of VOCs from the hydrosol and the fresh plant material. In the composition of the essential oil, the oxygenated sesquiterpenes spathulenol and caryophyllene oxide were the most abundant components. In the fresh plant material, non-oxygenated sesquiterpenes dominated, with β-caryophyllene and germacrene D being the main components. The hydrosol was dominated by monoterpenes, with the oxygenated monoterpene p-cymen-8-ol being the most abundant. Light and electron micrographs of the leaf of C. coloratum show secretory structures, and we hypothesize that glandular leaf trichomes, secretory epidermal cells and secretory canals are involved in the production of volatiles and their secretion on the leaf surface. Since the biological potential of C. coloratum is poorly investigated, we tested its cytotoxic activity on cancer and healthy cell lines and its antiviral activity on plants infected with tobacco mosiac virus (TMV). Our results dealing with the composition, ultrastructure and biological activity show that C. coloratum represent a hidden valuable plant species with a potential for future research.

The genus Mentha has promising antifungal, antiviral, antibacterial, antioxidant and plant growth promoting activities. Mint hydrosols is a product of hydro-distillation of mint plants and is obtained during the extraction process of essential oils. The present study attempts to investigate the role of mint hydrosol in promoting growth of tomato plants. Seedlings of uniform size raised from healthy seeds were planted in pots under open field conditions. The well-established tomato plants were treated with different concentrations (0, 25, 50 and 100%) of freshly prepared mint hydrosol as foliar spray twice a week. The hydrosol was applied for six weeks. At the time of completion of the experiment, data for different vegetative growth parameters such as shoot length (cm), number of leaves, root length (cm) and stem diameter (cm) were noted. A suitable scale was used to measure the length of shoot and root. Increased root and shoot length (58.05 and 23.46 cm from 40.99 to 16.45 cm, respectively), fresh and dry weight of shoots and roots (28.0 and 3.43 g) were observed at 100% hydrosol treatment. There was a significant increase in number of flowers (5.41), leaves, and fruits (3.79) after 6 weeks at 100% hydrosol treatment. Fruit size and weight (3.79 cm, and 31.12 g, respectively) was also higher in tomato plants treated with 100% mint hydrosol. Activities of antioxidant enzymes were also significantly enhanced, e.g., superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) (41.0 U. mg − 1 of protein, 5.1 U. mL − 1 of enzyme and 5.28 U. mL − 1 of enzyme from 23.09 U. mg − 1 of protein, 3.01 U. mL − 1 of enzyme and 3.12 U. mL − 1 of enzyme, respectively) by treatment with 100% hydrosol. Relative water content, total chlorophyll content, total phenols, polyphenols oxidase and uptake of various ions (Na + 1 , K + 1 , Mg + 2 , and Zn + 2 ) also increased significantly (45.1 mg. L − 1 , 34.67 mg. L − 1 , 1.59 mg. L − 1 , 1.03 mg. L − 1 , respectively) in hydrosol treated plants. It can, therefore, be concluded that application of peppermint hydrosol enhances the growth, antioxidant activity and mineral uptake in tomato.

In this study, the changes in the bioactive components, antioxidant properties and phenolic compositions of the hydrosols of the aerial parts of Satureja hortensis, Petroselinum crispum, Thymus siypleus, Rosmarinus officinalis and Salvia officinalis plants obtained at different distillation times were investigated by spectrophotometric and HPLC. Total phenolic amounts of the summer savory and thyme hydrosols were assigned to be between 362.30 (60 min) and 442.46 mg gallic acid equivalent (GAE)/L (120 min) to 363.10 (1.min (initial stage)) and 625.79 mg GAE/L (120 min), respectively. In addition, total phenolic amounts of the parsley hydrosols changed between 1.98 (120 min) and 14.84 mgGAE/L (1.min). Total flavonoid values of the summer savory and thyme hydrosols were specified to be between 21.43 (60 min) and 35.71 mg/L (120 min) to 50.00 (1.min) and 92.86 mg/L (120 min), respectively. In general, the highest total phenol, total flavonoid and antioxidant activity values were determined in hydrosols of summer savory and thyme plants. Although there were partial differences between the values of bioactive properties of parsley, rosemary and sage hydrosols, they were found to be close to each other. The catechin amounts of the summer savory and thyme hydrosols obtained in different distillation times were identified between 12.86 (1.min) and 216.47 mg/L (120 min) to 17.12 (1.min) and 126.25 mg/L (120 min), respectively. The catechin contents of the parsley and rosemary hydrosols changed between 23.44 (1.min) and 215.83 mg/L (120 min) to 24.35 (1.min) and 123.20 mg/L(120 min), respectively. The majority of the phenolic compounds of the hydrosols showed an increase at 60 and 90 min of distillation. Graphical Abstract In this study, the changes in the bioactive components, antioxidant properties and phenolic compositions of the hydrosols of the aerial parts of Satureja hortensis , Petroselinum crispum , Thymus siypleus , Rosmarinus officinalis and Salvia officinalis plants obtained at different distillation times were investigated.

