Native Extracts Research Articles

Nanoencapsulation of Phenolic Extracts from Native Potato Clones (Solanum tuberosum spp. andigena) by Spray Drying.

Native potato clones grown in Peru contain bioactive compounds beneficial to human health. This study aimed to optimize the spray-drying nanoencapsulation of native potato phenolic extracts utilizing a central composite design and response surface methodology, obtaining the optimal treatment to an inlet temperature of 120 °C and an airflow of 141 L/h in the nano spray dryer B-90, which allowed maximizing the yield of encapsulation, antioxidant capacity (DPPH), encapsulation efficiency (EE), total phenolic compounds, and total flavonoids; on the other hand, it allowed minimizing hygroscopicity, water activity (Aw), and moisture. Instrumental characterization of the nanocapsules was also carried out, observing a gain in lightness, reddening of the color, and spherical nanoparticles of heterogeneous size (133.09-165.13 nm) with a negative ζ potential. Thermal, infrared, and morphological analyses confirmed the encapsulation of the core in the wall materials. Furthermore, an in vitro release study of phenolic compounds in an aqueous solution achieved a maximum value of 9.86 mg GAE/g after 12 h. Finally, the obtained nanocapsules could be used in the food and pharmaceutical industry.

Mexican Native Black Bean Anthocyanin-Rich Extracts Modulate Biological Markers Associated with Inflammation.

This work aimed to obtain and characterize anthocyanin-rich extracts (ARE) from native black beans and evaluate their antioxidant and anti-inflammatory potential. The initial extract was obtained by supercritical fluids (RE) and purified using Amberlite® XAD-7 resin (PE). RE and PE were fractionated using countercurrent chromatography, and four fractions were obtained (REF1 and REF2 from RE, PEF1, and PEF2 from PE). ARE and fractions were characterized, and the biological potential was evaluated. ABTS IC50 values ranged from 7.9 to 139.2 (mg C3GE/L), DPPH IC50 ranged from 9.2 to 117.2 (mg C3GE/L), and NO IC50 ranged from 0.6 to143.8 (mg C3GE/L) (p < 0.05). COX-1 IC50 ranged from 0.1 to 0.9 (mg C3GE/L), COX-2 IC50 ranged from 0.01 to 0.7 (mg C3GE/L), and iNOS IC50 ranged from 0.9 to 5.6 (mg C3GE/L) (p < 0.05). The theoretical binding energy for phenolic compounds ranged from -8.45 to -1.4 kcal/mol for COX-1, from -8.5 to -1.8 kcal/mol for COX-2, and from -7.2 to -1.6 kcal/mol for iNOS. RE and REF2 presented the highest antioxidant and anti-inflammatory potential. Countercurrent chromatography effectively isolates and purifies bioactive compounds while maintaining their biological potential. Native black beans present an attractive phytochemical profile and could be used as ingredients in nutraceuticals and functional foods.

Structural analysis of an endogenous 4-megadalton succinyl-CoA-generating metabolon

The oxoglutarate dehydrogenase complex (OGDHc) participates in the tricarboxylic acid cycle and, in a multi-step reaction, decarboxylates α-ketoglutarate, transfers succinyl to CoA, and reduces NAD+. Due to its pivotal role in metabolism, OGDHc enzymatic components have been studied in isolation; however, their interactions within the endogenous OGDHc remain elusive. Here, we discern the organization of a thermophilic, eukaryotic, native OGDHc in its active state. By combining biochemical, biophysical, and bioinformatic methods, we resolve its composition, 3D architecture, and molecular function at 3.35 Å resolution. We further report the high-resolution cryo-EM structure of the OGDHc core (E2o), which displays various structural adaptations. These include hydrogen bonding patterns confining interactions of OGDHc participating enzymes (E1o-E2o-E3), electrostatic tunneling that drives inter-subunit communication, and the presence of a flexible subunit (E3BPo), connecting E2o and E3. This multi-scale analysis of a succinyl-CoA-producing native cell extract provides a blueprint for structure-function studies of complex mixtures of medical and biotechnological value.

