Antioxidant synergism between fruit juice and <Emphasis Type="Italic">α</Emphasis>-tocopherol. A comparison between high phenolic black chokeberry (<Emphasis Type="Italic">Aronia melanocarpa</Emphasis>) and high ascorbic blackcurrant (<Emphasis Type="Italic">Ribes nigrum</Emphasis>)

Black chokeberry juice (Aronia melanocarpa, Elliot), blackcurrant juice (Ribes nigrum, Ben Lomond) and α-tocopherol were found to protect phosphatidyl choline against oxidation in a peroxidating liposome system as evidenced by lag phases for formation of conjugated dienes. When present together, black chokeberry juice and α-tocopherol showed a clear synergistic effect on the length of the lag phase, while effects of blackcurrant juice and α-tocopherol were additive. The concentration of total phenolics in black chokeberry juice was six times higher than in blackcurrant juice (gallic acid equivalents). Ascorbic acid corresponded to 1% of total phenolics in black chokeberry juice and 10% in blackcurrant juice. Based on the length of the lag phase, the phenolics present in black chokeberry were on an average, twice efficient as scavengers of lipid peroxyl radicals as phenolics in blackcurrant. Black chokeberry was by HPLC analysis of peroxidating liposomes, in contrast to blackcurrant, found to protect α-tocopherol efficiently against oxidation to the end of the lag phase. The phenolics present in black chokeberry juice were concluded to be more efficient in regenerating or protecting α-tocopherol than ascorbic acid or the phenolics in blackcurrant. As for the phenolics, this was further evidenced by ranking of their radical scavenging activity as studied by ESR-spectroscopy.     

Dark chocolates supplemented with <Emphasis Type="Italic">Lactobacillus</Emphasis> strains

Dark chocolate masses and chocolates were supplemented with viable cells of two bacterial strains Lactobacillus caseii and Lactobacillus paracasei with potential probiotic properties, which were lyophilized in milk. Total number of live bacteria in the lyophilizate was 7.9×10⁹ cfu/g. Sucrose or isomalt and aspartame were used as bulking substances and sweeteners. Sensory attributes of these chocolates were not different from that of traditional chocolates. Calorie value of sucrose-free chocolate was lower by approximately 11.1–14.6% (dependent on their formulation) relative to chocolate sweetened with sucrose. Chocolate, which contains isomalt and aspartame can be consumed by diabetics. Numbers of live L. casei and L. paracasei cells in the examined batches of chocolate were very high and approached 10⁶–10⁷ cfu/g after 12 months of keeping at 4 and 18 °C. Neither the texture nor the total and volatile acidity of chocolate masses were changed by addition of the lyophilized preparation of Lactobacillus cells. Casson yield values of dark sucrose-free chocolate masses supplemented with this lyophilizate were decreased by approximately 3–55% (dependently on fat contents in these masses) as compared to that of analogous chocolate masses sweetened with sucrose.     

Production of biogenic amines by<Emphasis Type="Italic"> Morganella morganii</Emphasis>,<Emphasis Type="Italic"> Klebsiella pneumoniae</Emphasis> and<Emphasis Type="Italic"> Hafnia alvei</Emphasis> using a rapid HPLC method

The histidine decarboxylating activity and production of biogenic amines by Morganella morganii (NCIMB, 10466), Klebsiella pneumoniae (NCIMB, 673) and Hafnia alvei (NCIMB, 11999) were investigated using a rapid HPLC method. Derivatisation of the bacterial samples was carried out using benzoyl chloride. A gradient elution system was used for analysis with a mixture of acetonitrile and HPLC grade water. Bacterial strains not only produce histamine in histidine-enriched broth but also the other biogenic amines. The chromatographic results show that bacterial strains are also capable of producing spermine and spermidine in histidine-enriched broth. Bacterial ammonia production by all three strains was clearly detected since ammonia is generated during the degradation of histidine. The study demonstrates that the highest histamine production was obtained by Morganella morganii, followed by Klebsiella pneumoniae, and the lowest with the Hafnia alvei. Therefore, Morganella morganii and Klebsiella pneumoniae have strong histidine decarboxylase activity since they are prolific histamine-forming bacteria     

Tyramine production of technological important strains of <Emphasis Type="Italic">Lactobacillus</Emphasis>, <Emphasis Type="Italic">Lactococcus</Emphasis> and <Emphasis Type="Italic">Streptococcus</Emphasis>

