Anthocyanin composition and content of the Vaccinium uliginosum berry

Vaccinium uliginosum L. (bog bilberry) and the search for its alleged toxicity: a review

Bog bilberry (Vaccinium uliginosum L.) is a wild-growing berry native to all circumboreal regions. There is however a significant discrepancy in the uses of bog bilberry fruits around the world. There exists a strong prejudice against the use of these berries in many European countries as well as a few incidences of poisoning reported between 1906 and 1944. In Asia and North America, this fear is completely absent from the local knowledge and the bog bilberry is valued as an excellent food and medicinal plant. There has been a lack of research on the topic in the last 50 years and thus the presumed toxicity remains unproven. This review aims to gather the conflicting information from all regions where bog bilberry grows and present them in a critical way to elucidate the possible explanations for the discrepancies. There are several possible explanations for the alleged toxicity of the bog bilberry, including a fungal infection of the fruits, individual intolerance or accidental poisoning by a different plant species; the local names meaning "drunk, inebriating, vomit-inducing berry" may be related to the alcoholic drinks made from them. This review highlights the gap in knowledge and serves as a theoretical framework for future research.

Anthocyanins distribution, transcriptional regulation, epigenetic and post-translational modification in fruits

Anthocyanins have indispensable functions in plant resistance, human health, and fruit coloring, which arouse people's favorite. It has been reported that anthocyanins are widely found in fruits, and can be affected by numerous factors. In this review, we systematically summarize anthocyanin functions, classifications, distributions, biosynthesis, decoration, transportation, transcriptional regulation, DNA methylation, and post-translational regulation in fruits.

Quantification of Xanthone and Anthocyanin in Mangosteen Peel by UPLC-MS/MS and Preparation of Nanoemulsions for Studying Their Inhibition Effects on Liver Cancer Cells

Mangosteen peel, a waste produced during mangosteen processing, has been reported to be rich in xanthone and anthocyanin, both of which possess vital biological activities such as anti-cancer properties. The objectives of this study were to analyze various xanthones and anthocyanins in mangosteen peel by UPLC-MS/MS for the subsequent preparation of both xanthone and anthocyanin nanoemulsions to study their inhibition effects on liver cancer cells HepG2. Results showed that methanol was the optimal solvent for the extraction of xanthones and anthocyanins, with a total amount of 68,543.39 and 2909.57 μg/g, respectively. A total of seven xanthones, including garcinone C (513.06 μg/g), garcinone D (469.82 μg/g), γ-mangostin (11,100.72 μg/g), 8-desoxygartanin (1490.61 μg/g), gartanin (2398.96 μg/g), α-mangostin (51,062.21 μg/g) and β-mangostin (1508.01 μg/g), as well as two anthocyanins including cyanidin-3-sophoroside (2889.95 μg/g) and cyanidin-3-glucoside (19.72 μg/g), were present in mangosteen peel. The xanthone nanoemulsion was prepared by mixing an appropriate portion of soybean oil, CITREM, Tween 80 and deionized water, while the anthocyanin nanoemulsion composed of soybean oil, ethanol, PEG400, lecithin, Tween 80, glycerol and deionized water was prepared as well. The mean particle size of the xanthone extract and nanoemulsion were, respectively, 22.1 and 14.0 nm as determined by DLS, while the zeta potential was -87.7 and -61.5 mV. Comparatively, xanthone nanoemulsion was more effective than xanthone extract in inhibiting the growth of HepG2 cells, with the IC₅₀ being 5.78 μg/mL for the former and 6.23 μg/mL for the latter. However, the anthocyanin nanoemulsion failed to inhibit growth of HepG2 cells. Cell cycle analysis revealed that the proportion of the sub-G1 phase followed a dose-dependent increase, while that of the G0/G1 phase showed a dose-dependent decline for both xanthone extracts and nanoemulsions, with the cell cycle being possibly arrested at the S phase. The proportion of late apoptosis cells also followed a dose-dependent rise for both xanthone extracts and nanoemulsions, with the latter resulting in a much higher proportion at the same dose. Similarly, the activities of caspase-3, caspase-8 and caspase-9 followed a dose-dependent increase for both xanthone extracts and nanoemulsions, with the latter exhibiting a higher activity at the same dose. Collectively, xanthone nanoemulsion was more effective than xanthone extract in inhibiting the growth of HepG2 cells. Further research is needed to study the anti-tumor effect in vivo.