Encapsulation of St. John's Wort extract in β-Cyclodextrin carrier: In-vitro antioxidant, antimicrobial and Caco-2 cell viability studies

St. John's wort (SJW) is a plant flowering species, and its extract shows antidepressant, anticancer, wound-healing, antibiotic, antiviral, antioxidant, anxiolytic and anti-inflammatory activities. However, SJW extract has low aqueous solubility and biological efficacy; it might be due to the presence of lipophilic components such as hyperforin and hypericin. To increase the aqueous solubility of SJW extract, in the present report an attempt has been made to prepare SJW extract/β-cyclodextrin inclusion complex (IC). The LCMS analysis of SJW extract showed the presence of hyperforin and hypericin components. Morphological investigation depicted the spherical shaped mono-disperse particles of 30 nm size and DLS confirmed hydrodynamic diameter around 100 nm. The encapsulation efficiency of IC was 76%, and 92% SJW components were released from IC in 13.3 h. Caco-2 cell viability study pointed towards improved safety profile of SJW extract after β-CD complex formation. Furthermore, synthesized IC showed higher antioxidant activity than native SJW extract. The prepared IC showed moderate antimicrobial activity for Escherichia coli (E. coli), Enterococcus faecalis (E. faecalis) and Bacillus cereus (B. cereus. The work would help to enhance the biological efficacy of SJW extract.

Does AlphaFold2 model proteins’ intracellular conformations? An experimental test using cross-linking mass spectrometry of endogenous ciliary proteins

A major goal in structural biology is to understand protein assemblies in their biologically relevant states. Here, we investigate whether AlphaFold2 structure predictions match native protein conformations. We chemically cross-linked proteins in situ within intact Tetrahymena thermophila cilia and native ciliary extracts, identifying 1,225 intramolecular cross-links within the 100 best-sampled proteins, providing a benchmark of distance restraints obeyed by proteins in their native assemblies. The corresponding structure predictions were highly concordant, positioning 86.2% of cross-linked residues within Cɑ-to-Cɑ distances of 30 Å, consistent with the cross-linker length. 43% of proteins showed no violations. Most inconsistencies occurred in low-confidence regions or between domains. Overall, AlphaFold2 predictions with lower predicted aligned error corresponded to more correct native structures. However, we observe cases where rigid body domains are oriented incorrectly, as for ciliary protein BBC118, suggesting that combining structure prediction with experimental information will better reveal biologically relevant conformations.

Enabling cryo-EM density interpretation from yeast native cell extracts by proteomics data and AlphaFold structures.

In the cellular context, proteins participate in communities to perform their function. The detection and identification of these communities as well as in-community interactions has long been the subject of investigation, mainly through proteomics analysis with mass spectrometry. With the advent of cryogenic electron microscopy and the "resolution revolution," their visualization has recently been made possible, even in complex, native samples. The advances in both fields have resulted in the generation of large amounts of data, whose analysis requires advanced computation, often employing machine learning approaches to reach the desired outcome. In this work, we first performed a robust proteomics analysis of mass spectrometry (MS) data derived from a yeast native cell extract and used this information to identify protein communities and inter-protein interactions. Cryo-EM analysis of the cell extract provided a reconstruction of a biomolecule at medium resolution (∼8 Å (FSC=0.143)). Utilizing MS-derived proteomics data and systematic fitting of AlphaFold-predicted atomic models, this density was assigned to the 2.6 MDa complex of yeast fatty acid synthase. Our proposed workflow identifies protein complexes in native cell extracts from Saccharomyces cerevisiae by combining proteomics, cryo-EM, and AI-guided protein structure prediction.

