Carotenoid deposition in plant and animal foods and its impact on bioavailability.

Over the past decades, an enormous body of literature dealing with the natural deposition of carotenoids in plant- and animal-based foods has accumulated. Prominent examples are the large solid-crystalline aggregates in carrots and tomatoes or the lipid-dissolved forms in dairy products and egg yolk. Latest research has identified lipid-dissolved forms in a rare number of plant foods, such as tangerine tomatoes and peach palm fruit (Bactris gasipaes Kunth). In addition, liquid-crystalline forms were assumed in so-called tubular chromoplasts of numerous fruits, e.g., in papaya, mango, and bell pepper. The bioavailability of carotenoids from fresh and processed foods strongly depends on their genuine deposition form, since their effective absorption to the human organism requires their liberation from the food matrix and subsequent solubilization into mixed micelles in the small intestine. Consequently, a broad overview about the natural array of carotenoid deposition forms should be helpful to better understand and modulate their bioavailability from foods. Furthermore, naturally highly bioavailable forms may provide biomimetic models for the improved formulation of carotenoids in food supplements. Therefore, this review paper presents scientific evidence from human intervention studies associating carotenoid deposition forms with their bioavailability, thus suggesting novel technological and dietary strategies for their enhanced absorption.

Detailed analyses of fresh and dried maqui (Aristotelia chilensis (Mol.) Stuntz) berries and juice.

In this study, a detailed chemical characterization of nutritionally-relevant, quality-determining constituents in dried and fresh fruits as well as juices of maqui (Aristotelia chilensis (Mol.) Stuntz) is provided. A total of 8 glycosylated anthocyanins was characterized in maqui fruits, being composed of differently substituted cyanidin and delphinidin derivatives. During processing into juice, a substantial loss in total anthocyanin contents (TAC) was observed. TAC values were also reduced after drying of maqui berries. Likewise, the browning index (BI) of fresh fruits increased during processing. Being composed of flavonol glycosides and ellagic acids, 17 non-anthocyanin phenolics were characterized in all maqui samples. Besides characterizing phenolic compounds, antioxidant activities, total phenolics, major sugars, non-volatile organic acids, minerals and trace elements were quantitated. Moreover, total lipid contents and the fruits' mainly unsaturated fatty acid profiles are reported. The presented results indicate the high potential of maqui as so far under-utilized but extremely pigment-rich "superfruit".

Jagua blue derived from Genipa americana L. fruit: A natural alternative to commonly used blue food colorants?

Due to consumers' increasing health awareness, food industry aims at replacing synthetic dyes by natural counterparts. The substitution of blue synthetic dyes is particularly challenging since current natural alternatives such as phycocyanin (Spirulina) suffer from poor stability. Jagua blue (produced from Genipa americana L. fruit) might represent a potential novel blue pigment source. However, only little is known about its color properties, and application in food systems. Therefore, the blue color and the stability of Jagua blue were assessed for the first time and compared to commonly used colorants, namely, Spirulina, brilliant blue FCF (Blue no. 1), and indigo carmine (Blue no. 2). The reaction rate of Jagua blue was independent of its concentration, confirming thermal degradation to follow first-order kinetics. Between pH 3.6 and 5.0, the color hue of Jagua blue solutions was similar to that of Blue no. 2. However, Jagua blue revealed markedly higher storage stabilities (t1/2=86-105days) than Blue no. 2 (t1/2≤9days) and was less susceptible to acidic pH of 3.6 (t1/2=86days) than Spirulina (t1/2=70days). High negative b* values (blueness) of colored gelatin gels were only obtained for Jagua blue and Spirulina, and the former exhibited higher light stabilities (t1/2=15days) than Spirulina gels (t1/2=4days). Our findings indicate Jagua blue to be a most promising alternative to synthetic dyes, providing relevant information regarding potential food applications.

Stabilisation of strawberry (Fragaria x ananassa Duch.) anthocyanins by different pectins.

