Search Results (60)

The processing of peaches generates large quantities of by-products, including peels, pomace, and seeds. Despite containing high levels of bioactive compounds with antioxidant properties, these by-products are often discarded as waste, thereby contributing to increased food waste. The present paper aimed to evaluate the total bioactive compound content in peach pomace and biscuits fortified with various concentrations of peach pomace (5%, 10%, and 15%), with a view to utilizing this valuable by-product in functional foods. Compositional analysis revealed that peach pomace is a significant source of polyphenols (1771.64 mg GAE 100 g⁻¹), flavonoids (478.99 mg RE 100 g⁻¹), and anthocyanins (21.18 mg C3GE 100 g⁻¹), and has a radical scavenging capacity of 40.41%. The FTIR analysis confirmed the presence of multiple functional groups in peach pomace that can be associated with polyphenols, polysaccharides, organic acids, esters, monosaccharides, and structurally bound water. Among the individual phenolic compounds, high concentrations of rutin (8.12 mg 100 g⁻¹), chlorogenic acid (3.77 mg 100 g⁻¹), and sinapic acid (2.70 mg 100 g⁻¹) were recorded. Following the replacement of wheat flour with peach pomace, increases in the content of bioactive compounds were observed. At the maximum level of 15% pomace, the biscuits presented the highest concentrations of polyphenols (444.04 mg GAE 100 g⁻¹), flavonoids (211.11 mg RE 100 g⁻¹), anthocyanins (25.43 mg C3GE 100 g⁻¹), sugars (46.48 g GluE 100 g⁻¹), and radical scavenging activity (27.21%). Similar bands were found in the FTIR spectra of the biscuits, indicating the presence of phenolic compounds and glycosides. The 1366 cm⁻¹ band, which is associated with C–O stretching and C–H and N–H deformation in peach pomace, appeared in the enriched biscuit samples at 1340–1374 cm⁻¹ but not in the control sample. These results suggest that peach pomace represents an ingredient with significant potential for use in the food industry, having the ability to improve the nutritional value of biscuits. Full article

The cheese industry produces millions of tons of lactose-rich whey yearly, of which 50% is discharged into water and soil, leading to significant environmental challenges. In Mexico, cheese whey is repurposed for traditional cheese production. However, another by-product named secondary whey (SW) remains. This study focused on the production of exopolysaccharides (EPSs) via SW fermentation of kefir grains, yielding 632.6 ± 30.8 mg/L of a freeze-dried solid, and the carbohydrate-to-protein ratio stood at 2.89, corresponding to the bound EPS protein content. Through the analysis of Fourier Transform Infrared Spectroscopy (FTIR) spectra, it was determined that EPSs were successfully produced, as a signal was observed between 1200 and 1000 cm⁻¹, characteristic of the glycosidic bonds in polysaccharides. Full article

Dragon fruit (Hylocereus spp.), a globally popular tropical fruit, is highly regarded for its unique sensory attributes and potential health benefits. However, the volatile organic compound (VOC) profiles that define its aroma and flavor are underexplored. This exploratory study investigates the VOC profiles of Australian-grown and imported dragon fruit, focusing on free volatiles and glycosidically bound volatiles released through acid and enzymatic hydrolysis. The analysis aims to uncover the competitive advantages of Australian-grown dragon fruit, providing a scientific foundation for establishing industry standards in Australia, where such standards are currently absent. Using gas chromatography–mass spectrometry (GC-MS) and statistical analysis such as principal component analysis (PCA), this study revealed significant differences in VOC profiles influenced by variety and growing region. Northern Territory-grown white-fleshed dragon fruit (NTW) displayed the most diverse and unique volatile profile, with key unique contributors such as acetoin, phenylethyl alcohol, and prenol, highlighting its potential as a premium product. Despite regional similarities, Queensland-grown white- (QLDW) and red-fleshed (QLDR) dragon fruit exhibited distinct profiles, with compounds such as farnesol and linoleic acid ethyl ester serving as distinguishing markers. Overseas white- (OverseasW) and red-fleshed (OverseasR) samples had less complex profiles, likely related to earlier harvesting and postharvest treatments, emphasizing the impact of such practices on volatile complexity. Glycosidically bound volatiles were identified as latent precursors that enhance aroma during ripening and processing. This research underscores the importance of VOC profiling in potentially assisting with establishing industry standards for Australian dragon fruit, enabling the differentiation of domestic varieties from imports and enhancing market competitiveness. As this is a novel and exploratory study, future research should prioritize the identification of unknown compounds and refine methodologies to better understand the dynamic changes in VOCs during storage and ripening. These findings provide valuable insights for optimizing postharvest practices and developing standards that support the Australian dragon fruit industry’s growth and global positioning. Full article