Synthesis of ZnO nanoparticles from zinc acetate dihydrate – An environmental friendly technique

The present work describes a plant-mediated method for the synthesis of Zinc Oxide (ZnO) nanoparticles. The native medicinal herb Pistia Stratiotes plant extract and the Zinc Acetate derivative were used to successfully produce the ZnO nanoparticles (NPs). Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy were used to analyze the ZnO nanoparticles that were produced. The morphology and shape of the NPs were examined using SEM. The functional group present in the leaf extract was determined by FTIR spectroscopy and the CH stretching and NH bonding of ZnO were also observed. The antibacterial activity of ZnO NPs was examined against gram-negative and gram-positive bacterial strains such as Klebsiella Pneumoniae and Bacillus Subtilis in different solvent extracts. The synthesized ZnO NPs exhibited significant inhibitory activity against the pathogenic bacterial strains.

Chemical Composition and Biological Activities of Lavandula coronopifolia Poir Extracts: A Comparison between Callus Culture and Native Plant

Nowadays, according to the development and high functions of in vitro cultivation, one of the questions that researchers are looking for is whether the characteristics and compositions of the obtained product meet the needs of the society or not. Therefore, this research was done aimed to compare the bioactive characteristics of callus and native plant aqueous extracts of Lavandula coronopifolia Poir. Thus, two different culture media were utilized for calluses’ growth. Extracts from these calluses and native plants were obtained using the sequential ultrasound-microwave assisted extraction (SUMAE) method. The extraction conditions were a constant temperature of 70°C ultrasound in 20 min at 250 W and 8 minutes at 800 W for microwave at 85°C. At first, results revealed that callus cultures were not able to produce any significant amounts of essential oil. Therefore, aqueous extracts obtained from calluses as well as the natural plant were examined in terms of antioxidant activity, total phenolic content, total flavonoid content, and antimicrobial activity. Moreover, their volatile components were detected with GC-MS. Both DPPH and FRAP techniques demonstrated that the callus on MS + Auxin had stronger antioxidant activity than the other callus and native plant. It also had the greatest total phenolic content. In terms of total flavonoid content, the native plant has the highest value. Generally, it can be concluded that the extract of callus on MS + Auxin has shown significant activity against the tested microorganisms than the other samples.

Phytochemicals, Antioxidant Activities, and Toxicological Screening of Native Australian Fruits Using Zebrafish Embryonic Model.

Phytochemicals play a pivotal role in human health and drug discovery. The safety evaluation of plant extracts is a prerequisite to ensure that all phytochemicals are safe before translational development and human exposure. As phytochemicals are natural, they are generally considered safe, although this is not always true. The objective of this study was to investigate and compare the phytochemical composition, antioxidant potential, and safety evaluation of native Australian Muntries (Kunzea&amp;nbsp;pomifera), Kakadu plum (Terminalia&amp;nbsp;ferdinandiana), Davidson plum (Davidsonia) and Quandong peach (Santalum&amp;nbsp;acuminatum) through the in vivo vertebrate zebrafish embryonic model. The highest total phenolic content (TPC; 793.89 ± 22.27 μg GAE/mg) was quantified in Kakadu plum, while the lowest TPC (614.44 ± 31.80 μg GAE/mg) was quantified in Muntries. Developmental alterations, mortality, and morbidity were assessed for toxicological screening of these selected native Australian fruit extracts. In this study, muntries were quantified as having the least LC50 value (169 mg/L) compared to Davidson plum (376 mg/L), Kakadu plum (&gt;480 mg/L), and Quandong peach (&gt;480 mg/L), which indicates that muntries extract was more toxic than other fruit extracts. Importantly, we found that adverse effects were not correlated to the total phenolic content and antioxidant potential of these native Australian fruits and cannot simply be predicted from the in vitro analysis. Conclusively, these selected native Australian fruit extracts are categorized as safe. This study could explore the use of these native Australian fruits in cosmetics, pharmaceuticals, and drug discovery.

