Water-insoluble Fraction Research Articles

On the use of isotopic differences of carbon fractions of biomass in plants to study transport flows and source-sink relations under different light conditions

It is shown that the differences in the isotopic composition of carbon in the water-soluble and water-insoluble fractions of plant leaf biomass, as well as phloem, are evolutionarily determined. They associated with metabolic reactions during assimilation and photorespiration and do not depend on the illumination mode and on the spectral ranges of headlights used in illumination. The above isotopic shifts are the cause of isotopic differences in assimilatory and photorespiratory carbon stocks that feed various metabolic processes. Due to the strict temporal and spatial organization of metabolism, carbon fluxes from the funds retain isotopic differences without complete mixing. The differences in the isotopic composition of carbon of the water-soluble fraction of biomass and carbon of phloem juice from carbon of the water-insoluble fraction are small (1–3%), but they are quite stable and easily fixed. The carbon of the water-soluble fraction is very close in isotopic composition to the carbon of the phloem and is noticeably enriched with the isotope 13C relative to the water-insoluble fraction, which makes it possible to use it as a marker in the study of assimilate transport in plants, especially during budding and fruiting. It is shown that the reason for the enrichment of autotrophic organs and tissues with isotope 12C relative to carbon of heterotrophic parts of the plant is the predominant participation in their formation of an isotopically light assimilation fund, whereas an isotopically heavy photorespiratory fund takes part in the formation of heterotrophic organs. It is shown that the manifestation of the formation of two isotopically different funds is the discovered relationship of the carbon isotope composition of leaves with their age.

MiPrime: A Model for the Microbially Mediated Impacts of Organic Amendments on Measurable Soil Organic Carbon Fractions and Associated Priming Effects

Priming effects can influence the efficiency with which organic amendments sequester carbon in the soil. Yet few soil models currently include priming effects. Those models that do are often based on operationally defined soil pools and implicitly allow only for positive priming effects. This limits the verification of model processes with experimental data and hinders the optimization of our carbon sequestration strategies. To address these shortcomings, we developed MiPrime, which offers a framework for the mechanistic modelling of organic amendment impacts on microbially mediated transformation of carbon fractions that are quantifiable through parsimonious soil extraction methods. MiPrime allows for assessment of organic amendment impacts on soil carbon dynamics, including priming effects, by simulating changes in mineralized, microbial biomass, dissolvable, hot water extractable and insoluble carbon fractions in soil exogenous (i.e. organic amendment-derived) and endogenous (i.e. soil) pools. After calibration of model parameters using Markov Chain Monte Carlo methods to incubation data of three types of isotopically labelled roadside grasses (a fresh grass product, a compost thereof, and a Bokashi-fermented product thereof), MiPrime was able to simulate changes in carbon fractions of the soil with a good degree of accuracy for five compositionally complex organic amendments, namely the three types of roadside grasses, as well as non-isotopically labelled wood chips and water weeds and reeds. Validation of the model results with experimental data demonstrates that changes in total carbon were very well predicted but that there is room for improvement in predicting mineralization rates and changes in dissolvable, hot water extractable and insoluble carbon fractions in the soil endogenous pool. MiPrime thus offers an initial step towards the mechanistic modelling of organic amendment impacts on measurable soil carbon fractions and can operate as a new tool for designing effective carbon sequestration strategies and understanding organic amendment impacts.

Amino acids in the water-soluble and water-insoluble fractions of the aerosols at a forested site in Japan

