Remigijus Daubaras

Antioxidant properties, phenolic composition and potentiometric sensor array evaluation of commercial and new blueberry (Vaccinium corymbosum) and bog blueberry (Vaccinium uliginosum) genotypes.

Antioxidant properties of juices of newly bred and known blueberry (Vaccinium corymbosum) genotypes and wild bog blueberry (Vaccinium uliginosum) were evaluated by ABTS(+) scavenging capacity (RSC), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), total phenolic content (TPC) and total anthocyanin content (TAC) assays. TPC varied in the range of 0.85-2.81 mg gallic acid equiv./mL, RSC, FRAP and ORAC values were 6.38-20.9, 3.07-17.8 and 4.21-45.68 μmol Trolox equiv./g, respectively. New blueberry genotypes and bog blueberry demonstrated stronger antioxidant properties and TAC than other studied genotypes. The content of quinic (203-3614 μg/mL), chlorogenic (20.0-346.8 μg/mL) acids and rutin (0.00-26.88 μg/mL) measured by UPLC/ESI-QTOF-MS varied depending on the genotype. Juices were evaluated by electronic tongue; PCA score plot showed that the method discriminates different genotypes although some juice samples were located very closely and overlapping. Significant differences were observed between L(∗), a(∗), b(∗) colour parameters of some genotypes.

Antioxidant properties and polyphenolic compositions of fruits from different European cranberrybush (Viburnum opulus L.) genotypes

Antioxidant properties of fruit juices of six Viburnum opulus genotypes were evaluated by DPPH, ABTS(+) radical scavenging capacity (RSC), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC) and Folin-Ciocalteu total phenolic content (TPC) assays. TPC varied in the range of 5.4-10.6 mg gallic acid equivalents/g, RSC (ABTS(+)), FRAP and ORAC values were 31.9-109.8, 32.3-61.8 and 141.6-260.4 μmol trolox equivalents/g, respectively. V. opulus var. sargentii fruit juice was a remarkably stronger antioxidant than the other five V. opulus genotypes. The content of chlorogenic acid (the main phenolic compound in berry juices) depending on plant cultivar varied in the range of 0.54-6.93 mg/ml. The RSC of individual constituents was measured by the on-line HPLC-UV-DPPH method: chlorogenic acid was the dominant radical scavenger in V. opulus P3 (74%), while epicatechin and catechin (the main antioxidants in V. opulus var. sargentii) contributed to 40% and 23% of the total RSC for the sargentii genotype. Nine constituents were identified in V. opulus juice by using ultra high performance liquid chromatography coupled to quadruple and time-of-flight mass spectrometers (UPLC-QTOF-MS). In general, the study demonstrated that V. opulus var. sargentii followed by V. opulus P3 and V. opulus var. americanum possessed the highest antioxidant capacity. The obtained results may assist in selecting the most valuable V. opulus genotypes for the production of fruits possessing strong antioxidant capacity and containing beneficial phenolic constituents.

Chitosan coating of red kiwifruit (Actinidia melanandra) for extending of the shelf life.

Commercial production of red kiwifruit (Actinidia melanandra) has been unsuccessful because of its short shelf life. Here in this study, we used chitosan to extend the shelf life of red kiwifruit berries. Chitosan (with 70-75% deacetylation degree and low molecular weight) was dissolved in acetic acid (at pH 2.0-2.3) to obtain gel material, which was used for coating of the fruit. The coated and uncoated samples were kept for 26 days at room temperature (20±2°C). The changes in the weight loss, firmness, soluble solid content, total polyphenol content and ascorbic acid content were evaluated. All these findings showed that chitosan could be an effective coating material for berries of red kiwifruit to extend its short shelf life.

Effect of molecular weight of chitosan on the shelf life and other quality parameters of three different cultivars of Actinidia kolomikta (kiwifruit)

The kiwi fruit, Actinidia kolomikta, has valuable properties such as high antioxidant activity, high vitamin C, polyphenols, chlorophylls and organic acids content, but the species are hardly commercialized due to their short shelf life (less than two days). In this study three different cultivars of A. kolomikta (Anykšta, Sentiabrskaya and VIR2) were coated with low, medium and high molecular weight chitosan bio-polymer with the aim to extend the shelf life. The changes in fruit firmness, mass, phenolic compound content, vitamin C content and subjective criteria (withering level, decoloration level and aesthetic appearance) were monitored. It was observed that high molecular weight chitosan had higher positive effect on the shelf life of Sentiabrskaya and Anykšta cultivars than VIR2. Low molecular weight chitosan was found effective on VIR2.