Octenyl succinylated potato starch-based film reinforced by honey-bee products: Structural and functional properties

Edible films were developed from native or octenyl succinylated potato starches and extracts from the following honey-bee products: multifloral honey, buckwheat honey, bee-pollen, bee-bread or propolis. Pasting and rheology properties of film-forming suspensions as well as structural characteristic and physical properties of the produced films were studied. The results showed that esterified starch and the honey-bee extracts (HBE) changed film properties in a different way, depending on the type of the extract. The pasting and rheological properties were improved as a result of both starch esterification and incorporation of the HBE. The FTIR-ATR spectroscopy of films indicated that some molecular interactions between the starch and the HBE may have occurred. The films made from the esterified starch showed significantly lower tensile strength, elasticity, thermal transition parameters (enthalpy - ΔH and onset - To, peak - Tp, end - Te temperatures), as well as higher swelling as compared to the native starch films. All films were characterized by a high structural integrity, however films based on esterified starch and reinforced with HBE exhibited a rough and folding surface. Bee-bread and propolis extracts seem to be the most promising HBE for production of films due to the ability to reduce solubility and thermal transition parameters as well as to improve mechanical properties of the films.

Pharmacognostic studies of Trifolium fragiferum L. flora of Southern Ukraine

The work is devoted to the study of herbs of the representative genus Clover Trifolium fragiferum L. from the south Ukrainian flora. The aim of this research is to investigate the representative of Southern Ukraine flora Trifolium fragiferum L. which has a sufficient raw material base and use in folk medicine. Materials and methods. Samples were grown in the suburbs of Zaporizhzhia and harvested during full flowering (May – June). Microscopic analysis was performed with temporary preparations of leaves and stems. Plant extracts were analyzed chromatographically using an Agilent Technologies 6890 gas chromatograph with mass spectrometric detection. Results. The leaf is covered with parenchymal cells with slightly thickened membranes with anocytic stomata. The main parenchyma is composed of rounded toxoid cells. Stem rounded, covered with elongated parenchymal cells with thin membranes with almost no stomata and pubescence. Central axial cylinder is of beam type. Beams are open collateral, large. Above the phloem of the bundles is a multilayered sclerenchyma. The core is partially filled, hollow in the center. 63 compounds were found in the native extract, of which 37 were identified: coumarins, fatty acids, diterpene alcohols, oxygenated hydrocarbons of terpenoid nature, higher hydrocarbons, representatives of phytosterols, and phytosterols. After acid hydrolysis with sulfuric acid, 58 compounds were found, of which 49 were identified: coumarins, alcohols and phenols, aldehydes and ketones, compounds of diterpene nature. Conclusions. Pharmacognostic analysis of the genus Clover Trifolium fragiferum L. revealed diagnostic microscopic signs of leaves and stems. The components of the native extract are compared, and after its acid hydrolysis. Certain regularities in the distribution of classes of substances that characterized certain types of extracts were revealed: monoterpenoids, aromatic, heterocyclic compounds characterized the hydrolyzed product. Sesquiterpenes and steroid compounds are found only in the native extract of strawberry clover herb. Alcohols, aldehydes, and ketones were the majority in the hydrolyzed extract, and hydrocarbons were observed more in the native. Only 5 components were identified in both extracts: nonacosan, 2-phenoxyethanol, loliolide, dihydroactinidiolide and coumarin with significant differences in amounts.

Metabolite Profiling and Biological Activity Assessment of Casuarina equisetifolia Bark after Incorporating Gold Nanoparticles.

Casuarina equisetifolia bark is rich in various active metabolites and selected to be studied due to limitation of the synthetic antioxidants that have adverse side effects. The present study aimed to enhance efficiency of the most effective extract by incorporating gold nanoparticles (Au-NPs). The phytochemical and biological measurements were carried out in total methanolic extract and its successive fractions. Moreover, these measurements were assayed in the most effective extract after incorporating Au-NPs. The study revealed that total methanolic extract exhibited the highest biological and cytotoxic activities as compared to other fractions. Therefore, it is considered as good candidate for nano-extract preparation. The methanolic extract incorporated with Au-NPs showed higher antioxidant, scavenging and cytotoxic activities in addition to higher inhibitory effect against α-amylase activity as compared to native extract itself. To pinpoint active agents in total methanolic extract, the secondary metabolite profiling via HPLC-MS showed that 33 and 17 metabolites were annotated in the extract before and after incorporating Au-NPs, respectively. The median lethal dose (LD50) showed that gold total methanolic nano-extract is safer than total methanolic extract. This study concluded that total methanolic C. equisetifolia bark extract is a valuable bioresource to synthesize an eco-friendly Au-NPs with health-enhancing effect as antioxidant, antidiabetic and cytotoxic agents. The present study is considered as the first report on utilization of C. equisetifolia bark in synthesis of Au-NPs by mean of green nanotechnology and investigation of its biological activity in relation to its metabolite fingerprint.

