Browsing by Author "Neves, Alcinda"
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- Anthocyanin concentration of "Assaria" pomegranate fruits during different cold storage conditionsPublication . Miguel, Maria Graça; Fontes, C.; Antunes, Maria Dulce; Neves, Alcinda; Martins, D.The concentration of anthocyanins in fruits of "Assaria" pomegranate, a sweet Portuguese cultivar typically grown in Algarve (south Portugal), was monitored during storage under different conditions. The fruits were exposed to cold storage (5 degrees C) after the following treatments: spraying with wax; spraying with 1.5% CaCl2; spraying with wax and 1.5% CaCl2; covering boxes with 25 mu c thickness low-density polyethylene film. Untreated fruits were used as a control. The anthocyanin levels were quantified by either comparison with an external standard of cyanidin 3-rutinoside (based on the peak area) or individual calculation from the peak areas based on standard curves of each anthocyanin type. The storage time as well as the fruit treatment prior to storage influenced total anthocyanin content. The highest levels were observed at the end of the first month of storage, except for the fruits treated with CaCl2, where the maximal values were achieved at the end of the second month. The anthocyanin quantification method influenced the final result. When total anthocyanin was calculated as a sum of individual pigments quantified based on standard curves of each anthocyanin type, lower values were obtained.
- Effects of post-harvest treatment and storage time on the organic acid content in Assaria and Mollar pomegranate (Punica granatum L.) fruitPublication . Miguel, Maria Graça; Fontes, C.; Martins, D.; Neves, Alcinda; Antunes, Maria DulceThe effects of postharvest treatment and storage at 5 degrees C on changes in the organic acid content in the juice of 'Assaria' and 'Mollar' pomegranate were monitored. The fruit was chill stored after the following treatments: covering boxes with a 25-mu thick low-density polyethylene film and spraying with 1.5% CaCl2; untreated fruit was used as the control. The results showed that citric acid is the main organic acid in the 'Mollar' cultivar, followed by tartaric acid, whereas three organic acids were present at similar levels in 'Assaria' pomegranate: citric, oxalic and tartaric acids. Differences in the main organic acid contents were detected when fruit was submitted to different treatments prior to cold storage. The different pretreatments did not significantly interfere with the accumulation of organic acids in either cultivar. There were two exceptions. The ascorbic acid content was significantly higher in the 'Mollar' cultivar when the fruit was treated with calcium, while the pyruvic acid content was significantly higher in the 'Assaria' cultivar in the untreated fruit.
- Genetic diversity assessment of the almond (Prunus dulcis (Mill.) DA Webb) traditional germplasm of Algarve, Portugal, using molecular markersPublication . Cabrita, L.; Apostolova, E.; Neves, Alcinda; Marreiros, A.; Leitão, JoséIn this study, 123 almond (Prunus dulcis (Mill.) D. A. Webb) trees identified among traditional orchards in the Algarve region and 53 trees of the local field collection managed by the regional office of the Portuguese Ministry of Agriculture (DRAALG) were assessed using isozyme, inter- single sequence repeat and simple sequence repeat or microsatellite techniques for the evaluation of genetic diversity and genetic relatedness and identification of new accessions for the field collection. The isozyme analysis allowed the distribution of the 176 plants into 13 different classes of enzyme similarity, while the use of DNA markers increased the distribution of the analysed trees among 140 discriminating DNA patterns. Multiple cases of homonymy and synonymy were identified in the local germplasm. Some traditional varieties, such as Lourencinha, appeared to be relatively homogeneous, while other local denominations, e.g. Galamba, included diverse genotypes. Of the 13 commercial varieties analysed in this study, 11 assembled in one major cluster clearly differentiated from the majority of the local genotypes. These results reinforced the perception that the Algarve traditional germplasm constitutes an important repository of genetic diversity, eventually carrying alleles of high agricultural interest such as the recently identified Phomopsis resistance in the traditional variety Barrinho Grado.
