Search Results (33)

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

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

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

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

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

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

Cardiac glycosides are a large class of secondary metabolites found in plants. In the genus Asclepias, cardenolides in milkweed plants have an established role in plant–herbivore and predator–prey interactions, based on their ability to inhibit the membrane-bound Na⁺/K⁺-ATPase enzyme. Milkweed seeds are eaten by specialist lygaeid bugs, which are the most cardenolide-tolerant insects known. These insects likely impose natural selection for the repeated derivatisation of cardenolides. A first step in investigating this hypothesis is to conduct a phytochemical profiling of the cardenolides in the seeds. Here, we report the concentrations of 10 purified cardenolides from the seeds of Asclepias curassavica. We report the structures of new compounds: 3-O-β-allopyranosyl coroglaucigenin (1), 3-[4′-O-β-glucopyranosyl-β-allopyranosyl] coroglaucigenin (2), 3′-O-β-glucopyranosyl-15-β-hydroxycalotropin (3), and 3-O-β-glucopyranosyl-12-β-hydroxyl coroglaucigenin (4), as well as six previously reported cardenolides (5–10). We test the in vitro inhibition of these compounds on the sensitive porcine Na⁺/K⁺-ATPase. The least inhibitory compound was also the most abundant in the seeds—4′-O-β-glucopyranosyl frugoside (5). Gofruside (9) was the most inhibitory. We found no direct correlation between the number of glycosides/sugar moieties in a cardenolide and its inhibitory effect. Our results enhance the literature on cardenolide diversity and concentration among tissues eaten by insects and provide an opportunity to uncover potential evolutionary relationships between tissue-specific defense expression and insect adaptations in plant–herbivore interactions. Full article

Both free and glycosidically bound forms of volatile compounds in Vidal grapes from the Shangri-La high-altitude region during the on-vine non-destructive dehydration process were investigated by headspace solid-phase micro-extraction (HS-SPME) combined with gas chromatography–mass spectrometry (GC-MS), following which the data were processed by multivariate statistical analysis. Fatty-acid-derived volatiles (FADs), amino-acid-derived volatiles (AADs), and isoprene-derived volatiles (IPDs), which occurred mainly in bound forms, were the three major volatiles in dehydrated Vidal grapes. Water-loss concentration, biosynthesis, and biodegradation all occurred during dehydration, eventually modifying some volatiles significantly, especially some powerful odorants such as hexanal, trans-2-hexenal, 2-phenethyl acetate, β-myrcene, linalool, geraniol, cis-rose oxide, and β-damascenone. 1-Octen-3-ol was relatively stable during the non-destructive on-vine dehydration process and its content in grape juice was mainly determined by the concentration effect. 2,4-Di-tert-butylphenol, 2-phenethyl acetate, 2-methyl-1-propanol, and hexanol were screened as some of the most important metabolic markers to discriminate grapes at different dehydration degrees. Our study also highlights the fundamental importance of the expression of volatile content in the metabolomic study of grape berries. Full article

As the major byproduct of the winemaking industry, grape pomace remains an untapped source of valuable bioactive phenolic compounds. This study elucidated the optimal aqueous extraction parameters for maximizing phenolic extractability, while avoiding the use of harsh conventional solvents and limiting water usage, from Cabernet Sauvignon grape pomace in which the red grape was processed for white wine. In the single-stage aqueous extraction process (AEP), the concurrent impact of pH (2.64–9.36), solids-to-liquid ratio (SLR, g pomace/mL water) (1:50–1:5), and temperature (41.6–58.4 °C) on the total phenolic content (TPC) of Cabernet Sauvignon pomace was evaluated alongside a kinetic study (15–90 min). Optimal single-stage extraction conditions (pH 9.36, 1:50 SLR, 50 °C, 75 min) guided the development of a two-stage countercurrent extraction process (pH 9.36, 1:10 SLR, 50 °C, 75 min) to further reduce water consumption without compromising overall extractability. The countercurrent process reduced fresh water usage by 80%, increased the TPC of the extracts by 18%, and improved the in vitro antioxidant activities (ABTS and ORAC) of the extracts. Untargeted metabolomics enabled the identification of a diverse pool of phenolics, especially flavonol glycosides, associated with grape pomace, while further phenolic quantitation detected improvements in the release of commonly bound phenolics such as ferulic acid, p-coumaric acid, syringic acid, and protocatechuic acid in alkaline extracts compared to the ethanolic extract. This investigation provides an efficient, eco-friendly extraction strategy suitable for applications in functional food, beverage, nutraceutical, and cosmetic industries. Full article

