Solvent Effects on the Phenolic Compounds and Antioxidant Activity Associated with Camellia polyodonta Flower Extracts.

Camellia polyodonta flowers contain limited information available regarding the composition of their bioactive compounds and activity. The objective of this study was to identify phenolic compounds and investigate the effect of different solvents (ethanol and methanol) on the phenolic content and antioxidant activity in C. polyodonta flowers. The analysis using UPLC-Q-TOF-MS/MS revealed the presence of 105 phytochemicals and the most common compounds were flavonols, procyanidins, and ellagitannins. Interestingly, flavonol triglycosides were identified for the first time in these flowers. The study demonstrated that the concentration of the solvent had a significant impact on the total phenolic compound (TPC), total flavonoid compound (TFC), and total proanthocyanidin content (TPAC). The TPC, TFC, and TPAC showed a remarkable increase with the increasing concentration of the solvent, reaching their maximum levels (138.23 mg GAE/g DW, 421.62 mg RE/g DW, 60.77 mg PB2E/g DW) at 70% ethanol. However, the total anthocyanin content reached its maximum at low concentrations (0.49 mg CGE/g DW). Similar trends were observed in the antioxidant activity, as measured by the DPPH· assay (DPPH radical scavenging activity), ABTS·+ assay (ABTS radical cation scavenging activity), and FRAP assay (Ferric reducing antioxidant power). The maximum antioxidant activity was observed at 100% solvents and 70% methanol. Among the 14 individual phenolic compounds, 70% methanol yielded the highest content for 8 (cyanidin-3-O-glucoside, procyanidin B2, procyanidin B4, epicatechin, rutin, kaempferol-3-O-rutinoside, astragaline and quercitrin) out of the 14 compounds. Additionally, it was found that epicatechin was the most abundant phenolic compound, accounting for approximately 20339.37 µg/g DW. Based on these findings, it can be concluded that 70% methanol is the most effective solvent for extracting polyphenols from C. polyodonta flowers. These results provided chemical information and potential antioxidant value for further research in C. polyodonta flowers.

Purification of Phenolic Compounds from Camellia polyodonta Flower: Composition Analysis, Antioxidant Property, and Hypolipidemic Activity In Vitro and In Vivo.

Camellia polyodonta flowers are rich sources of phenolics and less attention has been paid to their potential biological activity. This study aims to explore the crude extracts and resulting purified fractions (CPFP-I, II, III, and IV) through compositional analysis and antioxidant and hypolipidemic activities in vitro and in vivo. Among four fractions, CPFP-II contained the highest total phenolic content and flavonoid content, while CPFP-III exhibited the greatest total proanthocyanidin content. Among the 14 phenolic compounds, CPFP-II displayed the highest content of procyanidin B2, B4, and C1, whereas CPFP-III contained the highest amount of 1,2,3,6-tetragalloylglucose. The DPPH, ABTS, and FRAP assessments demonstrated a consistent trend: CPFP-II > CPFP-III > CPFP-I > CPFP-IV. In vivo experiments showed that that all four fractions significantly reduced lipid levels in hyperlipidemic C. elegans (p < 0.05), with CPFP-II exhibiting the most potent effect. Furthermore, CPFP-II effectively bound to bile acids and inhibited the enzymatic activity of pancreatic lipase in vitro. Consequently, CPFP-II should be prioritized as a promising fraction for further exploration and should provide substantial support for the feasibility of the C. polyodonta flower as a natural alternative.

Phytochemical composition of Tibetan tea fermented by Eurotium cristatum and its effects on type 1 diabetes mice and gut microbiota.

"Golden-flower" Tibetan tea (GTT) is an innovative dark tea fermented via fungus Eurotium cristatum. To study GTT effects on alleviating the symptoms of type 1 diabetes mellitus (T1DM), GTT's extract (GTTE) was prepared. GTTE chemical compositions were analyzed via HPLC, pyrolysis-gas chromatography-mass (Py-GC-MS) spectrometry analysis, and chemistry analyses. GTTE effects on T1DM were explored on T1DM mice model induced by streptozotocin (STZ). GTTE was composed mainly of tea pigment theabrownin (TB) (49.18%), with high percentages of polysaccharide (16.93%), protein (10.15%), polyphenols (13.90%), amino acids (5.89%), caffeine (1.83%), and flavonoids (0.67%). Py-GC-MS results exhibited that GTTE constituted of phenols, lipids, sugars, and proteins. GTTE attenuated T1DM conditions of mice, relieved their liver and pancreatic injury, restored damaged islet cells, decreased oxidative stress by increasing superoxide dismutase (SOD) and catalase (CAT) levels, modulated cytokine expression leading to the decreasing pro-inflammatory cytokines TNF-α and IL-6, increased anti-inflammatory cytokines IL-4 to improve inflammatory responses, and optimized gut microbiota composition and structure based on high-throughput 16S rDNA sequencing, suggesting multi-channel anti-diabetes mechanisms.