Agunmu (ground herbal medicine) is a form of West African traditional medicine consisting of a cocktail of herbs. The goal of this study is to evaluate a formulation of Agunmu made from M. indica, A. repens, E. chlorantha, A. boonei, and B. ferruginea, sold in the open market and commonly used for the treatment of malaria by the locals, for its antimalarial effects and to determine the active principles that may contribute to the antimalarial effect. The ethanolic extract obtained from this formulation (Ag-Iba) was analyzed, using TLC, LC-MS, and Tandem-MS techniques, to determine its phytochemical properties. The extract was tested in vitro against representative bacteria strains, cancer and normal human cell lines, and susceptible (D6) and resistant (W2) Plasmodium falciparum. In subsequent in vivo experiments, graded doses of the extract were used to treat mice infected with chloroquine-susceptible (NK-65) and chloroquine-resistant (ANKA) strains of Plasmodium berghei. Bacteria growth was monitored with a disc diffusion assay, cancer cell viability was determined with MTS assay, and percentage parasitemia and parasite clearance were determined by microscopy. Bound heme content, host mitochondria permeability transition (mPT) pore opening, F₀F₁-ATPase, and lipid peroxidation were determined via spectrophotometry. Indices of oxidative stress, anti-oxidant activities, toxicity, cell death, and inflammatory responses were obtained using biochemical and ELISA techniques. The histology of the liver and spleen was performed using the standard method. We elucidated the structures of the critical active principles in the extract to be flavonoids: kaempferol, quercetin, myricetin, and their glycosides with little or no detectable levels of the toxic Aristolochic acids that are found in Aristolochia repens, one of the components of the formulation. The extract also showed anti-plasmodial activity in in vitro and in vivo models. Furthermore, the extract dose-dependently decreased mitochondrial dysfunction, cell death, and inflammatory and oxidative damage but increased antioxidant potentials. Presumably, the active principles in the extract work as a combinatorial therapy to elicit potent antimalarial activity. Overall, our study unraveled the active components from a commercial herbal formulation that could be reformulated for antimalarial therapy. Full article

Shiikuwasha, a citrus fruit native to Okinawa, Japan, has various cultivation lines with distinct free volatile and non-volatile components. However, the glycosylated volatiles, which are sources of hidden aromas, remain unknown. This study aimed to characterize the chemical profiles of free and glycosidically bound volatile as well as non-volatile components in the mature fruits of six Shiikuwasha cultivation lines: Ishikunibu, Izumi kugani-like, Kaachi, Kohama, Nakamoto seedless, and Ogimi kugani. Free volatiles were analyzed using solid-phase microextraction–gas chromatography–mass spectrometry. Glycosides were collected via solid-phase extraction and hydrolyzed with β-glucosidase, and the released volatiles were measured. Additionally, the non-volatile components were determined using non-targeted proton nuclear magnetic resonance analysis. Total free and bound volatiles ranged from 457 to 8401 µg/L and from 104 to 548 µg/L, respectively, and the predominant free volatiles found were limonene, γ-terpinene, and p-cymene. Twenty volatiles were released from glycosides, including predominant 1-hexanol and benzyl alcohol, with Kaachi and Ogimi kugani showing higher concentrations. Principal component analysis (PCA) revealed that taste-related compounds like sucrose, citrate, and malate influenced line differentiation. The PCA of the combined data of free and bound volatile and non-volatile components showed flavor component variances across all lines. These findings provide valuable insights into the chemical profiles of Shiikuwasha fruits for fresh consumption and food and beverage processing. Full article

