Browsing by Author "Salazar, Miguel"
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- Código de boas práticas de higiene no processamento de citrinos para comercialização em frescoPublication . Duarte, Amílcar; Marques, Carla; Nunes, Carla; Lopes, Luís; Salazar, MiguelA citricultura constitui um dos mais importantes sectores da fruticultura nacional, sendo o mais importante no Algarve, onde gera um valor superior a 30% do Produto Agrícola Bruto e é responsável por mais de 4.000 postos de trabalho. Quanto às outras regiões do país, observa-se um aumento de investimento neste sector no Alentejo.A implementação da Protecção Integrada e, mais recentemente, da Produção Integrada têm contribuído para a adopção de tecnologias de produção mais seguras e com menor impacte ambiental, as quais correspondem às novas exigências dos consumidores.
- Effect of electrolyzed water as a disinfectant for fresh-cut fruitPublication . Graça, Ana; Salazar, Miguel; Quintas, Célia; Manso, Teresa; Nunes, Carla; Nunes, CarlaIn fresh-cut processing the disinfection is the most important step. This process can affect the quality and the safety of the end product as well as its shelf life. Chlorine is the most used disinfectant in fresh-cut industry but due to its association with environmental and health risks, the development of alternative sanitizers is emergent. Electrolyzed water (EW) may be an alternative to the use of chlorine sanitizers and both acidic electrolyzed water (AEW) and neutral electrolyzed water (NEW) can be used with this purpose. In fact, several studies have shown that EW can be effective in reducing pathogenic bacteria on the surface of fruits and vegetables. This manuscript presents a review of electrolyzed water approaches, its antimicrobial activity in fresh-cut produce and the results of a study undertaken in our laboratory to evaluate the disinfection efficacy of AEW and NEW on fresh-cut apples and oranges. Fresh-cut apples and fresh cut oranges were inoculated with a suspension of Listeria innocua and fresh-cut oranges with Escherichia coli at a concentration of 107 cfu mL-1 and treated with the different solutions. Untreated freshcut fruits were used as control. The best sanitizing treatment for both pathogens and fruits was AEW at 200 ppm of free chlorine applied during 5 minutes.
- Efficacy of electrolyzed water to inactivate foodborne pathogens on fresh-cut applesPublication . Graça, Ana; Nunes, C.; Quintas, Célia; Abadias, Maribel; Usall, J.; Salazar, MiguelChlorine is the most common disinfectant used in the fresh-cut industry but nowadays environmental and health risks have led to the need to find new sanitizers. Electrolyzed water (EW) appears to be a promising alternative. In this work, disinfection efficacy of acidic (AEW) and neutral (NEW) electrolyzed water in fresh-cut apple slices inoculated with Escherichia coli, Listeria innocua or Salmonella choleraesuis was studied. Apple slices were inoculated with a 10(7) cfu/ml suspension of pathogens and treated with the sanitizer EW solutions, with 100 or 50 ppm of free chlorine solutions and with distilled water. Population reduction was determined 30 min after washings and untreated apple slices were used as control in all assays. AEW100 was the treatment with more effective bactericidal activity followed by NEW100 and AEW50. EW had higher or similar efficacy than chlorine treatments in all tested conditions.
- Influence of cultivation salinity in the nutritional composition, antioxidant capacity and microbial quality of Salicornia ramosissima commercially produced in soilless systemsPublication . Lima, Alexandre R.; Castaneda-Loaiza, Viana; Salazar, Miguel; Nunes, Carla; Quintas, Celia; Gama, Florinda; Pestana, Maribela; Correia, Pedro J.; Santos, Tamara; Varela, João; Barreira, Luísathe consumption of halophytes as healthy gourmet food has increased considerably in the past few years. However, knowledge on the nutritional profile of domesticated halophytes is scarce and little is known on which cultivation conditions can produce plants with the best nutritional and functional properties. In this context, Salicornia ramosissima J. Woods was cultivated in six different salt concentrations, ranging from 35 to 465 mM of NaCl. Both the nutritional profile, the antioxidant capacity, and microbial quality of the produced plants were evaluated including minerals and vitamins. Salt has a marked effect on growth, which decreases for salinities higher than 110 mM. Nonetheless, plants cultivated with intermediate levels of salinity (110 and 200 mM) revealed better antioxidant status with higher amounts of phenolic compounds. Overall, results from this paper indicated that soilless culture systems using low-intermediate salinities produces S. ramosissima plants fit for commercialization and human consumption.