Comprehensive Analysis of Phenolic Constituents, Biological Activities, and Derived Aroma Differences of Penthorum chinense Pursh Leaves after Processing into Green and Black Tea.

Penthorum chinense Pursh (Penthoraceae) is a traditional herb used in Miao medical systems that is also processed into foods (e.g., tea products) in China. Different processing methods significantly affect the volatile compounds, phenolic constituents, and biological activities. This study aimed to produce P. chinense green tea leaves (GTL), black tea leaves (BTL), and untreated leaves (UL) to investigate differences in their flavor substances, functional components, antioxidant activity, alcohol dehydrogenase (ADH) activity, and acetaldehyde dehydrogenase (ALDH) activity. The results showed that 63, 56, and 56 volatile compounds were detected in UL, GTL, and BTL, respectively, of which 43 volatile compounds were identified as differential metabolites among them. The total phenolic content (97.13-179.34 mg GAE/g DW), flavonoid content (40.07-71.93 mg RE/g DW), and proanthocyanidin content (54.13-65.91 mg CE/g DW) exhibited similar trends, decreasing in the order of UL > BTL > GTL. Fourteen phenolic compounds were determined, of which gallic acid, (-)-epicatechin, and pinocembrin 7-O-glucoside showed a sharp decrease in content from UL to BTL, while the content of pinocembrin 7-O-(3″-O-galloy-4″, 6″-hexahydroxydiphenoyl)-glucoside and pinocembrin significantly increased. GTL showed better DPPH/ABTS·+ scavenging ability and ferric-reducing ability than UL. The ADH and ALDH activities decreased in the order of GTL > UL > BTL. Therefore, tea products made with P. chinense leaves contained an abundance of functional compounds and showed satisfactory antioxidant and hepatoprotective activities, which are recommended for daily consumption.

Evaluation of the Antioxidant Potential of Citrus medica from Different Geographical Regions and Characterization of Phenolic Constituents by LC-MS.

The varying antioxidant potential of Citrus medica associated with different geographical regions makes the evaluation of C. medica for natural antioxidants essential. This work aimed to compare the antioxidant potential of the phenolic constituents from different geographical regions. The chemical compositions were characterized by ultra-high-performance liquid chromatography (UPLC) coupled with mass spectrometry (MS). A total of 67 compounds including 29 coumarin derivatives and 38 flavonoids were tentatively identified by UPLC-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). To evaluate the quality of C. medica from seven different geographical regions, water and 80% methanol fractions were subjected to quantitative analysis. Antioxidant potentials were determined by 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), iron chelation, and reduction methods. The samples collected from Sichuan province showed the highest content of total phenolic compounds. Combined with antioxidant results, the sample from Sichuan province presented good antioxidant activity. This study also showed that total phenolic compounds significantly contributed to the antioxidant activities (2,2-azinobis(3-ethyl-benzothiazoline-6-sulphonic acid) and radical scavenging activity) of C. medica samples (p < 0.01). These results provided chemical information and potential antioxidant value for further research, providing ideal evidence for the quality evaluation and exploitation of the source.

Integrated Analysis of Transcriptome and Metabolome Provides Insight into Camellia oleifera Oil Alleviating Fat Accumulation in High-Fat Caenorhabditis elegans.

Camellia oil (CO) is a high medicinal and nutritional value edible oil. However, its ability to alleviate fat accumulation in high-fat Caenorhabditis elegans has not been well elucidated. Therefore, this study aimed to investigate the effect of CO on fat accumulation in high-fat C. elegans via transcriptome and metabolome analysis. The results showed that CO significantly reduced fat accumulation in high-fat C. elegans by 10.34% (Oil Red O method) and 11.54% (TG content method), respectively. Furthermore, CO primarily altered the transcription levels of genes involved in longevity regulating pathway. Specifically, CO decreased lipid storage in high-fat C. elegans by inhibiting fat synthesis. In addition, CO supplementation modulated the abundance of metabolic biomarkers related to pyrimidine metabolism and riboflavin metabolism. The integrated transcriptome and metabolome analyses indicated that CO supplementation could alleviate fat accumulation in high-fat C. elegans by regulating retinol metabolism, drug metabolism-cytochrome P450, metabolism of xenobiotics by cytochrome P450, ascorbate and aldarate metabolism, and pentose and glucuronate interconversions. Overall, these findings highlight the potential health benefits of CO that could potentially be used as a functional edible oil.