Na⁺-K⁺ ATPase is an integral component of cardiac sarcolemma and consists of three major subunits, namely the α-subunit with three isoforms (α₁, α₂, and α₃), β-subunit with two isoforms (β₁ and β₂) and γ-subunit (phospholemman). This enzyme has been demonstrated to transport three Na and two K ions to generate a trans-membrane gradient, maintain cation homeostasis in cardiomyocytes and participate in regulating contractile force development. Na⁺-K⁺ ATPase serves as a receptor for both exogenous and endogenous cardiotonic glycosides and steroids, and a signal transducer for modifying myocardial metabolism as well as cellular survival and death. In addition, Na⁺-K⁺ ATPase is regulated by different hormones through the phosphorylation/dephosphorylation of phospholemman, which is tightly bound to this enzyme. The activity of Na⁺-K⁺ ATPase has been reported to be increased, unaltered and depressed in failing hearts depending upon the type and stage of heart failure as well as the association/disassociation of phospholemman and binding with endogenous cardiotonic steroids, namely endogenous ouabain and marinobufagenin. Increased Na⁺-K⁺ ATPase activity in association with a depressed level of intracellular Na⁺ in failing hearts is considered to decrease intracellular Ca²⁺ and serve as an adaptive mechanism for maintaining cardiac function. The slight to moderate depression of Na⁺-K⁺ ATPase by cardiac glycosides in association with an increased level of Na⁺ in cardiomyocytes is known to produce beneficial effects in failing hearts. On the other hand, markedly reduced Na⁺-K⁺ ATPase activity associated with an increased level of intracellular Na⁺ in failing hearts has been demonstrated to result in an intracellular Ca²⁺ overload, the occurrence of cardiac arrhythmias and depression in cardiac function during the development of heart failure. Furthermore, the status of Na⁺-K⁺ ATPase activity in heart failure is determined by changes in isoform subunits of the enzyme, the development of oxidative stress, intracellular Ca²⁺-overload, protease activation, the activity of inflammatory cytokines and sarcolemmal lipid composition. Evidence has been presented to show that marked alterations in myocardial cations cannot be explained exclusively on the basis of sarcolemma alterations, as other Ca²⁺ channels, cation transporters and exchangers may be involved in this event. A marked reduction in Na⁺-K⁺ ATPase activity due to a shift in its isoform subunits in association with intracellular Ca²⁺-overload, cardiac energy depletion, increased membrane permeability, Ca²⁺-handling abnormalities and damage to myocardial ultrastructure appear to be involved in the progression of heart failure. Full article

To fully leverage the advantages of both hot air drying and radio frequency vacuum drying, a segmented combination drying technique was applied to post-harvest Cistanche. This new drying method involves using hot air drying in the initial stage to remove the majority of free water, followed by radio frequency vacuum drying in the later stage to remove the remaining small amount of free water and bound water. During the radio frequency vacuum drying (RFV) phase, the effects of temperature (45, 55, and 65 °C), vacuum pressure (0.020, 0.030, and 0.040 MPa), plate spacing (65, 75, and 85 mm), and slice thickness (4, 5, and 6 mm) on the drying characteristics, quality, and microstructure of Cistanche slices were investigated. Additionally, infrared thermal imaging technology was used to examine the surface temperature distribution of the material during the drying process. The results showed that compared to radio frequency vacuum drying alone, the hot air–radio frequency combined drying significantly shortened the drying time. Under conditions of lower vacuum pressure (0.020 MPa), plate spacing (65 mm), and higher temperature (65 °C), the drying time was reduced and the drying rate increased. Infrared thermal imaging revealed that in the early stages of hot air–radio frequency vacuum combined drying, the center temperature of Cistanche was higher than the edge temperature. As drying progressed, the internal moisture of the material diffused from the inside out, resulting in higher edge temperatures compared to the center and the formation of overheating zones. Compared to natural air drying, the hot air–radio frequency vacuum combined drying effectively preserved the content of active components such as polysaccharides (275.56 mg/g), total phenols (38.62 mg/g), total flavonoids (70.35 mg/g), phenylethanoid glycosides, and iridoids. Scanning electron microscopy observed that this combined drying method reduced surface collapse and cracking of the material. This study provides theoretical references for future drying processes of Cistanche. Full article