In order to clarify the concentration levels and sources of the water-insoluble amino acids (WIAA) in aerosols that have been received little attention in previous studies and to discuss their potential impact on nitrogen deposition, the WIAA in the coarse-mode (d = 2.0–10 μm) and fine-mode (d < 2.0 μm) aerosols were measured at a forested site in Japan together with the water-soluble free and combined amino acids. The sum of the WIAA showed more than a 6-times higher concentration than that of the water-soluble amino acids in the coarse-mode range and a similar concentration to that in the fine-mode range, which suggests a significant contribution of the WIAA to the amino acids pool in aerosols. The WIAA were predominantly partitioned into the coarse-mode range. The concentration of the coarse-mode WIAA was the highest in the summer and a strong correlation was found between the coarse-mode WIAA and nss-K+ concentrations. These results suggest that plant debris and the associated materials are important sources for the coarse-mode WIAA and the increase in the suspension of these particulate materials caused the enhancement of the WIAA in the summer. Remarkably higher concentrations of the coarse-mode WIAA than the water-soluble amino acids would be caused by these particulate materials. In the fine-mode range, on the other hand, the concentration of the WIAA was the highest in the spring and strongly correlated with the fine-mode nss-K+ concentrations. The fine-mode WIAA would be mainly derived from the biomass burning particles. The coarse-mode WIAA were estimated to significantly contribute to the dry deposition flux of the total nitrogen. The present study implies a potential impact of the WIAA in the coarse aerosols on nitrogen deposition.

Assessment of Accelerated Aging Effect of Bio-Oil Fractions Utilizing Ultrahigh-Resolution Mass Spectrometry and k-Means Clustering of van Krevelen Compositional Space.

Bio-oils contain a substantial number of highly oxygenated hydrocarbons, which often exhibit low thermal stability during storage, handling, and refining. The primary objectives of this study are to characterize the hydroxyl group in bio-oil fractions and to investigate the relationship between the type of hydroxyl group and accelerated aging behavior. A bio-oil was fractionated into five solubility-based fractions, classified in two main groups: water-soluble and water-insoluble fractions. These fractions were then subjected to chemoselective reactions to tag molecules containing hydroxyl groups and analyzed by negative-ion electrospray ionization 21 T Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The fractions were also subjected to accelerated aging experiments and characterized by FT-ICR MS and bulk viscosity measurements. Extracting insightful information from ultrahigh-resolution data to aid in predicting upgrading methodologies and instability behaviors of bio-oils is challenging due to the complexity of the data. To address this, an unsupervised learning technique, k-means clustering analysis, was used to semiquantify molecular compositions with a close Euclidean distance within the (O/C, H/C) chemical space. The combination of k-means analysis with findings from chemoselective reactions allowed the distinctive hydroxyl functionalities across the samples to be inferred. Our results indicate that the hexane-soluble fraction contained numerous molecules containing primary and secondary alcohols, while the water-soluble fraction displayed diverse groups of oxygenated compounds, clustered near to carbohydrate-like and pyrolytic humin-like materials. Despite its high oxygen content, the water-soluble fraction showed minimal changes in viscosity during aging. In contrast, a significant increase in viscosity was observed in the water-insoluble materials, specifically, the low- and high-molecular-weight lignin fractions (LMWL and HMWL, respectively). Among these two fractions, the HMWL exhibited the highest increase in viscosity after only 4 h of accelerated aging. Our results indicate that this aging behavior is attributed to an increased number of molecular compositions containing phenolic groups. Thus, the chemical compositions within the HMWL are the major contributors to the viscosity changes in the bio-oil under accelerated aging conditions. This highlights the crucial role of oxygen functionality in bio-oil aging, suggesting that a high oxygen content alone does not necessarily correlate with an increase of viscosity. Unlike other bio-oil categorization methods based on constrained molecule locations within the van Krevelen compositional space, k-means clustering can identify patterns within ultrahigh-resolution data inherent to the unique chemical fingerprint of each sample.

Compositions and sources of fluorescent water-soluble and water-insoluble organic aerosols

