Fruit Anthocyanin Research Articles

Fruit Quality, Antioxidant Capacity, Related Genes, and Enzyme Activities in Strawberry (Fragaria ×ananassa) Grown under Colored Plastic Films

The influence of colored plastic films (red, yellow, green, blue, and white) on fruit quality, antioxidant capacity, and gene transcripts was studied in greenhouse-grown strawberries. Fruits grown under white plastic film were used as the controls. Results indicated that there was no difference in single fruit weight due to colored plastic films in the present study. The colored plastic films had significant effects on sugar and organic acid content. The content of total sugar (SUG) was increased by 10.39% and total organic acid (ACID) was decreased by 16.58% in fruit grown under blue plastic film compared with the controls. Fruit grown under blue plastic film had significantly higher SUG content and lower ACID content than fruit subjected to yellow and green plastic films and had the highest SUG/ACID ratio of 11.46. Colored plastic films had significant effects on bioactive compound (anthocyanin, flavonoid, phenolic) content and antioxidant capacity. The highest level of bioactive compound content was detected under red plastic film. The content of total phenolics, total flavonoids, and total anthocyanin (TAC) in fruits grown under red plastic film was respectively 23.10%, 25.37%, and 74.11% higher than that of the fruits grown under the control. The antioxidant capacities were highest in fruits grown under red plastic film. Fruits grown under red and yellow films had higher sucrose phosphate synthase (SPS) and sucrose synthase (SS) activity than those fruit covered with green, blue, and white plastic films at whole fruit development stages. Acid invertase (AI) activity was high in fruit grown under green plastic film and declined during development. Blue plastic film had mainly increased the FaSPS and FaAI transcript at the green stage, and decreased the expression of FaSS. It is proposed that colored plastic films can regulate the expression of genes involved in the flavonoid biosynthesis pathway, especially FaPAL, FaF3H, FaFGT, and FaMYB10, at half-red and red stages.

Anthocyanin concentration depends on the counterbalance between its synthesis and degradation in plum fruit at high temperature

Anthocyanin synthesis and degradation processes were analyzed at transcript, enzyme, and metabolite levels to clarify the effects of high temperature on the concentration of anthocyanin in plum fruit (Prunus salicina Lindl.). The transcript levels of PsPAL, PsCHS, and PsDFR decreased while those of PsANS and PsUFGT were similar at 35 °C compared with 20 °C. The activities of the enzymes encoded by these genes were all increased in fruits at 35 °C. The concentrations of anthocyanins were higher at 35 °C on day 5 but then decreased to lower values on day 9 compared with that at 20 °C. Furthermore, high temperature (35 °C) increased the concentration of hydrogen peroxide and the activity of class III peroxidase in the fruit. The concentration of procatechuic acid, a product of the reaction between anthocyanin and hydrogen peroxide, hardly changed at 20 °C but was significantly increased at 35 °C on day 9, indicating that anthocyanin was degraded by hydrogen peroxide, which was catalyzed by class III peroxidase. Based on mathematical modeling, it was estimated that more than 60–70% was enzymatically degraded on day 9 when the temperature increased from 20 °C to 35 °C. We conclude that at the high temperature, the anthocyanin content in plum fruit depend on the counterbalance between its synthesis and degradation.

Calcium and Potassium Foliar Sprays Affect Fruit Skin Color, Quality Attributes, and Mineral Nutrient Concentrations of ‘Red Delicious’ Apples

ABSTRACTThis study was conducted to evaluate the influences of foliar spray of potassium (K), calcium (Ca), and their combination on the fruit red skin color and quality attributes of ‘Red Delicious’ apple under conditions of south central Iran with warm and dry summer, where low and high temperature differences are low. The trees were sprayed five times using 5 g L–1 calcium chloride (CaCl2) at 3-week intervals starting from 3 weeks after full bloom and three times (at 9, 12, and 15 weeks after full bloom) using 2.5 g L–1 K sources [potassium chloride (KCl), potassium sulfate (K2SO4), and potassium nitrate (KNO3)] during two growing seasons in 2013 and 2014. Anthocyanin, some physicochemical attributes, and fruit mineral concentrations were measured at harvest. Results showed that spraying with K, CaCl2, and their combinations significantly increased fruit weight, sugar and anthocyanin concentrations, firmness, and K uptake. A combined foliar application of CaCl2 and each of the K sources was more effective on the improvement of fruit color, firmness, fruit K and Ca uptake, and K/Ca ratio as compared to the case when either K or Ca was applied alone.