Monoclonal antibodies (Mabs) are widely used in a variety of fields, including protein identification, life sciences, medicine, and natural product chemistry. This review focuses on Mabs against naturally occurring active compounds. The preparation of Mabs against various active compounds began in the 1980s, and now there are fewer than 50 types. Eastern blotting, which was developed as an antibody staining method for low-molecular-weight compounds, is useful for its ability to visually represent specific components. In this method, a mixture of lower-molecular-weight compounds, particularly glycosides, are separated by thin-layer chromatography (TLC). The compounds are then transferred to a membrane by heating, followed by treatment with potassium periodate (KIO₄) to open the sugar moiety of the glycoside on the membrane to form an aldehyde group. Proteins are then added to form Schiff base bonds to enable adsorption on the membrane. A Mab is bound to the glycoside moiety on the membrane and reacts with a secondary antibody to produce color. Double Eastern blotting, which enables the simultaneous coloration of two glycosides, can be used to evaluate quality and estimate pharmacological effects. An example of staining by Eastern blotting and a component search based on the results will also be presented. A Mab-associated affinity column is a method for isolating antigen molecules in a single step. However, the usefulness of the wash fractions that are not bound to the affinity column is unknown. Therefore, we designated the wash fraction the “knockout extract”. Comparing the nitric oxide (NO) production of a glycyrrhizin (GL)-knockout extract of licorice with a licorice extract revealed that the licorice extract is stronger. Therefore, the addition of GL to the GL-knockout extract of licorice increased NO production. This indicates that GL has synergic activity with the knockout extract. The GL-knockout extract of licorice inhibited high-glucose-induced epithelial–mesenchymal transition in NRK-52E cells, primarily by suppressing the Notch2 pathway. The real active constituent in licorice may be constituents other than GL, which is the causative agent of pseudohyperaldosteronism. This suggests that a GL-knockout extract of licorice may be useful for the treatment of diabetic nephritis. Full article

Barley is rich in phenolic compounds, providing health benefits and making it a valuable addition to a balanced diet. However, most studies focus on these compounds at barley’s final maturity, neglecting their synthesis during grain development and its impact on barley quality for food applications. This study investigates phenolic profiles during grain development in four hull-less barley genotypes with different grain colors, specifically bred for food applications. The objectives were to determine the phenolic profile and identify the optimal maturity stage for maximum phenolic content and antioxidant capacity. Using UPLC-MS/MS and in vitro antioxidant capacity assays, results show that total phenolic compounds decrease as grain matures due to increased synthesis of reserve components. Flavan-3-ols, phenolic acids, and flavone glycosides peaked at immature stages, while anthocyanins peaked at physiological maturity. The harvest stage had the lowest phenolic content, with a gradient from black to yellow, purple, and blue genotypes. Antioxidant capacity fluctuated during maturation, correlating positively with phenolic compounds, specially bound phenolic acids and anthocyanins. These findings suggest that early harvesting of immature grain can help retain bioactive compounds, promoting the use of immature barley grains in foods. To support this market, incentives should offset costs associated with decreased grain weight. Full article

