Soluble Phenolic Content Research Articles

Optimization of Phenolic Content Extraction and Effects of Drying Treatments on Physicochemical Characteristics and Antioxidant Properties of Edible Mushroom Pleurotus ostreatus (Jacq.) P. Kumm (Oyster Mushroom).

Edible mushrooms have been part of the human diet for centuries. Traditionally, they have been used for culinary and medicinal purposes due to their chemical composition and nutritional value, including their high antioxidant activity attributed to key metabolites such as phenolic compounds and ergothioneine. P. ostreatus mushrooms, known for their potent antioxidant activity, are prone to spoilage shortly after harvest, making preservation methods necessary. Various drying methods were evaluated to determine their effects on physicochemical characteristics, antioxidant properties, and ergothioneine content. Mushrooms were subjected to freeze-drying (FD), hot-air-drying (HAD), and microwave-vacuum-drying (MVD). The rehydration rate, color, and microstructural characteristics of extracts from fresh and dried P. ostreatus mushrooms were evaluated. Additionally, the total soluble phenolic content and antioxidant activity were assessed using DPPH and ORAC assays, along with the determination of ergothioneine content. FD and HAD at 40 °C showed the best results regarding the physicochemical characteristics. In terms of total soluble phenolic content, antioxidant activity, and ergothioneine content, the mushrooms dried using HAD at 40 °C showed the best retention of bioactive compounds. Among the evaluated methods, HAD at 40 °C proved to be a suitable alternative for processing P. ostreatus.

Increasing Soybean Resistance Against Rust Using a Product Containing Calcium and Nitrogen Complexed With Polyphenols

ABSTRACTAmong soybean diseases, rust, caused by Phakopsora pachyrhizi, stands out as one of the most destructive. Resistance inducers may be a great alternative to reduce the yield losses caused by this disease from the perspective of more sustainable agriculture. In this study, soybean plants were sprayed with water (control) or with Cautha [referred to as induced resistance (IR) stimulus after that] and inoculated or non‐inoculated with P. pachyrhizi. The germination of urediniospores was significantly reduced by 22%, 26%, 19%, and 25% for the IR stimulus rates of 2.5, 5, 10, and 20 mL/L, respectively. Rust severity was significantly reduced by 27%, 19%, 23%, 25%, and 41% at 7, 9, 11, 13, and 15 days after inoculation, respectively, and the area under the disease progress curve significantly decreased by 27% for IR stimulus‐sprayed plants compared to water‐sprayed plants. For infected plants, foliar concentrations of Ca, N, chlorophyll a + b, and carotenoids were higher for IR‐stimulus sprayed plants than for water‐sprayed plants. Lower concentrations of malondialdehyde (less cellular damage) and reactive oxygen species (hydrogen peroxide and superoxide anion radical) along with great activities of antioxidative enzymes (ascorbate peroxidase, catalase, glutathione reductase, and superoxide dismutase) helped to reduce rust symptoms for IR‐stimulus sprayed plants. On top of that, these plants also showed greater foliar concentrations of total soluble phenols and lignin as well as increased activities of defence‐related enzymes (chitinase, β‐1,3‐glucanase, phenylalanine ammonia‐lyase, peroxidase, polyphenoloxidase, and lipoxygenase). These results strongly support the potential of using this IR stimulus to increase soybean resistance against infection by P. pachyrhizi and, at the same time, to act directly against the germination of the urediniospores.

