Blueberry leaves from 73 different cultivars in southeastern China as nutraceutical supplements rich in antioxidants

Valorization of Berry Fruit By-Products: Bioactive Compounds, Extraction, Health Benefits, Encapsulation and Food Applications

The increased production of high-quality berry products in recent years has led to considerable quantities of by-products such as pomace (25-50%), which consists of skin, seeds, stems and leaves. The improper management of pomace can lead to environmental pollution and potential public health problems due to microbial contamination, and storage causes additional processing costs. However, due to their high content of various valuable bioactive compounds (BACs), berry by-products have gained much attention as sustainable and functional ingredients with applications in the food and nutraceutical industries. The health benefits are primarily attributed to the phenolic compounds, which exhibit numerous biological activities, especially good antioxidant and antibacterial activity as well as health-promoting effects. This review summarizes the bioactive content and composition of extracts from berry by-products (genera Ribes, Rubus, Fragaria, Sambucus, Aronia and Vaccinium) obtained using advanced extraction technologies and their stabilization through sophisticated encapsulation technologies that make them suitable for various food applications. The addition of berry pomace to beverages, bakery, dairy and meat products improves sensory quality, extends shelf life, increases nutritional value and reduces the environmental footprint. This information can provide food scientists with valuable insights to evaluate the potential of berry by-products as functional ingredients with health-promoting and disease-preventing properties that create value-added products for human consumption while reducing food waste.

Blueberry leaves as a promising sustainable source of polyphenols: Chemical composition, functional activities and future application perspectives

Blueberry leaves are a byproduct of blueberry cultivation, often overlooked despite their potential value. As global consumption of blueberries continues to rise, the area under cultivation expands, leading to an increased production of blueberry leaves. Blueberry leaves are a rich source of polyphenols, and in recent years, extensive research has been conducted on the composition and biological functions of these compounds. However, studies on blueberry leaves are often fragmented and lack a comprehensive overview of their potential applications. This review outlines the biosynthetic pathways of polyphenols in plants and compares the variations in polyphenol content and composition in blueberry leaves, influenced by factors such as cultivars, harvesting seasons, and extraction methods. Current research indicates that the primary constituents of blueberry leaf polyphenols (BLPs) are caffeoyl quinic acids, flavonols, and flavan-3-ols. These active compounds endow blueberry leaves with a range of functional properties, including antioxidant, anti-inflammatory, antibacterial, antiviral, antitumor, and metabolic syndrome-modulating effects. As a cost-effective and potentially beneficial by-product of agricultural production, blueberry leaves represent a promising area for further development. Therefore, this review discusses the opportunities and challenges associated with the applications of blueberry leaves, offering insights into their future processing, utilization, and potential for sustainable development.

Advanced technology in fruit preservation: Effects of nanoscale charged water particles on storage quality and reactive oxygen species in blueberries

During the postharvest period, blueberries with a short shelf life due to microbial activity and an overload of reactive oxygen species (ROS) were still a major unresolved problem. In this study, the effect of nanoscale charged water particles (NCWP) treatment on the postharvest characteristics and ROS metabolism in blueberries (Vaccinium ashei Reade) were investigated. The results showed that NCWP treatment significantly inhibited microbial growth, maintained high firmness and commercial acceptability, and extended the storage period of blueberries. The nutrient of blueberries was retained and elevated after NCWP treatment, especially in the 6 d of NCWP-9 h treatment, the total phenol and anthocyanin content reached the peak at 565.1 mg/L and 5.26 mg/g, which contribute to the total antioxidant capacity of blueberries increased. SEM showed that NCWP-9 h treatment maintained the integrity of the cuticular wax of the blueberry peel, which indirectly decelerated the decline of blueberry firmness. The NCWP treatment significantly enhanced the antioxidant enzyme system of blueberry peel. On days 2, 4 and 6 after NCWP-9 h treatment, the CAT, SOD and APX activities were significantly different from the control group (P < 0. 05), with 585.09 ΔA/min/g, 79.34 U/g and 3.32 umol/min/g, respectively, which effectively scavenged the oxidative stress markers (H2O2, O2-) accumulated in the blueberry peels, and slowed down the aging and deteriorated of the blueberry process. This finding demonstrates that NCWP is an effective postharvest preservation method for blueberries and provides a viable strategy for quality maintenance in the postharvest fruit and vegetable sector.

Seasonal variation of antioxidant bioactive compounds in southern highbush blueberry leaves and non-destructive quality prediction in situ by a portable near-infrared spectrometer

Blueberry leaves (BBL) are a natural source with strong antioxidant activity, but bioactive compounds and their seasonal variation remain vague. Here, two major classes of compounds including four caffeoylquinic acids and eight flavonoids were identified in two southern highbush cultivars ("Lanmei" #1 and "Jewel") grown in China. Major bioactive compounds were discovered using an online HPLC post-column derivatization system and determined as neochlorogenic acid (NeoCA), chlorogenic acid (CA), rutin, hyperoside, and isoquercitrin. CA contributed the most to the BBL antioxidant activity. "Lanmei" showed significant advantages in terms of rutin content and antioxidant activity over "Jewel" (P < 0.05). The highest CA content (CAC) of juvenile "Jewel" leaves reached 17.9%. July was the optimum harvest time for both cultivars after fruiting stage. Total phenolic content (TPC) and Trolox equivalent antioxidant capacity (TEAC) of fresh BBL were accurately predicted by a portable near-infrared (NIR) device in a rapid, low-cost, and non-destructive way in situ.