Optimization of Extraction Process, Structure Characterization, and Antioxidant Activity of Polysaccharides from Different Parts of Camellia oleifera Abel.

The flowers, leaves, seed cakes and fruit shells of Camellia oleifera are rich in bioactive polysaccharides, which can be used as additives in food and other industries. In this study, a Box-Behnken design was used to optimize the extraction conditions of polysaccharides from C. oleifera flowers (P-CF), leaves (P-CL), seed cakes (P-CC), and fruit shells (P-CS). Under the optimized extraction conditions, the polysaccharide yields of the four polysaccharides were 9.32% ± 0.11 (P-CF), 7.57% ± 0.11 (P-CL), 8.69% ± 0.16 (P-CC), and 7.25% ± 0.07 (P-CS), respectively. Polysaccharides were mainly composed of mannose, rhamnose, galacturonic acid, glucose, galactose, and xylose, of which the molecular weights ranged from 3.31 kDa to 128.06 kDa. P-CC had a triple helix structure. The antioxidant activities of the four polysaccharides were determined by Fe2+ chelating and free radical scavenging abilities. The results showed that all polysaccharides had antioxidant effects. Among them, P-CF had the strongest antioxidant activity, of which the highest scavenging ability of DPPH•, ABTS•+, and hydroxyl radical could reach 84.19% ± 2.65, 94.8% ± 0.22, and 79.97% ± 3.04, respectively, and the best chelating ability of Fe2+ could reach 44.67% ± 1.04. Overall, polysaccharides extracted from different parts of C. oleifera showed a certain antioxidant effect, and could be developed as a new type of pure natural antioxidant for food.

Comprehensive Profiling of Macamides and Fatty Acid Derivatives in Maca with Different Postharvest Drying Processes Using UPLC-QTOF-MS.

Macamides are characteristically found in maca (Lepidium meyenii Walper). Fatty acid derivatives are also an important type of constituent in maca, since they not only relate to the biosynthesis of macamides in the postharvest process but also possess some bioactivities. To study their comprehensive profiles in maca tubers processed via the air-drying method, ultraperformance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) analyses were performed to identify macamide and fatty acid molecules. Their contents in maca tubers that were processed via air drying and freeze drying, respectively, were further quantified using high-performance liquid chromatography (HPLC) analyses comparing with eight macamide and three fatty acid reference standards. A total of 19 macamides (including four novel ones) and 16 fatty acid derivatives (two found in maca for the first time) were identified. Quantification analyses results showed the eight macamides with contents ranging from 31.39 to 1163.19 µg/g (on dry tuber), and fatty acids from 18.71 to 181.99 µg/g in the air-dried maca, but there were only three macamides and one fatty acid detected with very low contents (3.97-34.36 µg/g) in the freeze-dried maca. The results demonstrated that the air-drying method can increase the accumulations of macamides and fatty acids in the metabolism of maca in the postharvest process. The biosynthesis of two types of macamides, i.e., N-benzyl-oxo-octadecadienamides and N-benzyl-oxo-octadecatrienamides, was further elucidated in detail. These results provide more valuable insights into the phytochemicals of maca, which is helpful to explain its health benefits.

Performance and mechanism of an innovative humidity-controlled hot-air drying method for concentrated starch gels: A case of sweet potato starch noodles.

The effects of humidity control on dried starch gels were investigated using starch noodles as a model. A two-stage innovative hot-air-drying regime was developed with the first stage humidity-controlled (70 °C, 60% RH) and the second at high temperature (100 °C). The proposed drying method is comparable to natural-air-drying in product quality and to conventional hot-air-drying (70 °C) in production efficiency. The operating humidity of the first stage predominated the swelling index and rehydration ratio of dry noodles as well as the hardness and chewiness of cooked noodles. The results from XRD, DSC, SEM, digital microscopy and low field TD 1H NMR evidenced that these outcomes were largely ascribed to the higher shrinkage, lower porosity, smoother surface, lesser shape deformation and higher starch retrogradation resulting from increased humidity. The results reported herein are valuable for regulating the physicochemical properties of dried starch gels and glimpsing the underlying mechanisms of related operations.