Mitochondrial membrane models built from native lipid extracts: Interfacial and transport properties.

The mitochondrion is an essential organelle enclosed by two membranes whose functionalities depend on their very specific protein and lipid compositions. Proteins from the outer mitochondrial membrane (OMM) are specialized in mitochondrial dynamics and mitophagy, whereas proteins of the inner mitochondrial membrane (IMM) have dedicated functions in cellular respiration and apoptosis. As for lipids, the OMM is enriched in glycerophosphatidyl choline but cardiolipin is exclusively found within the IMM. Though the lipid topology and distribution of the OMM and IMM are known since more than four decades, little is known about the interfacial and dynamic properties of the IMM and OMM lipid extracts. Here we build monolayers, supported bilayers and giant unilamellar vesicles (GUVs) of native OMM and IMM lipids extracts from porcine heart. Additionally, we perform a comparative analysis on the interfacial, phase immiscibility and mechanical properties of both types of extract. Our results show that IMM lipids form more expanded and softer membranes than OMM lipids, allowing a better understanding of the physicochemical and biophysical properties of mitochondrial membranes.

Potential for silvopastoral systems to control nematode burden in livestock farming in winter rainfall areas of South Australia, Australia

Gastrointestinal nematode infections cause significant production losses in ruminants. In southern Australia, the estimated annual cost of internal parasites in sheep, cattle and goats are $436million, $82m and $2.54m, respectively. An over-reliance on anthelmintic treatments has resulted in anthelmintic resistance becoming an increasing concern for producers. Reducing the need for chemical anthelmintics is desirable to lower producer costs and limit the development of anthelmintic resistance. Condensed tannins found in many trees and forages are a plant secondary compound receiving considerable interest as an alternative anthelmintic strategy. Direct anthelmintic effects from condensed tannins are associated with the binding of larval proteins; slowing egg hatching, larval development and exsheathment. Indirect effects are associated with improvements to protein metabolism and immune function within the animal. Several native Australian tree extracts have demonstrated anthelmintic properties, but further research is required to assess their suitability for silvopastoral systems in South Australia.

Evaluation of the skin protective effects of niosomal-entrapped annona squamosa against UVA irradiation.

Annona squamosa is a medicinal plant that has been used in folk medicine since antiquity. The goal of this study is to see how effective Annona squamosa leaf extract (A.S.L.E) or its niosomal-entrapped preparation is at protecting skin from UVA irradiation. The prepared niosomal-entrapped A.S.L.E has been characterized via spectrophotometry and transmission electron microscopy imaging. Furthermore, the entrapment efficiency and in vitro release of A.S.L.E were determined. In this study, ex vivo and freshly prepared samples from the dorsal region of the rats' skin were used as biological samples, which were divided into five groups: control UVA-unexposed, unprotected UVA-exposed, A.S.L.E-protected UVA-exposed, and niosomal-entrapped A.S.L.E UVA-exposed. UVA irradiation was performed by exposing the skin samples to a UVA-producing lamp for 4h. Samples from various groups were then examined using FTIR spectroscopy, histopathology, and protein electrophoresis methods. The results showed that A.S.L.E has a skin protective effect against UVA irradiation. The niosomal-entrapped A.S.L.E was more effective than the native plant leaf extract in protecting skin from the damaging effects of UVA. Therefore, the nanotechnologically formulated preparation, niosomal-entrapped A.S.L.E, can be used as an effective photoprotector (sunscreen) against the adverse effects of UVA radiation.