Current research does not fully elucidate the key compounds and their mechanisms that define the aroma profile of fresh jujube fruits. Therefore, this study conducted a comprehensive analysis of both free and glycosidically bound aroma compounds in fresh jujube fruits of ten cultivars. Utilizing gas chromatography–mass spectrometry (GC-MS), we identified 76 volatile free aroma compounds and 19 glycosidically bound volatile compounds, with esters, aldehydes, and ketones emerging as the predominant volatile compounds in the jujube fruits. Odor activity value (OAV) analysis revealed that the primary aroma profile of the jujubes is characterized by fruity and fatty odors, with β-damascenone being a key contributor to the fruity aroma, and (E)-2-oct-en-1-al and nonanal significantly influencing the fatty aroma. Moreover, the integration of sensory evaluation and partial least squares regression (PLSR) analysis pinpointed octanal, (E)-2-oct-en-1-al, nonanal, β-damascenone, and pentanal as significant contributors to the jujube’s characteristic aroma, while isoamyl acetate was identified as significantly influencing the fatty acid taste. This study not only underscores the complexity of the jujube aroma composition but also highlights the impact of environmental factors on aroma profiles, offering valuable insights into the sensory characteristics of jujube fruits. Full article

The species Prunus mume consists of uniquely aromatic woody perennials with large amounts of free aromatic substances in the flower cells. Uridine diphosphate glycosyltransferase (UGT) modifies these free aromatic substances into water-soluble glycoside-bound volatiles (GBVs) which play an important role in regulating the use of volatiles by plants for information exchange, defense, and stress tolerance. To investigate the changes in the glycosidic state of aromatic substances during the flowering period of P. mume and discern the location and expression of glycoside synthesis genes, we extracted and enzymatically hydrolyzed GBVs of P. mume and then utilized gas chromatography–mass spectrometry (GC–MS) to characterize and analyze the types and contents of GBV glycosides. Further, we identified and classified the members of the UGT gene family of P. mume using the bioinformatic method and analyzed the correlation between the expression of the UGT family genes in P. mume and the changes in glycosidic content. The results showed that the benzenoids were the main aromatic substance that was glycosylated during flowering in P. mume and that glycosidic benzaldehyde was the most prevalent compound in different flower parts and at different flowering stages. The titer of glycoside benzaldehyde gradually increased during the bud stage and reached the highest level at the big bud stage (999.6 μg·g⁻¹). Significantly, titers of glycoside benzaldehyde significantly decreased and stabilized after flowering while the level of free benzaldehyde, in contrast, significantly increased and then reached a plateau after the flowering process was completed. A total of 155 UGT family genes were identified in the P. mume genome, which were divided into 13 subfamilies (A–E, G–N); according to the classification of Arabidopsis thaliana UGT gene subfamilies, the L subfamily contains 17 genes. The transcriptome analysis showed that PmUGTL9 and PmUGTL13 were highly expressed in the bud stage and were strongly correlated with the content of the glycosidic form of benzaldehyde at all stages of flowering. This study provides a theoretical basis to elucidate the function of UGT family genes in P. mume during flower development, to explore the mechanism of the storage and transportation of aromatic compounds in flower tissues, and to exploit industrial applications of aromatic products from P. mume. Full article

Leaf removal is a cultural practice mainly aimed at improving cluster zone microclimates and impacting primary and secondary metabolites, such as volatiles. This research aimed to assess the impact of defoliation on free and glycosylated aromas of a neutral (‘Nebbiolo’) and a semi-aromatic (‘Aleatico’) red variety. Defoliation was performed at fruit set (BBCH 71) and, for ‘Nebbiolo’, also at berries touch (BBCH 81) phenological stages. Skins and pulps were separately analyzed by Solid Phase Extraction–Gas Chromatography/Mass Spectrometry. Results showed that the response to defoliation was variety-dependent. For ‘Nebbiolo’, especially when performed at the berries’ touch stage, defoliation had a significant effect on the accumulation of free volatiles and glycosidic precursors. Differently, free and bound ‘Aleatico’ volatiles were less impacted by defoliation. Interestingly, in both grapevine varieties, defoliation significantly enhanced the accumulation of aroma precursors in grapes’ skins, which is of particular relevance for red wine production and their aging potential. Moreover, results could be helpful for the management of grape quality, as defoliation is currently considered as a strategy to address climate change issues. Full article