The objective of the present study was to evaluate the effects of different pectins on strawberry anthocyanins in viscous model solutions at pH 3.0. For this purpose, low esterified amidated, low and high methyl esterified citrus and apple pectins, and a sugar beet pectin (SBP), respectively, were added to strawberry extracts. The latter were predominantly composed of pelargonidin-glycosides, containing either reduced (E-1) or original amounts of non-anthocyanin phenolics (E-2). Model systems were stored for 18 weeks at 20±0.5 °C protected from light, and anthocyanins were quantitated in regular intervals by HPLC-DAD analyses. Half-life (t1/2) and destruction (D) values were calculated based on first-order kinetics. Generally, significant differences in pigment retention could be ascribed to differing pectin sources, while variation in the degree of esterification and amidation, respectively, had negligible effects. Compared to systems without added pectin, apple pectins and SPB enhanced anthocyanin stability moderately, while stabilising effects of citrus pectins were poor or even imperceptible. Generally, the amount of non-anthocyanin phenolics and the addition of citrate did not markedly affect anthocyanin stability. However, pectins had no influence on total phenolic contents (Folin-Ciocalteu assay) and antioxidant capacities (FRAP and TEAC assay) of strawberry phenolics over time. For pelargonidin-3-glucoside and -rutinoside largely consistent stabilities were found in all model systems. In contrast, pelargonidin-3-malonylglucoside was less stable in the blank, and stabilisation by pectins was always negligible. The findings of the present study are contrary to results reported previously for the stabilisation of cyanidin- and delphinidin-glycosides in similar model systems prepared with black currant extracts, indicating a high impact of the number of hydroxyl groups in the anthocyanin B-ring.

Impact of pectin type on the storage stability of black currant (Ribes nigrum L.) anthocyanins in pectic model solutions.

The effects of different pectins on the stabilisation of black currant anthocyanins in viscous model solutions at pH 3.0 were investigated. For this purpose, low esterified amidated (AM), low (LM) and high (HM) methoxylated citrus and apple pectins and a sugar beet pectin were added to a purified anthocyanin extract (ACN-E) and to an extract containing anthocyanins and non-anthocyanin phenolics (PP-E). Model systems were stored at 20±0.5°C in the dark. Anthocyanin contents were monitored by HPLC analysis over a period of 18 weeks, and half-life and destruction values were calculated. In all pectic model solutions anthocyanin stability was significantly improved compared to stability of the extracts without added pectins (blank). Best stabilisation was obtained with AM pectin, followed by LM and HM pectins. In model systems containing citrus pectins, anthocyanin stabilisation was better compared to that of apple pectins having similar degrees of esterification and amidation, respectively. This was primarily due to the strong interaction of delphinidin glycosides with the citrus pectins, whereas stabilisation of cyanidin derivatives was less important. Sugar beet pectin improved anthocyanin stability only to a limited extent. In the presence of non-anthocyanin phenolics (PP-E) the impact of the pectin source was even more pronounced than the effect of the pectin type. Addition of citrate to pectic systems accelerated anthocyanin decay. Stabilising effects of pectins were hardly noticeable when evaluating total phenolic content (TPC, Folin-Ciocalteu) and antioxidant capacity during storage. Highest TPC, TEAC- and FRAP values were observed in systems containing citrus pectin, which was in contrast to sugar beet pectin, where values fell below those of the blank after storage.

Colour and stability assessment of blue ferric anthocyanin chelates in liquid pectin-stabilised model systems.

The formation of blue coloured ferric anthocyanin chelates and their colour stability during storage and thermal treatment were monitored in a pH range relevant to food (3.6-5.0). Liquid model systems were composed of different types of Citrus pectins, juices (J) and the respective phenolic extracts (E) from elderberry (EB), black currant (BC), red cabbage (RC) and purple carrot (PC) in the presence of ferric ions. For EB, BC and PC, pure blue colours devoid of a violet tint were exclusively observed for the phenolic extracts and at pH values ≥ 4.5 in model systems containing high methoxylated and amidated pectins, respectively. Colour and its stability strongly depended on the amount of ferric ions and the plant source; however, colour decay could generally be described as a pseudo-first-order kinetics. Despite optimal colour hues for RC-E and RC-J, storage and heat stabilities were poor. Highest colour intensities and best stabilities were observed for model systems containing PC-E at a molar anthocyanin:ferric ion ratio of 1:2. Ascorbic and lactic acids interfered with ferric ions, thus significantly affecting blue colour evolution and stability. Colour loss strongly depended on heat exposure with activation energies ranging between 60.5 and 78.4 kJ/mol. The comprehensive evaluation of the interrelationship of pigment source, pH conditions and pectin type on chelate formation and stability demonstrated that ferric anthocyanin chelates are promising natural blue food colourants.

