Individual Phenolic Compounds Research Articles

Green Synthesis of Metallic Nanoparticles from Quercus Bark Extracts: Characterization and Functional Properties

Quercus species are utilized for their durable wood, providing sustenance for wildlife, conserving biodiversity, and contributing ecological, medicinal, and esthetic benefits to ecosystems and landscapes. In this study, we aimed to use the bark of three Quercus species (Q. dalechampi, Q. fraineto, and Q. petraea) for the synthesis of silver and gold nanoparticles (AgNPs and AuNPs). The aqueous extracts from the bark of Quercus sp. acted both as reducing and stabilizing agent, facilitating the rapid synthesis of AuNPs (AuQD, AuQF, and AuQP) and AgNPs (AgQD, AgQF, and AgQP). The obtained nanoparticles were characterized using UV-vis spectroscopy, TEM, DLS, and FTIR. Characterizations revealed that the nanoparticles exhibited a variety of shapes, such as polygonal, triangular, and spherical forms, with sizes ranging between 14 and 24 nm for AuNPs and 45–70 nm for AgNPs. The total phenolic content was assessed through spectroscopic methods, while several individual phenolic compounds were identified and quantified using UPLC-PDA. Furthermore, we assessed the antioxidant, antibacterial, and antifungal capacities of AuNPs, AgNPs, and raw extracts. The highest antioxidant activity was observed for raw extracts, followed by AgNPs and AuNPs, while the most potent antibacterial and antifungal activity was observed in AgQP. Moreover, cytotoxicity was examined in a human keratinocyte cell line (HaCaT). The results indicated no cytotoxic effects for AuNPs, while AgNPs and the raw extracts exhibited cytotoxic effects after 48 h of incubation. This research underscores the multifaceted utility of Quercus bark extracts in the green synthesis of metallic nanoparticles and their subsequent bioactivity assessment, suggesting promising perspectives for their application in various fields while urging cautious consideration of their cytotoxic implications.

Preliminary Identification and Quantification of Individual Polyphenols in Fallopia japonica Plants and Honey and Their Influence on Antimicrobial and Antibiofilm Activities

Fallopia japonica (FJ), an invasive plant species known for its rich bioactive compounds, has been used for centuries in traditional Chinese medicine. Despite its significant beekeeping potential, this aspect of FJ remains underexplored. This research aims to investigate the antimicrobial and antibiofilm properties of FJ plants and honey. Notably, this study is the first to identify individual phenolic compounds in both FJ plant tissues and FJ honey, highlighting resveratrol as a marker of FJ honey. The study tested inhibitory activity against seven bacterial strains: Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, Salmonella enteritidis, and the yeast Candida albicans. Disk diffusion and microdilution methods were used to assess antimicrobial activity, while the crystal violet staining test evaluated antibiofilm activity. Results showed that FJ plant tissues and honey exhibited strong inhibition, particularly against Gram-negative bacterial strains. The most significant inhibition of biofilm formation, by both FJ plant tissues and honey, was observed against Staphylococcus aureus and Escherichia coli. A significant positive correlation was found between antimicrobial activity and individual polyphenols, especially resveratrol. The antibacterial and antibiofilm potential of FJ plant tissues and honey suggests promising applications in sustainable beekeeping. Further research is necessary to evaluate the bioactive compounds found in FJ honey and their health effects.

Unconventional technologies as a strategy to improve the phenolic and antioxidant potential of zucchini products enriched with blueberry juice

In this study, unconventional technologies were used to enhance the phenolic and antioxidant content of zucchini pieces by enriching them with blueberry juice. Our results indicated that ohmic heating (OH) increased the extraction rates of compounds with antioxidant potential in blueberry juice, mainly at 70 °C for 15 min and 7.8 V cm1. Furthermore, OH applied after vacuum impregnation led to higher retention rates of phenolic compounds and antioxidant capacity in zucchini pieces impregnated with blueberry juice, especially at 70 °C for 30 min and 7.8 V cm‐−1. The impregnation process also promoted the darkening of zucchini pieces (due to anthocyanin retention) and increased soluble solids. After drying by hot air and vacuum microwave, the phenolic content, antioxidant capacity, physicochemical and color characteristics of the impregnated and non-impregnated zucchinis were distinctly altered. However, vacuum microwave drying at 120 and 460 W can be suggested as the most suitable conditions for both zucchini products, as it resulted in high concentrations of individual phenolic compounds (e.g. up to 44.25, 8.15, and 2.56 mg 100 g‐−1 dry weight (DW) for catechin, gallic acid, and cyanidin, respectively), as well as total phenolic content of up to 484.37 mg gallic acid equivalent 100 g1 DW, total flavonoid content of up to 197.69 mg catechin equivalent 100 g‐−1 DW, and total monomeric anthocyanins of up to 9.48 mg cyanidin 3-glucosideo equivalent 100 g‐−1 DW.