- Innovative postharvest techniques for sustainable handling of horticultural productsPublication . Antunes, Maria Dulce; Miguel, Maria Graça; Neves, AlcindaFresh fruits and vegetables are important components of human food. However, horticultural products are highly perishable and losses can be of great importance if postharvest correct measures are not provided. There is a worldwide trend to explore new alternatives to increase storage life, giving priority to methods that reduce horticultural product decay avoiding negative effects to human heath and environment. The objective of our research was to apply environmental and human health friendly techniques to preserve fresh fruit quality through storage. Figs, apricots, oranges, pomegranates and kiwifruits were treated with sodium bicarbonate, calcium chloride, acetic acid or subjected to modified atmosphere packaging to increase their storage life with minimal quality loss, as well as damage to human health and environment. The use of these treatments and techniques gave a great performance in the reduction of fruit losses, weight loss and fruit softening. Postharvest techniques such as modified atmosphere and calcium, sodium bicarbonate and acetic acid treatments, when applied in adequate concentrations, help to keep fruit quality through storage, without damaging the environment and human health. The benefit of each treatment depends on the type of fruit.
- Sustainable postharvest handling of horticultural productsPublication . Antunes, Maria Dulce; Miguel, Maria Graça; Neves, AlcindaSustainable commercial horticultural success depends on satisfying consumer requirements. Fresh fruits and vegetables are important components of human food. However, horticultural products are highly perishable and losses can be of great importance if postharvest correct measures are not provided. Quality of fresh horticultural products can not be improved by postharvest technologies, only can be maintained, what means horticultural products must be of high quality at harvest. There is a worldwide trend to explore new alternatives to increase storage life, giving priority to methods that reduce horticultural product decay avoiding negative effects to human health and environment. The objective of our research was to apply environmental and human health friendly techniques to preserve fresh fruit quality through storage. Figs, apricots, oranges, pomegranates and kiwifruits were treated with sodium bicarbonate, calcium chloride, acetic acid or subjected to modified atmosphere packaging to increase their storage life with minimal quality loss, as well as damage to human health and environment. The use of these treatments and techniques gave a great performance in the reduction of fruit losses, weight loss and fruit softening. Postharvest techniques such as modified atmosphere and calcium, sodium bicarbonate and acetic acid treatments, when applied in adequate concentrations, help to keep fruit quality through storage, without damaging the environment and human health. The benefit of each treatment depends on the type of fruit.
- Tetragonia tetragonioides - a potential salt removing species. Response to the combined effects of salts and calciumPublication . Neves, Alcinda; Miguel, Maria Graça; Marques, C.; Panagopoulos, ThomasThe best way to control the salination process and to maintain the sustainability of landscape is the use of environmentally safe and clean techniques. One of these new techniques is the use of salt removing species. In order to study the potential capacity to remove soil salts, several wild halophytic species were being studied. Two experiments with Tetragonia tetragonioides were carried out involving 1) the effects of salts, 2) and the combined effects of salts and calcium. It is shown that T. tetragonioides, besides its high salt removal potential, has other interests, as follows: 1) high biomass production potential; 2) several harvests during the year (summer and winter); 3) high content of minerals; 4) horticultural importance, as a leaf vegetable crop; 6) easy multiplication (seed propagation) and easy crop management; 7) tolerance to drought and hot conditions; 8) soil erosion control due to its excellent soil covering. The obtained results suggest that plants supplemented with the high calcium level had longer internodes than plants in the low calcium level, at high salinity levels.
- The combined effects of salts and calcium on growth and mineral accumulation of Tetragonia tetragonioides - A salt removing speciesPublication . Neves, Alcinda; Miguel, Maria Graça; Marques, C.; Panagopoulos, Thomas; Beltrão, JoséHigh soil salinity levels have drastic effects on the growth and yield of horticultural crops. Salination may be controlled by environmentally safe and clean techniques as the use of salt removing species. Tetragonia tetragonioides, a wild halophytic species has been studied for this purpose. It was studied the effect of high salt concentrations on growth and mineral composition and the influence of high calcium concentration on plant response. Plants were grown in 5 litters in randomized pots and were daily irrigated. The NaCl concentration of the irrigation solution ranged from 0 up to 200 mM. Additionally, the irrigation solution provided plants with two calcium concentrations: 2 and 10 mM of CaCl2. T. tetragonioides present high ability for sodium and chloride leaf accumulation. Besides that, the species provide more advantages: 1) high biomass production potential; 2) several harvests during the year (summer and winter); 3) high content of minerals; 4) horticultural importance, as a leaf vegetable crop; 6) easy multiplication (seed propagation) and easy crop management; 7) tolerance to drought and warm conditions; 8) soil erosion control due to its excellent soil covering. The obtained results suggest that plants supplemented with the high calcium level had longer stems than plants in the low calcium level, accumulated greater amounts of calcium at high salinity levels and present similar leaves dry matter.