Brown carbon (BrC), the light-absorbing component of organic aerosols, plays a significant role in climate change and atmospheric photochemistry. However, the water-insoluble fractions of BrC have not been extensively studied, limiting the assessment of the overall climate effects of BrC. In this study, water-soluble and -insoluble organic carbon (i.e., WSOC and WIOC) in wintertime aerosols in Hefei were subsequently fractionated, and their fluorescence properties were comparatively investigated with the excitation–emission matrix method. WIOC contributing 57.1 % was the major component of organic carbon. WSOC with the largest contribution from humic-like regions exhibited a redshift compared to WIOC. Three humic-like substances (HULIS) with different oxidation degrees and one protein-like substances (PRLIS) were identified as the major fluorescent components by the parallel factor analysis. WSOC had more highly oxygenated HULIS, whereas low-oxygenated HULIS dominated WIOC. Nighttime WIOC contained more less-oxygenated species. The positive matrix factorization analysis suggested that biomass burning (43 %) was the largest source of both fluorescent WSOC and WIOC. Coal combustion contributed much more to fluorescent WIOC (40 %), whereas secondary formation contributed more to fluorescent WSOC (12 %). During aerosol pollution episodes, the increase in fluorescence efficiency was much greater for WIOC (25 %) than for WSOC (12 %), and WSOC and WIOC experienced a redshift and blueshift in emission wavelength, respectively. WSOC had more highly oxygenated HULIS, while WIOC had more less-oxygenated HULIS in aerosol episodes than the non-episodic periods. In addition, aerosol pollution was accompanied by the increased contributions of biomass burning and coal combustion to both fluorescent WSOC and WIOC, while the decreased relative contribution of secondary formation to fluorescent WSOC. Our findings highlighted the different fluorescence properties, compositions and sources of fluorescent WSOC and WIOC, providing a comprehensive view of BrC aerosols.

The Waxy Gene Has Pleiotropic Effects on Hot Water-Soluble and -Insoluble Amylose Contents in Rice (Oryza sativa) Grains.

Rice (Oryza sativa) is a cereal crop with a starchy endosperm. Starch is composed of amylose and amylopectin. Amylose content (AC) is the principal determinant of rice quality, but varieties with similar ACs can still vary substantially in their quality. In this study, we analyzed the total AC (TAC) and its constituent fractions, the hot water-soluble amylose content (SAC) and hot water-insoluble amylose content (IAC), in two sets of related chromosome segment substitution lines of rice with a common genetic background grown in two years. We searched for quantitative trait loci (QTLs) associated with SAC, IAC, and TAC and identified one common QTL (qSAC-6, qIAC-6, and qTAC-6) on chromosome 6. Map-based cloning revealed that the gene underlying the trait associated with this common QTL is Waxy (Wx). An analysis of the colors of soluble and insoluble starch-iodine complexes and their λmax values (wavelengths at the positions of their peak absorbance values) as well as gel permeation chromatography revealed that Wx is responsible for the biosynthesis of amylose, comprising a large proportion of the soluble fractions of the SAC. Wx is also involved in the biosynthesis of long chains of amylopectin, comprising the hot water-insoluble fractions of the IAC. These findings highlight the pleiotropic effects of Wx on the SAC and IAC. This pleiotropy indicates that these traits have a positive genetic correlation. Therefore, further studies of rice quality should use rice varieties with the same Wx genotype to eliminate the pleiotropic effects of this gene, allowing the independent relationship between the SAC or IAC and rice quality to be elucidated through a multiple correlation analysis. These findings are applicable to other valuable cereal crops as well.

Comparative in vitro toxicological effects of water-soluble and insoluble components of atmospheric PM2.5 on human lung cells

Fine particulates in city air significantly impact human health, but the hazardous compositional mechanisms are still unclear. Besides the toxicity of environmental PM2.5 to in vitro human lung epithelial cells (A549), the independent cytotoxicity of PM2.5-bound water-soluble (WS-PM2.5) and water-insoluble (WIS-PM2.5) fractions were also compared by cell viability, oxidative stress (reactive oxygen species, ROS), and inflammatory injury (IL-6 and TNF-α). The cytotoxicity of PM2.5 varied significantly by sampling season and place, with degrees greater in winter and spring than in summer and autumn, related to corresponding trend of air PM2.5 level, and also higher in industrial than urban site, although their PM2.5 pollution levels were comparable. The PM2.5 bound metals (Ni, Cr, Fe, and Mn) may contribute to cellular injury. Both WS-PM2.5 and WIS-PM2.5 posed significant cytotoxicity, that WS-PM2.5 was more harmful than WIS-PM2.5 in terms of decreasing cell viability and increasing inflammatory cytokines production. In particular, industrial samples were usually more toxic than urban samples, and those from summer were generally less toxic than other seasons. Hence, in order to mitigate the health risks of PM2.5 pollution, the crucial targets might be components of heavy metals and soluble fractions, and sources in industrial areas, especially during the cold seasons.