Effect of Tapioca and Tragacanth based edible coatings on the physiological, chemical, microbial, and phytochemical quality of Tomato fruits

AbstractIn recent years, edible coatings have emerged as a promising solution to extend the shelf life, and maintain the quality of fruits and vegetables. The purpose of the study was the development and application of gum Tragacanth and Tapioca‐based edible coatings to extend the storability and quality of tomato (Solanum Lycopersicum L). Different treatments were prepared with combinations of Tragacanth gum (0.5, 1, 1.5 g) and Tapioca (1, 1.5, 2 g). Parameters such as weight loss, sugars, decay percentage, pH, titratable acidity, total soluble solids, antioxidant capacity, phenolic and flavonoid contents, microbial counts, and sensory evaluation were measured during 14 days storage. Results revealed that the application of gum Tragacanth and Tapioca‐based coatings significantly reduced weight loss, decay percentage, and microbial counts of treated tomatoes as compared to the control group. The coated tomatoes exhibited improved sensory features, with a slower rate of softening, during the storage. There was a significant increment in total phenolic and flavonoid contents and antioxidant capacity of coated fruits during 7 days of storage. The observed improvements in the postharvest quality attributes suggest that the gum Tragacanth and Tapioca‐based edible coatings have the potential to retain and enhance the nutritional and bioactive contents and shelf life of tomato.

Caffeine removal and compositions losses from whole Robusta coffee beans during conventional and ultrasound-assisted aqueous decaffeination

Whole Robusta coffee beans were decaffeinated using conventional aqueous extraction (CAE) and ultrasound-assisted aqueous extraction (UAAE). Changing of extraction water at time intervals to enhance caffeine removal efficiency is proposed as novel decaffeination technique. Kinetic modelling of caffeine content evolutions during CAE and UAAE, with and without water changing, was performed to confirm benefit of newly proposed technique. Losses of soluble carbohydrates, phenolics, sugars, flavonoids and organic acids from decaffeinated beans were investigated. Recycling of extraction water as way to recover lost compositions was tested. Water changing enhanced caffeine removal efficiency, especially in case of UAAE; caffeine could be removed by 98%. Kinetic model well described caffeine content evolutions (R2 = 0.99). This strategy nevertheless led to significant losses (p < 0.05) of bean compositions when compared to CAE. UAAE with water recycling could not help recover bean compositions, but drying and soaking beans in spent extraction water from second round of decaffeination significantly increased (p < 0.05) total soluble carbohydrates and phenolics contents.

In Vitro Digestion of Vacuum-Impregnated Yam Bean Snacks: Pediococcus acidilactici Viability and Mango Seed Polyphenol Bioaccessibility.

This study investigates the in vitro digestion of vacuum-impregnated yam bean snacks enriched with Pediococcus acidilactici and mango seed polyphenols, focusing on bacterial survival and polyphenol bioaccessibility. The snacks were prepared by vacuum impregnation (VI) with solutions containing either mango seed extract, P. acidilactici, or a combination of both, followed by dehydration. The antimicrobial activity of the treatments was assessed against pathogens, revealing limited effectiveness, likely due to insufficient concentrations of mango seed extract and the intrinsic resistance of the bacteria. VI of mango seed extract improved the total soluble phenols (TSP) content up to 400% and maintained the initial probiotic concentration (106 cell/mL). In vitro digestion was performed to simulate gastrointestinal conditions, measuring the stability of TSP and the survival of P. acidilactici. The results indicated that the viability of P. acidilactici fluctuated throughout the digestion process (106 to 104 log UFC/g), the polyphenols showed varying degrees of bioaccessibility (11 to 30%), and the TSP content in the intestinal fraction ranged from 1.95 to 6.54 mg GAE/g. The study highlights the potential of VI for incorporating functional components into plant-based snacks, though further optimization is necessary to enhance the stability of P. acidilactici and the effectiveness of the bioactive ingredients.

