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- Effect of storage time at low temperature on the volatile compound composition of Sevillana and Maravilla raspberriesPublication . Morales, M. L.; Callejon, R. M.; Ubeda, C.; Guerreiro, Adriana; Gago, Custódia; Miguel, Maria Graça; Antunes, Maria DulceIn this study, the effect of storage time at low temperature on volatile compounds in two cultivars of raspberry, Rubus idaeus L. cv. Sevillana and Maravilla, was determined. A total of 28 compounds were identified in both cultivars and showed quantitative differences between the cultivars. The Sevillana cultivar was richer in volatile compounds than the Maravilla cultivar. beta-Ionone had the highest concentration in both cultivars. We observed opposing trends in the volatile compound composition for the cultivars during storage at low temperature, in which 'Sevillana' lost compounds and 'Maravilla' was enriched. Therefore, storage at low temperature causes important changes in the volatile compound profile of raspberry, particularly the Sevillana cultivar, with significant decreases in C-13-norisoprenoids and increases in terpenes. These changes are most likely responsible for the aromatic differences between the cultivars because of the presence of terpenes in 'Sevillana' and C-13-norisoprenoids in 'Maravilla'. (C) 2014 Elsevier B.V. All rights reserved.
- The effect of alginate-based edible coatings enriched with essential oils constituents on Arbutus unedo L. fresh fruit storagePublication . Guerreiro, Adriana; Gago, Custódia; Faleiro, Leonor; Miguel, Maria Graça; Antunes, Maria DulceThe effect of coating Arbutus unedo fresh fruit with alginate-based edible coatings enriched with the essential oils compounds (EOC) eugenol (Eug) and citral (Cit) was studied. The minimum inhibitory concentrations (MIC) against the main postharvest pathogens were determined for Eug and Cit giving values of 0.10 and 0.15 (w/v), respectively. Twelve formulations of edible coatings were used: sodium alginate (AL) was tested at 1 and 2% (w/v) with incorporation of Eug and Cit at MIC and double MIC or their combination at MIC. Arbutus berries were dipped in those solutions for 2 min, and then stored at 0.5 degrees C. Control consisted of uncoated fruit. On days 0, 14 and 28, samples were taken to perform physicochemical and biochemical analysis [color CIE (L*, h degrees), firmness, soluble solids content (SSC), weight Loss, trolox equivalent antioxidant capacity (TEAC), microbial growth and taste panels]. Results showed that edible coatings of 1% AL were the best to maintain most quality attributes of the commodity through storage at 0.5 degrees C. The incorporation of Cit and Eug into the alginate edible coatings improved the coatings in most cases, AL 1% + Eug 0.20% and AL 1% + Cit 0.15% + Eug 0.10% being those that better preserved sensory and nutritional attributes and reduced microbial spoilage. Thus, these coatings may be useful for improving postharvest quality and storage life of fresh arbutus fruit. (C) 2014 Elsevier B.V. All rights reserved.