Bathochromic and stabilising effects of sugar beet pectin and an isolated pectic fraction on anthocyanins exhibiting pyrogallol and catechol moieties.

The formation of anthocyanin-metal chelates, exhibiting intense blue colours was monitored over a period up to 10 weeks. Evaluating normalised absorption spectra in the range of 580-700 nm and their proportion of the total area under the curve (AUC), provided information about the blue colour hue, intensity and stability. Colour stability in model solutions containing commercial sugar beet pectin or an isolated pectic polysaccharide fraction (PPF) therefrom, both being naturally enriched in aluminium and ferric ions, was assessed in a pH range of 3.6-7.0. The pectic structures stabilised anthocyanin-metal chelates, and thus blue colours by efficiently preventing complex precipitation. Highest bathochromic shifts and most intense blue colours were observed in PPF model solutions containing delphinidin-3-glucoside (Dpd-3-glc), exhibiting a pyrogallol moiety in the flavylium B-ring, compared to cyanidin- (Cyd-3-glc) and petunidin-3-glucoside (Pet-3-glc), both carrying a catechol substituted B-ring. Hue and intensity of the blue colour at pH 5.0 were only insignificantly influenced by the buffer system except for citrate and phosphate buffers, which both annihilated anthocyanin-metal chelate formation. The blue colours faded following first order kinetics. Best stabilities as deduced from storage experiments performed at 20 ± 2°C in the dark were observed for Dpd-3-glc. In contrast, Cyd-3-glc displayed shortened half-life values, whereas blue Pet-3-glc chelates decomposed rapidly. These results demonstrate that the solubilisation of anthocyanin-metal chelates by pectic structures is a promising option for developing water soluble natural blue food colourants.

Efficacy of an aqueous Pelargonium sidoides extract against herpesvirus.

The compounds of an aqueous root extract of the African medicinal plant Pelargonium sidoides were analysed by LC-MS spectroscopy and the antiviral effect of this extract against herpes simplex virus was examined in cell culture. Besides predominant coumarins, simple phenolic structures as well as flavonoid and catechin derivatives were identified as major constituents in the Pelargonium extract. The inhibitory activity of this extract against herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) was tested in vitro on RC-37 cells using a plaque reduction assay and exhibited high antiviral activity against both herpesviruses in viral suspension tests. The 50% inhibitory concentration (IC(50)) of the aqueous Pelargonium sidoides extract for herpes simplex virus plaque formation was determined at 0.00006% and 0.000005% for HSV-1 and HSV-2, respectively. At maximum noncytotoxic concentrations of the extract, plaque formation was significantly reduced by more than 99.9% for HSV-1 and HSV-2 and a clear concentration-dependent antiviral activity against HSV could be demonstrated for this extract. In order to determine the mode of antiviral action, the extract was added at different times to the cells or viruses during the infection cycle. Both herpesviruses were significantly inhibited when pretreated with the plant extract or when the extract was added during the adsorption phase, whereas acyclovir demonstrated antiviral activity only intracellularly during replication of HSV. These results indicate that P. sidoides extract affected the virus before penetration into the host cell and reveals a different mode of action when compared to the classical drug acyclovir. Hence this extract is capable of exerting an antiviral effect on herpes simplex virus and might be suitable for topical therapeutic use as antiviral drug both in labial and genital herpes infection.

Power Doppler 'blanching' after the application of transducer pressure.

The aim of this study was to determine if transducer pressure modifies power Doppler assessments of rheumatoid arthritis synovium at the metacarpophalangeal joints and metatarsophalangeal joints. Five rheumatoid arthritis patients of varying degrees of 'disease activity' and damage were assessed with power Doppler ultrasound scanning of the dominant hand second to fifth metacarpophalangeal joints. Two rheumatoid arthritis patients had their dominant foot first to fifth metatarsophalangeal joints assessed with power Doppler ultrasound. Ultrasonography was performed with a high frequency transducer (14 MHz) with a colour mode frequency of 10 Mhz, and a standard colour box and gain. In the joint that showed the highest power Doppler signal, an image was made. A further image was taken after transducer pressure was applied. In all patients, there was increased flow to at least one joint. After pressure was applied, power Doppler signal intensity markedly reduced in all images and in some there was no recordable power Doppler signal. Increased transducer pressure can result in a marked reduction or obliteration in power Doppler signal. This power Doppler 'blanching' shows the need for further studies to evaluate sources of error and standardization before power Doppler ultrasound becomes a routine measure of 'disease activity' in rheumatoid arthritis.