Influence of phenolic acids/aldehydes on color intensification of cyanidin-3-O-glucoside, the main anthocyanin in sugarcane (Saccharum officinarum L.)

Sugarcane contains various anthocyanins, which are responsible for the colors present in sugarcane. In this study, the color intensification of the major anthocyanin, cyanidin-3-O-glucoside, by phenolic acids/aldehydes (ferulic acid, vanillic acid, p-coumaric acid, syringic aldehyde and vanillic aldehyde) was investigated. The color enhancement of cyanidin-3-O-glucoside (hyperchromic effect and bathochromic shift) was affected by the temperature and concentration of phenolic acids/aldehydes present. Reactions were spontaneous and exothermic, as determined using different thermodynamic parameters (ΔG⁰, ΔH⁰, ΔS⁰). Quantum chemical calculations demonstrated their intermolecular interaction differences, and AIM analysis indicated that hydrogen bonds and van der Waals force interactions contributed to color. Pyranoanthocyanins derived from cyanidin-3-O-glucoside and ferulic/p-coumaric acids during storage were recognized as cyanidin-3-O-glucoside-vinylphenol and cyanidin-3-O-glucoside-vinylguaiacol, respectively, by UPLC-ESI-QTOF-MS/MS. The electron-donating substituents on the aromatic ring of ferulic/p-coumaric acids stabilized the intermediately formed carbenium ion. Decarboxylation and further oxidation of the pyran moieties to the aromatic heterocycles resulted in the final products.

Expression of the ANS, CHS and DFR genes involved in the biosynthesis of anthocyanins in Vaccinium floribundum Kunth from Ecuador, using RT-qPCR

Vaccinium floribundum Kunth, a wild native species of berry in Ecuador, presents a lot of phenolic compounds, specifically anthocyanins; hence it is considered a natural nutraceutical due to all its nutritional properties. The comparison of the expression of genes is involved in the biosynthesis pathway of anthocyanin of several populations. The aim of the research was to analyze the expression levels of three genes involved in the biosynthesis of anthocyanin in this species collected in two areas of the province of Pichincha: Machachi population of the Mejía canton, with geographic coordinates 0 ° 31′04.8 ″ S 78 ° 37′07.4 ″ W and altitude 3200 meters above sea level, and Pintag population of the Quito cantón, with geographic coordinates 0 ° 24′00.0 ″ S 78 ° 24′00.0 ″ W and altitude 3000 meters above sea level. The gene expression analysis was performed using the quantitative polymerase chain reaction technique and reverse transcription (RT-qPCR). For the population of Machachi, the glyceraldehyde-3-phosphate dehydrogenase gene had an average concentration of 648.59 ng/µL, followed by the chalcone synthase gene with 143.71 ng/µL, then by the dihydroflavonol 4-reductase gene with 59.58 ng/µL and finally by the anthocyanin synthase gene with 39 ng/µL. For the population of Pintag, the glyceraldehyde-3-phosphate dehydrogenase gene has an average concentration of 667.32 ng/µL, followed by the chalcone synthase gene with 157.22 ng/µL, then by the dihydroflavonol 4-reductase gene with 60.42 ng/µL, and finally by the anthocyanin synthase gene with 44.40 ng/µL. Each gene has a similar expression level in both populations, but there are differences when comparing the expression level among genes. Many enzymes, structural genes, and regulatory elements have been observed as transcription factors involved in anthocyanin biosynthesis.