- The effect of two methods of pomegranate (Punica granatum L) juice extraction on quality during storage at 4 degrees CPublication . Miguel, Maria Graça; Dandlen, S. A.; Antunes, Maria Dulce; Neves, Alcinda; Martins, D.The effect of two extraction methods of pomegranate juice on its quality and stability was evaluated. The first method consisted of separation of the seeds from fruits and centrifugation. The second method consisted of squeezing fruit halves with an electric lemon squeezer. During a period of 72 hours of cold storage at 4 degrees C, the juices were evaluated for the presence of sugars, organic acids, and anthocyanins. Delphinidin 3-glucoside was identified to be the major anthocyanin present at the level of 45-69 mg/L. Among the organic acids, oxalic and tartaric acids dominated. The major sugars detected in pomegranate juice were glucose and sucrose. No significant differences in the content of sugars, organic acids, or anthocyanins in juices obtained through application of the two different extraction methods were detected, with the exception of the drastic decrease of cyanidin 3,5-diglucoside level in juice obtained by seed centrifugation. The pH did not show differences between treatments. Titrable acidity and the level of sugars expressed as degrees Brix decreased after 32 and 15 hours after extraction, respectively, when juice was obtained by centrifuging the seeds.
- The effects of the use of organic solid wastes on the growth of citrus treesPublication . Costa, M.; Beltrão, José; De Brito, J. C.; Neves, Alcinda; Correia, Maribela Pestana; Guerrero, CarlosTwo types of organic solid wastes were selected to be applied in a citrus orchard: the sewage sludge (the most common on the settlements) and the manure (the most common on the agricultural fields). The sewage sludge is a residue originated from the wastewater treatment - the solid phase. Its application as an organic fertilizer may represent an alternative to the pollution effects in nature. In an orchard of orange-trees (Citrus sinensis [L.] Osbeck), the application of sludge was compared with the application of manure and with the control in order to observe the growth response of the trees. Biometric methods where used - number of leaves per tree, diameter of the trunk, leaf area, specific leaf areas and leaf chlorophyll content. In general, the citrus plants response to the application of sewage sludge and manure was positive for the plant growth, compared to the control. The application of the manure, and especially the sewage sludge (once this fertilizer / soil amendment is available in larger amounts) may be a profitable alternative application to the use of mineral fertilizers and to other soil amendments. Moreover, as the possible destinations of sewage sludge (sea, deposition in land fields, incineration) provoke environmental problems, its agricultural reuse is essential to avoid those problems, when correctly applied in relation to trace elements and to pathogenic parameters. The reuse of this solid waste may be a clean and a safe technique to preserve the environment contamination.
- Variability of olive oil cultivar on stability during storagePublication . Neves, Alcinda; Miguel, Maria Graça; Pedro, L. G.; Barroso, J. G.; Figueiredo, A. C.; Martins, D. S.; Dandlen, S. A.The fatty acid composition and stability of three Portuguese monovarietal olive oils, Cobrancosa, Macanilha and Verdeal, was studied, maintaining the olive oils at 60 degrees C for 75 and 102 days, respectively. Oleic acid was the main fatty acid (64-69%) in three olive oils cultivars, followed by palmitic acid (15-18%). The highest percentages of palmitic acid were observed in Macanilha olive oil (17-18%). Linolenic acid content was 3%, on average. Storing the oils at 60 degrees C over 75 days did not affect the levels of fatty acids. Cobrancosa and Macanilha olive oils were more resistant to hydroperoxide formation than Verdeal olive oil, whereas this oil and that of Macanilha were more resistant to the degradation of those peroxides. Cobrancosa olive oil possessed higher levels of phenols and higher ability for scavenging free radicals than the remaining oils. a-Tocopherol content was higher in Cobrancosa and Macanilha oils than in Verdeal, but a similar high degradation of this vitamin was observed in all oils, disappearing after 5 to 8 days of storage at 60 degrees C.