Schematic representation of the possible formation processes of hydrochars from lignocellulosic biomass via hydrothermal carbonization. Display omitted
► HTC allowed rapid conversion of biomass into ...a carbon-rich and lignite-like product. ► Carbonization involved in dehydration, decarboxylation, and demethanation processes. ► Solid residue and liquid product contained many value-added materials. ► Phenolic compounds and furan derivatives were analyzed by GC–MS.
Hydrothermal carbonization (HTC) is a novel thermochemical conversion process to convert lignocellulosic biomass into value-added products. HTC processes were studied using two different biomass feedstocks: corn stalk and Tamarix ramosissima. The treatment brought an increase of the higher heating values up to 29.2 and 28.4MJ/kg for corn stalk and T. ramosissima, respectively, corresponding to an increase of 66.8% and 58.3% as compared to those for the raw materials. The resulting lignite-like solid products contained mainly lignin with a high degree of aromatization and a large amount of oxygen-containing groups. Liquid products extracted with ethyl acetate were analyzed by gas chromatography–mass spectrometry. The identified degradation products were phenolic compounds and furan derivatives, which may be desirable feedstocks for biodiesel and chemical production. Based on these results, HTC is considered to be a potential treatment in a lignocellulosic biomass refinery.
•Mobile phase-dependent comprehensive 2DLC was used to separate licorice extracts.•Phenolic compounds were separated from saponins and flavonoid glycosides.•Different selectivity of MeOH and MeCN ...remarkably improved the orthogonality.•311 peaks (175 peaks at 250nm) were separated, and the orthogonality reached 79.8%.•8 phenolic compounds were discovered in G. uralensis for the first time by 2DLC/MS.
Licorice is one of the most popular herbal medicines worldwide. It contains a big array of phenolic compounds (flavonoids, coumarins, and diphenylethanones). Due to high structural diversity, low abundance, and co-elution with licorice saponins, these phenolic compounds are difficult to be separated by conventional chromatography. In this study, a mobile phase-dependent reversed-phase×reversed phase comprehensive two-dimensional liquid chromatography (RP×RP 2DLC) method was established to separate phenolic compounds in licorice (the roots of Glycyrrhiza uralensis). Organic solvents in the mobile phase were optimized to improve orthogonality of the first and second dimensions, and a synchronized gradient mode was used to improve chromatographic resolution. Finally, licorice extracts were eluted with methanol/water/formic acid in the first dimension (Acquity CSH C18 column), and acetonitrile/water/formic acid in the second dimension (Poroshell Phenyl-Hexyl column). By using this 2DLC system, a total of 311 compounds were detected within 40min. The practical and effective peak capacity was 1329 and 524, respectively, and the orthogonality was 79.8%. The structures of 21 selected unknown compounds were tentatively characterized by mass spectrometry, and 8 of them were discovered from G. uralensis for the first time. The mobile phase-dependent 2DLC/MS system could benefit the separation and characterization of natural products in complicated herbal extracts.
Introduction Capparis spinosa is a perennial herb from the Capparidaceae family that is mainly distributed in arid and semi-arid regions. Its fruits are oval shaped, approximately 3 cm long, ...greenish in color with red pulp. Capparis spinosa extract is a rich source of phenolic compounds. The instability of phenolic compounds in the environmental conditions as well as their bitter or astringent taste has created challenges for the use of these compounds in the food industry. Encapsulation is a method that can positively affect bioaccessibility and bioavailability as it ensures the coating of the active component and its targeted delivery to a specific part of the digestive tract and controlled release. Encapsulation using nanoliposomes seems to be an appropriate technique to overcome these issues. Nanoliposomes are the nanometric version of liposomes. Liposomes are spherical particles composed of lipid molecules (mainly phospholipids) that tend to accumulate in polar solvents such as water in the form of bilayer membranes. Encapsulation with liposomes is an effective way to preserve the intrinsic properties of bioactive compounds during storage and production of foods fortified with them, as well as a physicochemical barrier against prooxidant agents such as free radicals, oxygen and UV. Materials and Methods Materials: Capparis spinosa fruits, were collected from subtropical regions of Ilam province (Iran). Folin ciocalteu, gallic acid and tween 80 from Merck (Germany), cholesterol and phosphatidylcholine from Sigma- Aldrich (Germany) were obtained. Methods: The extract was obtained from capparis spinosa fruit powder using ultrasonic bath (Backer, vCLEAN 1- L6, Iran). The phenolic content was measured by folin ciocalteu method. Nanoliposomes containing capparis spinosa extract were prepared in ratios of 60- 0, 50- 10, 40- 20 and 30- 30 w/w lecithin- cholesterol. Then, particle size, PI and zeta potential were measured by DLS (Horiba, Japan) at 25 oC. After calculating the encapsulation efficiency using its corresponding equation, the investigation of possible reactions between capparis