The dominant allele Aft induces a shift from flavonol to anthocyanin production in response to UV-B radiation in tomato fruit.

The introgression of the A ft allele into domesticated tomato induced a shift from flavonol to anthocyanin production in response to UV-B radiation, while the hp - 1 allele negatively influenced the response of flavonoid biosynthesis to UV-B. Introgression of the dominant allele Anthocyanin fruit (Aft) from Solanum chilense induces anthocyanin accumulation in the peel of tomato (Solanum lycopersicum L.) fruit. UV-B radiation can influence plant secondary metabolism regulating the expression of several genes, among which those involved in flavonoid biosynthesis. Here, we investigated whether post-harvest UV-B treatment could up-regulate flavonoid production in tomato fruits and whether the Aft allele could affect flavonoid biosynthesis under UV-B radiation. Mature green fruits of an anthocyanin-rich tomato mutant line (SA206) and of its wild-type reference, cv. Roma, were daily subjected to post-harvest UV-B treatment until full ripening. Up-regulation of CHS and CHI transcription by UV-B treatment induced flavonoid accumulation in the peel of cv. Roma. Conversely, UV-B decreased the total flavonoid content and CHS transcript levels in the SA206 peel. SA206 being a double mutant containing also hp-1 allele, we investigated also the behavior of hp-1 fruit. The decreased peel flavonoid accumulation and gene transcription in response to UV-B suggest that hp-1 allele is involved in the marked down-regulation of the flavonoid biosynthesis observed in SA206 fruit. Interestingly, in SA206, UV-B radiation promoted the synthesis of delphinidin, petunidin, and malvidin by increasing F3'5'H and DFR transcription, but it decreased rutin production, suggesting a switch from flavonols to anthocyanins. Finally, although UV-B radiation does not reach the inner fruit tissues, it down-regulated flavonoid biosynthesis in the flesh of both genotypes. This study provides, for the first time, evidence that the presence of the functional Aft allele, under UV-B radiation, redirects flavonoid synthesis towards anthocyanin production and suggests that the hp-1 allele negatively influences the response of flavonoid biosynthesis to UV-B.

Effect of methyl jasmonic acid on peach fruit ripening progress

In order to investigate the role of jasmonates (JAs) during the ripening of peach fruit, two concentrations of methyl jasmonate (MeJA, 10 and 100mM) were evaluated using field system. Fruit quality parameters, such as the contents of anthocyanin, volatile compounds and cell wall enzymes, and the transcriptional profiles of several ripening-related genes were analyzed. Our results showed that MeJA promoted fruit chlorophyll degradation and anthocyanin accumulation, volatile compounds enhancement, but it would also delay fruit softening through regulation cell wall enzymes activities of PG and cellulase. MeJA increased fruit anti-stress because of the promotion of SOD, POD, CAT, PPO enzyme activities. MeJA reduced fruit endogenous ethylene content, although ethylene accelerated fruit softening and decreased titratable acidity that resulted in fruit ripening. MeJA altered the expression profiles of its biosynthesis pathway genes of PpLOX, PpAOS, and PpOPR3, which resulted the accumulation of JA accumulation in peach fruit. MeJA also increased the expression levels of anthocyanin-associated genes PpMYB, PpPAL, PpCHS, PpCHI, PpF3H, PpDFR, and PpUFGT. MeJA increased chlorophyll degradation gene of PpPAO, as well as decreased its biosynthesis gene of PpPORC, which led to chlorophyll reduction. However, ethylene had a reverse effect on the genes’ expression levels, and it inhibited anthocyanin accumulation. Ultimately, heterologous expression peach PpAOS in strawberry showed that JA promoted fruit anthocyanin accumulation. The present findings suggest that JA promotes peach fruit ripening through regulation anthocyanin accumulation, which is different from the way triggered by ethylene in regulation peach fruit ripening.