Influence of Bemisia argentifolii (Homoptera: Aleyrodidae) infestation and squash silverleaf disorder on zucchini seedling growth.

We investigated the effect of different levels of infestation by whiteflies, Bemisia argentifolii Bellows & Perring, on the growth and pigment concentrations of seedlings of zucchini, Cucurbita pepo L., that differed in their tolerance to squash silverleaf disorder. Genetically similar sister lines that were either tolerant (ZUC76-SLR) or susceptible (ZUC61) to silverleaf disorder exhibited reduced plant height, internode length, plant dry weight, and petiole length in response to whitefly feeding. Similar plant growth responses to whitefly feeding were observed despite that the foliage of ZUC61 silvered severely, whereas the foliage of ZUC76-SLR showed no silvering in a greenhouse experiment conducted in the spring and showed only minimal silvering in a similar greenhouse experiment conducted in the fall. In plants of both sister lines infested with 50 pairs of whiteflies and their progeny, petioles, but not the leaf blades, of uninfested leaves had reduced chlorophyll content. In another experiment, two different genetic sources of tolerance to silverleaf disorder (ZUC33-SLR/PMR and ZUC76-SLR) and a commercial silverleaf-susceptible zucchini hybrid ('Zucchini Elite') responded similarly to whitefly feeding, except the tolerant genotypes did not exhibit leaf silvering. All genotypes, silverleaf tolerant or not, had reduced dry weight, plant height, and internode length that became more pronounced as whitefly infestation increased. All genotypes had reduced levels of chlorophylls and carotenoids in uninfested young leaf blades and petioles from infested plants. Petioles, however, were more affected by feeding than leaf blades, showing a 66% reduction in chlorophylls a+b and carotenoids at the lowest infestation level (30 pairs of whitefly and their progeny), whereas pigments in leaf blades declined more slowly in response to whitefly feeding density, averaging 14-15% less at the highest infestation level (90 pairs of whitefly and their progeny). We conclude that tolerance to silverleaf disorder does not prevent stunting in zucchini seedlings nor does it protect against the systemic loss of photosynthetic and protoprotectant pigments induced by feeding of B. argentifolii whiteflies.

Impact of Bemisia argentifolii (Homoptera: Auchenorrhyncha: Aleyrodidae) infestation and squash silverleaf disorder on zucchini yield and quality.

Fruit yield and quality of zucchini, Cucurbita pepo L., plants infested with Bemisia argentifolii Bellows & Perring were evaluated in a screenhouse under spring and fall growing conditions by using closely related sister lines that were either susceptible (ZUC61) or tolerant (ZUC76-SLR) to squash silverleaf disorder. Our objective was to test separately the effects of level of whitefly infestation and expression of silverleaf symptoms on zucchini yield and quality. In a second experiment, yield and quality of fruit produced by silverleaf-tolerant zucchini genotypes incorporating two different sources of tolerance (ZUC76-SLR and ZUC33-SLR/PMR) were compared with that of 'Zucchini Elite', a silverleaf-susceptible commercial hybrid. Zucchini fruit yield was reduced in plants exposed to repeated infestations of whiteflies in spring and fall of both experiments. In addition, fruit grew to harvestable size more slowly under the highest whitefly infestations. Fruit quality was reduced at high infestations because of uneven and reduced pigmentation. The fruit yield and quality of ZUC61 and ZUC76-SLR were similarly affected by whitefly infestation despite differences in their susceptibility to squash silverleaf disorder. Fruit from infested plants showed decreased levels of chlorophyll and carotenoids causing the "blanching" of the fruit that is associated with loss of quality and reduced marketability. Leaves of infested plants of all genotypes had reduced levels of photosynthetic and photoprotectant pigments, possibly leading to reduced photosynthesis and consequently reduced yield. We conclude that feeding by high whitefly populations rather than expression of squash silverleaf disorder is responsible for yield and quality reduction in zucchini.

Determination of phenolic acids and flavonoids of apple and pear by high-performance liquid chromatography.