Determination of phytochemical quality of leaves Vaccinium vitis-idaea L. and Vaccinium myrtillus L. from the polluted and non-polluted areas

Elemental composition of Vaccinium myrtillus L. and Vaccinium vitis-idaea L. has not been determined yet in detail. In our study, a scanning electron microscope coupled with an energy dispersive X-ray analyser (SEM-EDX) ensured the determination of 15 elements in the leaves of Vaccinium sp. growing in the control and the mine polluted locality. The soil elemental analyses showed a higher content of 11 elements from all determined in the mine-influenced samples. Elemental analyses of the control leaves showed the highest contents of all determined elements for V. vitis-idaea, except for carbon. The impact of pollution on V. myrtillus leaves caused significant increase in oxygen, natrium, magnesium, sulphur, chlorine, potassium and calcium content. The contents of carbon, nitrogen and silicon decreased substantially. In the case of the V. vitis-idaea leaves, the content of most of elements reduced, and in the case of six elements, even significantly. A significant increase was recorded for carbon, iron and copper. The effect of the environment has influenced the production of phytochemicals, assessed by HPLC-DAD. The production of flavonoids (hyperoside, isoquercetin) increased significantly in V. myrtillus and decreased to a detectable minimum in V. vitis-idaea. In the case of chlorogenic acid, arbutin and hydroquinone, their levels changed minimally in V. myrtillus, but significantly more in the V. vitis-idaea leaves. The importance of elemental analyses lies in detecting the presence of toxic elements or their harmful concentrations in plants that are the source of food or dietary supplements.

The delayed senescence in harvested blueberry by hydrogen-based irrigation is functionally linked to metabolic reprogramming and antioxidant machinery

Molecular hydrogen is beneficial for fruits quality improvement. However, the mechanism involved, especially cellular metabolic responses, has not been well established. Here, the integrated widely targeted metabolomics analysis (UPLC-MS/MS) and biochemical evidence revealed that hydrogen-based irrigation could orchestrate, either directly or indirectly, an array of physiological responses in blueberry (Vaccinium spp.) during harvesting stage, especially for the delayed senescence in harvested stage (4 °C for 12 d). The hubs to these changes are wide-ranging metabolic reprogramming and antioxidant machinery. A total of 1208 distinct annotated metabolites were identified, and the characterization of differential accumulated metabolites (DAMs) revealed that the reprogramming, particularly, involves phenolic acids and flavonoids accumulation. These changes were positively matched with the transcriptional profiles of representative genes for their synthesis during the growth stage. Together, our findings open a new window for development of hydrogen-based agriculture that increases the shelf-life of fruits in a smart and sustainable manner.

Content of Bioactive Compounds in Highbush Blueberry Vaccinium corymbosum L. Leaves as a Potential Raw Material for Food Technology or Pharmaceutical Industry

This study was performed to investigate the content of selected phenolic compounds, antioxidant activity and the levels of arbutin and hydroquinone in 25 varieties of highbush blueberry (Vaccinium corymbosum) leaf samples. An analysis of the bioactive components was performed using the HPLC technique and the antioxidant activity was determined via spectrophotometric methods. The content of chlorogenic acid in the analysed leaf extracts ranged from 52.76 mg/g (Spartan variety) to 32.37 mg/g (Nelson variety) and was present in the highest concentration among all the analysed phenolic acids. Particularly large levels of isoquercetin were found in the Aurora, Ivanhoe and Toro varieties (28.40 mg/g, 26.24 mg/g and 21.57 mg/g, respectively). An exceptionally high rutin content (p < 0.05) was found in the Ivanhoe variety (27.19 mg/g) as compared to the other varieties, where it ranged from 2.06 mg/g (Earliblue and Patriot varieties) to 10.55 mg/g (Bluejay variety). The Patriot variety was determined to possess the highest antioxidative activity using the FRAP method (1086.15 μmol Trolox/g d.w.) and based on its DPPH radical scavenging activity (1124.17 μmol Trolox/g d.w.). The total phenolic content (TPC) determined via spectrophotometry ranged from 48.11 mg GAE/g d.w. (Elizabeth variety) to 177.31 GAE/g d.w. (Patriot variety). The arbutin content in the leaves of all tested varieties exceeded 2%, so it can be concluded that they constitute a stable source of arbutin. Three varieties (Bonus, Chanticleer and Herbert) can be considered a potential alternative to bearberry and lingonberry leaves. The hydroquinone content in the analysed extracts was determined to be at a lower level. V. corymbosum leaves can be considered an interesting herbal material for use in traditional herbal medicinal products but not directly for food products and dietary supplements.

