Artículos de revista DTA - ETS Aldizkari artikuluak

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Browsing Artículos de revista DTA - ETS Aldizkari artikuluak by Subject "Antioxidant activity"

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    PublicationOpen Access
    Andean blackberries (Rubus glaucus Benth) quality as affected by harvest maturity and storage conditions
    (Elsevier, 2017) Horvitz Szoichet, Sandra Susana; Chanaguano, Diana; Arozarena Martinicorena, Íñigo; Tecnología de Alimentos; Elikagaien Teknologia
    Maturity stage at harvest and storage conditions are critical factors determining fruit postharvest quality. Physicochemical (fruit size, mass loss, color, firmness, pH, total soluble solids, titratable acidity), microbiological (total aerobic mesophiles, psychrotrophes, and yeasts and molds) and sensory quality of Andean blackberries harvested at two maturity stages and stored under room (18 ± 2 °C) and cold storage (8 ± 1 °C) was studied. Total phenolic compounds, anthocyanins and organic acids content, and antioxidant activity were also evaluated. The more mature fruit was classified as “big”, according to the Ecuadorian Standard and showed lower acidity and higher total soluble solids, anthocyanins content and sensory scores compared with the fruit harvested earlier, whilst maturity at harvest did not affect the microbial counts of any of the groups studied. Cold storage was effective in delaying weight loss, softening and microbial growth and also in maintaining a better sensory quality of the blackberries. What’s more, under refrigeration it was possible to extend the shelf-life of the fruit to up to 8 d. The main limiting factors for shelf-life were microbial growth and loss of firmness at room storage and cold storage, respectively. Based on these results, it would be advisable to harvest the fruit at maturity stage 5 in order to achieve an appropriate fruit size, a high anthocyanin concentration, a better sugars/ acids equilibrium, and a better sensory quality and the fruit should be maintained under refrigerated storage.
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    PublicationOpen Access
    Color, phenolics, and antioxidant activity of blackberry (Rubus glaucus Benth.), blueberry (Vaccinium floribundum Kunth.), and apple wines from Ecuador
    (Wiley, 2013) Ortiz, Jacqueline; Marín Arroyo, Remedios; Noriega Domínguez, María José; Navarro Huidobro, Montserrat; Arozarena Martinicorena, Íñigo; Tecnología de Alimentos; Elikagaien Teknologia
    Seventy wines were produced in Ecuador under different processing conditions with local fruits: Andean blackberries (Rubus glaucus Benth.) and blueberries (Vaccinium floribundum Kunth.) and Golden Reinette apples. Wines were evaluated for antioxidant activity (AA) using the radical scavenging capacity (DPPH) method, total phenolic content (TPC) using the Folin–Ciocalteu method, total monomeric anthocyanins (TMAs) using the pH differential test, and color parameters using VIS-spectrophotometry. For blackberry wines, ellagitannins and anthocyanins were also analyzed using high-performance liquid chromatography with diode-array detection (HPLC-DAD). Apples wines (n=40) hadthe lowest TPC (608±86 mg/L) and AA (2.1±0.3 mM Trolox). Blueberry wines (n=12) had high TPC (1086±194 mg/L) and moderate AA (5.4±0.8 mM) but very low TMA (8±3 mg/L), with a color evolved toward yellow and blue shades. Blackberry wines (n=10) had the highest TPC (1265±91 mg/L) and AA (12±1 mM). Ellagitannins were the major phenolics (1172±115 mg/L) and correlated well with AA (r=0.88). Within anthocyanins (TMA73±16 mg/L), cyanidin-3-rutinoside (62%) and cyanidin-3-glucoside (15%) were predominant. Wines obtained by cofermentation of apples and blackberries (n=8) showed intermediate characteristics (TPC 999±83 mg/L, AA 6.2±0.7 mM, TMA 35±22 mg/L) between the blackberry and blueberry wines. The results suggest that the Andean berries,particularly R. glaucus, are suitable raw materials to produce wines with anin vitroantioxidant capacity that is comparable to red grape wines.
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    PublicationOpen Access
    Effect of fermentation and roasting on the phenolic concentration and antioxidant activity of cocoa from Nicaragua
    (Wiley, 2014) Suazo Mercado, Yader Salvador; Davidov Pardo, Gabriel; Arozarena Martinicorena, Íñigo; Tecnología de Alimentos; Elikagaien Teknologia
    The aim of this work was to quantify the changes in the total phenolic content (TPC), antioxidant activity (AA) and color hue (CH) of cocoa (Theobroma cacao) beans of group Trinitario from Nicaragua after fermentation and roasting. Cocoa beans with three different grades of fermentation (nonfermented, poorly fermented and fermented) were put under three different roasting temperatures (110, 130 and 150C). The kinetics of the roasting at 130C for 60 min was also studied. After each treatment, TPC, AA and CH were determined. For all the quantified parameters, significant differences (P < 0.05) were found between fermentations and roasting conditions. TPC and AA showed decrease with fermentations and CH showed increases. Roasting decreased TPC except for the 150C treatment, while AA and CH increased. When studying the kinetics at 130C, TPC showed greater reductions with longer treatments while AA and CH showed increases.