Mediterranean Wild Pear Fruits as a Neglected but Valuable Source of Phenolic Compounds

The genus Pyrus has a long history in Sardinia (Italy), where two wild pear species (P. spinosa Forssk. and P. pyraster (L.) Burgsd.) and Pyrus communis L. cultivars are extensively distributed. Even if neglected, these taxa represent well-adapted key resources for redesigning sustainable farming systems. This report aims at shedding light on the phenolic fingerprint and antioxidant properties of wild pear fruits and comparing their traits with those of the studied pear cultivar germplasm (PCG). Fruits of wild pear species were collected, and flesh, peel, and core subsamples were analyzed. Moreover, available data from previous research on PCG were analyzed. The contents of total phenolics (TotP), total flavonoids (TotF), and condensed tannins (CT), as well as the antioxidant capacity, were similar in the flesh of the two wild species. However, P. spinosa had significantly higher values of TotP (89 g GAE kg−1 DM) and CT (33 g DE kg−1 DM) in the peel. Eleven individual phenolic compounds were identified and quantified in the fruit flesh, 14 in both peel and core. For both wild species, arbutin and chlorogenic acid were the main phenolic compounds, followed by the quercetin glycosides. Comparing the antioxidant capacity and TotF fruit flesh values of wild pears with those of PCG, the latter resulted up to 15-fold lower. The wild types showed unique metabolite profiles. Results support novel insights on the phytochemicals of wild pear fruits.

AN INVESTIGATION OF THE ACE INHIBITORY ACTIVITY, ANTIOXIDANT CAPACITY, AND PHYTOCHEMICAL CONSTITUENTS OF POLAR AND NON-POLAR EXTRACTS OF ZIZIPHUS JUJUBA FRUIT: STATISTICAL SCREENING THE MAIN COMPONENTS RESPONSIBLE FOR BIOACTIVITY

Herein, the angiotensin I-converting enzyme (ACE) inhibitory activity, antioxidant capacity, total polyphenol contents (TPC), and phytochemical profiles of polar and non-polar extracts of dried Ziziphus jujuba fruits were investigated, along with the statistical determination of the main components responsible for ACE inhibitory activity. The non-polar extract expressed the strongest ACE inhibitory activity (99.81%) among the extracts. The non-polar extract also exhibited the highest DPPH scavenging activity (IC50 of 30.63), linoleic acid/β-carotene bleaching capacity (89.31%), and TPC (59.47 mg GAE/g). The phenolic profiles of the extracts were identified by LC-MS/MS, and the presence of seven triterpenoid species in the extracts was examined using GC-MS techniques. The principal constituents included 19 phenolics, 2 organic acids, and 4 triterpenoids. A Pearson correlation and principal component analysis were conducted to find the correlation between individual phenolic compounds and ACE inhibitory activity.

Assessment of the Antioxidant and Hypolipidemic Properties of Salicornia europaea for the Prevention of TAFLD in Rats.

Halophyte species represent valuable reservoirs of natural antioxidants, and, among these, Salicornia europaea stands out as a promising edible plant. In this study, young and old S. europaea leaves were compared for the content of bioactive compounds and antioxidant activity to assess changes in different growth phases; then, the potential protective effects against low-dose CCl4-induced toxicant-associated fatty liver disease (TAFLD) were investigated by administering an aqueous suspension of young leaves to rats daily for two weeks. Quantification of total and individual phenolic compounds and in vitro antioxidant activity assays (DPPH, FRAP, and ORAC) showed the highest values in young leaves compared to mature ones. Salicornia treatment mitigated CCl4-induced hepatic oxidative stress, reducing lipid peroxidation and protein carbonyl levels, and preserving the decrease in glutathione levels. Electronic paramagnetic resonance (EPR) spectroscopy confirmed these results in the liver and evidenced free radicals increase prevention in the brain. Salicornia treatment also attenuated enzymatic disruptions in the liver's drug metabolizing system and Nrf2-dependent antioxidant enzymes. Furthermore, histopathological examination revealed reduced hepatic lipid accumulation and inflammation. Overall, this study highlights Salicornia's potential as a source of bioactive compounds with effective hepatoprotective properties capable to prevent TAFLD.