- Influencia del modo de producción en la sensibilidad poscosecha de cítricos a PenicilliumPublication . Nunes, C.; García, J. M.; Cayuela, J. A.; Manso, T.; Yousfi, K.; Salazar, Miguel; Duarte, AmílcarUtilizando naranjas (citrus sinensil L. cv. "Valencia") de cuatro diferentes procedencias de España (Lepe y Rio Tinto en Huelva) y Portugal (Tavira y Silves) y tres diferentes modos de producción (convencional, integrada y ecológico) se ha estudiado si ambos factores (procedencia y sistema de producción) afectaban sobre grado de sensibilidad a Penicillium digitatun y P. italicum de estos frutos, evaluando la incidencia de podrido que presentaban los mismos tras una conservación de 7 días a 24 º c, después de ser inoculdos con los citados hongos.
- Low dose UV-C illumination as an eco-innovative disinfection system on minimally processed applesPublication . Graça, Ana; Salazar, Miguel; Quintas, Célia; Nunes, C.In this study, the efficacy of UV-C illumination for inactivate Escherichia coli, Listeria innocua or Salmonella enterica, individually or in a mixture, in vitro and on apple slices was determined. Apple slices inoculated with a 10(7) cfu/mL suspension of above indicated pathogens were irradiated on both sides with UV-C illumination, with doses of 0.5 and 1.0 kJ/m(2). UV-C illumination disinfection efficacy was compared to that of washings with sodium hypochlorite at 100 ppm of free chlorine and with distilled water. Bactericidal activity of each treatment was assessed after 30 min and after 7 and 15 days of storage at 4 degrees C. Results showed that UV-C illumination at 1.0 kJ/m(2) could be an alternative to the wash with hypochlorite solutions. On the in vitro study, these doses completely inhibited the growth of the three bacteria either as pure cultures or in a mixture. In fresh-cut apple, the pathogens were also affected by the UV-C illumination, the 1.0 kJ/m(2) dosage being the one that resulted in higher bacteria inhibition in almost every case. The UV-C treatment did not affect the quality properties of fresh-cut apple. 2013 Elsevier B.V. All rights reserved.
- Métodos eco-inovadores de desinfecção para fruta cortada de modo de produção biológicoPublication . Duarte, Amílcar; Graça, Ana; Salazar, Miguel; Nunes, CarlaO cloro é o desinfectante de uso habitual a indústria de fruta cortada mas apresenta problemas de eficácia, de saúde e ambientais, pelo que há uma tendência para ser eliminado do processo de desinfecção, não apenas para os alimentos de modo de produção biológico (MPB) mas também de alimentos convencionais. Neste trabalho foi testada em pêra 'Rocha'cortada a actividade biocida de três sistemas eco-inovadores de desinfecção (iluminação UV-C, água electrolisada e água ozonizada). Cubos de pêra foram inoculadas com uma suspensão de Escherichia coli, Listeria innocua ou Salmonella choleraesuis e tratados com os sistemas eco-inovadores. Para cada um testaram-se diferentes doses ou tempos de exposição (UV-C: 0-10 kJ.m-2 ; água electrolisada: 10-200 ppm cloro livre, 5 min; e água ozonizada: 0,4 ppm, 1-5 min). Como testemunha utilizou-se o tratamento com hipoclorito de sódio a 100 ppm. Os resultados demonstram que o sistema mais eficaz foi a iluminação UV-C, seguido de água electrolisada e de água ozonizada. A iluminação UV-C e a água electrolisada apresentaram, de um modo geral, eficácia superior à do hipoclorito de sódio e o ozono, eficácia similar. Dos métodos testados, o mais promissor para uso em alimentos MPB e numa agricultura sustentável é a iluminação UV-C, pois, além de elevada eficácia, apresenta a vantagem de não utilizar água nem produzir resíduos nem subprodutos nos frutos nem no ambiente.