McMYB10 regulates anthocyanins and quercetin accumulation during the fruit development of crabapples

ABSTRACTCrabapple (Malus spp.) trees constitute an important worldwide germplasm resource with high ornamental, agricultural, and nutritional value. The content and composition of flavonoids in fruits are major determinants of the colouration and nutritional value of fruits; however, the mechanisms of red colouration and flavonoid biosynthesis in crabapple fruits are not yet fully understood. Two crabapple cultivars, the ever-red fruited ‘Royalty’ and the green-to-red fruited ‘Flame’, were studied during fruit development. In both cultivars, our results showed that the McMYB10 transcript level is associated with fruit colouration and anthocyanin and quercetin contents in fruit peel during fruit development. Shading treatments affected fruit colouration by regulating the expression levels of McMYB10 in ‘Royalty’. Transient over-expression of McMYB10 in crabapple fruit promoted transcription of some flavonoid biosynthetic genes and induced anthocyanin and quercetin accumulation and red colouration in crabapple fruits. Our study indicates that McMYB10 is a key regulator of anthocyanin and quercetin biosynthesis during crabapple fruit development.

The effects of selected metal ions on the stability of red cabbage anthocyanins and total phenolic compounds subjected to encapsulation process

In this study, the stability of red cabbage anthocyanins and total phenolic compounds (TPC) co-pigmented with various metals ions (Al3+, Ca2+, Fe3+, and Sn2+) under thermal treatment, spray drying, and storage was investigated. In general, it was found that the addition of metal ions accelerated the anthocyanins degradation but delayed TPC loss. Thermally treated samples experienced the highest loss of anthocyanins (k = 0.00173 min−1) when Sn2+ was added whereas less detrimental effect (k = 0.00106 min−1) was observed with aluminum ion (Al3+). During spray drying, metal ions, excluding Al3+, induced significant losses of anthocyanins, ranging from 7.3% to 10.6%. However, TPC degradation of samples containing metal ions (18.6–22.2%) was less than control samples (26.7%). Similarly, degradation of anthocyanins during storage was more severe in samples containing Sn2+ (k = 0.03602 week−1) than in control samples (0.00644 week−1) but TPC retention could be improved up to 6% by metal ions. Practical application Anthocyanins in fruits and vegetables are important sources of natural colorants. Co-pimentation with metal ions is a viable mechanism to impart the color and improve the stability of anthocyanins from plant and fruit extracts. However, its implications in anthocyanins treatments and preservation remain unknown. This study reported potential effects of metal ions on the stability of anthocyanins and other phenolic compounds under thermal treatment, encapsulation, and storage.

Improving Quality of Wonderful Pomegranate by Using Bagging and Different Agrochemical Treatments

The present study was carried out during the two successive seasons of 2014 and 2015 on five years old Wonderfulpomegranate cultivar (Punica granatum, L) in order to investigate the effect of fruit bagging, spraying with lime milk,super nano, CaCO3, vitamin C and kaolin, as well as, nitrogen and potassium fertilization on the fruit quality especiallythe incidence of sunburn. The obtained results showed that all treatments significantly affected fruit sunburn percentageand number of sunburned fruits, especially bagging, super nano and kaolin sprays. A significant decrease in the sunburnseverity occurred with the bagging and super nano sprays treatments. All different treatments increased fruit TSS andvitamin C. Spraying super nano on the fruit was the best in increasing TSS/acidity ratio. Spraying lime milk or super nanoon the tree and were the best in increasing fruit anthocyanin content.

The Effect of High Pressure Techniques on the Stability of Anthocyanins in Fruit and Vegetables.