Microencapsulated Bilberry and Chokeberry Leaf Extracts with Potential Health Benefits

The aim of the research was to develop microencapsulated powders of bilberry and chokeberry extracts via the spray drying technique. Two biopolymers, pectin alone and in combination with HP-β-CD, were used to preserve the antioxidant, hypoglycemic, photoprotective, and antimicrobial bioactivity of the berry leaf extracts. Moreover, the formed powders were characterized in terms of technological, chemical, and several biological properties. The obtained micro-sized powders (mean average particle diameter from 3.83 to 5.94 µm) demonstrated a process yield of up to 73%. The added biopolymers improved the flowability and cohesive properties of the powders and increased their thermal stability to 170 °C. The total content of polyphenolics in the powders ranged from 323.35 to 367.76 mg GAE/g DW for bilberry and from 186.85 to 227.59 mg GAE/g DW for chokeberry powders; meanwhile, chlorogenic acid was the predominant compound in powders. All samples showed stronger α-glucosidase inhibitory activity (IC50 values ranged from 5.00 to 19.59 µg/mL) compared with the reference standard. The study confirmed that spray drying is a suitable method for the preservation of the polyphenolic-rich extracts, while the addition of carriers has a positive effect on the improvement of microencapsulated powders' properties.

Optimisation of Polyphenols Extraction from Wild Bilberry Leaves-Antimicrobial Properties and Stability Studies

Polyphenolic extracts from natural sources have received great interest due to their beneficial properties for human health. A method to reduce their variability is to use the design of experiments which allows a limited number of experiments to be performed while exploring the experimental space. Firstly, a 23-full factorial model was used to investigate the polyphenols extraction from wild bilberry leaves. Spectrophotometric data (the content of polyphenols, flavonoids, chlorophyll and radical scavenger activity) and extraction yield were used as responses, and six statistical models were determined depending on the two numerical factors (temperature and alcohol % of ethanol-water mixture) being significant (p < 0.05) in all cases. Numerical optimisation performed by Design Expert 13 software correlates well with the chemical profile determined by high-performance liquid chromatography and the amount of the polyphenol. Afterwards, under the optimised conditions, an extract was prepared in three extraction steps for which composition, chemical stability and antimicrobial properties were evaluated. The antimicrobial potential of the extract was compared with that of the standard compounds (rutin and chlorogenic acid), and the results supported a synergistic effect of the extract components.

In vivo antioxidant activity of rabbiteye blueberry (Vaccinium ashei cv. 'Brightwell') anthocyanin extracts

Blueberries are rich in phenolic compounds including anthocyanins which are closely related to biological health functions. The purpose of this study was to investigate the antioxidant activity of blueberry anthocyanins extracted from 'Brightwell' rabbiteye blueberries in mice. After one week of adaptation, C57BL/6J healthy male mice were divided into different groups that were administered with 100, 400, or 800 mg/kg blueberry anthocyanin extract (BAE), and sacrificed at different time points (0.1, 0.5, 1, 2, 4, 8, or 12 h). The plasma, eyeball, intestine, liver, and adipose tissues were collected to compare their antioxidant activity, including total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity and glutathione-peroxidase (GSH-PX/GPX) content, and the oxidative stress marker malondialdehyde (MDA) level. The results showed that blueberry anthocyanins had positive concentration-dependent antioxidant activity in vivo. The greater the concentration of BAE, the higher the T-AOC value, but the lower the MDA level. The enzyme activity of SOD, the content of GSH-PX, and messenger RNA (mRNA) levels of Cu,Zn-SOD, Mn-SOD, and GPX all confirmed that BAE played an antioxidant role after digestion in mice by improving their antioxidant defense. The in vivo antioxidant activity of BAE indicated that blueberry anthocyanins could be developed into functional foods or nutraceuticals with the aim of preventing or treating oxidative stress-related diseases.

Analysis of Phenolic Acids and Flavonoids in Rabbiteye Blueberry Leaves by UPLC-MS/MS and Preparation of Nanoemulsions and Extracts for Improving Antiaging Effects in Mice

Rabbiteye blueberry leaves, a waste produced after harvest of blueberry, are rich in polyphenols. This study aims to analyze phenolic acids and flavonoids in blueberry leaves by UPLC-MS/MS and prepare nanoemulsions for determining anti-aging activity in mice. Overall, 30% ethanol was the most suitable extraction solvent for total phenolic acids and total flavonoids. A total of four phenolic acids and four flavonoids were separated within seven minutes for further identification and quantitation by UPLC-MS/MS in selective reaction monitoring (SRM) mode, with 3-O-caffeoylquinic acid being present in the highest amount (6474.2 μg/g), followed by quercetin-3-O-galactoside (1943.9 μg/g), quercetin-3-O-rutinoside (1036.6 μg/g), quercetin-3-O-glucoside (867.2 μg/g), 5-O-caffeoylquinic acid (815.8 μg/g), kaempferol-3-O-glucoside (309.7 μg/g), 3,5-dicaffeoylquinic acid (195.3 μg/g), and 4,5-dicaffeoylquinic acid (60.8 μg/g). The blueberry nanoemulsion was prepared by using an appropriate ratio of soybean oil, Tween 80, glycerol, ethanol, and water at 1.2%, 8%, 2%, 2%, and 86.8%, respectively, and mixing with dried blueberry extract, with the mean particle size and zeta potential being 16 nm and -54 mV, respectively. A high stability was observed during storage of nanoemulsion for 90 days at 4 °C and heated at 100 °C for 2 h. An animal study revealed that this nanoemulsion could elevate dopamine content in mice brain as well as superoxide dismutase, glutathione peroxidase, and catalase activities in mice liver while reducing the contents of malondialdehyde and protein carbonyl in mice brains. Collectively, the high-dose nanoemulsion possessed the highest efficiency in improving mice aging with a promising potential for development into a health food.