Assessing thermal hazards in bio-oil-glyoxal polymerization and curing with DGEBA and bio-char

Traditional novolac resin uses formaldehyde and an excess of phenol under an acid catalyst which has a remarkable production and wide applications, however, the polymerization and its curing reaction are highly exothermic and heat generation with the release of harmful gases (formaldehyde and phenol) link to a high potential of thermal runaway hazard and the possibility of explosions in resin factories. To make a sustainable novolac-type resin, the water-insoluble fraction of bio-oil glyoxal (BOG) resin was utilized as an ideal phenol bioresource. The safety criteria of renewable resins polymerization and its curing reaction were investigated using the Differential Scanning Calorimeter (DSC) and evaluated by comparing the critical runaway conditions with those of traditional non-renewable resins. The reaction mechanism of the novolac resin synthesis and curing reaction were discussed as well. The results indicate that the use of bio-oil can reduce the heat risk of polymerization reactions. The introduction of biochar for the first time in curing reactions has shown a potential beyond anticipation in reducing the heat risk of curing reactions.

Measurement report: Brown carbon aerosol in polluted urban air of the North China Plain – day–night differences in the chromophores and optical properties

Abstract. Brown carbon (BrC) aerosol is light-absorbing organic carbon that affects radiative forcing and atmospheric photochemistry. The BrC chromophoric composition and its linkage to optical properties at the molecular level, however, are still not well characterized. In this study, we investigate the day–night differences in the chromophoric composition (38 species) and optical properties of water-soluble and water-insoluble BrC fractions (WS-BrC and WIS-BrC) in aerosol samples collected in Shijiazhuang, one of the most polluted cities in China. We found that the light absorption contribution of WS-BrC to total BrC at 365 nm was higher during the day (62±8 %) than during the night (47±26 %), which is in line with the difference in chromophoric polarity between daytime (more polar nitrated aromatics) and nighttime (more less-polar polycyclic aromatic hydrocarbons, PAHs). The high polarity and water solubility of BrC in the daytime suggests the enhanced contribution of secondary formation to BrC during the day. There was a decrease in the mass absorption efficiency of BrC from nighttime to daytime (2.88±0.24 vs. 2.58±0.14 for WS-BrC and 1.43±0.83 vs. 1.02±0.49 m2 g C−1 for WIS-BrC, respectively). Large polycyclic aromatic hydrocarbons (PAHs) with four- to six-ring PAHs and nitrophenols contributed to 76.7 % of the total light absorption between 300–420 nm at nighttime, while nitrocatechols and two- to three-ring oxygenated PAHs accounted for 52.6 % of the total light absorption during the day. The total mass concentrations of the identified chromophores showed larger day–night difference during the low-pollution period (day-to-night ratio of 4.3) than during the high-pollution period (day-to-night ratio of 1.8). The large day–night difference in BrC composition and absorption, therefore, should be considered when estimating the sources, atmospheric processes, and impacts of BrC.

Solid-State 13C Nuclear Magnetic Resonance Study of Soluble and Insoluble β-Glucans Extracted from Candida lusitaniae.