Vaccinium Species (Ericaceae): From Chemical Composition to Bio-Functional Activities

The genus Vaccinium L. (Ericaceae) includes more than 450 species, which mainly grow in cooler areas of the northern hemisphere. Vaccinium species have been used in traditional medicine of different cultures and the berries are widely consumed as food. Indeed, Vaccinium supplement-based herbal medicine and functional food, mainly from V. myrtillus and V. macrocarpon, are used in Europe and North America. Biological studies support traditional uses since, for many Vaccinium components, important biological functions have been described, including antioxidant, antitumor, anti-inflammatory, antidiabetic and endothelium protective activities. Vaccinium components, such as polyphenols, anthocyanins and flavonoids, are widely recognized as modulators of cellular pathways involved in pathological conditions, thus indicating that Vaccinium may be an important source of bioactive molecules. This review aims to better describe the bioactivity of Vaccinium species, focusing on anti-inflammatory and endothelial protective cellular pathways, modulated by their components, to better understand their importance for public health.

Ultrasound-assisted enzymatic extraction of anthocyanins from grape skins: optimization, identification, and antitumor activity

Grape skins produced during the grape juice production and processing contain abundant anthocyanins and other active compounds. Consequently, this study optimized the extraction conditions for ultrasound-assisted enzymatic extraction (UAEE) of anthocyanins from grape skins via response surface methodology coupled with genetic algorithm. The optimum extraction parameters to achieve the highest anthocyanins yield (3.01 ± 0.04) mg/g from grape skins by UAEE were obtained under an extraction temperature of 50 °C, ultrasonic power of 400 W, pectinase dosage of 0.16%, and extraction time of 28 min. The AB-8 macroporous resin combined Sephadex LH-20 techniques were further employed to purify the anthocyanins extracts obtained under optimum extraction conditions (AEOEC), and the main anthocyanins were identified using high-performance liquid chromatography tandem mass spectrometry. The purified anthocyanins contained two anthocyanins in terms of delphinidin-3,5-O-diglucoside and cyanidin-3-O-rutinoside with purity of 91.35% and 92.64%, respectively. Ultimately, we further evaluated the antitumor activity of AEOEC and two purified anthocyanins on breast cancer. The results indicated that the antitumor effect of AEOEC on breast cancer MCF-7 cells was better than that of two purified anthocyanins. In addition, AEOEC could memorably increase intracellular reactive oxygen species levels and apoptosis of MCF-7 cells, and arrest MCF-7 cells in the G2/M phases. The findings provide an effective and feasible method for anthocyanins extraction and reduce the environmental burden of this waste.

Chemopreventive Properties of Extracts Obtained from Blueberry (Vaccinium myrtillus L.) and Jabuticaba (Myrciaria cauliflora Berg.) in Combination with Probiotics

The association of probiotics and fruit extracts may influence the chemopreventive effect of colorectal cancer. In this context, antiproliferative activity was evaluated to select the best extracts that would be added probiotics, after addition of Bifidobacterium or Lactobacillus in the extracts the antiradical and antioxidant activity, quinone reductase (QR) assay and apoptosis assay were evaluated. Four extracts were isolated: E1: rich in total phenolic compounds; E2: rich in water-soluble phenolic compounds; E3: rich in most apolar phenolic compounds and E4: rich in anthocyanins. The antiproliferative results showed that the best extracts for blueberry and jabuticaba were, respectively the extract E4 and E2. After addition of the probiotic bacteria in these best extracts, it was observed that E2 from jabuticaba presented significantly higher antiradical and antioxidant activity values compared to E4 from blueberry before and after addition of probiotics. There was also a 9-fold increase in activity of QR by the E2 from jabuticaba with Lactobacillus (JL). Likewise, this same extract showed a significant increase both in apoptotic and necrotic cells for both cells. In conclusion, extract rich in water-soluble phenolic compounds (E2) from jabuticaba presented a greater chemopreventive effect compared to the others.