Enhancement on antioxidant, anti-hyperglycemic and antibacterial activities of blackberry anthocyanins by processes optimization involving extraction and purification

This research aimed to recover anthocyanin-rich extracts from blackberry (Rubus spp. Hull cultivar) by optimizing the processing conditions, and to characterize anthocyanin individuals and determine influences of optimization on enhancement of antioxidant and anti-hyperglycemic activities of anthocyanins as natural supplements. The ethanol concentration of 69.87%, HCl dosage of 0.53%, solid-to-liquid ratio of 1:19.06 at 47.68°C for 17.04 h were optimal to obtain the highest extraction yield of anthocyanins at 0.72 mg/g. By using AB-8 macroporous resins, the anthocyanin concentration of 3.0 mg/mL, ethanol concentration of 90%, and elution rate of 2.0 mL/min were selected to boost the anthocyanin purity up to be 60.11%. Moreover, the purified anthocyanin extracts from blackberry contained nine main pigments which could be divided into three aglycone-based forms, and cyanidin-3-O-glucoside was the most abundant among them. Due to the successive processes of extraction and purification, the blackberry purified anthocyanin extracts (BA-PAE) showed much higher bioactive capacities than the blackberry crude anthocyanin extracts (BA-CAE) and blackberry fruit slurry extracts (BA-FSE), e.g., DPPH and ABTS radical scavenging activities (EC₅₀ = 0.08 and 0.04, 0.32 and 0.24, and 1.31 and 0.41 mg/mL), oxygen radical absorbance capacity (1.60, 0.59, and 0.15 mmol TEAC/g), cytoprotective effects against oxidative stress in PC12 cells (1.69-, 1.58-, and 1.50-fold cell viability compared to oxidative group), α-amylase and α-glucosidase inhibitory activities (IC₅₀ = 0.10 and 0.06, 0.56 and 0.32, and 3.98 and 2.16 mg/mL), and antibacterial activity (93.23, 40.85, and 80.42% reduced biofilm).

Effect of Fermentation on the Biochemical Parameters Antioxidant Capacity and Dispersed Composition of Plant Beverages Based on Barley and Hemp Seeds

Enzymatic processes play a key role in the production of grain-containing food due to their effect on the nutritional properties, rheological characteristics, and contribution to improving the functional and antioxidant proprieties. Eight samples of beverages based on barley grain and hemp seeds were produced (control beverages and beverages fermented by bifidobacteria and propionic acid bacteria). It was found that lactic acid accumulated during fermentation alongside a gradual shift in the pH level in the acidic direction. A comparative analysis of the DPPH activity revealed the highest values for barley-based beverages, ranging from 71.0 to 100.7%, while for the hemp seed-based beverages, the DPPH activity was 64.1–97.9%. The maximum values of DPPH activity were observed during fermentation with a combination of bifidobacteria and propionic acid bacteria concentrates. The highest concentration of polyphenolic compounds and flavonoids was found in barley-based beverages fermented with Propionibacterium freudenreichii (1.26 mg GAE/g and 0.11 mg EQ/g) and a combination of Propionibacterium freudenreichii and Bifidobacterium longum (1.24 mg GAE/g and 0.14 mg EQ/g). Studies have shown an increase in the nutrient content for fermented beverages compared to the control samples. The barley-based beverages exhibited the largest average dynamic particle diameter, and all beverage samples showed a more uniform particle size distribution after microbial fermentation.

Prediction of the Adult T-Cell Leukemia Inhibitory Activity of Blueberry Leaves/Stems Using Direct-Injection Electron Ionization-Mass Spectrometry Metabolomics

Although Vaccinium virgatum Aiton leaves and stems inhibit adult T-cell leukemia (ATL) cells, leaves and stems can differ between individual plants and by time and location. In this study, leaf and stem components were profiled in the same individual plant using direct-injection electron ionization-mass spectrometry (DI-EI-MS) metabolomics, with the aims of analyzing the anti-ATL activity, and quantifying proanthocyanidins (PACs). Leaves, stems, and leaf/stem mixtures showed distinct and characteristic spectra. Anti-ATL activity was stronger in stems than leaves, and the PAC content was higher in stems than leaves. These data were subjected to bivariate analysis to identify the factor (m/z) responsible for the inhibitory effect of ATL based on the highest coefficient of determination (R2). The results of this DI-EI-MS metabolomics analysis suggest that among PACs contained in V. virgatum stems and leaves, the fragment ion at m/z 149 contributes significantly to anti-ATL activity.