The aim of this paper was to study the biogenic amines (histamine, tyramine, putrescine, cadaverine, agmatine, spermine and spermidine) production of selected technological important lactic acid bacteria (strains of the genera Lactococcus, Lactobacillus and Streptococcus). Three methods (ion-exchange chromatography (IEC), PCR and cultivation method with pH indicator) were used. Within the 39 strains of lactic acid bacteria tested, the production of tyramine (formed by tyrosine decarboxylase) was detected in eight strains (3 strains of Lactococcus lactis subsp. lactis, three strains of Lactococcus lactis subsp. cremoris, 1 strain of Streptococcus thermophilus and 1 strain of Lactobacillus delbrueckii subsp. bulgaricus). The other tested biogenic amines were not detected. Cultivation in decarboxylation broth seems to be the least accurate method for the detection of biogenic amines due to enhanced risk of false-positive reactions. Therefore, in order to detect bacteria producing biogenic amines, the combination of PCR and chromatographic methods (e.g. IEC) can be recommended.     

Total,cumulative fast-kinetics and cumulative slow-kinetics antiradical activities of juices from clementine (<Emphasis Type="Italic">Citrus clementina</Emphasis>), clementine-hybrids and satsuma (<Emphasis Type="Italic">Citrus unshiu</Emphasis>) cultivars and their utility as discriminant variables

Mandarin juices from three pure clementine (Citrus clementina Hort. ex Tan.) cultivars: Clemenules, Hernandine and Marisol, two clementine-hybrid cultivars: Nova (clementine×tangelo Orlando) and Fortune (clementine× mandarin Dancy), one mandarin-hybrid cultivar: Ortanique (mandarin×orange) and one satsuma (Citrus unshiu Marc) cultivar: Clauselline have been analysed for determination of total, cumulative fast-kinetics and cumulative slow-kinetics antiradical activities. Total antiradical activity followed the order: pure clementine and Nova> Ortanique>Fortune and Clauselline. Cumulative fast-kinetics antiradical activity was the major contributor to total antiradical activity, accounting for about 87% as average. Ascorbic acid content was the major contributor to cumulative fast-kinetics antiradical activity, accounting for about 93.5% as average. A weak correlation (r ²=0.151) between total flavanone-7-O-glycosides (FGs, Narirutin, Hesperidin and Didymin) content and cumulative slow-kinetics antiradical activity was observed. However, ascorbic acid and total FGs contents showed a significant negative correlation (r ²=0.658). By using the cumulative fast-kinetics and slow-kinetics antiradical activities as variables, all the assayed juices were significantly discriminated (<0.05) by statistical multivariate discriminant analysis.     

Short anoxic treatments to enhance <Emphasis Type="Italic">trans</Emphasis>-resveratrol content in grapes and wine

In a search for a method to improve the (endogenous) trans-resveratrol content in post harvested grapes, several short anoxic treatments with dry nitrogen have been assayed. A significant enhancement of the trans-resveratrol content was obtained, especially for treatments under 24 h; moreover, with shorter treatments (e.g. 6 or 15 h) the induced higher content of trans-resveratrol was maintained during several days with no appreciable anoxic damage of the grapes. These results allowed the design of an anoxic treatment protocol for wine grapes prior to the vinification process that led to a trans-resveratrol enriched wine.     

Evaluation of novel lactose-positive and exopolysaccharide-producing strain of <Emphasis Type="Italic">Pediococcus pentosaceus</Emphasis> for fermented foods

A novel strain of lactic acid bacteria Pediococcus pentosaceus P 773 was isolated from spoiled beer and identified by means of 16S rDNA sequence analysis. The ability to assimilate lactose as a sole carbon source as a specific feature for this strain was detected and confirmed on dairy substrates. In the presence of sucrose containing substrates (sucrose, raffinose) this P. pentosaceus P 773 lactose-positive strain produced a complex of extracellular polysaccharides (Qp = 0.08 g/l/h) with a molecular mass about 2,000 kDa composed by glucose and fructose residues at a ratio 3:1, respectively. These exopolysaccharides were capable to stimulate the growth rate and biomass productivity of common constituent cultures of probiotic dairy starters (Bifidobacterium lactis, Lactobacillus acidophilus, Streptococcus thermophilus) as well as were assimilated as a sole carbon source by these strains. The present study confirmed the presence of lactose-positive and exopolysaccharide-producing strain of P. pentosaceus in natural environment which could be used as a starter culture to impart more functional attributes to fermented food.     