β-glucans are widely known for their biological activities. However, the choice of extraction method can significantly influence their structural characteristics, thereby potentially impacting their biological functions. In this paper, three fractions of β-glucans were obtained from Candida lusitaniae yeast via alkali and hot-water extraction methods and were analyzed using solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Solid-state NMR spectroscopy was used as a nondestructive technique that preserves the structure of the analyzed molecules. The results suggest that differences in the β-glucan structure are affected by the choice of extraction method. The main difference occurred in the 82-92 ppm region with signal presence suggesting that β-glucans have a linear structure when hot-water-extracted, which is absent in alkali-extracted fractions resulting in the acquisition of β-glucans with an ordered, possibly helical structure. A hot-water extracted water-insoluble (HWN) fraction consists of linear β-1,3-glucans with other signals indicating the presence of β-1,6-linked side chains, chitin and small amounts of α-glucan impurities. For those that are alkali-extracted, alkali-insoluble (AN) and water-soluble (AWS) fractions are structurally similar and consist of an ordered β-1,3-glucan structure with β-1,6-linked side chains and a significant amount of α-glucan and chitin in both fractions.

Oxidative potential, environmentally persistent free radicals and reactive oxygen species of size-resolved ambient particles near highways

Particulate matter (PM) is a group of atmospheric pollutants with an uncertain toxicity, particularly when collected near highways. This study examined the oxidative potential (OP) of, as well as the environmentally persistent free radicals (EPFRs) and reactive oxygen species (ROS) present in PM samples collected near highways in Xiamen, China. Our findings revealed that PM had a relatively high OP, ranging from 3.8 to 18.5 nmol/min/μg, surpassing values reported in previous research. The oxidative potential of the water-insoluble fraction (OPWIS), which accounted for 68% of the total oxidative potential (OPTotal), demonstrated rapid toxicity, whereas the oxidative potential of the water-soluble fraction (OPWS) displayed a steadier toxicity release pattern. The primary free radicals detected in PM were oxygen-centered. The measured concentration of EPFRs was 6.073 × 1014 spins/m3, which is lower than that reported in previous studies, possibly because of the high relative humidity of the road environment in Xiamen. We also investigated the interaction between PM and water near highways and observed the generation of R and OH radicals. Additionally, we analysed the sample composition and evaluated the contributions of the different components to OPTotal. Transition metals (Fe, Cu, and Zn) were identified as the major contributors, accounting for 33.2% of the OPTotal. The positive correlation observed between EPFRs and ROS suggests that EPFRs may be involved in ROS generation. The correlation analysis indicated that the oxidative potential measured using the DTT method (OPDTT) could serve as an indicator of ROS generation. Finally, based on the relationship between OPDTT, EPFRs, and ROS, we propose that reducing the emission of transition metals, particularly Fe, represents an effective control measure for mitigating PM toxicity near highways.

Production of pyrolytic lignin for the phenolic resin synthesis via fast pyrolysis

Recycling of waste wood into resol type phenol-formaldehyde (PF) resins via fast pyrolysis was demonstrated. Waste wood collected from the building demolition site in Finland was pyrolyzed with 20 kg/h circulating fluidized bed pyrolysis pilot unit. Pilot was operated with high organic liquid yield (60 wt% on average) and the produced fast pyrolysis bio-oil was fractionated by water addition into aqueous phase and water insoluble phase. The obtained fractions were characterized, and the water-insoluble viscous lignin fraction was used in the synthesis of PF-resins. Commercial phenol was successfully replaced by pyrolytic lignin fraction at 10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt% producing resins of low in free formaldehyde content, but resins with high replacement ratio exhibited higher viscosities. The use of H2O/n-butanol mixture as solvent at a ratio 70:30 wt/wt% proved capable to prolong the storage time of the resin and helped to maintain the viscosity at acceptable values for at least 2 weeks before their use in the targeted application. Finally, the gluing performance of the resins was evaluated by measuring the tensile shear strength of lap joints formed by gluing 5 mm thick beech wood veneers. All the produced resins fulfilled a dry strength limit of ≥ 10 N/mm2. Wet strength limit ≥ 7 N/mm2 was fulfilled by the resins with the replacement ratio up 40 wt%, but resins with replacement ratio of 50 wt% had somewhat reduced wet strength. These results confirm a promising protentional application of pyrolysis derived lignin fraction in phenolic wood adhesives, at least in dry conditions.