Cinnamomoum osmophloeum Kanehira (C. osmophloeum) contains various biologically active antioxidant compounds such as flavonoids, phenolic acids and cinnamaldehyde. Type 2 diabetes mellitus is a chronic disease of metabolic abnormality caused by insulin deficiency or resistance. The objectives of this study were to analyze various bioactive compounds in C. osmophloeum leaves by ultra-high-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS), and compare the effects of hydrosol, extract and nanoemulsion prepared from C. osmophloeum leaves on improving type 2 diabetes in rats. Our results show that a total of 15 bioactive compounds in C. osmophloeum leaves, including quercetin, quercetin-3-O-galactoside, quercetin-3-O-glucoside, rutin, caffeic acid, benzoic acid, 5-O-caffeoylquinic acid, kaempferol 3-β-D-glucopyranoside, trans-cinnamic acid, coumarin, cinnamyl alcohol, p-coumaric acid, eugenol, kaempferol and cinnamaldehyde, were separated within 14 min for subsequent identification and quantitation by UPLC-MS/MS. The nanoemulsion was successfully prepared by mixing C. osmophloeum leaf extract, soybean oil, lecithin, Tween 80 and deionized water in an appropriate proportion with a mean particle size, polydispersity index, zeta potential and encapsulation efficiency of 36.58 nm, 0.222, −42.6 mV and 91.22%, respectively, while a high storage and heating stability was obtained. The animal experiment results reveal that the high-dose nanoemulsion was the most effective in reducing both fasting blood glucose and oral glucose tolerance test value, followed by low-dose nanoemulsion, high-dose extract, low-dose extract and leaf powder in hydrosol. A similar trend was shown in reducing serum insulin and the homeostatic model assessment of insulin resistance index. In addition, the contents of serum biochemical parameters, including total cholesterol, triglyceride, aspartate aminotransferase, alanine aminotransferase, uric acid, urea nitrogen and creatinine, were reduced, with the high-dose nanoemulsion showing the most pronounced effect. Collectively, the high-dose nanoemulsion may possess great potential to be developed into a hypoglycemic health food or botanic drug.

Different amounts of a stable aqueous TiO2 hydrosol were used to fabricate paper sheets having photocatalytic activity. The TiO2 hydrosol was prepared in aqueous medium using titanium butoxide as precursor and acetic acid as catalyst for the hydrolysis of titanium butoxide. An aging process at room temperature and atmospheric pressure was finally applied to obtain crystalline anatase TiO2 hydrosol. The effects of different TiO2 hydrosol loadings on the mechanical strength and barrier properties of modified paper sheets were investigated in detail. The photocatalytic behavior of TiO2-modified paper sheets was investigated as well using methylene blue (MB) as target pollutant.

Cellulose nanocrystals (CNC) were prepared by destruction of cotton cellulose using phosphotungstic acid in acetic acid medium. The study shows the influence of the heteropolyacid concentration, pre-activation, and hydrogen peroxide addition on the size of CNC particles. CNC were characterized using the methods of dynamic light scattering, FTIR-spectroscopy, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, scanning and transmission electron microscopy, and potentiometric titration. CNC particles have highly-crystalline structure and rod-like morphology. Freeze-dried CNC hydrosols form lamellar or fibrous agglomerates, depending on the initial concentration of the CNC sol. Potentiometric titration results show increase in surface activity index and offset of pK a values for CNC active centers in comparison to initial cellulose material.

The chemical profile, antiproliferative, antioxidant and antiphytoviral activities of the species Hypericum perforatum ssp. veronense (Schrank) H. Lindb. (Clusiaceae) were investigated. Free volatiles were isolated and the chemical composition was determined in the lipophilic fraction (essential oil) and for the first time in the water fraction (hydrosol). The aim is to provide phytochemical data for H. perforatum ssp. veronense useful for distinguishing ssp. veronense from ssp. angustifolium, as there are taxonomic disagreements between them and the composition of the secretory products may be helpful in this respect. In the essential oil, the most abundant compounds identified were α-pinene and n-nonane, while in the hydrosol, myrtenol, carvacrol and α-pinene were the most abundant. Overall, the class of monoterpenes and oxygenated monoterpenes dominated in the EO and hydrosol samples. The essential oil showed high antioxidant activity, in contrast to the antiproliferative activity, where the hydrosol showed exceptional activity against three cancer cell lines: Hela (cervical cancer cell line), HCT116 (human colon cancer cell line) and U2OS (human osteosarcoma cell line). Both the essential oil and hydrosol showed antiphytoviral activity against tobacco mosaic virus infection on the local host plants. This is the first report dealing with biological activities of hydrosol of H. perforatum ssp. veronense, and the obtained results suggest that this traditional medicinal plant is a valuable source of volatiles with promising antiproliferative, antioxidant and antiphytoviral activities.