Anthocyanins are a group of phenolic compounds responsible for red, blue and violet colouration of many fruits, vegetables and flowers. The high content of these pigments is important as it influences directly their health promoting properties as well as the sensory quality of the product; however they are prone to degradation by, inter alia, elevated temperature and tissue enzymes. The traditional thermal methods of food preservation cause significant losses of these pigments. Thus, novel non-thermal techniques such as high pressure processing, high pressure carbon dioxide and high pressure homogenization are under consideration. In this review, the authors attempted to summarize the current knowledge of the impact of high pressure techniques on the stability of anthocyanins during processing and storage of fruit and vegetable products. Furthermore, the effect of the activity of enzymes involved in the degradation of these compounds has been described. The conclusions including comparisons of pressure-based methods with high temperature preservation techniques were presented.

Isolation, antioxidant property and protective effect on PC12 cell of the main anthocyanin in fruit of Lycium ruthenicum Murray

The fruit of Lycium ruthenicum Murray has been widely used as a precious Chinese herbal medicine. In this study, the major anthocyanin in L. ruthenicum fruit was obtained via an AKTA purifier system with YMC-Pack ODS-A column and identified by mass and nuclear magnetic resonance spectroscopy to be petunidin 3-O-[6-O-(4-O-(trans-p-coumaroyl)-α-l-rhamnopyranosyl)-β-d-glucopyranoside]-5-O-[β-d-glucopyranoside] (compound 1). Compound 1 exhibited higher scavenging activities against 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), 1,1-diphenyl-2-picrylhydra-zyl and superoxide radicals than the crude extract of anthocyanins. Moreover, compound 1 was demonstrated to have potential cytoprotective effect on hydrogen peroxide-induced intracellular reactive oxygen damage in neuronlike rat pheochromocytoma line cells by promoting cell proliferation, mitigating lipid peroxidation and regulating endogenous antioxidant enzymes (glutathione peroxidase, superoxide dismutase and catalase).

РАЗРАБОТКА ТЕХНОЛОГИИ ПРИГОТОВЛЕНИЯ И ПРИМЕНЕНИЯ ГИСТОЛОГИЧЕСКИХ КРАСИТЕЛЕЙ НА ОСНОВЕ ЭКСТРАКТОВ БУЗИНЫ ЧЕРНОЙ, БАРХАТЦЕВ РАСПРОСТЕРТЫХ И ДОННИКА ЛЕКАРСТВЕННОГО

On the basis of ethanol extracts of fruits of black elderberry ( Sambucus nigra L.), marigold ( Tagetes patula L.) and melilot ( Melilotus officinalis L.) flowers new histological dyes were obtained. Anthocyanins of elderberry fruits that contain a positively charged oxygen provide basic properties of the corresponding dye, which selectively stains the nuclei and the basophilic structures of the cytoplasm. Donor-acceptor bonds between the heterocyclic oxygen atom of anthocyanins and a metal-complexing agent (copper) in the copper sulfate play an important role in the staining mechanism. Flavonoids of the marigold and melilot flowers, by contrast, show weakly acidic properties due to the presence of hydroxyl groups and predominantly stain the cytoplasm and the cell membrane. The chemical mechanism of the staining can be explained by the formation of stable complexes between ferric ions and phenolic hydroxyl and carbonyl groups of flavonoids. In this regard, the new stains should be considered as mordant dyes. Their advantages include the availability and wide distribution of vegetable raw materials, usage of nontoxic and affordable ingredients, easy preparation of solutions and the possibility of their long-term storage and reuse. Moreover, the nuclear dye from black elderberry can be used for combined histological staining with cytoplasmic dyes based on the marigold and melilot flowers.

Effect of nitric oxide on biochemical and antioxidant properties of pomegranate fruit cv. Shishe-kab during cold storage

Pomegranate is a subtropical fruit that is widely consumed as fresh fruit and juice, however, its postharvest life is limited mainly due to storage disorders. The aim of this study was to determine the effect of nitric oxide (NO) on antioxidant activity and quality attributes of pomegranate fruit. The fruits were dipped for two minutes into different NO concentrations (0, 30, 100, 300 or 1000 µM). Then, the fruits were stored in cold room at 5 °C and RH 85%. After 90 days storage, changes in chilling injury, electrolyte leakage, titratable acidity (TA), total soluble solids (TSS), pH, antioxidant activity and total anthocyanin were evaluated. The results showed that 1000 µM NO application resulted in significant decrease in electrolyte leakage and TSS and maintained antioxidant activity and total anthocyanin in pomegranate fruit. However, no significant effect of NO treatment was observed on TA and chilling injury index. In conclusion, postharvest application of NO may be a promising method for maintaining quality of pomegranate fruit during cold storage.