A new HPLC stationary phase has been applied to the analysis of phenolic acids and flavonoids with diode array and mass spectrometric detection. The separation of 26 standard compounds was achieved within 1 h. The stationary phase displayed excellent resolution especially of flavonol glycosides. The analytical system has been used for the determination of phenolic compounds in apple pomace and apple juice, and in extracts of pear fruits of different cultivars. Apple pomace was found to be a promising source of phenolics. However, yields are affected by the drying conditions applied. Furthermore, the applicability of the analytical system for the authenticity control of apple and pear juice was demonstrated by determination of characteristic quercetin and isorhamnetin glycosides, and dihydrochalcones, respectively. Since isorhamnetin-3-glucoside was present in all pear cultivars investigated, the usefulness of arbutin as a specific marker of pear products appears to be doubtful.

The treatment of negative symptoms: a clinical and methodological study.

The primary objective of this study was to evaluate the efficacy, safety and tolerability of remoxipride (controlled release) versus haloperidol in patients with negative symptoms. The study comprised a multicentre, randomised, double-blind, parallel-group clinical trial. Two hundred and five patients were randomised to either remoxipride or haloperidol. Patients eligible for this study were aged 18-65 years, met the DSM-III-R diagnosis for chronic schizophrenia and the Positive and Negative Symptoms Scale (PANSS) criteria for predominant negative symptoms. There was a statistically significant reduction in the PANSS scores of at least 20% from baseline to last rating for 39 remoxipride (49.4%) and 45 haloperidol (47.6%) treated patients. There were no statistical differences found between the two treatment groups with respect to improvement of negative symptoms and adverse events. The PANSS data suggest that both remoxipride and haloperidol improve the cluster of negative symptoms concerned with social functioning. In addition, the design of the study provides a methodology that is appropriate to the study of primary negative symptoms in schizophrenia.

Amino acid composition and betaxanthin formation in fruits from Opuntia ficus-indica.

In contrast to earlier reports high levels of taurine (2-aminoethanesulfonic acid) were found in fruit juices of three cultivars of Opuntia ficus-indica (L.) Mill. Whereas the occurrence of taurine in plant tissue was thought to be restricted to algae, fungi, and the endosperm of some higher plants, prickly pear proved to be a rich source of dietary taurine. Using L-taurine as the amino compound, a new betaxanthin was synthesized by partial synthesis. On the basis of chemical and spectral evidence its structure was determined to be the taurine-immonium-conjugate of betalamic acid. Also betalamic acid could be detected in yellow and orange coloured cultivars of Opuntia ficus-indica for the first time. In spite of the high levels of L-taurine accompanied by the occurrence of betalamic acid, the corresponding betaxanthin could not be detected in the fruit tissue.

Purification and Characterization of a Flavone 7-O-Glucoside-Specific Glucosidase from Ligulate Florets of Chamomilla recutita.

Flavone content and glucosidase activity were analyzed in various species of the genera Chamomilla, Matricaria, and Anthemis, especially during the development of the chamomile flower heads. The accumulation profile of flavonoids and the increase in enzyme activity were similar during ontogenesis. The accumulation of apigenin derivatives in closely related species was always linked to the occurrence of a catabolic beta-glucosidase in the respective plant organ. The flavone-glucoside-cleaving beta-glucosidase (FGG) from the ligulate florets of chamomile was purified to electrophoretic homogeneity by the following procedure: ammonium sulphate fractionation, anion exchange on Mono Q, hydrophobic interaction chromatography on Bio-Gel TSK Phenyl-5-PW, and gel filtration on Superose 12. The M (r) of the native enzyme was determined by gel filtration (500 kDa) and native PAGE (334 kDa). Only one subunit with an M (r) of 60 kDa could be detected after SDS-PAGE. The isoelectric point as determined by chromatofocussing on Mono P was at pH 4.6. During the purification procedure only one glucosidase activity appeared. A partially purified enzyme was used for characterization. The temperature optimum was at 37 degrees C and the pH-optimum 5.6. Energy of activation was 32.9 kJ/mol. The determination of the kinetic constants with various aryl glycosides proved a high affinity of the FGG towards flavone 7- O-glucosides. alpha-Glycosides and disaccharides were not hydrolyzed. Transglucosylation to an acceptor other than water was observed. Reagents interacting with sulfhydryl-groups strongly inhibited the enzyme.