Vaccinium myrtillus L. Fruits as a Novel Source of Phenolic Compounds with Health Benefits and Industrial Applications - A Review

Consumers' demand for healthier foods with functional properties has had a clear influence on the food industry and in this sense, they have been attaching natural sources of bioactive ingredients into food products. Vaccinium myrtillus L. (bilberry) is known to be a functional food, presenting its fruits in the form of a small dark blueberry. This coloration is due to its high content in anthocyanin, being also associated with bilberries' beneficial health effects. In the bilberry industry, there is a very high annual loss of this fruit due to the less aesthetic shape or appearance, in which they cannot be considered suitable for sale and are therefore disposed of as biological waste. Therefore, it is of great importance to valorize this fruit and this review aimed to completely characterize the fruits of V. myrtillus in order to comprehend the relationship between their consumption and the beneficial effects regarding consumer's health. Thus, this review provides a description of the nutritional and bioactive compounds present in bilberry fruits, followed by their beneficial health effects. An overview of the natural pigments present in these fruits was also explored, focusing particularly in the anthocyanins composition, which represents the most widely studied class of bioactive compounds of V. myrtillus fruits. Finally, industrial applications of these fruits and by-products, as an efficient approach to the production of value-added products with economical and environmental impact, were also discussed. In general, V. myrtillus is a rich source of micronutrients and phytochemical compounds, such as organic acids, sugars, vitamins, fibers and phenolic compounds (anthocyanin and non-anthocyanin compounds), with nutritional and functional properties, that justify the growing interest in these berries, not only for food applications, but also in the pharmaceutical industry.

RNA-seq, de novo transcriptome assembly and flavonoid gene analysis in 13 wild and cultivated berry fruit species with high content of phenolics

BACKGROUND

Flavonoids are produced in all flowering plants in a wide range of tissues including in berry fruits. These compounds are of considerable interest for their biological activities, health benefits and potential pharmacological applications. However, transcriptomic and genomic resources for wild and cultivated berry fruit species are often limited, despite their value in underpinning the in-depth study of metabolic pathways, fruit ripening as well as in the identification of genotypes rich in bioactive compounds.

RESULTS

To access the genetic diversity of wild and cultivated berry fruit species that accumulate high levels of phenolic compounds in their fleshy berry(-like) fruits, we selected 13 species from Europe, South America and Asia representing eight genera, seven families and seven orders within three clades of the kingdom Plantae. RNA from either ripe fruits (ten species) or three ripening stages (two species) as well as leaf RNA (one species) were used to construct, assemble and analyse de novo transcriptomes. The transcriptome sequences are deposited in the BacHBerryGEN database (http://jicbio.nbi.ac.uk/berries) and were used, as a proof of concept, via its BLAST portal (http://jicbio.nbi.ac.uk/berries/blast.html) to identify candidate genes involved in the biosynthesis of phenylpropanoid compounds. Genes encoding regulatory proteins of the anthocyanin biosynthetic pathway (MYB and basic helix-loop-helix (bHLH) transcription factors and WD40 repeat proteins) were isolated using the transcriptomic resources of wild blackberry (Rubus genevieri) and cultivated red raspberry (Rubus idaeus cv. Prestige) and were shown to activate anthocyanin synthesis in Nicotiana benthamiana. Expression patterns of candidate flavonoid gene transcripts were also studied across three fruit developmental stages via the BacHBerryEXP gene expression browser (http://www.bachberryexp.com) in R. genevieri and R. idaeus cv. Prestige.

CONCLUSIONS

We report a transcriptome resource that includes data for a wide range of berry(-like) fruit species that has been developed for gene identification and functional analysis to assist in berry fruit improvement. These resources will enable investigations of metabolic processes in berries beyond the phenylpropanoid biosynthetic pathway analysed in this study. The RNA-seq data will be useful for studies of berry fruit development and to select wild plant species useful for plant breeding purposes.