Chitosan-cellulose nanocrystal microencapsulation to improve encapsulation efficiency and stability of entrapped fruit anthocyanins

For improving stability of fruit anthocyanins (ACN), this study investigated the use of cellulose nanocrystal (CNC) as a macroion crosslinking agent to develop blueberry anthocyanin extract (BB)-loaded chitosan (CH)-CNC microcapsules, and compared with CH-sodium tripolyphosphate (TPP) ones. The yield of microcapsules (∼6.9g) and total monomeric anthocyanin recovery (∼94%) were significantly (P<0.05) higher in CH-CNC microcapsules than those (∼0.3g and ∼33%, respectively) in CH-TPP microcapsules. ACN distribution (%) in CH-CNC microcapsules was 61% on the surfaces, 12% bound with the matrix, and 27% in cores, but that in CH-TPP microcapsules was mostly presented on the surfaces (99%). CH-CNC microcapsules were more stable at pH 7.4 buffer by showing less ACN release (%) than that of CH-TPP, but no difference at pH 1.2. CH-CNC and CH-TPP microcapsules showed different structural and morphological properties. This study demonstrated that CNC is a promising crosslinking agent forming stable BB-loaded CH microcapsules.

Optical properties of natural dyes on the dye-sensitized solar cells (DSSC) performance

This study reported several natural dyes for application in dye-sensitized solar cells (DSSC). This study aims was to determine the effect of optical absorption properties of natural dyes on efficiency of DSSC. The sandwich structure of DSSC consist of TiO2 as working electrode, carbon layer as counter electrode, natural dyes as photosensitizer, and electrolyte as electron transfer media. The natural dyes used in this experiment were extracted from dragon fruit anthocyanin, mangosteen peels anthocyanin, and red cabbage anthocyanin. The absorbance of dyes solutions and the adsorption of the dye on the surface of TiO2 were characterized using UV-Vis spectrophotometer, the quantum efficiency versus wavelength was characterized using incident photon-to-current efficiency (IPCE) measurement system, and the efficiency of DSSC was calculated using I-V meter. UV-Vis characteristic curves showed that wavelength absorption of anthocyanin dye of red cabbage was 450 - 580 nm, anthocyanin of mangosteen peels was 400 - 480 nm, and anthocyanin of dragon fruit was 400 - 650 nm. Absorption spectra of the dye adsorption on the surface of TiO2 which was resulted in the highest absorbance of red cabbage anthocyanin. IPCE characteristic curves with anthocyanin dye of red cabbage, mangosteen peels anthocyanin, and dragon fruit anthocyanin resulted quantum efficiency of 0.058%; 0.047%; and 0.043%, respectively at wavelength maximum about 430 nm. I-V characteristic curves with anthocyanin dye of red cabbage, mangosteen peels anthocyanin, and dragon fruit anthocyanin resulted efficiency of 0.054%; 0.042%; and 0.024%, respectively.

Characterization of Acylated Anthocyanins in Red Cabbage via Comprehensive Two-Dimensional High Performance Liquid Chromatography and HPLC-MS