Structure and emulsifying properties of unprecedent glucomannan oligo- and polysaccharides from Amazonia Acrocomia aculeata palm fruit

Acrocomia aculeata fruit pulp contains oil (4.1–82.8 % fresh matter) and carbohydrates (6.6–98.0 % fresh matter). To date, only the oil fraction is valorized because very little is known about the nature of carbohydrates. This study explores new ways of adding value to this pulp by developing simple and efficient extraction processes for its carbohydrate components and characterizing their structure and physicochemical properties over two harvest periods. A water-soluble monosaccharide fraction F1 (solubility limit (SL): 98.5–99.3 g/L) (yield: 21 % dry pulp (DP)), a water-soluble polysaccharide fraction F2 (SL: 93.3–95.3 g/L) (yield: 26 % DP) and two additional water-insoluble polysaccharide fractions F3 and F4 (SL: <8 g/L) (yields: 10 and 19 % DP, respectively) were isolated. NMR structural characterizations of fraction F2 revealed it to be a linear glucomannan with β-(1 → 4) osidic linkages between d-Manp and d-Glcp residues. F2 is unique for its d-Manp/d-Glcp ratio of 3:1 and the position of its acetyl group (13–14 %, C-2 d-Manp). Finally, the polysaccharide showed a molecular weight (Mw) variation ranging from 8.2 × 104 to 1.1 × 103 Da over the two harvest periods, with remarkable emulsifying properties associated with a low Mw of F2 (stability >6 months, 1 % w/v in a water-in-oil emulsion).

Investigation of the biopotential of products of hydrolysis of waste from cutting the white-legged shrimp Penaeus vannamei

The relevance of studying the biopotential of shrimp waste and their hydrolysates is due to the need for complex processing of secondary raw materials of aquatic organisms to obtain useful products. At the fish processing plant Vichyunai-Rus LLC when manufacturing food products from white-legged shrimp, up to 60 % of the mass of waste (cephalothorax, shell) remains. This raw material contains valuable organic components, but is not processed. The paper proposes its complex processing with the production of hydrolysates in two ways – high-temperature and enzymatic. During thermohydrolysis in the aquatic environment, three fractions are formed from shrimp waste (fatty, water-soluble and water-insoluble). After separation, the water-soluble fraction was sublimated, and the water-insoluble fraction was dried by convection. The fat fraction was further purified by washing in warm water. The general chemical composition of shrimp waste and hydrolysis products has been studied. It has been shown that water-soluble hydrolysates are a good source of protein components (66.6–71.6 %). In comparative studies of the amino acid composition of water-soluble hydrolysates, the presence of all essential amino acids is established with minor differences between the samples. Both hydrolysates are dominated by alanine, arginine, glycine, isoleucine, lysine, aspartic acid, tyrosine, valine (3.3–6.4 g/100 g of protein). In terms of formol-titratable nitrogen in fermentolisates, alkalase ferments shrimp waste more actively than collagenase. The fatty acid composition of lipids isolated by thermohydrolysis from shrimp waste has been analyzed. Shrimp oil is characterized by a high content of polyunsaturated fatty acids (44.7 %) with a relatively low content of omega-3 family acids (10.7 %) and a high content of omega-6 (33.9 %) at a ratio of 1 : 3.2 (close to the physiologically recommended). The organoleptic characteristics of water-soluble and water-insoluble shrimp hydrolysates have been studied. Due to the content of valuable biologically active components in hydrolyzates, their use as food and feed additives – sources of active peptides, high-molecular proteins, minerals and chitinous components – is recommended.