Treatment of slices from carrot (<Emphasis Type="Italic">Daucus carota</Emphasis>) using high intensity white pulsed light

Experiments with washing of carrot slices using distilled water and 0.9% (w/w) NaCl in combination with varying number and pulses of high intensity white were carried out. Slices of carrot 3.5 cm in diameter and 2 mm thick were inoculated using diluted dispersions of yeasts (Saccharomyces cerevisiae) for varying time (0–240 min) and then the slices were treated with high intensity pulsed white light (one pulse = 0.7 J/cm²) using from none to 24 pulses. The major part of the yeast cells were killed using two pulses of light. The studies included washing of inoculated slices up to five times using salt 0.9% (w/w) NaCl and distilled water and inoculation at 22 °C for between 5 and 120 min. It was concluded that treatment of carrot slices with high intensity white light may reduce the load of yeast cells with up to 6 log cycles. Inoculation time at 22 °C had no effect on the maximum load of yeast cells.     

Antioxidant activity of half <Emphasis Type="Italic">N</Emphasis>-acetylated water-soluble chitosan in vitro

Different molecular weight water-soluble chitosan (half N-acetylated chitosan) was prepared and the structure of water-soluble chitosan was characterized by FT-IR. The pH dependence of water solubility of water-soluble chitosan was evaluated from turbidity. Total antioxidant activity, reducing power, superoxide anion radical and hydroxyl radical quenching assay, metal chelating activity, and H₂O₂ scavenging activity were used for the evaluation of different molecular weight half N-acetylated chitosan in vitro. Low-molecular weight water-soluble chitosan (WSC4) exhibited high reductive capacity and expressed good inhibition of linoleic acid peroxidation in the linoleic acid model system. WSC4 (0.25 mg/mL) scavenged 78.8% of superoxide radical. At 5 mg/mL, scavenging percentage of WSC1, WSC2, WSC3, and WSC4 against hydroxyl radical was 49.3%, 66.8%, 77.1%, and 83.7%, respectively. These results indicate that water-soluble chitosan is an ideally natural antioxidant, and its antioxidant activity depends on its molecular weight.     

Cholesterol lowering activity of mango ginger (<Emphasis Type="Italic">Curcuma amada</Emphasis> Roxb.) in induced hypercholesterolemic rats

Mango ginger (Curcuma amada Roxb.) is a spice commonly consumed in Asian countries. Health beneficial hypotriglyceridemic property of mango ginger has been reported earlier. In this investigation, the anti-hypercholesterolemic influence of dietary mango ginger was evaluated in experimental rats. Dietary mango ginger powder (10%) or its equivalent of 10 mg% curcumin-containing portion was fed along with 1% cholesterol supplemented diet in Wistar rats for 5 weeks. The treatment countered the liver and serum total and LDL + VLDL associated cholesterols and increased the HDL associated cholesterol while it had no influence on cholesterol levels in animals, maintained on normal diet. Dietary C. amada and its curcumin-free portion were effective in lowering liver cholesterol in animals, maintained on basal diet, while the curcumin-containing component of C. amada was ineffective. The biliary secretion of total lipids and bile acids was increased by dietary C. amada and both of its components. While biliary cholesterol was increased in animals fed with whole mango ginger, no such increases were noticed in groups fed with either components of mango ginger. Cholesterol absorption in ligated rat intestinal loops was not affected by mango ginger or either of its components. Thus, the present study has evidenced that the spice mango ginger possesses beneficial anti-hypercholesterolemic activity in hypercholesterolemic situation. This information is complementary to the earlier report on the health beneficial hypotriglyceridemic influence of this spice.     

Phytochemical and biological investigation of <Emphasis Type="Italic">Stevia rebaudiana</Emphasis> Bertoni; 1-labdane-type diterpene

Five labdane diterpenoids, austroinulin, iso-austroinulin, sterebin E, sterebin E acetate, and sterebin A acetate, along with hydrocarbons, aliphatic alcohols, β-amyrin, β-sitosterol and stigmasterol were isolated from the chloroform soluble fraction of the methanol extract of Stevia rebaudiana leaves. Chlorogenic and caffeic acids were isolated from the EtOAc fraction. All the isolated compounds were identified using spectral tools. The chloroform and methanol extracts proved significant anti-inflammatory effect and caused marked inhibition of carrageenan-induced paw oedema in rats.     