Red cabbage (Brassica oleracea L. Var. Capiata L.) is a fresh edible vegetable abundant in acylated anthocyanins with high antioxidant properties and is a promising resource for the functional food industry. Anthocyanin characterization of red cabbage is not a new topic, but the predominant anthocyanins have been co-eluted using high performance liquid chromatography (HPLC) because of their similar polarities, and it was difficult to achieve a baseline separation of anthocyanins in red cabbage. In the present paper, we optimized the separation of anthocyanins using a two-dimensional HPLC system (2DLC). Using a selective separation column, adjusting the switching time, and optimizing the elution program, seven anthocyanins were separated quickly with a good resolution, and identified via HPLC-mass spectrometry. Therefore, the 2DLC technique proved to be a powerful method of qualitative and quantitative analysis for the anthocyanins of red cabbage. Additionally, this method provides a good reference for the separation of acylated anthocyanins in fruits and vegetables. Practical Applications Red cabbage (Brassica oleracea L. Var. Capiata L.) is a fresh edible vegetable abundant in acylated anthocyanins with high antioxidant properties, and is a promising resource for the functional food industry. This paper describes the development and evaluation of a two-dimensional HPLC system (2DLC) method for the separation of acylated anthocyanins from red cabbage, which provides a good reference for the separation of acylated anthocyanins in fruits and vegetables. And there are many thousands of scientists whose work involve flavonoids, and our work offers a clear example of how new analytical approaches can be employed to increase analytical resolution and therefore enable researchers to clarify previously ambiguous or confounding results. We believe our findings are of interest to readers in food analysis, post-harvest and storage physiology, and to plant biologists that are trying to solve biochemical questions that previous analytical methods have failed to address adequately.

Calcium/calmodulin alleviates substrate inhibition in a strawberry UDP-glucosyltransferase involved in fruit anthocyanin biosynthesis.

BackgroundUDP-glucosyltransferase (UGT) is a key enzyme for anthocyanin biosynthesis, which by catalyzing glycosylation of anthocyanidins increases their solubility and accumulation in plants. Previously we showed that pre-harvest spray of CaCl2 enhanced anthocyanin accumulation in strawberry fruit by stimulating the expression of anthocyanin structural genes including a fruit specific FvUGT1.ResultsTo further understand the regulation of anthocyanin biosynthesis, we conducted kinetic analysis of recombinant FvUGT1 on glycosylation of pelargonidin, the major anthocyanidin in strawberry fruit. At the fixed pelargonidin concentration, FvUGT1 catalyzed the sugar transfer from UDP-glucose basically following Michaelis-Menten kinetics. By contrast, at the fixed UDP-glucose concentration, pelargonidin over 150 μM exhibited marked partial substrate inhibition in an uncompetitive mode. These results suggest that the sugar acceptor at high concentration inhibits FvUGT1 activity by binding to another site in addition to the catalytic site. Furthermore, calcium/calmodulin specifically bound FvUGT1 at a site partially overlapping with the interdomain linker, and significantly relieved the substrate inhibition. In the presence of 0.1 and 0.5 μM calmodulin, Vmax was increased by 71.4 and 327 %, respectively.ConclusionsFvUGT1 activity is inhibited by anthocyanidin, the sugar acceptor substrate, and calcium/calmodulin binding to FvUGT1 enhances anthocyanin accumulation via alleviation of this substrate inhibition.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-016-0888-z) contains supplementary material, which is available to authorized users.

Study of betacyanin level from cactus fruit (Opuntia elatior Mill) in Palu city using spectrophotometry UV-VIS

A research has been done about comparative study of the levels of total anthocyanin fruit cactus ( Opuntia elatior Mill) from Palu city using UV-Visible spectrophotometry in order to determine the levels of total betasianin cactus fruit that comes from the Mantikulore, East Palu and South Palu Subdistrict. Betacyanin pigment extraction using maceration method with a ratio of solvent : the sample (1: 1), then the separation using a centrifuge and filtered, the filtrate obtained was concentrated using a rotary evaporator at 35 °C to obtain a concentrated extract of ± 4 ml. The extraction is performed three times. The extract was tested qualitatively using reagent HCl 2 M and NaOH 2 M and for quantitative assay using UV-Vis spectrophotometry at wavelength of 538 nm. The results obtained in qualitative tests showed the three sampling sites containing betacyanin. On the quantitative test results betacyanin total levels from Mantikulore subdistrict of 0.022 mg/100 g, East Palu subdistrict of 0.021 mg/100 g and South Palu subdistrict of 0.021 mg /100 g.

