31 research outputs found

    Distinctive anthocyanin accumulation responses to temperature and natural UV radiation of two field-grown (<i>Vitis vinifera</i> L.) cultivars

    Get PDF
    The responses of two red grape varieties, Bovale Grande (syn. Carignan) and Cannonau (syn. Grenache), to temperature and natural UV radiation were studied in a three-years field experiment conducted in Sardinia (Italy), under Mediterranean climate conditions. Vines were covered with plastic films with different transmittances to UV radiation and compared to uncovered controls. Light intensity and spectral composition at the fruit zone were monitored and berry skin temperature was recorded from veraison. Total skin anthocyanin content (TSA) and composition indicated positive but inconsistent effects of natural UV light. Elevated temperatures induced alterations to a greater extent, decreasing TSA and increasing the degree of derivatives acylation. In Cannonau total soluble solids increases were not followed by increasing TSA as in Bovale Grande, due to both lower phenolic potential and higher sensitivity to permanence of high temperatures. Multi linear regression analysis tested the effects of different ranges of temperature as source of variation on anthocyanin accumulation patterns. To estimate the thermal time for anthocyanin accumulation, the use of normal heat hours model had benefit from the addition of predictor variables that take into account the permanence of high (&gt;35 °C) and low (&lt;15 °C and &lt;17 °C) temperatures during ripening

    Bioconversion of ovine scotta into lactic acid with pure and mixed cultures of lactic acid bacteria.

    Get PDF
    Abstract Scotta is the main by-product in the making of ricotta cheese. It is widely produced in southern Europe and particularly in Italy where it represents a serious environmental pollutant due to its high lactose content. With the aim of evaluating whether scotta bioconversion into lactic acid can be considered as an alternative to its disposal, besides providing it with an added value, here the growth, fermentative performances, and lactic acid productions of pure and mixed cultures of Lactobacillus casei, Lactobacillus helveticus, and Streptococcus thermophilus were evaluated on ovine scotta-based media, without and with the addition of nutritional supplements. The outcomes indicate that ovine scotta can be utilized for the biotechnological production of lactic acid with yields up to 92%, comparable to those obtained on cheese-whey. Indeed, the addition of nutritional supplements generally improves the fermentative performances of lactic acid bacteria leading to about 2 g l−1 h−1 of lactic acid. Moreover, the use of mixed cultures for scotta bioconversion reduces the need for nutritional supplements, with no detrimental effects on the productive parameters compared to pure cultures. Finally, by using L. casei and S. thermophilus in pure and mixed cultures, up to 99% optically pure l-lactic acid can be obtained

    La Deumidificazione su piccola scala dei frutti di fico

    Get PDF
    Niedda longa fig fruits (Ficus carica L.) were dried by dehumidification. Fruits were divided in two different size groups, and dried for 120 h (A) or 96 h (B) in a room (8.5 m3), in which 30.5°C-32.0°C of temperature and 34-40% of relative humidity were held by a small dehumidifier (29 kg weight). The lots A and B reached respectively 79.3±0.88% and 69.6±4.74% of dry matter content, at the end of the process. Following drying, fruits were sprayed with a potassium sorbate solution, then film packaged in air or in modified atmosphere and transferred at 20 °C to simulate shelf life. Lot A fruits were the most similar for chemical composition to imported dried figs. However, neither lot A nor B substantially differed, after 3 months of shelf life, for external-total count of yeasts, moulds and bacteria from the purchased fruits. Thus, the combination between dehumidification and potassium-sorbate treatment may allow for safe dried figs to be obtained. Si riferisce su una prova di essiccazione per deumidificazione di frutti di fico (Ficus carica L.) della cv "Niedda longa". I frutti, separati in due lotti differenti per il peso, venivano essiccati per 120 h (A) o 96 h (B), con un deumidificatore, di 29 kg di peso, che manteneva i valori di temperatura e di umidità relativa di un ambiente di 8,5 m3, rispettivamente tra 30,5°-32,0°C e 34-40%. I lotti A e B rispettivamente, al termine dell'essiccazione, avevano un contenuto di sostanza secca del 79,3±0,88% e del 69,6±4,74%. Alla fine i frutti venivano trattati con potassio sorbato, confezionati anche in regime di atmosfera modificata e conservati per 3 mesi a 20°C. Il lotto A era il più simile, per composizione chimica, ai fichi secchi d'importazione. Comunque, per quanto riguarda le conte di lieviti, muffe e batteri epifitici, entrmabi i lotti non presentavano differenze degne di nota, rispetto ai fichi d'importazione. Sembra pertanto che l'abbinamento tra deumidificazione e trattamento con potassio sorbato permetta di produrre fichi essiccati stabili nel tempo

    Cytoprotective, antioxidant, and anti-migratory activity of Pistacia lentiscus L. supercritical carbon dioxide extract on primary human endothelial cells

    Get PDF
    Green chemistry is a useful tool for producing valuable chemicals from biomass. However, extracted compounds need to be tested for safety and efficacy before their use in humans. Here we investigate the chemical composition and biological effects of a leaves Pistacia lentiscus L. supercritical carbon dioxide (SCCO2) extract. Terpenes represented the main extract fraction, with Germacrene D (11.18%), delta-cadinene (10.54%), and alpha-pinene (8.7%) the most abundant molecules. Challenged with endothelial cells (ECs), increasing extract concentrations failed to affect cell proliferation or promote cell toxicity. ROS assessment in unstressed and H2O2-treated ECs revealed an extract dose-dependent antioxidant activity. Exposition of H2O2-treated ECs to increasing extract concentrations dose-dependently counteracted H2O2-induced cell impairments. The extract significantly counteracted fetal calf serum-induced ECs migration. For the first time, we report that a SCCO2 extract obtained from PL leaves is safe on ECs and may be a useful source of valuable compounds with vasculoprotective properties.Open Access funding was provided by the Qatar National Library