Bioactive compounds of Citrus hystrix peel ethanolic extract and their antioxidant potential under hydrogen peroxide-induced oxidative stress in Caco-2 cells

Citrus hystrix is a fruit native to tropical Southeast Asia and Southern China. The fruits and leaves are well-known spice ingredients in Asian dishes, but the peels are usually discarded, producing a large amount of waste despite the presence of phenolic compounds. Phenolic compounds are essential for scavenging reactive oxygen species (ROS) generated naturally during metabolism. This study aimed to investigate the profile of phenolic compounds (total phenolic content, total flavonoid content, and individual phenolic compounds) and antioxidant activities (2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, ferric reducing antioxidant power, and oxygen radical absorbance capacity) of Citrus hystrix peel ethanolic extract (CHPPE). Their functional properties in a biological model (cell viability and intracellular ROS) were also evaluated using Caco-2 cells under H2O2-induced oxidative stress. We identified 37 compounds, including flavonoids (26), phenolic acids (3), stilbenes (2), lignans (1), and other phenolic compounds (5). CHPPE contained (mg/g CHPPE) hesperidin (16.10±0.05), diosmin (1.95±0.08), neohesperidin (23.83±0.06), and naringin (2.39±0.03). CHPPE exhibited remarkable antioxidant activity, which significantly improving cell viability and reducing the presence of intracellular ROS. The cytoprotective effect of CHPPE was higher than that of ascorbic acid, indicating a strong natural antioxidative capacity. Our research reveals the potential of CHPPE as a functional ingredient in the food and pharmaceutical industries.

Improving Soluble Phenolic Profile and Antioxidant Activity of Grape Pomace Seeds through Fungal Solid-State Fermentation.

Grape pomace seeds contain abundant phenolic compounds, which are also present in both soluble and insoluble forms, similar to many other plant matrices. To further increase the extractable soluble phenolics and their antioxidant activities, grape pomace seeds were fermented with different fungi. Results showed that solid-state fermentation (SSF) with Aspergillus niger, Monascus anka, and Eurotium cristatum at 28 °C and 65% humidity had a significantly positive impact on the release of soluble phenolics in grape pomace seeds. Specifically, SSF with M. anka increased the soluble phenolic contents by 6.42 times (calculated as total phenolic content) and 6.68 times (calculated as total flavonoid content), leading to an overall improvement of antioxidant activities, including DPPH (increased by 2.14 times) and ABTS (increased by 3.64 times) radical scavenging activity. Furthermore, substantial changes were observed in the composition and content of individual phenolic compounds in the soluble fraction, with significantly heightened levels of specific phenolics such as chlorogenic acid, syringic acid, ferulic acid, epicatechin gallate, and resveratrol. Notably, during M. anka SSF, positive correlations were identified between the soluble phenolic content and hydrolase activities. In particular, there is a strong positive correlation between glycosidase and soluble phenols (r = 0.900). The findings present an effective strategy for improving the soluble phenolic profiles and bioactivities of grape pomace seeds through fungal SSF, thereby facilitating the valorization of winemaking by-products.

Scrutinizing the Antimicrobial and Antioxidant Potency of European Cranberry Bush (Viburnum opulus L.) Extracts

