Protein Fractionation of Green Leaves as an Underutilized Food Source—Protein Yield and the Effect of Process Parameters

Green biomass has potential as a sustainable protein source for human consumption, due to its abundance and favorable properties of its main protein, RuBisCO. Here, protein fractionation outcomes of green leafy biomass from nine crops were evaluated using a standard protocol with three major steps: juicing, thermal precipitation, and acid precipitation. Successful protein fractionation, with a freeze-dried, resolubilized white protein isolate containing RuBisCO as the final fraction, was achieved for seven of the crops, although the amount and quality of the resulting fractions differed considerably between crops. Biomass structure was negatively correlated with successful fractionation of proteins from biomass to green juice. The proteins in carrot and cabbage leaves were strongly associated with particles in the green juice, resulting in unsuccessful fractionation. Differences in thermal stability were correlated with relatedness of the biomass types, e.g., Beta vulgaris varieties showed similar performance in thermal precipitation. The optimal pH values identified for acid precipitation of soluble leaf proteins were lower than the theoretical value for RuBisCO for all biomass types, but with clear differences between biomass types. These findings reveal the challenges in using one standard fractionation protocol for production of food proteins from all types of green biomass and indicate that a general fractionation procedure where parameters are easily adjusted based on biomass type should instead be developed.

Innovative Characterization of Particulate Matter Deposited on Urban Vegetation Leaves through the Application of a Chemical Fractionation Procedure

In this study, we have evaluated the efficiency of a chemical fractionation procedure for the characterization of both the water-soluble and the insoluble fraction of the main elemental components of particulate matter (PM) deposited on urban leaves. The proposed analytical approach is based on the chemical analysis of leaf washing solutions and membrane filters used for their filtration. The ionic concentration of leaf washing solutions was compared with their electrical conductivity, making it a valuable proxy for the quantification of the water-soluble and ionic fraction of leaf deposited PM. The chemical composition of both the water-soluble and the insoluble fraction of PM, resulting from this fractionation procedure, was compared with results obtained by scanning electron microscopy coupled with energy-dispersed X-Rays spectroscopy (SEM/EDX) and processed through chemometrics. Results obtained proved that the proposed approach is able to provide an estimation of total leaf deposited PM and it is highly reliable for the evaluation of the emission impact of different PM sources, being able to increase the selectivity of PM elemental components as specific source tracers; consequently providing useful information also for the assessment of human health risks.

Lignin Precipitation and Fractionation from OrganoCat Pulping to Obtain Lignin with Different Sizes and Chemical Composition

Fractionation of lignocellulose into its three main components, lignin, hemicelluloses, and cellulose, is a common approach in modern biorefinery concepts. Whereas the valorization of hemicelluloses and cellulose sugars has been widely discussed in literature, lignin utilization is still challenging. Due to its high heterogeneity and complexity, as well as impurities from pulping, it is a challenging feedstock. However, being the most abundant source of renewable aromatics, it remains a promising resource. This work describes a fractionation procedure that aims at stepwise precipitating beech wood (Fagus sp.) lignin obtained with OrganoCat technology from a 2-methyltetrahydrofuran solution, using n-hexane and n-pentane as antisolvents. By consecutive antisolvent precipitation and filtration, lignin is fractionated and then characterized to elucidate the structure of the different fractions. This way, more defined and purified lignin fractions can be obtained. Narrowing down the complexity of lignin and separately valorizing the fractions might further increase the economic viability of biorefineries.

ENRICHMENT AND BIOAVAILABILITY OF TOXIC ELEMENTS IN INTENSIVE VEGETABLE PRODUCTION AREAS1

ABSTRACT Vegetable cultivation stands out for intensive use of agricultural inputs due to high nutritional requirements of plants within a short period and their high susceptibility to pests and diseases. This study aimed to identify the main factors responsible for changes in pseudo-total and bioavailable contents of Cd, Cu, Cr, Mn, Ni, Pb, and Zn in soils under intensive vegetable cultivation. Soil samples were collected from 146 sites in Petrópolis (RJ), Brazil, in 2017. The samples were collected at a depth of 0-20 cm in family farm systems during vegetable production period. Pseudo-total contents of toxic elements were determined by the EPA 3050B method. Geochemical fractionation procedure was used based on the BCR method. Pollution indices were also calculated. In general, vegetable producing areas presented low contamination by Cu, Zn, Pb, Mn, and Ni, except for Cd, which showed severe contamination. In areas with the lowest slopes, most of the toxic elements showed increasing contents, reflecting relief influence. Overall, inadequate soil management, intensive application of phosphate, potassium, and organic fertilization, and relief were the most influencing parameters on the enrichment and bioavailability of toxic elements in the soil.

Bioguided Isolation and Structure Identification of Acetylcholinesterase Enzyme Inhibitors from Drynariae Rhizome

Drynariae Rhizome, widely distributed in southern China, was clinically used as a traditional treatment for cognitive disfunction, such as Alzheimer’s disease (AD). The aim of our work was to evaluate the AChE inhibition activities of extracts of Drynariae Rhizome and pure compounds using a bioguided fractionation procedure. The classical approach for screening potential AChE inhibitors was developed by Ellman. However, the background color of compounds or herb extracts remained uncertain and frequently interfered with the detection of the secondary reaction, thereby easily yielding false positive or false negative results. Here, a high-throughput assay monitoring the transformation of iodized choline from iodized acetylcholine catalyzed by AChE was established based on UPLC-MS/MS. The bioguided fractionation of the extract using this method resulted in the isolation of eight AChE inhibitory flavonoids, including naringenin, eriodictyol, kaempferol, luteolin, astragalin, luteolin-7-O-β-D-glucoside, naringin, and neoeriocitrin, with the IC50 values of 3.81 ± 0.21 μM, 7.19 ± 0.62 μM, 11.09 ± 1.02 μM, 17.26 ± 0.23 μM, 18.24 ± 2.33 μM, 17.13 ± 1.02 μM, 26.4 ± 1.17 μM, and 22.49 ± 1.25 μM. It is assumed that the identified flavonoids contribute to the AChE inhibition activity of Drynariae Rhizome. These results are in agreement with the traditional uses of Drynariae Rhizome for AD.