Enhancing moisture transfer and quality attributes of tomato slices through synergistic cold plasma and Osmodehydration pretreatments during infrared-assisted pulsed vacuum drying

The present study examines the impacts of combined cold plasma treated water (PW) and osmodehydration (OD) pretreatment (PO), and operation parameters like PW duration and voltage of treatment on the dehydration, functional and sensory characteristics of sliced tomato fruits subjected to simultaneous infrared-assisted pulsed vacuum drying (IR-PVD). From the results, PO pretreatment modified the surface structures by the formation of microchannels and cavities through impingements from the reactive species (RS), and was improved due to increased treatment duration and voltage, and resulted in accelerating the transfer of moisture from the slices to the surroundings during the dehydration process. Consequently, PO pretreatment achieved an enhancement in the moisture diffusivity by up to 64.83%, shortened the total drying time by up to 40%, and presented substantial improvements in the physicochemical properties including vitamin C, lycopene, colour, total soluble solids, phenolic and flavonoid contents, and overall human acceptability. However, significant decreases in rehydration and hardness properties were shown compared with control, and higher rehydration by up to 21.66% at higher treatment duration and voltage when compared with OD pretreatment. Overall, PO pretreatment incited an effective moisture removal and retention of vital physicochemical and bioactive constituents in the slices due to the activities of plasma injected RS. This study provides an empirical basis for the application of PO during IR-PVD of fruits and vegetables and demonstrated as a suitable energy-saving alternative for improving the conventional OD of foods in the industry.

Botánica aplicada: radiación UV-B para la obtención de brotes de quinua enriquecidos en compuestos fenólicos, con probables usos en protectores solares naturales o como alimentos funcionales

The objective was to evaluate the use of a microgreen system and very short UV-B radiation dose to obtain plant biomass as a source for phenol-enriched extracts with probable cosmetic and/or food uses. Quinoa seedlings, a native species of the Andes, of two different ages were used. The seedlings were irradiated with different doses of UV-B and then evaluated by quantifying indicators of oxidative damage. Also, the contents of phenolic compounds, photosynthetic pigments, antioxidant capacity, and sun protection factor were determined. The results showed that the youngest seedlings responded better to short UVB doses, increasing the content of soluble and insoluble phenols, without showing oxidative damage. These results were correlated with the greater antioxidant power of the extracts and an intermediate sun protection factor. We conclude that this species, grown in a microgreen system, is a promising alternative to obtain phenol-enriched extracts with possible use in formulations of natural sunscreens. In this sense, these results can serve as a starting point for optimization studies through the response surface methodology.

Coupling Low-Frequency Ultrasound to a Crossflow Microfiltration Pilot: Effect of Ultrasonic Pulse Application on Sono-Microfiltration of Jackfruit Juice.

To reduce membrane fouling during the processing of highly pulpy fruit juices into clarified beverages, a crossflow Sono-Microfiltration (SMF) system was employed, strategically equipped with an ultrasonic probe for the direct application of low-frequency ultrasound (LFUS) to the juice just before the entrance to the ceramic membrane. Operating conditions were standardized, and the application of LFUS pulses in both corrective and preventive modes was investigated. The effect of SMF on the physicochemical properties and the total soluble phenol (TSP) content of the clarified juice was also evaluated. The distance of ultrasonic energy irradiation guided the selection of the LFUS probe. Amplitude conditions and ultrasonic pulses were more effective in the preventive mode and did not cause membrane damage, reducing the operation time of jackfruit juice by up to 50% and increasing permeability by up to 81%. The SMF did not alter the physicochemical parameters of the clarified juice, and the measured LFUS energy ranges did not affect the TSP concentration during the process. This study is the first to apply LFUS directly to the feed stream in a pilot-scale crossflow microfiltration system to reduce the fouling of ceramic membranes and maintain bioactive compounds in jackfruit juice.

The Effect of Putrescine and Modified Atmosphere Packaging (MAP) Treatments on Fruit Quality Characteristics of Strawberry (Kabarla cultivar) During Cold Storage