KCNQ5 activation by tannins mediates vasorelaxant effects of barks used in Native American botanical medicine.

Tree and shrub barks have been used as folk medicine by numerous cultures across the globe for millennia, for a variety of indications, including as vasorelaxants and antispasmodics. Here, using electrophysiology and myography, we discovered that the KCNQ5 voltage-gated potassium channel mediates vascular smooth muscle relaxant effects of barks used in Native American folk medicine. Bark extracts (1%) from Birch, Cramp Bark, Slippery Elm, White Oak, Red Willow, White Willow, and Wild Cherry each strongly activated KCNQ5 expressed in Xenopus oocytes. Testing of a subset including both the most and the least efficacious extracts revealed that Red Willow, White Willow, and White Oak KCNQ-dependently relaxed rat mesenteric arteries; in contrast, Black Haw bark neither activated KCNQ5 nor induced vasorelaxation. Two compounds common to the active barks (gallic acid and tannic acid) had similarly potent and efficacious effects on both KCNQ5 activation and vascular relaxation, and this together with KCNQ5 modulation by other tannins provides a molecular basis for smooth muscle relaxation effects of Native American folk medicine bark extracts.

In Vitro Study on Effect of Zinc Oxide Nanoparticles on the Biological Activities of Croton tiglium L. Seeds Extracts.

Croton tiglium L. seeds were studied against colon cancer induced chemically in rats after incorporating silver nanoparticles (Ag-NPs) but the body has no the ability to discrete silver or silver ions. Therefore, the present study was designed to reveal the biological activities of different C. tiglium L. seeds extracts incorporated with zinc oxide nanoparticles (ZnO-NPs). It was found that C. tiglium L. seeds provided with high contents of total protein (27.43 g/100g), carbohydrate (18.29 g/100 g) and lipid (46.31 g/100 g). The chromatographic techniques revealed that concentrations of the predominant compounds increased in all studied extracts (ethanolic, aqueous and petroleum ether) after incorporating ZnO-NPs. The in vitro biological activities showed that the aqueous extract possessed the highest antioxidant and scavenging activities. It exhibited the highest inhibitory effect on α-amylase (41.89%) and acetyl cholinesterase (AChE) (23.00%) in addition to its higher anti-arthritic activity. All the biological activities increased after incorporating ZnO-NPs. It showed the highest cytotoxic activity that increased after incorporating ZnO-NPs against human colon carcinoma (CACO-2) cells. Therefore, this extract was selected for undergoing further studies on CACO-2 cells. The aqueous extract incorporated with ZnO-NPs arrested growth of CACO-2 cells at G2/M and increased percentage of total apoptotic cells and necrosis. The median lethal dose (LD50) showed that the extracts incorporated with ZnO-NPs were safer than the native extracts. The study showed that the aqueous extract was the most active extract that consequently exhibited promising biological activities after incorporating ZnO-NPs.

Isolation and Characterization of Uricase Produced from Chicken Liver

Uricase is an enzyme that degrades uric acid into allantoin. One of the uricase sources is obtained from chicken species (Gallus gallus domesticus) liver which are broiler and native chicken. This study aims to determine the maximum uricase activity in broiler and native chicken liver. The uricase activity was obtained by measuring the uric acid concentration as uricase substrate using spectrophotometric method and wavelength at 291 nm. Uricase isolation was carried out into extraction process, ammonium sulfate fractionation (0-60% saturation of ammonium sulfate), and dialysis. During isolation process, centrifugation speed was also optimized to obtain the maximum uricase crude extract and uricase activity. The molecular weight of uricase was also determined by SDS PAGE. The result showed that the highest uricase activity remained using centrifugation speed of 15,000 rpm. The optimum uricase fraction for broiler chicken liver was obtained at 20-40% saturation of ammonium sulfate with uricase activity was 1.854 x 10-2 U/mg, and the uricase fraction for native chicken liver was obtained at 40-60% saturation of ammonium sulfate with uricase activity was 2.496 x 10-2 U/mg. The optimum fraction for uricase production and isolation is carried out to the dialysis process. The optimum uricase activity of broiler chicken liver crude extract was 4.921 x 10-4 U/mg, the uricase fraction was 3.989 x 10-3 U/mg, and the dialysate was 5.120 x 10-3 U/mg. While the native chicken liver crude extract was 2.980 x 10-4 U/mg, the uricase fraction was1.415 x 10-2 U/mg, and the dialysate was 1.753 x 10-2 U/mg. The molecular weight of the uricase was around 35 kDA according to the SDS PAGE result.