Production of malic and succinic acids by sugar-tolerant yeast <Emphasis Type="Italic">Zygosaccharomyces rouxii</Emphasis>

Zygosaccharomyces rouxii V19 was grown in YPG medium (yeast extract, 0.5%, peptone, 1.0%, glucose, 10%). Fermented broth was purified through a series of ion-exchange columns and ODS column and the purified sample was TMS-esterified. Malic and succinic acids were identified with GC-MS analysis. The yeast was cultivated under various cultural conditions and quantitative determination of the organic acids was carried out with HPLC on Shodex column. Glucose concentration of 30%, initial pH 5.0, and 25 °C incubation temperature were the optimum conditions. Inclusion of glutamic, malic, and succinic acid precursors in the medium increased the production of malic acid. On the other hand, only addition of malic acid enhanced the production of succinic acid. Maximum amount of malic acid produced was 74.9 g/L (32.8% yield, based on glucose consumption) in the medium with 0.5% glutamic acid supplement, and that of succinic acid was 7.7 g/L (8.1% yield) when 0.3% malic acid was added in the medium.     

Sensitive and rapid detection of freshwater crustacean <Emphasis Type="Italic">Spiroplasmas</Emphasis> by ISRs-sequence-targeted species-specific primers

For the rapid and sensitive identification of the Spiroplasmas in the Chinese mitten crab Eriocheir sinensis, a species-specific PCR primer-pair was designed according to Spiroplasma sp. strain CRAB-specific segments of the previously sequenced 16S–23S rRNA intergenic spacer region (ISR). The PCR-mediated assay allowed identification of Spiroplasmas from different aquatic crustacean hosts, E. sinensis and red swamp crayfish Procambarus clarkia, in different geographical areas in China. No cross-reaction could be observed with other three available terrestrial plants/insects Spiroplasma strains (Spiroplasma sp. CH-1, Spiroplasma sp. CR-1 and Spiroplasma sp. M10). The sensitivity of detection of the Spiroplasma sp. strain CRAB could get as little as 100 fg of DNA template. The presented PCR method is useful for sensitive and specific detection of Spiroplasma from freshwater cultured crustaceans in the trade of aquatic products.     

Reevaluation of bioactivity and antioxidant activity of <Emphasis Type="Italic">Myrtus communis</Emphasis> extract before and after encapsulation in liposomes

The antioxidant and antimicrobial activity of Myrtus communis extract was determined before and after its encapsulation in liposomes of different composition. Evaluation of the sunflower oil oxidation by the Rancimat stability test and malondialdehyde formation by HPLC were used to measure the antioxidant action in comparison with common commercial antioxidants, such as butylated hydroxytoluene and α-tocopherol. The thermal-oxidative decomposition of the samples, the modification of the main transition temperature for the lipid mixture and the splitting of the calorimetric peak in the presence of the antioxidants were studied by differential scanning calorimetry. The size and the surface charge of liposomes were also studied. The extract showed antioxidant and antimicrobial activity. Αt concentrations up to 160 ppm, the extract showed superior activity than α-tocopherol. When the extract was encapsulated in liposomes, its antioxidant as well as its antimicrobial activity proved to be superior from that of itself in pure form.     

Inclusion interactions and molecular microcapsule of <Emphasis Type="Italic">Salvia sclarea</Emphasis> L. essential oil with β-cyclodextrin derivatives

The inclusion interactions of β-cyclodextrin (β-CD), heptakis (2,6-di-methyl)-β-CD (DM-β-CD), mono[2-O-(2-hydroxyethyl)]-β-CD (2-HE-β-CD), and mono[2-O-(2-hydro-xypropyl)]-β-CD (2-HP-β-CD) with Salvia sclarea L. essential oil (SEO) were investigated by spectrofluorimetry, and the various factors affecting the inclusion process were examined in detail. At the same time, the formation constants at different temperatures and the thermodynamic parameters (ΔH, ΔS and ΔG) were calculated. The molecular microcapsule of SEO with β-CD was prepared by the method of saturated aqueous solution, and the stability of the microcapsule was determined. The results suggest that the stoichiometry of the SEO–CDs inclusion complexes was 1:1 (molar ratio), the formation constants of CDs with SEO decreased with the increasing of temperature, and the order that the capability associated with SEO was β-CD > DM-β-CD > 2-HE-β-CD > 2-HP-β-CD. The thermodynamic measurements showed that the inclusion process was an exothermic and enthalpy-driven process accompanied with a negative entropic contribution, and Van der Waals force plays an importance role in the process. In addition, the content of SEO in the microcapsule was 0.14 g/g and its stabilization was obviously improved.     