Strawberry is a fruit species that must be harvested at full ripening and at the same time has an extremely short shelf life and deteriorates rapidly. Therefore, it is important to extend the shelf life after harvest. In this study, putrescine and modified atmosphere packaging (MAP) were applied during cold storage in order to maintain the quality and extend the shelf life of strawberry fruit. The commercial ripening fruit were treated with 1 mM putrescine and stored in MAP for 20 days. The quality characteristics such as weight loss, soluble solids content, titratable acidity, fruit color, organic acid and phenolic content were measured and analyzed on days 4, 8, 12, 16 and 20 of storage. At the end of 20 days of the cold storage, the highest weight loss was in control treatment (%). The decrease in soluble solids content (SSC) and titratable acidity (TA) values during cold storage was slowed down by MAP and putrescine treatments. Organic acids and phenolic compounds were significantly affected by storage time and MAP and putrescine treatments. After 20 days of the cold storage, citric acid (748.91 mg 100 g -1) and malic acid (258.34 mg 100 g-1), which were determined as basic organic acids, were highest in putrescine treatment. Shikimic acid (0.77 mg 100 g-1) and isocitric acid (112.58 mg 100 g-1) as phenolic compounds were highest in MAP and MAP+ putrescine treatments, respectively. These results releaved that the application of putrescine and modified atmosphere packaging (MAP) during cold storage significantly extends the market life of strawberries by preserving their quality attributes.

Biochemical Characterization of Brinjal (Solanum melongena L.) Leaves Infected with Little Leaf Disease

The experiment was conducted during September, 2023 to February, 2024 at the Department of Biochemistry, Anand Agricultural University, Anand, Gujarat, India. Total 28 genotype originating from a cross between a little leaf resistance parent AB 15-06 (S. melongena) and a susceptible parent GRB 5 (S. melongena). Disease incidence recorded from 14 each of highly resistant and susceptible genotypes and their parents AB 15-06 (Resistance against little leaf disease) and GRB 5 (Susceptible against little leaf disease) were selected for biochemical attributes comprised of chlorophyll (0.73–0.98 mg g-1), moisture (76.77–97.43%), phenol (0.43–3.26 mg g-1), total soluble sugar (2.36–4.57 mg g-1), membrane injury (24.56–69.87%). Correlation analysis of biochemical characters like chlorophyll and moisture were observed negatively correlated with disease incidence while rest of biochemical parameters total soluble solids, membrane injury and phenol content were positively correlated. Membrane injury (0.254), moisture (0.026), TSS (0.030), and phenol content (0.016) showed positive skewness whereas chlorophyll (-1.318), membrane injury (-1.540), moisture (-1.543), total soluble sugar (-1.160) and phenol content (-1.626) detected negative kurtosis. GCV, PCV and heritability analysis for all biochemical characters recorded were chlorophyll (36.46%, 36.5% and 99.82%), membrane injury (61.52%, 61.96% and 98.59%), moisture (7.55%, 8.73% and 13.44%), total soluble sugar (99.39%) and phenol content (46.76%, 46.83% and 99.67%).

Phytochemical Composition and Antimicrobial and Antibiofilm Effect of Myrciaria cauliflora Hydroethanolic Extract against Staphylococcus aureus and Acinetobacter baumannii.

Staphylococcus aureus and Acinetobacter baumannii are opportunistic pathogens, and both are involved in different oral infections. This work aimed to analyze the phytochemical composition of Myrciaria cauliflora hydroethanolic extract and to evaluate its antimicrobial and antibiofilm action against Staphylococcus aureus (ATCC 6538) and Acinetobacter baumannii (ATCC 19606; multi-resistant clinical strains 58004, 50098, 566006, and H557). Myrciaria cauliflora hydroethanolic extract was prepared, and the content of soluble solids, flavonoids, and phenols was quantified. High-performance liquid chromatography (HPLC) was performed later. The minimum inhibitory concentration was determined using the broth microdilution method according to the Clinical and Laboratory Standards Institute, standard M7-A6, and subsequently, its minimum bactericidal concentration was determined. Then, the most effective concentrations were analyzed against biofilms. Statistical analysis was performed using the ANOVA method with Tukey's test. The soluble solids content in the prepared hydroethanolic extract of M. cauliflora was 2.22%. Additionally, the total flavonoid content, measured using the quercetin standard curve, was 0.040 mg/mL. Furthermore, the total phenol content, determined using the gallic acid standard curve, was 0.729 mg/mL. HPLC analysis presented peaks of gallic acid (11.80 m), p-coumaric acid (12.09 m), cinnamic acid derivative (19.02 m), and ellagic acid (29.83 m). The extract demonstrated antimicrobial and antibiofilm action against all tested strains. However, the most effective antibacterial concentration against all the tested bacteria was 5.55 mg/mL. Therefore, these chemical components justify that M. cauliflora hydroethanolic extract is effective in reducing biofilm formation in S. aureus (standard strain) and A. baumannii (standard and clinical strains).