Estimation of Iron Availability in Modified Cereal β-Glucan Extracts by an in vitro Digestion Model.

For cereal-based foods rich in dietary fibers, iron bioavailability is known to be poor. For native cereal β-glucan extracts, literature has demonstrated that the main factor impacting the bioavailability is phytic acid, which is often found in association with dietary fibers. During food processing, β-glucan can undergo modifications which could potentially affect the equilibrium between phytic acid, fiber, and iron. In this study, an in vitro digestion was used to elucidate the iron dialysability, and hence estimate iron availability, in the presence of native, chelating resin (Chelex)-treated, oxidised, or partially hydrolysed oat and barley β-glucan extracts (at 1% actual β-glucan concentration), with or without phytase treatment. It was confirmed that pure, phytic acid-free β-glucan polysaccharide does not impede iron availability in cereal foods, while phytic acid, and to a smaller extent, also proteins, associated to β-glucan can do so. Neither Chelex-treatment nor partial hydrolysis, 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) or NaIO4 oxidation significantly influenced the phytic acid content of the β-glucan extracts (ranging 2.0–3.9%; p > 0.05). Consequently, as long as intrinsic phytic acid was still present, the β-glucan extracts blocked the iron availability regardless of source (oat, barley) or Chelex-treatment, partial hydrolysis or NaIO4-oxidation down to 0–8% (relative to the reference without β-glucan extract). Remarkably, TEMPO-oxidation released around 50% of the sequestered iron despite unchanged phytic acid levels in the modified extract. We propose an iron-mobilising effect of the TEMPO product β-polyglucuronan from insoluble Fe(II)/phytate/protein aggregates to soluble Fe(II)/bile salt units that can cross the dialysis membrane. In addition, Chelex-treatment was identified as prerequisite for phytase to dramatically diminish iron retention of the extract for virtually full availability, with implications for optimal iron bioavailability in cereal foods.

Effect of Steam Explosion on Structural Characteristics of β-Conglycinin and Morphology, Chemical Compositions of Soybean Meal.

In this study, steam explosion was applied as a means to degrade β-conglycinin. We investigated changes in morphology, the chemical composition of soybean meal, and the structural characteristics of β-conglycinin. The results showed that steam explosion at 0.7 MPa for 8 min could effectively decrease the β-conglycinin content of soybean meal while the histamine content was not increased. The structural characteristics of soybean meal proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared spectroscopy (FTIR), circular dichroism (CD), and X-ray diffraction (XRD). Steam explosion caused the degradation of high weight proteins and reduced the band density of α’, α, and β subunits in β-conglycinin. The micro-surface of soybean meal seemed to be in the cracked or puffed stage and the color became brown or dark after steam explosion. Steam explosion facilitated the dissolution of water-extractable arabinoxylans, which are 4.81 fold higher than that of native soybean meal. Phytic acid was exposed to the hydrothermal environment of the steam explosion process and consequently degraded by 12.95–24.69%. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of soybean meal extract was gradually increased from 20.70 to 33.71% with the rising of treated pressure from 0.3 to 0.7 MPa, which was 1.11–1.81 fold of native extract. The steam explosion may be a new modification technology that could decrease antigenicity, and steam-exploded soybean meal (0.7 MPa, 8 min) with lower β-conglycinin and phytic acid content that could be widely used in food products.