Changes in Phytochemical Profiles and Biological Activity of Olive Leaves Treated by Two Drying Methods

Olive leaves, which are the most abundant byproducts of the olive industry, offer multiple health benefits. The investigation of the phytochemical profiles and relevant biological activities is an essential step toward transforming these low-value byproducts into value-added ones. This study systematically investigated the phytochemical profiles, antioxidant capacity, and inhibition rates of olive leaves from four cultivars on the α-glucosidase, α-amylase, and angiotensin-converting enzyme (ACE). The leaves were prepared using two common drying methods, namely, hot air-drying and freeze-drying. A total of 33 bioactive compounds were identified in the olive leaves, namely, 19 flavonoids, 2 phenylethanoids, 2 coumarins, 2 hydroxycinnamic acids, 2 iridoids, and 6 triterpenic acids. Quantification of the bioactive compounds revealed high amounts of polyphenols, especially flavonoids [2,027–8,055 mg/kg dry weight (DW)], iridoids (566–22,096 mg/kg DW), and triterpenic acids (13,824–19,056 mg/kg DW) in the olive leaves. The hot air-dried leaves showed significantly (P < 0.05) higher iridoid (oleuropein and secoxyloganin) content than the fresh leaves, while freeze-drying resulted in significantly (P < 0.05) higher flavonoid aglycone and hydroxytyrosol content. Additionally, freeze-drying led to samples with the highest radical scavenging, α-amylase, α-glucosidase, and ACE inhibition abilities. The flavonoid (e.g., quercetin, luteolin, eriodictyol, kaempferol-7-O-glucoside, and luteolin-7-O-glucoside), hydroxytyrosol, and oleanolic acid contents in the olive leaves were positively correlated (P < 0.05) with their bioactive potentials.

Effective Utilization of Vaccinium virgatum Aiton Stems as Functional Materials: Major Constituent Analysis and Bioactivity Evaluation

We previously reported that rabbit-eye blueberry (Vaccinium virgatum Aiton) leaves exhibit multiple functions. In this study, we evaluated whether V. virgatum stems can also be used as functional materials similar to leaves and clarified the major constituents and their biological activity (antioxidant activity and anti–adult T cell leukemia (ATL) activity). Water extracts of V. virgatum stems were separated into 19 fractions using a Diaion HP-20 open column. Sugars and organic acids were detected in the highly water-soluble fractions. Polyphenols and proanthocyanidin were detected in the hydrous methanol-soluble fractions. In biological activity evaluations, a difference in antioxidant activity was observed in the water-containing methanol-eluted fractions, and fractions exhibiting anti-ATL activity differed depending on cell type. These results suggest that blueberry stems, like leaves, are rich in polyphenols and exhibit antioxidant activity and inhibit ATL cell growth. In the future, aerial parts of blueberries, including stems and leaves, could be used as functional materials and/or medicinal resources.

Comparative Evaluation of the Phytochemical Profiles and Antioxidant Potentials of Olive Leaves from 32 Cultivars Grown in China

Olives (Olea europaea L.) are a significant part of the agroindustry in China. Olive leaves, the most abundant by-products of the olive and olive oil industry, contain bioactive compounds that are beneficial to human health. The purpose of this study was to evaluate the phytochemical profiles and antioxidant capacities of olive leaves from 32 cultivars grown in China. A total of 32 phytochemical compounds were identified using high-performance liquid chromatography–electrospray ionization–tandem mass spectrometry, including 17 flavonoids, five iridoids, two hydroxycinnamic acids, six triterpenic acids, one simple phenol, and one coumarin. Specifically, olive leaves were found to be excellent sources of flavonoids (4.92–18.29 mg/g dw), iridoids (5.75–33.73 mg/g dw), and triterpenic acids (15.72–35.75 mg/g dw), and considerable variations in phytochemical content were detected among the different cultivars. All tested cultivars were classified into three categories according to their oil contents for further comparative phytochemicals assessment. Principal component analysis indicated that the investigated olive cultivars could be distinguished based upon their phytochemical profiles and antioxidant capacities. The olive leaves obtained from the low-oil-content (<16%) cultivars exhibited higher levels of glycosylated flavonoids and iridoids, while those obtained from high-oil-content (>20%) cultivars contained mainly triterpenic acids in their compositions. Correspondingly, the low-oil-content cultivars (OL3, Frantoio selection and OL14, Huaou 5) exhibited the highest ABTS antioxidant activities (758.01 ± 16.54 and 710.64 ± 14.58 mg TE/g dw, respectively), and OL9 (Olea europaea subsp. Cuspidata isolate Yunnan) and OL3 exhibited the highest ferric reducing/antioxidant power assay values (1228.29 ± 23.95 mg TE/g dw and 1099.99 ± 14.30 mg TE/g dw, respectively). The results from this study may be beneficial to the comprehensive evaluation and utilization of bioactive compounds in olive leaves.