In the process of considering the documented health benefits of Viburnum opulus L. (V. opulus), including its anti-inflammatory and antioxidant activities, the present study was designed to qualitatively and quantitatively evaluate the biochemical profile and antimicrobial potency of four commercially available V. opulus extracts. These extracts were obtained from its flowers, bark, berries, and a mixture thereof by cold ultrasound-assisted extraction. An examination of the V. opulus extracts indicated a relative abundance of group compounds, such as phenolics, flavonoids, tannins, and anthocyanins, which are responsible for antioxidant activity (AOA). The widest range in all of the four group compounds was detected in the V. opulus extract sourced from berries, whereas the narrowest range was found in those obtained from flowers. The HPLC-ESI-TQ-MS/MS technique displayed relative fluctuations in the concentrations of individual amino acids (AAs) over the four V. opulus extracts. The prevalence of proline was marked in the flower-derived extract, which made up 63.3% of the total AAs, while aspartic and glutamic acids dominated in the berry-derived extract by contributing up to 29.2 and 24.4% to the total AA content, respectively. Profiling of the individual phenolic compounds disclosed the superiority of chlorogenic acid (up to 90.3%) in the berry and mixed extracts, as well as catechin (up to 57.7%) and neochlorogenic acid (11.1%) in the bark extract, which conveyed a remarkable contribution toward antimicrobial activity. The lowest content of individual phenolics was found in the flower extract. Owing to its substantially denser bioactive composition, the V. opulus berries and bark extracts exhibited markedly better AOA, which was pinpointed by three independent methods, i.e., DPPH•, FRAP, and ABTS•+, than those obtained from flowers or a mixture of V. opulus morphological parts. As part of the antimicrobial activity testing, the V. opulus extracts exhibited outstanding inhibitory activity and a homeopathic mode of action. The V. opulus extracts obtained from a mixture, bark, and berries were more active against 8 out of 19 selected test microorganisms at minimum inhibitory concentration (MIC) values that ranged from 0.24 to 0.49 µL mL−1. Overall, the extracts of V. opulus were found to be effective against Gram-positive and Gram-negative bacteria. However, their conceivable exploitation as functional or pharmaceutical ingredients must be further clarified within in vivo models.

Microwave hydrodistillation of Pelargonium graveolens L’Her leaves: Essential oil profile, phytochemical composition of wastewater, histo-anatomical structure

By-products with remarkable bioactive properties are formed in extraction processes of essential oils from plant materials. In present study, it was aimed to determine the concentration of individual phenolic and organic acid compounds by LC-MS/MS of the by-product (wastewater) collected after the essential oil isolation from Pelargonium graveolens L. and to determine some bioactive properties of this by-product. In addition, the chemical analysis and antibacterial activity of the essential oil extracted from P. graveolens were determined and the histo-anatomical characterization of the glandular trichomes in the leaf sample was performed. As a result, quercetin (95862.22 μg/kg), myricetin (59834.32 μg/kg) and rutin (36522.90 μg/kg) were the phenolic compounds determined in the highest concentrations in the by-product extracted using two different extraction techniques (non-hydrolysis and hydrolysis methods). Moreover, the individual organic acids of the by-product screened in LC-MS/MS was found to be 4487.17 mg/kg in total. When the essential oil component profile of the plant sample was examined, the citronellol (38.78%) compound was found to be dominant, and it was also detected that the essential oil had remarkable bioactive properties. In conclusion, it can be stated that both the essential oil obtained from P. graveolens and the by-product obtained during essential oil isolation can be considered as a source of some bioactive components in many different industrial applications.

Sensory and molecular insights into the bitterness of Wuyi rock tea

Wuyi Rock Tea (WRT) is widely appreciated for its unique rocky flavor and floral essence. However, the characterization of taste attributes, particularly bitterness, in this premium tea remains largely underexplored. This study aims to assess the perception of bitterness in WRT through an integrated approach, including sensory evaluation, phenolic compound analysis, and cell-based calcium imaging assay. Sensory evaluation revealed distinct bitterness intensities among nine selected typical WRT samples. Utilizing UHPLC-Q-Orbitrap-MS, 54 phenolics were tentatively identified, comprising of 24 flavanols, 18 flavonols, and 12 phenolic acids. The cell-based calcium imaging assay revealed diverse intracellular calcium responses and half-maximum effective concentration (EC50) values across the tested samples. Notably, correlation analysis unveiled a strong negative correlation between sensory scores and EC50 values. Furthermore, 11 individual phenolic compounds, such as epigallocatechin gallate and epicatechin gallate, demonstrated significant correlation with sensory scores and bitter taste receptor activation, suggesting their potential role as key contributors shaping the bitter taste perception of WRT. This study provides comprehensive insights into the nuanced bitterness of WRT, bridging sensory and molecular perspectives to enhance our understanding of the taste profile of this premium tea.