On the Influence of Wavelengths of Different Ranges of Photosynthetically Active Radiation on the Carbon Isotope Composition of Plant Biomass and Its Fractions (Using as the Example Lettuce (&lt;i&gt;Lactuca sativa&lt;/i&gt; L.) of the Aficion Variety)

The influence of incident wavelengths of four ranges: short-wave red (623–641 nm), long-wave red (646–667 nm), far red (727–751 nm) and blue (452–477 nm) on the carbon isotopic composition of lettuce biomass (Lactica sativa L.) of the Aficion variety was studied. Lettuce was grown in climatic chambers, lighting was provided by irradiators based on narrow-band LEDs. Monochromatic blue and red light have the strongest multidirectional influence. Radiation from the blue range shifts the carbon isotopic composition of lettuce biomass towards enrichment in 12C. Radiation from the red range shifts the carbon isotopic composition of lettuce biomass towards enrichment in 13C. Based on the previously developed model of carbon isotope fractionation in a photosynthesizing cell, carbon isotopic shifts of plant leaf biomass were analyzed. It is shown that in the dark period the biomass is enriched in 12C. This is a consequence of dark respiration, during which the plant loses CO2 enriched in 13C. It is shown that the reason for the observed isotopic differences between the water-soluble and water-insoluble fractions of the leaf biomass is a result of the different participation of the assimilatory carbon flux, enriched in 12C, and the photorespiratory carbon flux, enriched in 13C, in the formation of these fractions during photosynthesis.

Impact of the solubility of phenolic compounds from Highland Barley (Hordeum vulgare L.) on their antioxidant property and protein binding affinity

The impact of the solubility of phenolic compounds (PCs) from highland barley (HB) on their antioxidant property and protein binding affinity was investigated. HB-PCs from the phenolic extract (HBE) were analyzed through the UPLC-QTOF-MS, and five fractions were further divided based on their water solubility. Representative compounds of proanthocyanidins, (+)-catechins, and (−)-epicatechin from water fraction (HB–W, 197.67 ± 4.8 μmol GAE/100 g) were significantly correlated with the antioxidant activity of the HBE. In contrast, the PCs enriched in the acetone fraction (HB-A, 60.2 ± 3.1 μmol GAE/100 g) with a structure of 2-phenyl chromogen ketone group (such as rutin, kaempferol, hesperidin, and quercetin) were positively correlated with the protein binding affinity. Further analysis showed that the water-insoluble HB-A fraction significantly lowered the starch digestibility (37.5%) and postprandial glycemia (17.8%) compared to HB-W fractions. Thus, the solubility of PCs is intimately associated with their biological functions as antioxidants or protein-binding ligands, indicating PCs with strong antioxidant properties or high protein binding affinity are structurally distinct from each other, and the physical properties of phenolic compounds might be an important factor to further the understanding of their health functions and mechanisms.

Lactic Acid Production from Lignocellulosic Residues: A Case Study Toward Process Integration

AbstractIn this study, the production of lactic acid from municipal forestry and greening wastes processed by steam explosion (SE) and enzymatic hydrolysis is addressed. The liquid fraction hydrolysate (LFH) obtained after filtration of the steam‐exploded slurry (previously subjected to detoxification) and the enzymatic hydrolysate resulting from the water insoluble solid fraction (WIS‐derived hydrolysate, WDH) are studied as substrate for lactic acid fermentation using an integrated strategy. The fermentation process of WDH using Bacillus coagulans and Lactobacillus rhamnosus shows similar sugar conversion yields of about 0.9 g g−1 (based on consumed glucose). In contrast, the use of detoxified LFH (d‐LFH) completely inhibits B. coagulans, making necessary a previous dilution with the WDH to trigger fermentation when using this microorganism. The best integrated strategy using both d‐LFH and WDH streams and B. coagulans as fermentative strain has a 1:3 d‐LFH:WDH ratio, yielding 0.93 g lactic acid g−1 of consumed sugars and a lactic acid concentration of about 50 g L−1.

Characteristics of Organic Matter Composition and Oxidation Potential in Road Dust in Winter in Xi'an

