Browsing by Author "Gomes, Maria Helena"
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- Antioxidant properties and fruit quality during long-term storage of “rocha” pear: effects of maturity and storage conditionsPublication . Silva, Filipe J. P.; Gomes, Maria Helena; Fidalgo, Fernanda; Rodrigues, José A.; Almeida, Domingos P. F.Free radical scavenging activity and the content of ascorbic acid and glutathione were investigated during long-term storage of the pear (Pyrus communis L. ‘Rocha’) fruit harvested at different maturity stages, stored in air or under controlled atmosphere and subjected to postharvest treatments with diphenylamine (DPA) and 1-methylcyclopropene (1-MCP). Harvest maturity had a significant effect on storage disorders, fruit firmness, soluble solids content and acidity. Differences in ascorbate content and free radical scavenging activity at harvest did not persist during storage. Controlled atmosphere and DPA strongly reduced the incidence and severity of browning disorders and superficial scald, whereas 1-MCP provided the most effective control. Neither DPA nor 1-MCP affected the free radical scavenging activity
- Bioactive phytochemicals in apple cultivars from the Portuguese protected geographical indication “Maçã de Alcobaça”: basis for market segmentationPublication . Almeida, Domingos P. F.; Gião, Maria S.; Pintado, Manuela; Gomes, Maria HelenaPhytochemical composition and antioxidant activity of eight apple (Malus domestica) cultivars (“Casa Nova,” “Fuji,” “Golden Delicious,” “Granny Smith,” “Jonagored,” “Reinette Grise,” “Royal Gala,” and “Starking”) from the “Maçã de Alcobaça” protected geographic indication, Portugal, were characterized to support market segmentation based on phytochemical content. Total phenolics, flavonoids, and anthocyanin contents, individual polyphenols and antioxidant activity were assessed in the flesh and skin of fruit at the ripe stage. A market segmentation of apple cultivars based on these bioactive phytochemicals is proposed. Fruit eaten with the peel can be segmented in three classes: (1) the flavonoid-rich “Starking,” “Reineta,” “Galaxy,” “Casa Nova,” Jonagored;” (2) the quercetin-rich “Fuji,” “Galaxy,” “Casa Nova;” and (3) flavonol and procyanidin-rich “Starking,” “Reinette,” “Jonagored,” “Casa Nova.” When apples were peeled before consumption, two phytochemical classes were proposed: (1) the flavonoid-rich “Reinette” and “Casa Nova,” and the (2) chlorogenic acid-rich “Reineta,” “Casa Nova,” and “Starking.”
- Effect of modified atmosphere on phytochemical profile of pasteurized peach puréesPublication . Oliveira, Ana; Coelho, Marta; Alexandre, Elisabete; Gomes, Maria Helena; Almeida, Domingos P. F.; Pintado, ManuelaPeach phytochemical profile was analysed during 90 days storage under three different gas mixtures: 10 kPa O2+90 kPa N2, 100 kPa N2 and air (78 kPa N2+21 kPa O2+0.03 kPa CO2) for both 4 and 23 °C. The antioxidant activity increased when peach purée was stored under air at 4 °C and 100 kPa N2 at 23 °C, while total phenolic content was not affected by atmospheres. Total carotenoids were more stable for 100 kPa N2, where it decreases 48 and 58% respectively for 4 and 23 °C. The content of (+)-catechin decreased 42% for 10 kPa O2 at 4°C, remaining constant in other atmospheres. Chlorogenic and neochlorogenic acids were well preserved in atmospheres containing oxygen, presenting an increase of 14 and 24% for 10 kPa O2 at 4°C. The higher content of carotenoids was obtained for 100 kPa N2 at 23 °C. Principal component analysis shows that atmospheres variance was associated with carotenoids while storage time was more related with total phenolics and total antioxidant capacity.