Pomological, organoleptic, and biochemical values of Norwegian heritage apple cultivars

ABSTRACT Almost 10,000 of apple cultivars are described worldwide but only a few of them are dominating in commercial apple orchards. The decline in genetic diversity could lead to negative consequences in terms of adaptability, resistance and even consumption. Apple genetic resources in Norway are conserved in several local clonal archives. The aim of this study was to evaluate Norwegian heritage apple cultivars from a pomological, agronomical, and chemical point of view, identify the most important quality parameters, and select cultivars with desirable traits for modern markets and breeding purposes. In total 75 heritage and 4 standard apple cultivars were evaluated at the Norwegian Institute of Bioeconomy Research – NIBIO Ullensvang, during 2018–2020. Based on individual investigations of various fruit quality characters, cultivar groups with special properties were selected for the industry, for making concentrate and fresh juice, and for medical properties. According to the soluble solid content, sweetness index, fruit size, acid, dry matter, and phenolic content, several groups of cultivars have high potential value for modern breeding programmes. Based on overall fruit quality, heritage cultivars Løeeple, Raud Gravenstein, and Rondestveit were selected for fresh consumption.

Comparative analysis of nutrient composition and antioxidant activity in three dragon fruit cultivars.

Dragon fruit has significant economic value in many countries due to has excellent nutritional content, health advantages, and adaptability to different climates, making it an important crop in the global fruit industry. This study aimed to gather comprehensive nutritional data on three dragon fruit cultivars by analysing the levels of micronutrients, fibre, carbohydrates, antioxidants, vitamins, and minerals in their pulps. Uniform dragon fruit samples underwent thorough analysis for proximate composition, mineral content, pigments, antioxidants, and vitamin C, with statistical methods used to assess significant differences among the parameters studied. The proximate composition analysis revealed significant differences among the three dragon fruit cultivars. Among the proximate components, protein (0.40±0.02g/100 g), moisture (91.33±0.88%), crude fibre (0.32±0.07 g/100 g), and ash (1.27±0.09 g/100 g) were more abundant in Hylocereus costaricensis than in Hylocereus undatus and Hylocereus megalanthus. On the other hand, Hylocereus undatus had higher carbohydrate (17.02±0.63 g/100 g) and energy (69.74±2.44 kcal/100 g) contents. K (7.23±0.35 mg/100 g), Ca (1.61±0.13 mg/100 g), Fe (1.84±0.05 mg/100 g), and Zn (0.37±0.034 mg/100 g) are highly abundant in H. costaricensis. Additionally, Hylocereus costaricensis had the highest anthocyanin content (120.15±3.29 mg/g FW) and total carotenoid content (72.51±1.62 mg/g FW), along with the highest vitamin C content (8.92±0.13 mg/g FW) and total soluble phenolic content (572.48±20.77 mg/100 g). Its remarkable antioxidant activity was further highlighted by the lowest SC50 value (13.50±0.4 mg/mL) for its DPPH radical scavenging capacity. The total soluble sugar content was highest in Hylocereus megalanthus (8.72±0.30 g/100 g FW). Hierarchical clustering analysis revealed distinct trait and genotype associations; among the studied cultivars, Hylocereus costaricensis demonstrated superior performance across multiple traits. Correlation analysis indicated significant positive correlations among several traits, while principal component analysis highlighted the contribution of each trait to overall variance, with PC1 explaining 73.95% of the total variance. This study highlights the nutritional variations among dragon fruit cultivars, with Hylocereus costaricensis showing superior performance, guiding dietary planning and functional food development.