Hulless Black Barley as a Carrier of Probiotics and a Supplement Rich in Phenolics Targeting Against H2O2-Induced Oxidative Injuries in Human Hepatocarcinoma Cells

Lactic acid bacteria can provide benefits to human beings and transform phenolic substances to improve their potential functionality. It was of interest to develop black barley as a carrier of probiotics and nutraceutical supplement rich in more antioxidants. Due to fermentation, bacterial counting and free phenolic content in black barley increased to 9.54 ± 0.22 log cfu/mL and 5.61 ± 0.02 mg GAE/mL, respectively. Eleven phenolic compounds, including nine isoflavones and two nitrogenous compounds were characterized using UPLC-QTOF-MS, among which epicatechin, hordatine, and pelargonidin aglycone were largely enriched. Moreover, free phenolic extracts from fermented barley (F-BPE) played a greater role in scavenging DPPH radicals, reducing Fe3+ to Fe2+, and increasing oxygen radical absorbance capacity, compared phenolic extracts from unfermented barley [UF-BPE (1.94-, 1.71-, and 1.35-fold at maximum for F-BPE vs. UF-BPE, respectively)]. In hepatocarcinoma cells, F-BPE also better inhibited ROS production and improved cell viability, cell membrane integrity, SOD activity, and non-enzymatic antioxidant GSH redox status (2.85-, 3.28-, 2.05-, 6.42-, and 3.99-fold at maximum for F-BPE vs. UF-BPE, respectively).

Vaccinium virgatum Aiton Leaves Extract Suppressed Lipid Accumulation and Uric Acid Production in 3T3-L1 Adipocytes

Blueberry (Vaccinium virgatum Aiton; Kinisato 35 Gou) leaves have recently attracted increasing attention as a useful material for the prevention of lifestyle diseases. Here, we examined the effects of the hot water extract of blueberry leaves (BLEx) on lipogenesis and uric acid production in 3T3-L1 adipocytes. The results showed that BLEx suppressed lipid accumulation and the mRNA expression of differentiation markers in 3T3-L1 adipocytes. A fractionation study showed that the highly polymerized proanthocyanidin-rich fraction was responsible for this effect. Upon maturation to adipocytes, 3T3-L1 cells produced uric acid and tumor necrosis factor-α, and hypoxia stimulated the production of uric acid and xanthine oxidoreductase activity. BLEx suppressed the production of uric acid under these conditions. Although BLEx inhibited the enzymatic activity of xanthine oxidase, this activity was observed in several fractions containing catechin, epicatechin, chlorogenic acid, rutin, and low molecular weight proanthocyanidins. Taken together, these results indicate that BLEx contains various compounds with the ability to suppress lipid accumulation and uric acid production in adipocytes.

Phenolic Compounds and Antioxidant Properties of Field-Grown and In Vitro Leaves, and Calluses in Blackberry and Blueberry

The aim of this study was to evaluate the content and profile of the phenolic compounds (PCs) and antioxidant properties of field-grown leaves, in vitro leaves and in vitro callus cultures of the blackberry ‘Čačanska Bestrna’ and blueberry ‘Toro’. In vitro shoots of the selected genotypes were grown either on original Murashige and Skoog (MS) medium containing 1 mg/L BA, 0.1 mg/L IBA and 0.1 mg/L GA3 (‘Čačanska Bestrna’) or on MS medium with macroelements reduced to ½, 2 mg/L zeatin and 0.2 mg/L IAA (‘Toro’). Callus cultures were induced from in vitro leaves and established on MS medium with 2 mg/L BA and 2 mg/L 2,4-D (‘Čačanska Bestrna’) or MS medium with half strength macroelements, 2 mg/L BA, 2 mg/L 2,4-D and 1 mg/L NAA (‘Toro’). Total phenolic (TPC) and flavonoid content (TFC) were the highest in blueberry leaves, whereas low TPC and TFC values were obtained in callus cultures of both cultivars. A higher content of PCs in blueberry leaves compared to blackberry leaves was determined by the UHPLC-DAD MS/MS technique. Quercetin derivatives and phenolic acids were the dominant PCs in the leaves of both berries, whereas gallocatechin was present in a significant amount in blueberry leaves. Callus cultures of both berries had a specific PC profile, with none detected in the leaves except quercetin-3-O-glucoside and quercetin-3-O-rutinoside. Blackberry leaves showed the best antioxidant properties as estimated by ferric reducing power (FRP), ABTS•+ and DPPH• scavenging activity assays. Callus cultures of both berries exhibited three to five times lower ABTS•+ and ten to seventeen times lower DPPH• scavenging activity compared to corresponding leaves. The analyzed leaves and callus cultures can be a good source of PCs with good antioxidant properties and specific phenolics, respectively, for applications in the food and pharmaceutical industries.