Bioactive compounds of fresh tea shoots plucked in different seasons: optimization of extraction of polyphenols

AbstractIn this study, the effects of harvest year and period on the total polyphenol (TP), radical scavenging activity (RSA), total flavonoid (TF) and ascorbic acid (AA) contents of fresh tea leaves were investigated. Extraction of polyphenols from the tea leaf was optimized using the response surface methodology (RSM). The effect of the independent variables ((solvent concentration, extraction time and solid to solvent (S/S) ratio)) on TP and RSA was studied using Box-Behnken design (BBD). The results showed that extraction parameters selected were significant in the extraction procedure regarding TP and RSA (p < 0.05). The optimum extraction conditions were obtained as 1/60.86 of S/S ratio, 84.65% of ethanol concentration and the extraction time of 50 min. As a result of the extraction of tea leaves under optimum conditions, the TP, RSA and TF contents of the leaves harvested in September in 2020 were found to be higher. In addition, the individual phenolic compounds of these leaves were analyzed by high performance liquid chromatography (HPLC) and epigallocatechin gallate (EGCG) was detected the most (57.52 mg/g DM). After in-vitro digestion of the same samples, TP and RSA values ​​were significantly decreased, mostly at intestinal stage (p < 0.05), and the bioaccessibility of the polyphenols was determined as 48.98%. As a result of AA analysis by HPLC of the, the highest contents for 2019 and 2020 were observed in the leaves harvested in May (41.92 mg/100 g DM) and those in July (38.55 mg/100 g DM), respectively.

Dehydration of phenolic-rich extract from rambutan (Nephelium lappaceum L.) peel by foam mat drying

Foam mat drying was used for the dehydration of a phenolic-rich rambutan peel extract. Foam products were evaluated for their physicochemical stability during storage. Experiments were carried out to determine the effect of foaming (10% of egg albumin/soy protein/pea protein) and stabilizing agents (0.5% of methylcellulose); storage conditions i.e. type of packages (polyethylene, glass), packaging techniques (modified atmosphere packaging, vacuum) under light or dark at 30 °C on phenolic compositions, antioxidant activity, water activity (aw), and color of foam products during 5 months storage. Foam products produced from egg albumin showed the highest total phenolic content (TPC) (8.73 ± 0.17 mg GAE/g) and antioxidant activity (7.47–9.70 mg TE/g). During storage, TPC, antioxidant activity, and the amount of individual phenolic compounds (geraniin, corilagin, rutin, ellagic acid, and quercetin) mostly decreased independent of the presence of light. Aw in all samples increased from 0.25 to 0.38 - 0.45 (except for the samples in glass packaging); whereas the color of the samples was insignificantly changed for 5 months. Rambutan peel phenolic-rich extract encapsulated within egg albumin can be stored at least 5 months with minimal quality changes and might be used as a food preservative ingredient.

COMPONENT COMPOSITIONS OF THE ESSENTIAL OIL AND PHENOLIC COMPOUNDS OF THE AERIAL PART OF LOPHANTHUS SCHTSCHUROVSKIANUS

The component composition of the essential oil (EO) obtained by hydrodistillation from the air dried aerial part of the Lophanthus schtschurowskianus (Regel) Lipsky, growing in the Surkhandarya region of the Republic of Uzbekistan, was studied. By the GC-MS method were identified 57 components in the composition of EO, which was 93.8% of the total amount of oil, of which 52 volatile compounds were identified. The main components of the essential oil were 1,8-cineol (13.4%), viridiflorol (8.5%), α-terpineol (4.3%), terpinen-4-ol (4.2%), τ-cadinol (4.1%), β-spatulenol (3.9%), α-p-dimethylstyrene (2.1%). Oxygenated monoterpenes (33.6%) and oxygenated sesquiterpenes (24.7%) predominate in the composition of the essential oil; compounds related to sesquiterpene hydrocarbons (8.6%) were also found. The composition of the EO components of L. schtschurowskianus significantly differs from the EOs of other studied plant species of the genus Lophanthus.
 The antibacterial and antifungal activity of the essential oil, as well as various extracts from the aerial parts of L. schtschurowskianus, was studied using a modified agar diffusion method. Gram-positive bacteria were found to be susceptible to all the studied samples. Among the studied samples, the essential oil showed the highest antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli.
 Three individual phenolic compounds were isolated from various fractions of a 75% alcoholic extract of the aerial part of L. schtschurowskianus, which, based on the study of 1H, 13C NMR, HSQC and HMBC spectra, were identified as caffeic, rosmarinic acids and luteolin.