- Antioxidant activities of eight Algerian plant extracts and two essential oilsPublication . Boulanouar, B.; Abdelaziz, G.; S, Azza; Gago, Custódia; Miguel, Maria GraçaTotal phenol, hydroxycinnamic acid derivatives, flavone/flavonol and flavanones/dihydroflavonol contents of hydro-alcoholic extracts, obtained by sonication, from the aerial parts of Artemisia campestris L., Anthemis arvensis L., Haloxylon scoparium Pomel, Juniperus phoenicea L., Arbutus unedo L., Cytisus monspessulanus L., Thymus algeriensis Boiss et Reut, Zizyphus lotus L (Desf.) collected in Djebel Amour (Sahara Atlas, Algeria) were quantified by spectrophotometric methods. The chemical composition of the essential oils obtained by hydrodistillation from Artemisia campestris L. and Juniperus phoenicea I aerial parts were also evaluated by gas chromatography (GC) and gas chromatography coupled to mass spectrometry (GC-MS). The antioxidant activity of the extracts and essential oils was assessed measuring the capacity for preventing lipid peroxidation using two lipidic substrates (egg yolk and liposomes), the capacity for scavenging DPPH, ABTS, superoxide anion radicals, hydroxyl radicals and peroxyl radicals. Anti-inflammatory activity was assessed by measuring the capacity for inhibiting lipoxygenase. Reducing power and chelating capacity were also assayed. The results showed different amounts of total phenols depending on the method used: A. campestris extract had the highest levels of total phenols when the measurement was made at lambda = 280 nm, whereas H. scoparium and A. unedo extracts showed the highest levels of total phenols with Folin-Ciocalteau. C. monspessulanus had the highest levels of flavones/flavonols and flavanones/dihydroflavonols. The essential oils of A. campestris and J. phoenicea were mainly constituted by alpha-pinene, beta-pinene and sabinene; and a-pinene, respectively. The methods used for assaying the capacity for preventing lipid peroxidation revealed to be inadequate for extracts due to the great interferences detected. The essential oils were more active than the generality of extracts for scavenging peroxyl radicals and for inhibiting lipoxygenase, whereas A. unedo extract was the most active for scavenging ABTS, DPPH, superoxide anion radicals and it also had the best reducing capacity. In a general way, the great majority of the antioxidant activities correlated well with the phenol content although such correlation was not so clear with the flavonoid content. (c) 2013 Elsevier B.V. All rights reserved.
- Combined effect of temperature and controlled atmosphere on storage and shelf-life of 'Rocha' pear treated with 1-methylcyclopropenePublication . Gago, Custódia; Miguel, Maria Graça; Cavaco, A. M.; Almeida, Domingos P. F.; Antunes, Maria DulceThe combination of temperature and atmosphere composition for storage of Pyrus communis L. Rocha' treated with 1-methylcyclopropene was investigated. Fruits treated with 312nll(-1) 1-methylcyclopropene were stored at 0? and 2.5? in air and controlled atmosphere (CA) (3.04kPa O-2+ 0.91kPa CO2). Fruits were removed from storage after 14, 26 and 35 weeks, transferred to shelf-life at approximately 22? and assessed for ripening and quality, symptoms of superficial scald and internal browning and the accumulation of biochemical compounds related to scald after 0, 1 and 2 weeks. Superficial scald occurred only in fruits stored for 35 weeks in air at 2.5?. Levels of conjugated trienols and -farnesene increased during the first 26 weeks in storage, remaining constant thereafter. During shelf-life, conjugated trienols were higher in fruits stored in air at 2.5?. Internal browning developed in shelf-life after 26 weeks at 2.5?. Pears in air at 2.5? were not able to stand a 2-week shelf-life after 35 weeks of storage, while fruits stored at 0? under CA ripened slowly after the same storage period. The retention of firmness during shelf-life of 1-methylcyclopropene-treated Rocha' pear can be overcome by elevating the storage temperature from 0? to 2.5?, but CA is a required complement to avoid excessive softening after long-term storage. The ratio carotenoid/chlorophyll increased during storage and shelf-life, as plastids senesced. CA reduced the rate of chlorophyll loss during the first 14 weeks in storage, but its effect was reduced afterwards. Rocha' pear treated with 1-methylcyclopropene had a similar post-harvest behaviour during long-term storage at 0? in air or at 2.5? under CA.
- The effect of temperature and film covers on the storage ability of Arbutus unedo L. fresh fruitPublication . Guerreiro, Adriana; Gago, Custódia; Miguel, Maria Graça; Antunes, Maria DulceThe strawberry tree (Arbutus unedo L) fruits are used in small quantities for fresh consumption despite their excellent flavor. The aim of this work was to evaluate the storage ability of strawberry tree fruits for fresh consumption. Harvested fruits were stored in polystyrene foam trays covered with two film types: linear low density polyethylene of 10 mu m thickness (PPL) or polyethylene film perforated with holes of 10 mm diameter spaced 50 mm (PP). Through 15 days storage at 0,3 and 6 degrees C, fruits were analyzed for quality parameters. The strawberry tree fruits presented relevant qualitative properties and were appreciated by panelists. Color parameters (L*, h degrees, C*) had higher decrease at 3 and 6 degrees C than at 0 degrees C. The degrees Brix almost did not change and firmness decreased mainly in the first 4 days storage. Ethanol and weight loss increased with temperature mostly from 3 to 6 degrees C. Strawberry tree fruits are a good source of ascorbic acid, glucose, fructose, anthocyanins and antioxidant activity. Those properties are maintained through 15 days storage at 0 degrees C followed by 3 degrees C. Film covers showed no significant differences between them. The temperature of 0 degrees C was the best for preservation of fruit quality through 15 days shelf-life. (C) 2013 Elsevier B.V. All rights reserved.