spinosa extract and phospholipids was performed using FTIR at a frequency of 400- 4000 cm-1. In order to observe shape and morphology of nanoliposomes loaded with capparis spinosa extract by field emission scanning electron microscopy (FESEM), a drop of sample was poured on the laboratory slide, dried at ambient temperature and then, the sample was coated with gold layer using an ion sputtering device. The stability of the samples was evaluated by visual observation of phase separation and the release rate of phenolic compounds encapsulated in nanoliposomes at ambient temperature over a period of 60 days. Results and Discussion The amount of phenolic extract was 6.328 mg of GAE/g dry sample. The average particle size (Z- Average) was in the range of 95.05 to 164.25 nm. Increasing the cholesterol concentration resulted in enhancement of particle size of nanoliposomes. The particle size distribution was in an acceptable range of 0.3 to 0.5 (PI 0.5). The PI of the cholesterol-free nanoliposomes was maximum and significantly higher than that of the others. Addition of cholesterol increased zeta potential from -60.40 to -68.55. Higher zeta potential values indicate a higher and long term stability of the particles. Also, cholesterol led to an increase of encapsulation efficiency (EE). The stability of phenolic compounds loaded in nanoliposomes was affected by cholesterol during storage time via reducing fluidity and permeability of liposomal membrane. Presence of cholesterol also inhibited the membrane rupture and any changes into it. Results of FTIR showed interactions between wall constituents of nanoliposome and capparis spinosa extract, and confirmed successful loading of the extract within nanoliposomes. Images of FESEM were in agreement with DLS results regarding particle size and particle size distribution. Conclusion This study indicate that the nanoliposomes have potential applications in improvement of the shelf life of nutraceuticals, stability of cosmetic materials and drug delivery systems. The phenolic compounds of encapsulated extract showed good stability within two months of storage at room temperature. The results showed that the problem of instability of phenolic compounds, which leads to their limited commercial application, can be solved by encapsulation.
•A chromatographic method for the separation of 52 phenolic standards was developed•The influence of glycosyl- substituents and their positions was assessed•QSRR models were developed to identify ...phenolic compounds using retention data•Three distinct set of molecules were used to build PLS, MLR and PLS-ANN models
Quantitative Structure-Retention Relationship models were developed to identify phenolic compounds using a typical LC- system, with both UV and MS detection. A new chromatographic method was developed for the separation of fifty-two standard phenolic compounds. Over 5000 descriptors for each standard were calculated using AlvaDesc software and then selected through Genetic Algorithm. The selected descriptors were used as variables for models construction and to obtain a better understanding of the retention behaviour of phenols during reverse-phase separation. Three distinct molecule sets, including fifty-two phenolic compounds (Set 1), 32 flavonoids (Set 2) and 15 mono-substituted flavonoids were divided into training and validation sets to build Partial Least Square, Multiple Linear Regression and Partial Least Square-Artificial Neural Network models. To assess the predictivity of the models, these were tested on a bergamot juice sample. Partial Least Square and Partial Least Square-Artificial Neural Network exhibit the lowest prediction error, and the latter showed the best predictive power in real sample recognition. The building and implementation of such predictive models showed to be a powerful tool to identify phenolic compounds based on retention data and avoiding the use of expensive and sophisticated detectors such as tandem MS.
In this investigation, we successfully synthesized magnetic FeOx nanosphere catalysts with mixed-valence and high operational stability through the pyrolysis of a hybrid material containing ...polyferrocenlyphosphazene with coordinating heteroatoms (N, P, O). We evaluated the degradation performance of these catalysts using the peroxymonosulfate (PMS) activation process against four different phenolic compounds, namely phenol, 4-nitrophenol, 2,4-dinitrophenol, and 2,4,5-trinitrophenol. Our results demonstrate the significant role of FeOx in the degradation process. The presence of mixed iron species, such as ferric iron, zero-valent iron, and iron oxides, activated PMS to generate radicals. Additionally, the heteroatoms facilitated the anchoring and dispersion of FeOx nanospheres while also breaking the inertness of the carbon structure. Notably, the FeOx-800 catalyst exhibited a maximum degradation activity of 98% for phenol, surpassing its counterparts. Electron paramagnetic resonance and free radical scavenging experiments confirmed that singlet oxygen (1O2) is the principal reactive oxygen species (ROS) that leads to the oxidative breakdown of phenolic compounds. This study introduces new concepts for designing Fenton-like catalysts incorporating heteroatoms into the carbon matrix. Due to their low cost and non-toxicity, these catalysts have recently received a great deal of attention for peroxymonosulfate (PMS) activation and environmental remediation.