    Effect of wine barrel ageing or sapa addition on total polyphenol content and antioxidant activities of some Italian craft beers

    No full text
    Beer is a complex mixture of bioactive polyphenols with positive health effects, and its composition is influenced by some technological variables. In this study, the total polyphenol content (TPC) and the antioxidant activity of some Italian craft beers produced by ageing in wood barrel that previously contained red or white wines, and by addition of sapa, a cooked must from wine grapes, were investigated. TPC greatly vary among different beer types. Craft beers stored in wood barrels that contained red wines, such as those added of sapa from red wine grapes, showed a TPC up to 2.5 times higher (1000 GAE mg L−1) compared with other craft beers, and 3.6 times higher than the industrial beer. The antioxidant activity is remarkably different depending on beer type and strictly correlated with TPC. Results indicate that antioxidant properties of the craft beers could be efficiently improved by the explored technological processes

    Distinctive Anthocyanin Accumulation Responses to Temperature and Natural UV Radiation of Two Field-Grown Vitis vinifera L. Cultivars

    No full text
    The responses of two red grape varieties, Bovale Grande (syn. Carignan) and Cannonau (syn. Grenache), to temperature and natural UV radiation were studied in a three-years field experiment conducted in Sardinia (Italy), under Mediterranean climate conditions. Vines were covered with plastic films with different transmittances to UV radiation and compared to uncovered controls. Light intensity and spectral composition at the fruit zone were monitored and berry skin temperature was recorded from veraison. Total skin anthocyanin content (TSA) and composition indicated positive but inconsistent effects of natural UV light. Elevated temperatures induced alterations to a greater extent, decreasing TSA and increasing the degree of derivatives acylation. In Cannonau total soluble solids increases were not followed by increasing TSA as in Bovale Grande, due to both lower phenolic potential and higher sensitivity to permanence of high temperatures. Multi linear regression analysis tested the effects of different ranges of temperature as source of variation on anthocyanin accumulation patterns. To estimate the thermal time for anthocyanin accumulation, the use of normal heat hours model had benefit from the addition of predictor variables that take into account the permanence of high (&gt;35 °C) and low (&lt;15 °C and &lt;17 °C) temperatures during ripening

    A Novel method for the determination of ascorbic acid and antioxidant capacity in <i>Opuntia ficus</i> indica using <i>in vivo</i> microdialysis

    No full text
    A simple and rapid method was developed for in vivo simultaneous determination of ascorbic-acid and antioxidant capacity in microdialysates from cladodes of Opuntia ficus-indica (L.) Miller. The method is verified in water-stressed plants, as compared with a well-watered test controls. The microdialysis probe construction and insertion procedure was specifically developed to minimise the tissue trauma of the plant and to obtain optimal dialysis performance. Microdialysis was performed using a flow rate of 3 μL/min and the samples were analysed by HPLC coupled to electrochemical detection of ascorbic-acid and DPPH-determined antioxidant capacity. Our data indicate exponential decay of the concentrations of the analysed compounds as a function of microdialysis sampling time. Water-stressed Opuntia show decreased ascorbic acid levels and increased the others antioxidants

    From Hop to Beer: Influence of Different Organic Foliar Fertilisation Treatments on Hop Oil Profile and Derived Beers’ Flavour

    No full text
    Foliar fertilisation is known to influence the physiological response of Humulus lupulus (hop plants), but its effect on the flavour profile of beer still has to be investigated. By comparing the effects of four fertilisation treatments, this study aims at determining whether different foliar fertilisation treatments have a significant impact on hop plants’ aromatic quality and that of the beer produced. Hop cones harvested from each experimental treatment were brewed to obtain five single dry-hopped beers, which were subsequently analysed. Gas chromatography–mass spectrometry (GC-MS) and electronic nose (Cyranose 320) analyses were performed on the hop cones, while headspace solid-phase microextraction–gas chromatography–mass spectrometry HS-SPME-GC-MS, electronic nose and sensory analyses were carried out on the beers produced. The analyses not only allowed for a differentiation between the hops from the four fertilisation treatments and the control but also enabled a differentiation between the beers produced for their identification. Sensory evaluation revealed consumer preferences regarding the dry-hopped beers analysed, evidencing their distinctive features, including significant differences in both aroma and flavour

    The Effect of Different Organic Foliar Fertilization on Physiological and Chemical Characters in Hop (Humulus lupulus L., cv Cascade) Leaves and Cones

    No full text
    Background: Hop cultivation requires an abundant quantity of nutrients to reach higher cone yield and quality. The aim of this work was the evaluation of different fertilization plans to obtain an improvement in product quality. Methods: Foliar analysis, anatomical analysis through the use of light microscope and SEM; physiological measurements through atLEAF, Handy PEA and spectrophotometry, were carried out to determine chlorophyll content, carotenoids and photosynthetic efficiency in two periods (t1, t2) for four experimental treatments and a Control (Treat 1, Treat 2, Treat 3, Treat 4, Untreat). Leaf texture (texture analyzer), color (colorimeter), DPPH activity (spectrophotometer), bitter acid content (HPLC-UV) and essential oil yields (steam distillation) and cone yields were measured. Results: Treat 2 showed the best performance: (i) in leaves, in terms of texture, chlorophyll content and color; (ii) in cones, with 6.98% of alpha acids, 1.78% of oil yield and 3.55 kg of fresh cones per plants. Conclusion: The fertilization plans caused alteration in micro and macro elements content in hop leaves and in the composition of hop cones. In our conditions, the best fertilization plan, in terms of cone productivity and quality, was Treat 2, highlighting the value of a customized organic foliar fertilization plan for hop cultivation
    corecore