- Microbial and sensory evaluation of Halophytes cultivated in a soilless system under different salinitiesPublication . Quintas, Célia; Ribeiro Lima, Alexandre; Gama, Florinda; Nunes, Carla; Salazar, Miguel; Barreira, LuísaThe increasing interest in halophytes as sustainable crops and their potential functional properties highlights the need to understand how cultivation conditions affect their quality for human consumption. The present study aimed to evaluate the influence of salinity on the microbial quality of the halophytes Disphyma crassifolium, Inula crithmoides, Mesembryanthemum nodiflorum, and Suaeda maritima, cultivated using a soilless system under different salinities. The sensorial quality of D. crassifolium and S. maritima was also assessed by an experienced panel of culinary chefs. The microbial quality was measured by counting aerobic microorganisms (30 °C and 6.5 °C), fungi, Escherichia coli, and coagulase-positive staphylococci. Salinity increase caused a concentration-dependent salt accumulation in the plants, triggering a rise in the microbial populations, namely aerobic and filamentous fungi on D. crassifolium and I. crithmoides and psychrotrophic microorganisms on S. maritima (p < 0.05). Except for M. nodiflorum, plants cultivated at the highest salinity (465 mM) had levels of filamentous fungi higher than 3 Log CFU/g. Concerning aerobes, plants presented a satisfactory microbiological quality (<6 Log CFU/g) even when cultivated at high salinity (465 mM), and yeasts, E. coli, and staphylococci were never detected. D. crassifolium and S. maritima cultivated at intermediate salinities were preferred by the sensory evaluation panel. In conclusion, soilless system cultivation produces plants adequate for consumption, considering their microbial and sensorial quality.
- Nutritional and functional evaluation of inula crithmoides and mesembryanthemum nodiflorum grown in different salinities for human consumptionPublication . Ribeiro Lima, Alexandre; Gama, Florinda; Castañeda-Loaiza, Viana; Costa, Camila; Schueler, Lisa M.; Santos, Tamara; Salazar, Miguel; Nunes, Carla; Cruz, Rui M. S.; Varela, J.; Barreira, LuísaThe nutritional composition and productivity of halophytes is strongly related to the biotic/abiotic stress to which these extremophile salt tolerant plants are subjected during their cultivation cycle. In this study, two commercial halophyte species (Inula crithmoides and Mesembryanthemum nodiflorum) were cultivated at six levels of salinity using a soilless cultivation system. In this way, it was possible to understand the response mechanisms of these halophytes to salt stress. The relative productivity decreased from the salinities of 110 and 200 mmol L−1 upwards for I. crithmoides and M. nodiflorum, respectively. Nonetheless, the nutritional profile for human consumption remained balanced. In general, I. crithmoides vitamin (B1 and B6) contents were significantly higher than those of M. nodiflorum. For both species, β-carotene and lutein were induced by salinity, possibly as a response to oxidative stress. Phenolic compounds were more abundant in plants cultivated at lower salinities, while the antioxidant activity increased as a response to salt stress. Sensory characteristics were evaluated by a panel of culinary chefs showing a preference for plants grown at the salt concentration of 350 mmol L−1. In summary, salinity stress was effective in boosting important nutritional components in these species, and the soilless system promotes the sustainable and safe production of halophyte plants for human consumption.
- Rehabilitation of abandoned areas from a Mediterranean nature reserve by Salicornia crop: Influence of the salinity and shadingPublication . Santos, Erika S.; Salazar, Miguel; Mendes, Susana; Lopes, Marco; Pacheco, Joana; Marques, DomitiliaIn Reserva Natural de Castro Marim e Vila Real de Santo Antonio (SE of Portugal), most of the salt marshes and saltpans are abandoned contributing to their degradation and, consequently, alteration of some ecological conditions. Rehabilitation of these areas by a Salicornia crop can contribute to their economic and environmental improvement by stimulation of biogeochemical processes and biomass commercialization. However, the development of agro-techniques adjusted to species and variable environmental conditions from Mediterranean are needed in order to improve the Salicornia crop. This study aimed to evaluate: i) potential use of seedlings from greenhouse in the field cultivation; and ii) survival, growth and yield of Salicornia under shading and different salinity conditions of the soils and irrigation waters. Autochthonous Salicornia species (S. ramosissima and S. patula) were tested. Germination tests under controlled conditions and in situ mesocosm assays were carried out. Assays were realized with a low density of seedlings from natural conditions and greenhouse, and soils and waters from estuary both with different salinities. Intermediate and high salinities (25-45dS/m) affected only S. patula germination. In general, Salicornia growing in soils with low salinity had great fresh biomass accumulation independently of seedling source (from natural conditions and greenhouse) and/or growing season. The shading seems to improve the fresh biomass accumulation and yield. Under Mediterranean conditions, the transplantation of Salicornia from greenhouse to the field was a promising technique, independently of the salinity conditions. This study demonstrated that the abandoned and saline areas can be rehabilitated by a sustainable crop of Salicornia.