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•The successful fabrication of mixed-valence FeOx nanospheres was achieved.•Heteroatoms improved the anchoring and dispersion of FeOx nanospheres.•FeOx nanospheres were tested for degrading various phenols by PMS activation.•Singlet oxygen is the primary reactive oxygen species for phenol degradation.•The efficacy of catalysts resembled a Fenton-like catalyst.
The phenolic compounds in extracts from pressed olive cake were investigated. Free phenolic compounds were extracted from olive cake using methanol. To liberate bound phenolic compounds, the olive ...cake was subjected to basic and acidic hydrolysis followed by methanol extraction. The individual phenolic compounds and antioxidant activity of the extracts were determined. The highest total phenolic content and antioxidant activity were obtained using methanol extraction for 12
h at 70
°C. The RP-HPLC profiles for full-fat and defatted olive cake showed that protocatechuic acid, hydroxybenzoic acid, sinapic acid,
p-coumaric acid, rutin and hesperidin were the predominant free phenolic compounds. Meanwhile, syringic acid, sinapic acid, caffeic acid and protocatechuic acid were the predominant bound phenolic acids. A positive correlation was observed between total phenolic content and antioxidant activity. The results indicated that most of the phenolic compounds in olive products were present in their free forms (75–90% of total phenolic content), while bound phenolic compounds were only a small proportion (10–25%) of total phenolic content.
Pomegranate peels contain a considerable amount of bioactive chemicals, such as phenolic compounds including gallic acid and ellagic acid. The current study aims to optimize the extraction of total ...phenolic content (TPC) and its antioxidant capacity from a Pomegranate peel using various approaches involving enzyme and ultrasound, also focusing on process intensification using combination. The optimal parameters for ultrasound treatment were established as treatment time of 25 min, 130 W power, 50 % duty cycle, and a liquid–solid ratio of 50:1 at a fixed 22 kHz frequency, resulting in maximum TPC (21.521 mg GAE/ml) and antioxidant capacity (17.962 mg GAE/ml). Similarly, enzymatic treatment was optimized resulting in best conditions of a time of 55 min, 50 °C as temperature, pH of 5, and a 2 % enzyme concentration. Ultrasound-assisted enzymatic extraction (UAEE) experiments revealed that combining 25 min of ultrasonic treatment with 25 min of enzymatic treatment yielded the highest TPC (30.608 mg GAE/ml) and antioxidant capacity (27.703 mg GAE/ml). It was clearly demonstrated that UAEE outperformed EAE and UAE in terms of Total Phenolic Compound extraction and antioxidant capacity, with the order of efficiency being UAEE > EAE > UAE.
Environmental stimuli modulate plant metabolite accumulation, facilitating adaptation to stressful conditions. In this study, the effects of blue and red light, photoperiod, CO2 concentration, and ...air temperature on the chlorogenic acid (CGA) and rutin contents of lettuce (Lactuca sativa L.) were evaluated. Under continuous blue light and a high CO2 concentration (1000 ppm), the CGA level increased. The increased expression of phenylalanine ammonia-lyase (PAL) and activity of its product were correlated with high expression of cinnamate 4-hydroxylase (C4H) and coumarate 3-hydroxylase (C3H). Furthermore, changes in PAL activity altered the CGA content in lettuce exposed to the three environmental factors, blue light, continuous lighting and high CO2 concentration. In addition, the expression levels of genes related to flavonoid biosynthesis increased in accordance with the promotion of CGA accumulation by the environmental factors. Under continuous blue light, 400 ppm CO2 promoted rutin accumulation to a greater degree compared to 1000 ppm CO2, by downregulating DFR expression. Low air temperature induced CGA accumulation in lettuce grown under continuous blue light and 1000 ppm CO2. Therefore, light quality, photoperiod, CO2 concentration, and air temperature exert synergistic effects on the CGA and rutin contents of lettuce by modulating activity in the corresponding biosynthesis pathways.
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•Multi environmental factors modulate key genes expressions for CGA synthesis.•Continuous blue lighting and high CO2 level increase PAL activity.•Low CO2 level under continuous blue lighting increases rutin content.•Low air temperature has a synergic effect with other factors on CGA accumulation.
The butterfly metamorphosis Within the cocoon's shell (aryl methyl ethers) is encased a secret beauty (phenols), how to liberate it? In their Review (e202317257), Bert U. W. Maes, and Bert F. Sels et ...al. comprehensively summarize the advancements and perspectives of lignin O‐demethylation (metamorphosis). The presence of methoxy groups (cocoon) limits the chemical reactivity and the applicability of lignin‐derived compounds. Through O‐demethylation (metamorphosis), the reborn product (butterfly) rich in phenolic functionality can start a versatile new life with broader applications.