Fruit plants produce various volatile compounds that emit distinct aroma characteristics and contribute to their flavor qualities. However, some of these substances, especially hydroxyl-group molecules, are in non-volatile glycosylated forms. This study aimed to determine free and glycosidically bound volatile compounds in three Okinawan pineapple cultivars (‘N67-10′, ‘Yugafu’, and ‘Yonekura’). The free volatile components of squashed pineapple juice were analyzed using solid-phase microextraction (SPME)–arrow-gas chromatography–flame ionization detection/mass spectrometry (GC-FID/MS). The glycosides were collected through solid-phase extraction, hydrolyzed by β-glucosidase, and the released volatile compounds were measured. The sugar moieties of the glycosides were confirmed using GC-MS, and their glycoside constituents were analyzed using liquid chromatography (LC)-MS. Okinawan pineapple varied in its content and composition of free volatile components, which were predominantly comprised of esters, followed by alcohols, terpenes, and ketones. Eight hydroxyl-group compounds, including chavicol, eugenol, geraniol, phenylethyl alcohol, benzyl alcohol, 2-ethyl-1-hexanol, 1-hexanol, and 3-methyl-2-butenol, were released from their glycosylated forms via enzymatic hydrolysis, wherein the amounts of most of them were greater in ‘Yonekura’ than in the other cultivars. Moreover, two glycosides, chavicol-O-β-D-glucopyranoside and eugenol-O-β-D-glucopyranoside, were identified in all the cultivars, wherein the aglycones of both glycosides could be potential odor sources of the medicinal-herbal aromas. These results provide important information regarding both volatile-aroma qualities and bounded-aroma resources in Okinawan pineapple for fresh consumption and agroindustrial processing. Full article

Free and glycosidically-bound aromatic characterization of 21 minority red grapevine varieties was carried out, along three consecutive vintages, using solid phase microextraction followed by gas chromatography-mass spectrometry methodology (SPME-GC-MS). The two main study aims were to evaluate the possibility of aromatically differentiated varieties based on their origin and to test the aromatic profile for being used as a chemotaxonomic tool. Based on the results obtained in this research, it would be also interesting to verify in future studies if this varietal diversity could translate into a diversification of quality products in the current globalized wine market. A volatile profile was established grouping aroma compounds into thirteen families: acids, alcohols, esters, C₆ compounds, thiols, ketones, aldehydes, phenols, terpenes, C₁₃-norisoprenoids, lactones, polycyclic aromatic hydrocarbons (PAHs), and sesquiterpenes. Significant differences were found among varieties for esters, phenols, terpenes, and total compounds in the free fraction and for alcohols, acids, C₆ compounds, C₁₃-norisoprenoids, terpenes, sesquiterpenes, and total compounds in the glycosidically-bound fraction. Subtle differentiation between different groups of varieties with common genetic origin was achieved by free aromatic profile (PCA) component analysis. Nevertheless, more in-depth studies are considered necessary to confirm the usefulness of the aromatic profile as a chemotaxonomic tool. Full article

In this study, the aroma profile of 12 minority grape varieties of Vitis vinifera L., included in the ‘Caiño group’, was defined along three vintages by solid phase microextraction followed by the gas chromatography–mass spectrometry method (SPME-GC-MS). Principal objectives were to assess the aromatic profile as a useful fingerprint to differentiate them, recover traditionally cultivated grape varieties for the differentiation of an important wine-growing area and discover their chemotaxonomic potential. In each variety, free and bound volatile profile was carried out by grouping varietal compounds into thirteen families. In total, 339 volatile compounds were identified, 230 as free forms and 205 as aromatic precursors. Remarkable quantitative differences were observed between aromatic profiles for terpenes in the free fraction and for C₆ compounds, alcohols, sesquiterpenes and phenols in the glycosidic fraction. Principal component analysis based on their aromatic profile highlights a good differentiation between varieties and suggests a certain degree of aromatic chemotaxonomic proximity between previously known parental varieties, ‘Caiño Blanco’ with respect to ‘Caiño Bravo’ and ‘Albariño’. This study shows the preliminary results of a large research project involving a larger number of grape varieties and thus a broader spectrum of genetic relationships between them. Full article