Organo-Mineral Interactions Are More Important for Organic Matter Retention in Subsoil Than Topsoil

Decomposing crop residues contribute to soil organic matter (SOM) accrual; however, the factors driving the fate of carbon (C) and nitrogen (N) in soil fractions are still largely unknown, especially the influence of soil mineralogy and autochthonous organic matter concentration. The objectives of this work were (1) to evaluate the retention of C and N from crop residue in the form of occluded and mineral-associated SOM in topsoil (0–20 cm) and subsoil (30–70 cm) previously incubated for 51 days with 13C-15N-labelled corn residues, and (2) to explore if specific minerals preferentially control the retention of residue-derived C and N in topsoil and subsoil. We used topsoil and subsoil having similar texture and mineralogy as proxies for soils being rich (i.e., topsoil) and poor (i.e., subsoil) in autochthonous organic matter. We performed a sequential density fractionation procedure and measured residue-derived C and N in occluded and mineral-associated SOM fractions, and used X-ray diffraction analysis of soil density fractions to investigate their mineralogy. In accordance with our hypothesis, the retention of C and N from crop residue through organo-mineral interactions was greater in subsoil than topsoil. The same minerals were involved in the retention of residue-derived organic matter in topsoil and subsoil, but the residue-derived organic matter was associated with a denser fraction in the subsoil (i.e., 2.5–2.6 g cm−3) than in the topsoil (i.e., 2.3–2.5 g cm−3). In soils and soil horizons with high clay content and reactive minerals, we find that a low SOM concentration leads to the rapid stabilization of C and N from newly added crop residues.

Baicalein-Enriched Fraction Extracted from Oroxylum indicum (L.) Benth. ex Kurz Leaves Exerts Antioxidant and Inhibitory Effects Against Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the most malignant subtype of primary brain cancer. To date, standard clinical treatment for GBM is limited in effectiveness and could impose additional side effects. Recently, numerous bioactive compounds isolated from natural plants appear to have beneficial anti-cancer properties. Here, the GBM inhibitory effect of baicalein, a bioactive flavonoid extracted from Oroxylum indicum (L.) Benth. ex Kurz, was evaluated. Firstly, three solvents were used to extract the baicalein. We found that the binary extraction system, using a combination of petroleum ether and methanol (PM), yielded the highest amount of baicalein (15%) compared to the mono extraction system using methanol (13%) or aqueous (0.04%) only. In order to further enhance the baicalein yield in PM crude extract, it was subjected to an enrichment fractionation procedure, which successfully increased the baicalein by nearly two-fold from the initial crude extract (15%) to the enriched fraction 5 (F5) (29%). The enriched F5 not only showed significantly higher (~2.5-fold) antioxidant properties as compared to the crude extract, it was also found to significantly suppress GBM cell proliferation ~2.5-fold better than the crude extract. In conclusion, this study successfully optimized an extraction procedure for increased yield of baicalein metabolite from O. indicum leaves and enhanced its therapeutic potential for GBM treatment.

Brisk Method for Fractionating and Separating Bio-Crude Oil

A new approach for the analysis of bio-crude oils (BCOs) has been qualitatively explored. The analytical scheme is based on the fractionation of BCO through precipitation in water, freeze-drying, solid phase extraction (SPE) and combinations of analytical techniques for the analysis of fractions. Monomeric components in BCO were characterised using gas chromatography coupled with mass spectrometer and flame ionisation detector (GC-MS/FID). The molecular mass distribution of oligomers was determined using gel permeation chromatography (GPC). The fractionation procedure appeared to have succeeded to a large extent as evident in the detection of various components along their expected fraction in the GC-MS/FID analysis. However, a quantitative analysis of the multiple components in different fractions appeared difficult owing to the loss of many volatile fractions through the fractionation procedure. And less than 7 wt. % of the sugar-related components in the acetylated polar SPE fraction were identified.

UPLC-QTOF-MS-guided isolation of anti-COPD ginsenosides from wild ginseng

Four previously undescribed ginsenosides, along with five known analogues were isolated from wild ginseng by a UPLC-QTOF-MS-guided fractionation procedure.

GEOCHEMICAL ANALYSIS OF KOSTOLAC POWER PLANT FLY ASH: WORKING AND LIVING ENVIRONMENT INFLUENCE ASPECT

The aim of this study is geochemical analysis of flying ash generated by the combustion of lignite in the Kostolac A and B thermal power plants. The fractionation procedure of fly ash samples was done firstly, and then stereomicroscopy, FTIR, SEM / EDS and ICP-OES analyzes. The contents of heavy metals V, Cr, Mn, Co, Ni, Cu, Zn, Cd and Pb were determined. The results showed that the concentrations of the tested heavy metals are within the limits that are not harmful to the human health. However, the mineralogical analysis of the mentioned ash indicates that the present glass and other high-temperature mineralogical components can cause respiratory problems and disfunction of other organs of the inhabitants of Kostolac and the immediate surrounding. The tested fly ash, also, can be used as a material in various fields of industry (e.g. construction). Key words: lignite, fly ash, Kostolac, heavy metals.