- Effect of modified atmosphere on polyphenols during storage of pasteurised strawberry puréesPublication . Oliveira, Ana; Alexandre, Elisabete M. C.; Coelho, Marta; Gomes, Maria Helena; Almeida, Domingos P. F.; Pintado, ManuelaThe minimum loss of processed fruit nutritional quality must been guaranteed during storage and the atmosphere can be a limiting step. Strawberry purees flushed with gas mixtures: 10 kPa O-2 + 90 kPa N-2, 100 kPa N-2 and air (78 kPa N-2 + 21 kPa O-2 + 0.03 kPa CO2) were stored for 90 days at 4 and 23 degrees C and revealed no effect in total antioxidant activity and in total phenolic content. The compounds (+)-catechin, (-)-epicatechin and quercetin-3-rutinoside were not affected by the atmospheres for both temperatures and ellagic acid was the exception within strawberry phytochemicals, where its concentration was higher for samples stored in air. Total anthocyanin content was better preserved when strawberry pur e was stored in 100 kPa N-2 at 4 and 23 degrees C, at which temperatures their levels decreased 24 and 77%, respectively. At 4 degrees C cyanidin-3-glucoside presented no significant differences between atmospheres. Pelargonidin-3-glucoside and pelargonidin-3-rutinoside decreased both 27% for 100 kPa N-2 and 45% for 10 kPa O-2 and air. All the individual anthocyanins were not affected by the atmospheres when stored at 23 degrees C. (C) 2014 Elsevier Ltd. All rights reserved.
- Impact of pH on the Phytochemical Profile of Pasteurized Peach Purée during StoragePublication . Oliveira, Ana; Gomes, Maria Helena; Alexandre, Elisabete M. C.; Almeida, Domingos P. F.; Pintado, ManuelaPeach purée was exposed to different pH (2.5, 3.0, 3.5, 4.0, and 4.5) conditions, and its phytochemical alteration was estimated after fruit pasteurization and over a 90 day storage period at both 4 and 23 °C. During the 90 day storage, the study demonstrated a decrease in total antioxidant activity of 34−40% and a decrease in total phenolics of 18−20% at 4 °C and the corresponding decreases at 23 °C were 55−56 and 30−40%, respectively. Neochlorogenic acid (34 and 27%) and chlorogenic acid (34 and 37%) presented lower retention at the higher pH (4.5) for both storage temperatures. The degradation of carotenoids was higher at pH of 4.0 and 4.5, and the highest retention was obtained at pH 3.0 and 3.5. Zeaxanthin was the carotenoid most affected with loses of 60−68% at 4 °C and 56−75% for 23 °C. Storage time and temperature were critical factors for peach purée phytochemical profile, more than pH variation.
- Phytochemicals preservation in strawberry as affected by pH modulationPublication . Oliveira, Ana; Gomes, Maria Helena; Alexandre, Elisabete M. C.; Poças, Fátima; Almeida, Domingos P. F.; Pintado, ManuelaStrawberries purees are incorporated in foods and subjected to pH modulation according to the expected final food matrix. The effect of pH on strawberry polyphenols stored at 4 and 23 degrees C for 90 days was evaluated. Total antioxidant activity and total phenolics content were only affected by time according to a first order model. The pH 4.5 induced higher decrease in (-)-epigallocatechin gallate (71% and 79%) and quercetin-3-glucoside (29% and 36%), for both storage temperatures. For pH 2.5 and 3.0, ellagic acid increased 84% for 4 degrees C. and 185% for 23 degrees C. Anthocyanins concentration changes along storage were well described by first order model. The pH value of 2.5 presented the lower kinetic constant rate where cyanidin-3-glucoside, pelargonidin-3-glucoside and pelargonidin-3-rutinoside had a k = 0.04, 0.05 and 0.03 day(-1). Lower storage temperature (4 degrees C) and lower pH (2.5) were the best condition for the preservation of polyphenols in pasteurized strawberry during a 90-day storage period.
- Uncoupling the sensory effects of 1-Methylcyclopropene and Ripening stage on 'Hayward' KiwifruitPublication . Almeida, Domingos P. F.; Gomes, Maria Helena'Hayward' kiwifruit were treated with 0.5 μL·L-1 of 1-methylcyclopropene (1- MCP) and stored in air at 0 °C. Treatment with 1-MCP reduced softening of kiwifruit during storage but did not affect soluble solids or titratable acidity. Sensory analyses were performed by a consumer panel and by trained panelists after 41, 77, and 161 days in storage. 1-MCP treatment negatively affected consumer preference, expressed as degree of liking. The trained panel clearly perceived 1-MCP-treated kiwifruit after 41 days in storage at 0 °C as more sour and firmer but less juicy, less sweet, and less flavorful than untreated fruit. After 161 days in storage, the perceived differences between 1-MCP-treated and untreated fruit had been reduced for sweetness and acidity, but the panel perceived 1-MCP-treated fruit as firmer and lagging behind in the ripening process. Altering the poststorage ripening rate, by placing 1-MCP-treated fruit at a higher temperature than untreated controls, allowed fruit to develop in such a way that a sensory panel was unable to distinguish between treatments. This result indicates that 1-MCP-treated fruit can be perceived by the consumer as similar to untreated fruit if adequately conditioned.