Determination of Phytochemical Composition in Fruits and Leaves from Different Origins: Black Mulberry, Chokeberry and Elderberry Genotypes

Black mulberry, chokeberry and elderberry have medicinal properties associated with the presence of phytochemicals which are compounds with potential antioxidant properties. The previously published reports have shown that these compounds significantly affect the course of disease processes by counteracting oxidative stress. In this study, the primary anthocyanins were identified using high-performance liquid chromatography – tandem mass spectrometry (LC-MS/MS). Individual phenolic compounds, tocopherols and amygdalin were quantified by high-performance liquid chromatography with diode-array detection (HPLC-DAD). Elemental contents were determined by inductively coupled plasma – optical emission spectroscopy (ICP-OES). The obtained results reveal the significant presence of primary and secondary compounds in the assessed fruits and leaves, with notable variations depending on fruit species and genotypes. The most abundant compounds were phenolic acids and flavonoids. Analyses indicated that chlorogenic acid, rutin, and cyanidin derivatives were predominant phenolic compounds in all fruit species, while phenolic acids and flavonoids were prominent in leaf samples. The highest chlorogenic acid was determined in black mulberry leaves (ranging from 2403.23 to 3542.53 mg/100 g). Generally, the concentration of phenolic compounds were higher in the leaves than in the fruits of the plant. The highest concentration of amygdalin was detected in black mulberry fruits, ranging from 102.12 to 272.46 mg/100 g. Calcium and potassium were the dominant elements in both berries and leaves.

Changes in Chemical Composition of Red and Black Currant Fruits and Leaves During Berry Ripening

ABSTRACT The composition and variations of sugars, organic acids and phenolic compounds of red and black currant fruits and leaves were studied during the last four weeks of ripening. The results showed that sugar content increased during berry ripening in both species. In comparison, organic acids decreased in red currant, whereas no differences between sampling dates were observed in black currant. Forty-seven individual phenolic compounds, belonging to anthocyanins, flavonols, flavanols, hydroxycinnamic acid derivatives and flavanones were identified in red currant fruits and 52 in black currant fruits by HPLC-MS analysis. In black currant fruits, the major phenolic compounds were anthocyanins (81.51–85.15% of total phenolics), which increased during ripening until the last sampling date. In both red and black currant leaves, 47 phenolic compounds were identified. The content of phenolic compounds in red currant leaves was 1.31-fold to 1.90-fold higher compared to the content in black currant leaves. The most abundant phenolics in both currant leaves were flavonol glycosides, accounting for 58.5–67.9% of total phenolics, and their content was the highest at the end of berry ripening.

Endogenous compound chenodeoxycholic acid in potatoes can delay enzymatic browning by inducing antioxidant capacity

Enzymatic browning is a primary factor affecting the quality of fresh-cut potatoes. Our previous research demonstrated that warming the tubers after cold storage can alleviate the enzymatic browning of fresh-cut potatoes. In this research, we explored if some new endogenous compounds play roles in browning inhibitory effects. Utilizing a non-targeted metabolomics approach on tubers subjected to pre-cutting different temperature treatments, thirteen differential metabolites in potatoes were revealed, and five compounds with anti-browning effects were screened out. Among these five compounds, chenodeoxycholic acid (CDCA) exhibited the best inhibitory effect on browning and has not been reported in plants till now. The changes in CDCA content in tubers of pre-cutting different temperature treatments were further confirmed by LC-MS/MS. Subsequent experiments showed that the anti-browning effect of pre-cutting CDCA treatment was much better than post-cutting. Pre-cutting CDCA treatment only at a low concentration of 5 mg L−1 for a 10 min soaking and then standing for 6 h extended the shelf life of fresh potato slices to 5 d from less than 1 d of control. Not a big difference in polyphenol oxidase (PPO) activity and tyrosine contents were caused by pre-cutting CDCA treatment compared with control. However, pre-cutting CDCA treatment caused a notable reduction in the contents of malondialdehyde (MDA), superoxide anion (O2-), H2O2, and lipoxygenase (LOX) activity, and elevated the activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). Meanwhile, CDCA suppressed phenylalanine ammonia-lyase (PAL) activity and reduced the contents of both individual and total phenolic compounds. These results suggest that CDCA, an endogenous compound in potato tuber, can improve the anti-browning ability of fresh-cut potatoes mainly by inducing the enhancement of antioxidant capacity.