Comparison of Nutritional and Nutraceutical Properties of Burdock Roots Cultivated in Fengxian and Peixian of China

This study aimed to analyze and compare the nutritional quality of powders of burdock root from Fengxian (FX) and Peixian (PX) in China. The nutrient composition including carbohydrates, protein, amino acids, vitamin C, carotenoids, as well as total phenols, total flavonoids and phenolic compounds were investigated in addition to in vitro antioxidant capacity. The results showed that the basic nutrients of burdock root powder (BRP) in both locations did not have significant differences (p > 0.05), although the in vitro antioxidant capacity of BRP of Fengxian (F-BRP) was greater than that of PX (p < 0.05). The burdock root peel powder (BRPP) possessed more phenolics and stronger in vitro antioxidant capacity than the burdock root powder (BRP) and peeled burdock root powder (PBRP) (p < 0.05). Moreover, better quality burdock root was obtained from FX. F-BRP was consequently analyzed by ultra-performance liquid chromatography tandem mass spectrometry for its phenolic composition. Seventeen phenolics, mainly caffeoylquinic acids, were detected. In addition, a total of 181 volatile compounds belonging to eight types were detected including alcohols, aldehydes, ketones, alkenes, esters, acids, linear or aromatic hydrocarbons, and others. The diverse compounds found in this study can provide a theoretical basis for the development and utilization of burdock in the food industry.

Phenolic compounds in Nordic berry species and their application as potential natural food preservatives

An increasing demand for natural food preservatives is raised by consumers. For Nordic berry species, abundance of phenolic compounds and potent activities of anti-oxidation and anti-bacteria enables a great potential as food preservatives. This review provides a systematic examination of current literature on phenolic profiles, anti-oxidative and anti-bacterial activities of various extracts of Nordic berry species, as well as the impact of various structure features of phenolics on the bioactivities. Special attention is placed on exploitation of leaves of berry species and pomaces after juice-pressing as side-streams of berry production and processing. The current progress and challenges in application of Nordic berry species as food preservatives are discussed. To fully explore the potential application of Nordic berry species in food industry and especially to valorize the side-streams of berry cultivation (leaves) and juice-pressing industry (pomaces), it is crucial to obtain extracts and fractions with targeted phenolic composition, which have high food preserving efficacy and minimal impact on sensory qualities of food products.

Chemical profile, antioxidant and anti-inflammatory properties of Miconia albicans (Sw.) Triana (Melastomataceae) fruits extract

ETHNOPHARMACOLOGICAL RELEVANCE

Miconia albicans (Sw.) Triana has been widely used in Brazilian popular medicine for the treatment of several diseases. Aerial parts are used as an infusion to treat arthrosis and arthritis, to relieve rheumatic and stomach pains, and intestinal disorders due to its anti-inflammatory, anti-mutagenic anti-nociceptive, digestive and hepatoprotective properties.

AIM OF THE STUDY

This study aimed to characterize the of M. albicans (Sw.) Triana fruits extract (MAFRE) chemical profile and to evaluate its antioxidant, anti-inflammatory and antitumor activities, as well as its toxicity.

MATERIALS AND METHODS

Maceration with methanol as liquid extractor was used to prepare MAFRE. M. albicans (Sw.) Triana fruits chemical composition was characterized by UHPLC-QTOF-MS/MS and GC-FID (fatty acid methyl esters composition from lyophilized fruits). MAFRE antioxidant potential was evaluated in vitro using a combination of assays: Folin-Ciocalteu reducing capacity, DPPH^• and ABTS radical scavenging ability and ferric reducing antioxidant power (FRAP). In vitro antiproliferative activity was investigated in four human tumor cell lines (U251, 786-0, HT29 and MDA-MB-231) while the effect on the non-tumor cell viability was assessed in the VERO cell line using the on-step MTT assay. In addition, in vivo anti-inflammatory effect was assessed by Croton oil-induced ear edema in mice followed by myeloperoxidase (MPO) activity evaluation.

RESULTS

Thirty-five compounds were identified by UHPLC-QTOF-MS/MS. Among it flavonoids derived from quercetin (8), myricetin (1), kaempferol (2), terpenoids (6) and other compounds (18). GC-FID analysis identified and quantified nine fatty acids: palmitic, stearic, arachidic, behenic, elaidic, oleic, eicosenoic, and linoleic acids. The most abundant fatty acids were polyunsaturated fatty acids (5.33 ± 0.17 mg g^-1), followed by saturated fatty acids (2.38 ± 0.07 mg g^-1) and monounsaturated fatty acids (1.74 ± 0.09 mg g^-1). The extract revealed high content of phenolic compounds (43.68 ± 0.50 mg GAE/g of extract), potent antioxidant, and ferrous chelating capacities. Morever, it proved to be non-toxic to the VERO cells, not affecting cells viability (95% of viable cells). No antiproliferative effect against human tumor cell lines were found. Furthermore, MAFRE significantly (p<0.05) reduced ear edema (≈35%) and MPO activity (84.5%) having a statistical effect similar to traditional steroidal and non-steroidal anti-inflammatory drugs.

CONCLUSIONS

Taken together, the results evidenced that M. albicans fruit extract has antioxidant properties, a higher concentration of phenolic compounds, flavonoids, fatty acids, and also topical anti-inflammatory activity with low toxicity of extract on VERO cells. Through the ethnomedicinal study, these findings supporting the popular use of M. albicans, but also highlight that not only aerial parts and leaves deserve attention, but the fruits also have anti-inflammatory proprieties and can be a source of phenolic compounds and other substances with potential health benefices.