In this study, we investigated the effects of germination on the secondary metabolite composition in spelt grains. Germination significantly increased the content of various metabolites in free and bound forms. Benzoxazinoids were the most important compounds in the free fraction of the 96 h germinated grains (MBOA content as the predominant compound was 277.61 ± 15.29 µg/g DW). The majority of phenolic acids were present in the bound fraction, with trans-ferulic acid as the main component, reaching 753.27 ± 95.87 µg/g DW. The often neglected cis-isomers of phenolic acids accounted for about 20% of the total phenolic acids. High levels of apigenin di-C-glycosides were found in spelt grains, and the schaftoside content was most affected by germination, increasing threefold. The accumulation of secondary metabolites significantly increased the antioxidant activity of germinated spelt. According to the results of this study, the content of most bioactive compounds was highest in spelt grains after 96 h of germination. These data suggest that germinated spelt could potentially be valuable for the production of functional foods. Full article

α-Glucosidase catalyzes the hydrolysis of α-d-glucosides and transglucosylation. Bacillus sp. AHU2216 α-glucosidase (BspAG13_31A), belonging to the glycoside hydrolase family 13 subfamily 31, specifically cleaves α-(1→4)-glucosidic linkages and shows high disaccharide specificity. We showed previously that the maltose moiety of maltotriose (G3) and maltotetraose (G4), covering subsites +1 and +2 of BspAG13_31A, adopts a less stable conformation than the global minimum energy conformation. This unstable d-glucosyl conformation likely arises from steric hindrance by Asn258 on β→α loop 5 of the catalytic (β/α)₈-barrel. In this study, Asn258 mutants of BspAG13_31A were enzymatically and structurally analyzed. N258G/P mutations significantly enhanced trisaccharide specificity. The N258P mutation also enhanced the activity toward sucrose and produced erlose from sucrose through transglucosylation. N258G showed a higher specificity to transglucosylation with p-nitrophenyl α-d-glucopyranoside and maltose than the wild type. E256Q/N258G and E258Q/N258P structures in complex with G3 revealed that the maltose moiety of G3 bound at subsites +1 and +2 adopted a relaxed conformation, whereas a less stable conformation was taken in E256Q. This structural difference suggests that stabilizing the G3 conformation enhances trisaccharide specificity. The E256Q/N258G-G3 complex formed an additional hydrogen bond between Met229 and the d-glucose residue of G3 in subsite +2, and this interaction may enhance transglucosylation. Full article

In this study, we aimed to isolate compounds from Stachys lavandulifolia (Lamiaceae) by chromatographic methods and perform tyrosinase, acetylcholinesterase, butyrylcholinesterase enzyme-inhibition and antimicrobial activity studies of these compounds by in vitro methods. In addition, a molecular docking study was planned for the molecule with the highest effect. Two flavone glycosides, apigenin-7-O-glucoside and luteolin-7-O-glucoside, were isolated from S. lavandulifolia. Both compounds were observed to be effective against Enterococcus faecalis, Klebsiella pneumoniae, and Staphylococcus aureus. The compounds showed weak tyrosinase and butyrylcholine esterase inhibition, while only luteolin-7-O-glucoside showed a more significant inhibitory effect against acetylcholinesterase (65 ± 2%). Therefore, molecular interactions between acetylcholinesterase and luteolin-7-O-glucoside were evaluated. In the docking study, it was observed that the molecule was bound to the enzyme with a low amount of free binding energy (Glide score: −8.31). As a result, the antibacterial effect of apigenin-7-O-glucoside and both antibacterial and acetylcholinesterase-inhibitory effects of luteolin-7-O-glucoside were determined. Full article