Effect of Lactobacillus acidophilus, Oenococcus oeni, and Lactobacillus brevis on Composition of Bog Bilberry Juice

This study investigated the impact of Lactobacillus acidophilus NCFM, Oenococcus oeni Viniflora^® Oenos and Lactobacillus brevis CICC 6239 on bog bilberry juice with a considerably low pH and rich in anthocyanins content. Moreover, the effects of the strains on the composition of phenolic compounds, amino acids, ammonium ion, biogenic amines, reduced sugars, organic acids, and color parameters of the juice were studied. All three bacteria consumed sugars and amino acids but exhibited different growth patterns. Lactic acid was detected only in L. acidophilus inoculated juice. The content of the phenolic compounds, especially anthocyanins, decreased in juice after inoculation. The CIELa*b* analysis indicated that the juice inoculated with L. acidophilus and O. oeni showed a decrease on a* and b* (less red and yellow) but an increase on L (more lightness), whereas the color attributes of L. brevis inoculated juice did not significantly change. Based on this study, L. brevis showed the most optimal performance in the juice due to its better adaptability and fewer effects on the appearance of juice. This study provided a useful reference on the metabolism of lactic acid bacteria in low pH juice and the evolution of primary and secondary nutrients in juice after inoculated with lactic acid bacteria.

Identification of Anthocyanins from Four Kinds of Berries and Their Inhibition Activity to α-Glycosidase and Protein Tyrosine Phosphatase 1B by HPLC-FT-ICR MS/MS

The polyphenolic profiles of four berries (blueberry, bilberry, mulberry, and cranberry) in China were investigated using Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). Thirty-nine polyphenols including 26 anthocyanins, 9 flavonoids, and 4 phenolic acids were identified accurately. Cyanidin aglycones are common in four berries, and malvidin aglycones are the main compounds found in bilberry and cranberry. The anthocyanin level in blueberry are the highest with 739.6 ± 17.14 mg/g DW and presented the strongest antioxidant capacity in DPPH, ABTS, FRAP, and ORAC assay. In α-glycosidase, the inhibition activity was in the following order: mulberry > bilberry > blueberry > cranberry. For the PTP1B inhibition assay, blueberry demonstrated the highest inhibitory effect with IC₅₀ 3.06 ± 0.02 μg/mL, followed by bilberry, mulberry, and cranberry. Molecular docking results showed that cyanidin aglycones had the highest inhibition activity to PTP1B.

Dibasic Ammonium Phosphate Application Enhances Aromatic Compound Concentration in Bog Bilberry Syrup Wine

A nitrogen deficiency always causes bog bilberry syrup wine to have a poor sensory feature. This study investigated the effect of nitrogen source addition on volatile compounds during bog bilberry syrup wine fermentation. The syrup was supplemented with 60, 90, 120 or 150 mg/L dibasic ammonium phosphate (DAP) before fermentation. Results showed that an increase of DAP amounts accelerated fermentation rate, increased alcohol content, and decreased sugar level. Total phenol and total flavonoid content were also enhanced with the increase of DAP amounts. A total of 91 volatile compounds were detected in the wine and their concentrations were significantly enhanced with the increase of DAP. Ethyl acetate, isoamyl acetate, phenethyl acetate, ethyl butanoate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, isobutanol, isoamyl alcohol, levo-2,3-butanediol, 2-phenylethanol, meso-2,3-butanediol, isobutyric acid, hexanoic acid, and octanoic acid exhibited a significant increase of their odor activity value (OAV) with the increase of DAP amounts. Bog bilberry syrup wine possessed fruity, fatty, and caramel flavors as its major aroma, whereas a balsamic note was the least present. The increase of DAP amounts significantly improved the global aroma attributes, thereby indicating that DAP supplementation could promote wine fermentation performance and enhance the sensory quality of bog bilberry syrup wine.