Biochemical and agro-biological diversity of Viburnum opulus genotypes

Interest in the biochemical composition of Viburnum opulus fruit has intensified due to the food industry’s demand for natural vitamins, pigments and other substances that enhance the value of different foods. The present study was conducted to determine the agro-biological and biochemical variability of V. opulus and to select the genotypes that could best serve as sources of health promoting substances. Twelve selected genotypes were evaluated. ‘Leningradskaya Otbornaya’, V. opulus var. americanum, ‘Zarnitsa’, and local clone P2 were determined to be the best genotypes for growth in commercial plantations. Fruits of the local clone P3 were characterised by large amounts of total phenolics, ascorbic acid, and reducing sugars. V. opulus var. sargentii and V. opulus var. americanum contained exceptionally large amounts of total phenolics, 1460.0 and 1400.0 mg/100 g, respectively. The amount of ascorbic acid varied from 12.4 to 41.4 mg/100 g, the amount of carotenoids varied from 1.4 to 2.8 mg/100 g, the amount of anthocyanins varied from 23.2 to 44.6 mg/100 g, and the amount of total phenolics varied from 753.0 to 1460.0 mg/100 g. The presence of these large amounts of biologically active compounds enables their use as potent antioxidants. The data describing agro-biological characteristics, biochemical components, and health promoting activities of V. opulus fruits will increase the understanding of this plant and facilitate its use in the food and pharmaceuticals industry.

Investigations of anthocyanins, organic acids, and sugars show great variability in nutritional value of European cranberry ( Vaccinium oxycoccos ) fruit

Increased consumer interest in nutraceutical-rich foods in relation to human health has resulted in the increased use of cranberries in the modern diet. Berries of wild European cranberry clones and cultivars show great variation in yield, colour and quantities of biologically active compounds. In the present study, we estimate the production of different phytochemical components in 40 genotypes of Vaccinium oxycoccos. Our main goal was to identify genotypes that have superior economic attributes, such as high levels of anthocyanins, organic acids and easily digestible carbohydrates. As a result, two wild clones of Lithuanian origin (98-C-17 and 98-C-15), and the Estonian cultivar ‘Maima’ were selected as the most valuable in terms of TAC, organic acid, fructose and glucose concentrations.

Genetic Structure of Isolated Vaccinium oxycoccus Populations in Lithuania

Genetic Structure of Isolated Vaccinium oxycoccus Populations in Lithuania The genetic population structure of the wild Cranberry Vaccinium oxycoccus was studied using RAPDs (random amplified polymorphic DNA). During the last century, intensive peat bogs drainage, regulation of water levels, and intensive cranberry picking has caused a risk for survival of wild cranberry Vaccinium oxycoccus populations in Lithuania. Genetic variation among and within isolated V. oxycoccus populations was investigated with RAPD profiles. Fifty-six clones were sampled in four populations at the Čepkeliai, Žuvintas, Kamanos Reserves and Aukštaitijos National Park. RAPD analyses of nine primers showed 213 polymorphic loci in the samples. The polymorphism level in the Čepkeliai rezerve population was 56.34%, in Žuvintas 49.77%, in Kamanos 46.95% and in Aukštatija 43.19%. Polymorphism among populations was 100%. For the total sample group, Shannons Information Index was 0.2 and Neis gene diversity 0.12. The estimated total proportion of diversity among populations (GST) and gene flow (Nm) were 0.14 and 3.1, respectively. The UPGMA analyses have revealed that populations of V. oxycoccus are clearly separated into four lineages and only one Čepkeliai lineage had a homogenous haplotype. Others Žuvintas, Kamanos and Aukštatijos lineages differed from each other. One clone sampled from Aukštatija National Park (a8) had a unique haplotype. Lietuvas Vaccinium oxycoccus Izolēto Populāciju Ģenētiskā Struktūra Ar RAPD molekulāriem marķieriem tika pētīts genētiskais polimorfisms vairākās Lietuvas izolētās savvaļas dzērveņu populācijās. Atrastas ļoti būtiskas genētiskās atšķirības starp pētītām populācijām, tiek apspriests šo atšķirību cēlonis

Phytochemical Composition of the Large Cranberry ( Vaccinium macrocarpon ) and the Small Cranberry ( Vaccinium oxycoccos )

Abstract The berries of the closely related large cranberry (Vaccinium macrocarpon) and small cranberry (Vaccinium oxycoccos) species are characterized by the accumulation of high concentrations of a diverse set of biologically active substances. Breeders have selected large and small cranberry cultivars with high contents of biologically active substances in the United States, Russia, Lithuania, and Estonia. Both cranberry species have been shown to be sources of phenolic compounds, such as anthocyanins, flavonols, and phenolic acids. Flavonoids were identified as the dominant compounds among over 150 individual components detected in the cultivars of the large cranberry. A comparison of different cultivars demonstrated differences in biochemical composition as functions of the specific cultivars, berry ripeness stage, harvesting time, and environmental conditions.