Roads are the main places where urban people are exposed to atmospheric particulate matter from outdoor activities, and certain oxidatively active substances contained in road particulate matter are important components that induce the generation of reactive oxygen species (ROS), which in turn endanger human health. Here, we explored the characteristics of organic matter composition in water-soluble (WSM) and methanol-soluble fractions (MSM) of road dust in Xi'an and its oxidation potential (OP). Additionally, we investigated the organic fractions and their distribution based on parallel factor analysis (PARAFAC) and analyzed the correlation between organic matter types and OP. The results showed that the water-insoluble fraction of road dust in Xi'an contained more chromophoric organic matter with an average total concentration of (4.71±1.27)×104 R.U., which was 12 times higher than that of WSM[(3.96±1.10)×103 R.U.], of which low-oxidizing humic-like substances (HULIS) were the main organic matter (34.8%-43.7% of the total organic matter). The results of cluster analysis showed that the important sources of organic matter in road dust in Xi'an were fuel combustion and industrial production. The mean value of dust oxidative toxicity was (0.34±0.08) pmol·(min·μg)-1, with the water-insoluble fraction providing 70% of the total oxidative toxicity of dust particles, which was 2.4 times higher than the water-soluble fraction. The main precursors of oxidative toxicity of dust particles were metal elements, and special types of organic substances were also one of the important oxidative toxicity precursors, among which chromophore organic matter was the main cause of OP production in the WSM fraction (r=0.35, P<0.01), and protein-like organic matter and highly oxidized HULIS in WSM may have been the main two types of organic substances for OP production. However, there was no significant correlation between organic matter concentration in MSM and water-insoluble OP (OPTotal-OPWSM) (r=-0.04, P>0.1), so the oxidative toxicity of the water-insoluble particulate matter fraction was mainly generated from non-organic matter.

Formulation and characterization of sustainable bioadhesive films for wound treatment based on barley β-glucan extract obtained using the high power ultrasonic technique

β-glucan is a well-known functional and bioactive food ingredient. Recently, some studies highlighted several interesting pharmacological activities, such as hypocholesterolemic, hypoglycemic, immunomodulatory, antitumor, antioxidant and anti-inflammatory. The aim of this study is to evaluate a novel application of β-glucan, obtained from barley, for the development of formulations for skin use. Several water suspensions were obtained from barley flour of different particle sizes treated by high power ultrasonic (HPU) technique. Barley flour fraction in the range of 400–500 μm allowed to obtain a stable suspension, represented both by a water soluble and water insoluble fraction of β-glucans, that showed excellent film forming ability. The plasticizer sorbitol as well as the bioadhesive biopolymer acacia gum were added to this suspension in order to obtain a gel suitable to prepare films by casting. The obtained films demonstrated suitable mechanical properties and ability to stimulate in vitro keratinocytes growth suggesting its possible application in dermatological field as for wound treatment. This study demonstrated the dual use of barley suspension: as excipient and as active ingredient.

More water-soluble brown carbon after the residential “coal-to-gas” conversion measure in urban Beijing

The implementation of air pollution reduction measures has significantly reduced the concentration of atmospheric fine particles (PM2.5) in Beijing, among which the “coal-to-gas” conversion measures may play a crucial role. However, the effect of this conversion measure on brown carbon (BrC) is not well known. Here, the chemical composition of BrC in humic-like fraction (HULIS-BrC) and water-insoluble fraction (WI-BrC) were characterized for ambient PM2.5 samples collected in Beijing before and after the “coal-to-gas” conversion measure. After the conversion measure, the number of HULIS-BrC compounds increased by ~14%, while the number of WI-BrC compounds decreased by ~8%. The intensity of over 90% of HULIS-BrC compounds also increased after the conversion measure, and correspondingly the O/C ratios of CHO and CHON compounds in HULIS-BrC fraction generally increased with the increase of intensity ratios after/before the conversion measure, indicating that there were more water-soluble highly oxygenated BrC compounds after “coal-to-gas” conversion measure. On the contrary, the intensity of more than 80% of WI-BrC compounds decreased after the conversion measure, and the O/C ratios of CHO and CHON compounds in WI-BrC fraction generally decreased with the decrease of intensity ratios after/before the conversion measure, indicating that after the “coal-to-gas” conversion measure the water-insoluble low oxygenated BrC compounds decreased. This work sheds light on the differences in the chemical composition of BrC between before and after the “coal-to-gas” conversion measure and suggests that future studies on the residential coal combustion BrC and secondary BrC deserve further exploration.