Polyphenolic Compositions and Chromatic Characteristics of Bog Bilberry Syrup Wines

Phenolic compounds determine the color quality of fruit wines. In this study, the phenolic compound content and composition, color characteristics and changes during 6 months of bottle aging were studied in wines fermented with bog bilberry syrup under three different pHs. The total anthocyanins and total phenols were around 15.12–16.23 mg/L and 475.82 to 486.50 mg GAE/L in fresh wines and declined 22%–31% and about 11% in bottle aged wines, respectively. In fresh wines, eight anthocyanins, six phenolic aids and 14 flavonols, but no flavon-3-ols were identified; Malvidin-3-O-glucoside, petunidin-3-O-glucoside and delphinium-3-O-glucoside were the predominant pigments; Chlorogentic acid was the most abundant phenolic acid, and quercetin-3-O-galactoside and myricetin-3-O-galactoside accounted for nearly 90% of the total flavonols. During 6 months of bottle storage, the amounts of all the monomeric anthocyanins and phenolic acids were reduced dramatically, while the glycosidyl flavonols remained constant or were less reduced and their corresponding aglycones increased a lot. The effects of aging on blueberry wine color were described as the loss of color intensity with a dramatic change in color hue, from initial red-purple up to final red-brick nuances, while the pH of the fermentation matrix was negatively related to the color stability of aged wine.

A screening method of oil-soluble synthetic dyes in chilli products based on multi-wavelength chromatographic fingerprints comparison

A multi-wavelength HPLC fingerprint comparison method was proposed for the screening of oil-soluble synthetic dyes in chilli products. The screening was based on the fingerprint differences of normal unadulterated chilli sample with tested chilli samples. The samples were extracted with acetone and fingerprinted by HPLC under four visible light wavelengths (450 nm, 490 nm, 520 nm, and 620 nm). It was found that the fingerprints of different chilli product samples had a relatively fixed number of peaks and stable retention time. When 16 kinds of known synthetic dyes were used as model analytes to assess the screening efficiency, 14 of them could be screened using fingerprint comparison method, with LOD of 0.40-2.41 mg/kg. The new screening method was simple and had the possibility of finding existence of the adulterated dyes which could not be identified using known standard analytes as control.

A study of controlled uptake and release of anthocyanins by oxidized starch microgels

Anthocyanins are well-known antioxidants, but they are sensitive to environmental conditions. Herein we used oxidized starch microgel to prevent their early degradation and deliver them to the target place. The aim of this study was to investigate the uptake and the release ability of anthocyanins by the oxidized starch microgels and measure their in vitro gastrointestinal release. The gels were made of oxidized potato starch polymers, which were chemically cross-linked by sodium trimetaphosphate (STMP). In this study, the uptake and release behaviors of anthocyanins by starch microgel were investigated under various pH and salt concentrations. The microgel of high degree of oxidation and high cross-link density had a high uptake capacity for anthocyanins at low pH and salt concentration; 62 mg anthocyanins had been absorbed per gram of dry DO100% (degree of oxidation 100%) microgel at pH 3 with ionic strength 0.05M. The in vitro study of the release was investigated under stimulated gastrointestinal fluid. The anthocyanins were identified and quantified by UV/vis detection. The results indicated that the oxidized starch microgels had a potential for being a carrier system for protecting anthocyanins from degradation in the upper gastric tract and for delivering them to the intestine. This paper provides a good reference for an intestinal-targeted delivery system of vulnerable functional ingredients by oxidized starch microgel.

Antioxidant capacity of anthocyanins from Rhodomyrtus tomentosa (Ait.) and identification of the major anthocyanins

The anthocyanins in the fruits of Rhodomyrtus tomentosa (ACN) were extracted by 1% TFA in methanol, and then purified by X-5 resin column and C18 (SPE) cartridges. The purified anthocyanin extract (ART) from the fruits of R. tomentosa showed strong antioxidant activities, including DPPH radical-scavenging capacity, ABTS radical scavenging capacity, reducing power and oxygen radical absorbance capacity (ORAC). The purified anthocyanin extract was analyzed by high performance liquid chromatography (HPLC). The major anthocyanins were purified by semi-preparative HPLC and Sephadex LH-20 column chromatography, and were identified as cyanidin-3-O-glucoside, peonidin-3-O-glucoside, malvidin-3-O-glucoside, petunidin-3-O-glucoside, delphinidin-3-O-glucoside and pelargonidin-3-glucoside by HPLC-ESI/MS and nuclear magnetic resonance spectroscopy (NMR). Cyanidin-3-O-glucoside was considered as the most abundant anthocyanin, which was 29.4 mg/100 g dry weight of R. tomentosa fruits. Additionally, all the major anthocyanins were identified from R. tomentosa fruit for the first time.