- Edible coatings enriched with essential oils and their compounds for fresh and fresh-cut fruitPublication . Gago, Custódia; Cavaco, A. M.; Miguel, Maria Graça; Antunes, Maria DulceFresh fruit and vegetables consumption has increased in the past few years due to the enhanced awareness of consumers for healthy food. However, these products are highly perishable, and losses can be of great significance if postharvest correct management is not provided. Fresh-cut products are of increasing importance, since they are presented to the consumer in a state that allows for direct and immediate consumption. However, those products are even more perishable since cutting can induce a series of senescence associated responses to wounding, and are more susceptible to microbial spoilage. Edible coatings, which intend to reduce ripening processes and protect the fruit from water loss and spoilage may be a good way to enhance the shelf life of these products. More recently, the inclusion of additives into these edible coatings to increase their effectiveness, such as essential oils and their constituents with antimicrobial and antioxidant activities, has been reported and patented. © 2012 Bentham Science Publishers.
- Refrigeration needs for sustainable preservation of horticultural productsPublication . Sousa, A. R.; Alves Julião, Miriam; Miguel, Maria Graça; Antunes, Maria Dulce; Panagopoulos, Thomas; Gago, CustódiaFresh horticultural products are highly perishable and need refrigeration for further preservation. Refrigeration needs energy consumption with consequent economical cost and damage for the environment. The objective of the present work was to use efficiently the refrigeration according to the product needs and time for consumption. Salicornia ramosissima and Sarcocornia perennis fresh branch tips, which are used for fresh salads, were stored at 1, 4 and 9 °C for up to 21 days. In both species, fresh tips were of good consumer acceptability for up to 14 days at 9°C. At 1 and 4 °C fresh tips could be stored in good conditions up to 21 days. For efficient use of energy in refrigeration of fresh salicornia and sarcocornia we conclude that if it is to put those products in the market earlier we can use the higher temperature for storage saving energy. Only for further storage we shall use the lower temperatures.
- Ammoides pusilla (Apiaceae) and Thymus munbyanus (Lamiaceae) from Algeria essential oils: chemical composition, antimicrobial, antioxidant and antiproliferative activitiesPublication . Tefiani, C.; Riazi, A.; Youcefi, F.; S, Azza; Gago, Custódia; Faleiro, Leonor; Pedro, L. G.; Barroso, J. G; Figueiredo, A. C.; Megias, C.; Cortes Giraldo, I.; Vioque, J.; Miguel, Maria GraçaThe chemical composition, and antioxidant, antimicrobial and anti-proliferative activities of the essential oils of Ammoides pusilla (Apiaceae) and Thymus munbyanus (Lamiaceae), collected in Algeria, were studied. Cumin alcohol (44%), p-cymene (18%), limonene (14%), thymol (11%) and gamma-terpinene (7%) predominated in A.pusilla essential oil, whereas carvacrol (71%) was dominant in T.munbyanus essential oil. The antibacterial activity of A.pusilla and T.munbyanus essential oils was studied by the agar diffusion method against Escherichia coli, Salmonella enterica serovar Thyphimurium, methicillin-resistant Staphylococcus aureus and Listeria monocytogenes. The tested bacteria were more susceptible to T.munbyanus essential oil. Ammoides pusilla essential oil was the most effective for scavenging the free radicals. Ammoides pusilla essential oil also had the best reducing power as well as the highest lipid peroxidation inhibition. Thymus munbyanus essential oil showed the best anti-proliferative activity of human acute monocytic leukemia cell line (THP-1).