Effect of gamma irradiation on some physicochemical properties and bioactive compounds of jujube (Ziziphus jujuba var vulgaris) fruit

Interest in the protection of bioactive compounds and a safe alternative method for preservation of processed fruits and fruit juices has recently increased significantly throughout the world. There is a distinct lack of information on the profile of bioactive compounds in jujube fruit (e.g. organic acids, anthocyanins, and water-soluble vitamins) and their changes during processing (e.g. gamma irradiation). Therefore, in this study, the effect of gamma irradiation at different doses (0.0, 0.5, 1.0, 2.5 and 5.0kGy) on some physicochemical properties and the bioactive compounds of jujube fruit was investigated. The total soluble solids (TSSs) values remained unaffected at various doses, while the level of total acidity (TA) showed a slight increase at doses ≥2.5kGy (p≤0.05). Irradiation up to 2.5kGy caused a significant increase in the total monomeric anthocyanin and the total phenolic content (about 12% and 6%, respectively), but a significant decrease was observed in both parameters immediately after irradiation at 5kGy. Moreover, irradiation treatment caused a significant decrease in L* value and a significant increase in a* and b* values (P≤0.05); however, changes of color were slight until the dose of 5kGy. Gamma irradiation up to 2.5kGy had no significant effect on the concentration of malic, citric and succinic acids, while the level of ascorbic acid decreased significantly at all irradiation doses (0–5kGy). Cyanidin-3, 5-diglucoside was determined as the major anthocyanin in the jujube fruit studied (about 68%), which was reduced significantly when 5kGy of irradiation was applied (degradation percentage: 27%). The results demonstrated that vitamins C, B2 and B1 are the most water-soluble vitamins in jujube fruit, respectively. Vitamins C and B1 content significantly decreased at all applied doses (0–5kGy), whereas B2 content at doses ≤2.5kGy was not significantly affected. The results of this study indicate that gamma irradiation at doses below 2.5kGy can be successfully used for improving the quality the jujube fruit.

Encapsulation of the elderberry fruit anthocyanins by spray drying

Spray-dried forms of anthocyanins were prepared in a maltodextrin matrix. The anthocyanins were extracted by maceration of elderberry fruits in 0.1 M HCl followed by extract filtration through a paper filter. The extract was partially purified by solid phase extraction in a column filled with styrene-divinylbenzene copolymer beads (Sepabeads SP859/L) or in syringe cartridges with C18 silica (BioChemMack ST, Moscow, RF) followed by re-extraction with aqueous HCl and alcohol mixtures. The procedure of reversed-phase HPLC determination of the extracted anthocyanin type is discussed in comparison to HILIC method in DIOL silica columns. The latter method was shown to be preferable to avoid systematic errors in the anthocyanin type determination. Solidphase extraction in syringe cartridges gave samples with very high anthocyanins concentration (up to 70 g of cyanidin-3-glucoside chloride equivalent). When using the copolymer sorbent, the concentration was somewhat lower: up to 27 g/l. After spray drying red powder samples with anthocyanins content more than 2% were prepared, although freeze drying gave only dark resin. The red color of the samples indicates the space separation of flavylium ions in the solid state by radicals of the maltodextrin background.

Seasonal variations of the phenolic constituents in bilberry (Vaccinium myrtillus L.) leaves, stems and fruits, and their antioxidant activity

The seasonal variations of the content and diversity of phenolic compounds, as well as the antioxidant activity of leaves, stems and fruits of bilberry collected in May, July and September, were evaluated for two consecutive years. UPLC/MSn analyses showed the predominance of anthocyanins in fruits, caffeic acid derivatives in leaves whereas flavanol oligomers represented more than half of the phenolic compounds in stems. Thioacidolysis revealed degrees of polymerization between 2 and 4 and (−)-epicatechin as the main flavanol unit. The sum of the phenolic compounds by UPLC was highly correlated with the total polyphenol content and the antioxidant activity in the DPPH test for all the extracts except for May leaves. The latter were relatively rich in p-coumaric acid derivatives. Seasonal effects were more marked for leaves, which exhibited higher antioxidant activities and phenolic contents in July and September when these parameters were at their highest in July for stems.