Proanthocyanidins isolated from the leaves of Photinia × fraseri block the cell cycle and induce apoptosis by inhibiting tyrosinase activity in melanoma cells

Tyrosinase is considered a molecular marker of melanoma, and few natural antitumor drugs targeting tyrosinase have been identified. In this study, proanthocyanidins (PAs) were isolated from the leaves of Photinia × fraseri and their structures were characterized by high performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and the effects of antityrosinase activity were investigated. The results showed that the basic structural units of PAs are composed of catechin and epicatechin and that oligomer is the main component. PAs exhibited better antityrosinase activity via chelation of copper ions and by disturbing o-quinone production. Furthermore, analyses of the cell cycle, apoptosis rate, and regulation of melanin protein expression revealed preliminarily that PAs could affect melanin production by downregulating microphthalmia transcription factor (MITF) expression and by inhibiting the activities of tyrosinase and tyrosinase related protein 1 (TRP-1), leading to cell cycle arrest and apoptosis of melanoma cells. Collectively, our study demonstrated that PAs are potential tyrosinase inhibitors and have good antimelanoma effects. These findings provide a theoretical support for the application of tyrosinase inhibitors and for further drug development.

Phenolics profiling by HPLC-DAD-ESI-MSn aided by principal component analysis to classify Rabbiteye and Highbush blueberries

Although blueberries are widely studied, little information exists on their composition and content of flavonol glycosides. Most studies identify only a few flavonols in blueberries due to separation and identification issues. In the present study, we identified 44 flavonols and chlorogenic acid in 30 samples of Highbush and Rabbiteye blueberry, using HPLC-DAD-ESI-MSⁿ. Highbush group fruits presented mainly quercetin-3-galactoside in their composition, while Rabbiteye group fruits exhibited higher levels of quercetin-3-rhamnoside and quercetin-3-glucuronide. Among the identified flavonols, 8 acylates (acetyl and hydroxymethylglutaroyl) were found, of which quercetin-3-O-[4″-(3-hydroxy-3-methylglutaroyl)]-α-rhamnoside was found for the first time in blueberries. This compound is exclusive to the cultivars Florida and Powderblue, where it is present in high quantities. Glucuronides of syringetin and laricitrin, and rhamnosyl-galactosides of myricetin, quercetin and isorhamnetin were also found for the first time in blueberries. The Principal Component Analysis showed that blueberry groups can be distinguished based on their phenolic compound profile.

New perspectives on the biosynthesis, transportation, astringency perception and detection methods of grape proanthocyanidins

Proanthocyanidins (PAs) are important secondary metabolites crucial for the quality of grape berry and wine. Despite important advances in our understanding of the structural and regulatory genes involved in the PAs biosynthesis pathway, our knowledge about the details of biosynthetic and regulatory networks, especially the mechanism of polymerization and transportation remains limited. We provided an overview of the latest discoveries related to the mechanisms of grape PAs structure, astringency properties, detection methods, biosynthesis and transportation. We also summarized the environmental influencing factors of PAs synthesis in grape. Future trends were discussed.

Chemometric Characterization of Strawberries and Blueberries according to Their Phenolic Profile: Combined Effect of Cultivar and Cultivation System

Chemical characterizations of leaves and fruits that were obtained from organically and integrally produced strawberries ('Favette', 'Alba', and 'Clery') and blueberries ('Bluecrop', 'Duke', and 'Nui') from western Serbia were undertaken in this study. Phenolic analysis was done while using ultra-high performance liquid chromatography coupled to a linear ion trap-Orbitrap hybrid mass analyzer, while total phenolic content (TPC), total anthocyanin content (TAC), and radical-scavenging activity (RSA) by spectrophotometry. In general, leaves and fruits from blueberry showed higher levels of TPC and TAC as compared to strawberry. These chemical traits were larger in organic grown fruits and larger in leaves than fruits. The most abundant phenolics in leaves and fruits of blueberry was 5-O-caffeoylquinic acid, followed by quercetin 3-O-galactoside, while catechin, quercetin, and kaempferol 3-O-glucosid were dominant in the leaves and fruits of strawberry. cis, trans-Abscisic acid was detected in all fruit samples, but not in leaves. Blueberries (both fruits and leaves) were separated from strawberries, but only organic blueberry fruits were distinguished from integrated fruits, according to principal component analysis. Quercetin, kaempferol, 5-O-caffeoylquinic acid, ferulic acid, caffeic acid, catechin, p-coumaric acid, and p-hydroxybenzoic acid were the most influential phenolic compounds for the separation. Much higher contents of TPC, RSA, TAC, quercetin 3-O-galactoside, and quercetin were found in fruits and TPC, RSA, catechin, p-hydroxybenzoicacid, p-coumaricacid, and ferulic acid in leaves in all three blueberry cultivars and the strawberry cultivar 'Clery'. These phenolic compounds are good sources of antioxidant compounds with potentially high beneficial effects on human health.