In Vitro Screening and Lipid-Lowering Effect of Prickly Pear (Opuntia Ficus-Indica L. Mill.) Fruit Extracts in 3T3-L1 Pre-Adipocytes and Mature Adipocytes

Opuntia ficus-indica fruits have been widely used due to their nutritional composition and beneficial effects on health, particularly against chronic diseases such as diabetes, obesity, cardiovascular diseases and cancer, among others. In recent years, prickly pear peel and pulp extracts have been characterised, and a high number of bioactive compounds have been identified. This study aimed to analyse the triglyceride-lowering effect of prickly pear peel and pulp extracts obtained from fruits of three varieties (Pelota, Sanguinos, and Colorada) in 3T3-L1 maturing and mature adipocytes. At a concentration of 50 µg/mL, peel extracts from Colorada reduced triglyceride accumulation in pre-adipocytes and mature adipocytes. Additionally, at 25 µg/mL, Pelota peel extract decreased triglyceride content in mature adipocytes. Moreover, maturing pre-adipocytes treated with 50 and 25 µg/mL of Sanguinos pulp extract showed a reduction of triglyceride accumulation. In addition, the lipid-lowering effect of the main individual betalain and phenolic compounds standards were assayed. Piscidic acid and isorhamnetin glycoside (IG2), found in Colorada peel extract, were identified as the bioactive compounds that could contribute more notably to the triglyceride-lowering effect of the extract. Thus, the betalain and phenolic-rich extracts from Opuntia ficus indica fruits may serve as an effective tool in obesity management.

Enzyme activity and nutritional profile of different-sized carrot cubes treated with supercritical carbon dioxide

This study evaluated changes in the enzyme activity, color, carotenoids, sugar profile, individual phenolic compounds, and antioxidant capacity of supercritical carbon dioxide (SCCD)-treated carrot cubes of different sizes (1 cm and 2 cm). Results demonstrated that SCCD reduced the activities of polyphenol oxidase (PPO) and peroxidase (POD) more in 1 cm carrot cubes than in 2 cm carrot cubes. Nevertheless, the a* , b* , and ∆E values of 1 cm SCCD-treated were enhanced compared to 2 cm SCCD-treated samples. The carotenoids, phenolic compounds, and antioxidant capacity of 1 cm SCCD-treated samples were increased under moderate processing conditions. In contrast, the nutritional composition in 1 cm SCCD-treated samples was lower than in 2 cm SCCD-treated samples at harsh processing conditions. The principal component and correction analysis displayed a visual variation between the enzyme activities and nutritional composition of 1 cm and 2 cm carrot cubes after SCCD processing. According to the results above, 1 cm carrot cubes processed with SCCD at 10 MPa, 35 ℃, and 45 min are the most effective at preserving fresh-cut carrots with relatively high enzyme inactivation and the highest retention of bioactive compounds. This work provides a more comprehensive theoretical basis for optimizing SCCD processing for fresh-cut carrots and recommendations for industrial production.

Total phenolic content and antioxidant activities in methanol extracts of medicinal herbs from Indo-Gangetic plains of India

The present study investigates total phenolics, flavonoids, and in vitro antioxidant activities in methanol extracts of roots, stems, leaves, and fruits of medicinal herbs (Phyllanthus fraternus G.L. Webster; Bhui-amla and Solanum nigrum L.; Makoi or black nightshade) of Indo-Gangetic plains of India. The results showed that biochemical attributes of methanol extracts of both the tested plants varied significantly with sites (P < 0.05). Contents of total phenolics and flavonoids and antioxidant properties were found highest in fruits followed by leaf, stem, and least in root of P. fraternus and leaves, fruits, stem, and roots of S. nigrum plants. The present investigation revealed that total phenolic content in fruits of P. fraternus ranged from 26.69 to 61.48 mg GAE/g fw and from 8.89 to 24.69 mg GAE/g fw in leaves of S. nigrum plants, and thus, these plant parts can be promoted for pharmaceutical purposes and health benefits. It is also suggested that the individual phenolic compound in the different parts of tested plants should be analyzed to identify their elite population for their mass cultivation, conservation, and sustainable utilization.