Differential Effects of In Vitro Simulated Digestion on Antioxidant Activity and Bioaccessibility of Phenolic Compounds in Purple Rice Bran Extracts.

Pigmented rice varieties are abundant in phenolic compounds. Antioxidant activity and bioaccessibility of phenolic compounds are modified in the gastrointestinal tract. After in vitro simulated digestion, changes in antioxidant activity and bioaccessibility of phenolic compounds (phenolic acids, flavonoids, and anthocyanins) in purple rice brans (Hom Nil and Riceberry) were compared with undigested crude extracts. The digestion method was conducted following the INFOGEST protocol. Antioxidant activity was determined using the ferric-reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity assays. The bioaccessibility index (BI) was calculated from the ratio of digested to undigested soluble phenolic content. Overall results showed that the in vitro simulated digested rice brans had lower antioxidant activity and lower total phenolic, flavonoid, and anthocyanin contents. However, the concentration of sinapic acid was stable, while other phenolic acids (gallic, protocatechuic, vanillic, ρ-coumaric, and ferulic acids) degraded after the oral, gastric, and intestinal phases. The BI of sinapic, gallic, vanillic, and ferulic acids remained stable, and the BI of quercetin was resistant to digestion. Conversely, anthocyanins degraded during the intestinal phase. In conclusion, selective phenolic compounds are lost along the gastrointestinal tract, suggesting that controlled food delivery is of further interest.

Synergistic modulation of oxidative peel browning in postharvest litchi through ultrasound and salicylic acid coupling

Pericarp browning in litchi is a major postharvest problem that drastically affects cosmetic appeal and marketability of fruits. This study explores the efficacy of postharvest treatments involving ultrasound (US) combined with salicylic acid (SA) in mitigating oxidative browning and preserving quality attributes during ambient storage. Results indicate that the combined treatment of US and SA, particularly at a concentration of 2 mM, effectively reduced weight loss, decay incidence, and the production of reactive oxygen species. Furthermore, this combination maintained higher levels of total soluble solids, titratable acidity, phenolic content, antioxidants, and phenylalanine ammonia-lyase activity while suppressed polyphenol oxidase activity. The combined US + SA (2 mM) synergistically delayed the quality deterioration and pericarp browning in litchi during storage.

Determination of sensory, microbiological and antioxidant properties of tortilla added with Roselle decoction calyxes powder

Background: Hibiscus (Hibiscus sabdariffa L.) is a flowering plant gaining interest for its potential health benefits due to its high content of phenolic compounds and antioxidant properties. These properties have been linked to various health improvements, including reduced risk of chronic diseases. Aims: The aim was to assess the sensory, microbiological, physical, and antioxidant properties of corn and wheat tortillas formulated with varying HDC concentrations. Material and Methods: Five formulations were prepared, incorporating HDC (5%, 20%, 50%, and 70%) into the corn and wheat flour blends. The formulation with the most favorable sensory profile was further evaluated for: microbiological analysis, tortilla quality properties (diameter, weight, yield, puffing degree, rollability, and moisture content), total soluble phenolic content (TSPCC), total flavonoid content (TFC), and antioxidant capacity (DPPH• and ABTS+• methods). Results: Sensory evaluation revealed that the corn and wheat tortillas with 20% HDC achieved the highest overall acceptability in terms of mouthfeel, color, and flavor attributes. The addition of HDC significantly reduced microbial growth compared to the control tortillas. All formulations displayed significant variations in quality properties. Tortillas containing HDC demonstrated significantly higher levels of TSPCC, TFC, and antioxidant capacity. Conclusion: The incorporation of 20% HDC flour presents a promising approach to developing functional tortillas with enhanced health benefits. These tortillas exhibit desirable sensory characteristics, improved microbiological safety, and increased antioxidant potential, potentially impacting the food industry and consumer health. Keywords: Tortilla, roselle decoction calyxes, phenolic compounds, corn, wheat, antioxidant capacity.