Protective effect of anthocyanins from lingonberry on radiation-induced damages

There is a growing concern about the serious harm of radioactive materials, which are widely used in energy production, scientific research, medicine, industry and other areas. In recent years, owing to the great side effects of anti-radiation drugs, research on the radiation protectants has gradually expanded from the previous chemicals to the use of natural anti-radiation drugs and functional foods. Some reports have confirmed that anthocyanins are good antioxidants, which can effectively eliminate free radicals, but studies on the immunoregulatory and anti-radiation effects of anthocyanins from lingonberry (ALB) are less reported. In this experiment, mice were given orally once daily for 14 consecutive days before exposure to 6 Gy of gamma-radiation and were sacrificed on the 7th day post-irradiation. The results showed that the selected dose of extract did not lead to acute toxicity in mice; while groups given anthocyanins orally were significantly better than radiation control group according to blood analysis; pretreatment of anthocyanins significantly (p < 0.05) enhanced the thymus and spleen indices and spleen cell survival compared to the irradiation control group. Pretreatment with anthocyanins before irradiation significantly reduced the numbers of micronuclei (MN) in bone marrow polychromatic erythrocytes (PCEs). These findings indicate that anthocyanins have immunostimulatory potential against immunosuppression induced by the radiation.

An optimized method for analysis of phenolic compounds in buds, leaves, and fruits of black currant ( Ribes nigrum L.)

Although the fruits are the economic driver for the black currant industry, the buds and leaves are excellent sources of beneficial phenolic compounds that may contribute to the future value of the crop. In this study, extraction of phenolic compounds for different parts of the black currant plant was optimized, and an efficient method for their separation by HPLC was developed. This allowed the simultaneous quantification of a range of hydroxycinnamic acids, flavan-3-ols, flavonols, and anthocyanins by DAD following their identification by HPLC-ESI-MS(n). A total of 23 compounds were detected in the buds, 22 of which were found in fruit and leaves. To the best of our knowledge, this is the first report of flavonol glycosides of quercetin, myricetin, isorhamnetin, and kaempferol along with hydroxycinnamic acids such as neo-chlorogenic acid and chlorogenic acid in the buds. Additionally, we provide the first evidence of kaempferol-3-O-rutinoside in black currant leaves. This approach offers avenues for superior combined compositional identification and cultivar selection targeted at the generation of polyphenol-rich products derived from the whole crop and not just the fruit.

Identification of anthocyanin components of wild Chinese blueberries and amelioration of light-induced retinal damage in pigmented rabbit using whole berries

Studies suggest that the consumption of berry fruits rich in anthocyanins may have beneficial effects on improving visual function. This study determined the total polyphenol and total anthocyanin contents in wild Chinese blueberries using the Folin-Ciocalteu reagent method and a pH differential method. Anthocyanin composition and quantity were characterized by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry coupled with mass selective detection. Total polyphenol and anthocyanin contents were 602.9 ± 9.2 and 177.8 ± 8.3 mg/100 g, respectively. Seventeen anthocyanins were discovered, and only 13 were tentatively identified in the wild blueberries. Anthocyanins of malvidin glycosylated with hexose or pentose accounted for >46% of total anthocyanin content. Furthermore, the effect of whole blueberries on retinal damage in pigmented rabbits upon light exposure was investigated, and the retinal functions were evaluated by electroretinogram (ERG). Pigmented rabbits were chosen for this experiment because of their large eyes, which facilitated the operative procedure and observation, and the similarity of their eyes to the human eye structure. Light-induced retinal damage was induced by exposure to white light at 15000 ± 1000 lx for 2 h. Feeding the rabbits with blueberries at a dosage of 1.2 or 4.9 g/kg/day for 4 weeks prior to light exposure effectively reduced photodamage to the retinas. This study adds to the growing body of data supporting the bioactivity of blueberries in improving mammal vision.