Probiotic <Emphasis Type="Italic">Enterococcus faecium</Emphasis> CRL 183 inhibit chemically induced colon cancer in male Wistar rats

Several animal studies have shown that supplementation with specific strains of lactic acid bacteria could prevent the establishment, growth, and metastasis of transplantable and chemically induced tumors. The goal of this study was to determine the effect of Enterococcus faecium CRL 183 on the incidence of colorectal tumors induced experimentally by dimethylhydrazine (DMH). We used thirty 4-week old male Wistar rat. The animals belonging to the DMH groups were injected s.c 20 mg/kg body weight of 1,2 dimethylhydrazine and 1 mM EDTA (pH 6.5), in a weekly dose, for 14 weeks. Three groups were used: (1) Control (not initiated); (2) Initiated with DMH; (3) Initiated with DMH + intake of E. faecium CRL 183. At the end of the 42nd week, all the animals were euthanized; the colons were removed and analyzed histologically. All the groups were compared histologically and IL-4, IFN-γ and TNF-α cytokines. The control group did not develop pre-neoplastic lesions. The E. faecium CRL 183-DMH group showed a 50% inhibition in incidence in average number of tumors (P < 0.001), reduced the formation of ACF (P < 0.001), the lowest number of adenocarcinoma being found in this group (P < 0.001) and enhanced the immune response by increasing IL-4, IFN-γ and TNF-α (P < 0.001) when compared with the DMH group.     

Selection of elderberry (<Emphasis Type="Italic">Sambucus nigra</Emphasis> L.) genotypes best suited for the preparation of juice

Experiments with elderberry genotypes, ripening stage and pectinolysis were carried out in order to investigate the possibility to improve different quality characteristics of elderberry juice. Raw juice was processed using either an optimised method with respect to enzyme concentration and treatment time or produced directly without any enzymatic treatment. Neochlorogenic acid, chlorogenic acid, cyanidin-3-sambubioside-5-glucoside, cyanidin-3,5-diglucoside, cyanidin-3-sambubioside, cyanidin-3-glucoside, quercetin-3-rutinoside (rutin) and quercetin-3-glucoside (isoquercitrin) were identified in the raw juice by liquid chromatography-mass spectrometry (LC-MS) and quantified by high-performance liquid chromatography-diode array detection (HPLC-DAD). The content of phenolic acids and flavonoids in elderberries were shown to be affected by berry development stage at harvest (ripening stage). Furthermore, a considerable variation in juice yield and physicochemical properties such as turbidity, soluble solids, titratable acidity, and content of phenolic acids and flavonoids was found between juices processed from elderberries by pectinolysis of different elderberry genotypes. Pectinolysis appeared not to have any major effect on juice yield and the content of phenolic acids and flavonoids in the juice compared to non-enzymatic processed juice. Factor analysis revealed correlations among quality characteristics such as soluble solids, titratable acidity, turbidity, and content of phenolic acids and flavonoids and it is shown that these correlations may be useful for the selection of elderberry genotypes best suited for the preparation of juice.     

<Emphasis Type="Italic">In vitro</Emphasis> characterization study of <Emphasis Type="Italic">Bacillus mojavensis</Emphasis> KJS-3 for a potential probiotic

The identification and characterization of Bacillus mojavensis KJS-3 was performed by in vitro tests. A 16S rDNA sequence and phylogenetic tree demonstrated that this isolate belongs to the B. mojavensis group. B. mojavensis KJS-3 supplies nutrients by synthesizing several vitamins. B. mojavensis KJS-3 produces α-amylase and protease. B. mojavensis KJS-3 is cultured well under aerobic conditions without gas production. B. mojavensis KJS-3 allows for assimilation of cholesterol and bile salt hydrolase activity. Finally, adhesion experiments using Caco-2 cells revealed that the adherence of B. mojavensis KJS-3 to Caco-2 cells was approximately 51.2±8.14%.