Effect of MnO2 Nanoparticles Stabilized with Cocamidopropyl Betaine on Germination and Development of Pea (Pisum sativum L.) Seedlings.

This study aimed to synthesize, characterize, and evaluate the effect of cocamidopropyl betaine-stabilized MnO2 nanoparticles (NPs) on the germination and development of pea seedlings. The synthesized NPs manifested as aggregates ranging from 50-600 nm, comprising spherical particles sized between 19 to 50 nm. These particles exhibited partial crystallization, indicated by peaks at 2θ = 25.37, 37.62, 41.18, 49.41, 61.45, and 65.79°, characteristic of MnO2 with a tetragonal crystal lattice with a I4/m spatial group. Quantum chemical modelling showed that the stabilization process of MnO2 NPs with cocamidopropyl betaine is energetically advantageous (∆E > 1299.000 kcal/mol) and chemically stable, as confirmed by the positive chemical hardness values (0.023 ≤ η ≤ 0.053 eV). It was revealed that the interaction between the MnO2 molecule and cocamidopropyl betaine, facilitated by a secondary amino group (NH), is the most probable scenario. This ascertain is supported by the values of the difference in total energy (∆E = 1299.519 kcal/mol) and chemical hardness (η = 0.053 eV). These findings were further confirmed using FTIR spectroscopy. The effect of MnO2 NPs at various concentrations on the germination of pea seeds was found to be nonlinear and ambiguous. The investigation revealed that MnO2 NPs at a concentration of 0.1 mg/L resulted in the highest germination energy (91.25%), germinability (95.60%), and lengths of roots and seedlings among all experimental samples. However, an increase in the concentration of preparation led to a slight growth suppression (1-10 mg/L) and the pronounced inhibition of seedling and root development (100 mg/L). The analysis of antioxidant indicators and phytochemicals in pea seedlings indicated that only 100 mg/L MnO2 NPs have a negative effect on the content of soluble sugars, chlorophyll a/b, carotenoids, and phenols. Conversely, lower concentrations showed a stimulating effect on photosynthesis indicators. Nevertheless, MnO2 NPs at all concentrations generally decreased the antioxidant potential of pea seedlings, except for the ABTS parameter. Pea seedlings showed a notable capacity to absorb Mn, reaching levels of 586.5 μg/L at 10 mg/L and 892.6 μg/L at 100 mg/L MnO2 NPs, surpassing the toxic level for peas according to scientific literature. However, the most important result was the observed growth-stimulating activity at 0.1 mg/L MnO2 NPs stabilized with cocamidopropyl betaine, suggesting a promising avenue for further research.

Effects of cofermentation of Saccharomyces cerevisiae and different lactic acid bacteria on the organic acid content, soluble sugar content, biogenic amines, phenol content, antioxidant activity and aroma of prune wine

To determine the effect of cofermentation of Saccharomyces cerevisiae and different LABs on prune wine quality, this study compared phenolic compounds, organic acids, soluble sugars, biogenic amines and volatile flavor compounds among different treatments. The results showed that inoculation of LAB increased DPPH and total flavonoid content. Malic acid content was reduced in HS, HB and HF. Histamine content in S, F and B was lower than the limits in French and Australian wines. 15 phenolic compounds were identified. Yangmeilin and chlorogenic acid were detected only in HS, HF and HB. 51 volatile flavor compounds were identified, esters being the most diverse and abundant. 14 volatile flavor compounds with OAV > 1 contributed highly to the aroma of prune wine. 9 chemical markers including resveratrol, rutin, and catechin were screened to explain intergroup differences by OPLS-DA. This study provides new insights into the processing and quality analysis of prunes.

Interaction of nickel with oxidative and antioxidative molecules in Cichorioideae species

The uptake of nickel (Ni) by Asteraceae/Cichorioideae species Cichorium intybus, Leontodon hispidus and Hieracium aurantiacum exposed to Ni (0.3 or 30 μM) over 14 days and subsequent changes of metabolites were compared in order to identify their phytoaccumulation potential. Hieracium contained the most Ni (194 and 1558 μg Ni/g DW at 30 μM Ni in shoots and roots) but had unchanged amount of antioxidants (vitamin C and thiols) in the shoots and an elevated amount in the roots, which may be the reason for the absence of visible damage. On the contrary, Leontodon reacted by a decrease in antioxidants to an excess of Ni, which can be related to enhanced oxidative stress (an increase in ROS and a decrease in nitric oxide detected by fluorescence microscopy). All roots were anatomically in the secondary state and Ni-induced cell wall thickening (i.e. lignin/suberin deposition) was most visible in Hieracium roots, which also contained 2-times more Ni than the other species. Among essential elements, mainly Fe accumulation was affected by Ni excess. The content of soluble phenols increased while organic acids (malic and citric) decreased sometimes extensively (up to 90%) in individual species. PCA analyses showed that especially ascorbic acid, thiols and phenols affect the separation in the shoots especially with regard to applied concentration of Ni, while these metabolites in the roots clearly separated the species (Cichorium from the others). The data show the highest tolerance to Ni in Hieracium, but the highest phytoaccumulation of Ni was found in Cichorium (626 μg Ni/plant or 122 μg Ni/shoot at a dose of 30 μM Ni).

Solid state fermentation of Diaphragma juglandis fructus with Aspergillus niger alleviates hydrogen peroxide-induced oxidative stress in HepG2 cells via Nrf2 signaling pathway

Diaphragma juglandis fructus (DJF) is a traditional medicine, which is rich in bioactive polyphenols and has been proven to exhibit better antioxidant activity. However, the potential effects of fermentation of DJF on oxidative stress remains unclear. Herein, this study aimed to investigate the impact of solid-state fermentation (SSF) with Aspergillus niger (A. niger) on the polyphenol content and biological activity in DJF. Furthermore, compared with unfermented Diaphragma juglandis fructus (UF-DJF) extracts, ellagic acid (EA), sinapic acid (SA) and (+)-catechin (CA) displayed the highest increase in soluble phenolics (SPs) of fermented Diaphragma juglandis fructus (F-DJF) extracts. Thus, we explored the protective effect of EA, SA, CA and co-existing of EA, SA, CA against hydrogen peroxide (H2O2)-induced oxidative stress in HepG2 cells. Our results demonstrated that the insoluble-bound phenolics (IBPs) could be released, thereby increasing the SPs content and in vitro antioxidant activity after SSF. In addition, we also found that F-DJF extracts had the best inhibitory effect on three digestive enzymes among UF-DJF, before fermented Diaphragma juglandis fructus (BF-DJF) and F-DJF extracts. Moreover, our results revealed that pre-treatment with EA, SA, CA and co-present of EA, SA, CA could protect HepG2 cells from oxidative damage through activating the Nrf2 signaling pathway and up-regulating the expression of heme oxygenase-1 (HO-1), NAD(P)H dehydrogenase quinone1 (NQO1), glutamate-cysteine ligase catalytic subunit (GCLC), cytoplasmic Cu-Zn-SOD (SOD1), mitochondrial Mn-SOD (SOD2) and catalase (CAT). Remarkably, the co-presence of EA, SA, CA showed the best protective effect. In conclusion, our research highlights SSF is an effective method for enhancing polyphenol content and biological activity in DJF. Moreover, these findings provide novel insights into the role of F-DJF extracts in prevention chronic diseases associated with oxidative stress and the possibility of their application in functional foods. In addition, fermentation may be a reliable strategy to enhance the medicinal value of DJF.