Loading...
21 results
Search Results
Now showing 1 - 10 of 21
- Colour and texture evaluation of whole tomatoes (Lycopersicum esculentum L.) at different ripening stagesPublication . Pinheiro, Joaquina; Alegria, C.; Abreu, Marta; Gonçalves, Elsa M.; Silva, Cristina L. M.
- Quality changes of frozen broccoli stored at different temperaturesPublication . Gonçalves, Elsa M.; Pinheiro, Joaquina; Abreu, Marta; Brandão, Teresa R. S.; Silva, Cristina L. M.
- Effect of postharvest treatment (hot water and thermosonication) on tomatoes (Lycopersicum esculentum L.) physical-chemical and nutritional quality during storagePublication . Pinheiro, Joaquina; Alegria, C.; Abreu, Marta; Gonçalves, Elsa M.; Silva, Cristina L. M.
- Modelización del cambio de color y firmeza de tomates (Lycopersicum esculentum L.) a diferentes condiciones del almacenamientoPublication . Pinheiro, Joaquina; Alegria, C.; Abreu, Marta; Gonçalves, Elsa M.; Silva, Cristina L. M.The effect of temperature and storage time on tomatoes (Lycopersicum esculentum L.) colour (a* and ºh) and firmness (maximum force) were analysed at 2º, 5º, 10º, 15º and 20 ºC. The development of these quality attributes followed a fractional kinetic model. The regression coefficient (R2) for the generated models were high, 0.94 for both colour parameters (a* and ºh) and 0.84 for firmness. A significant (p<0.05) increase and decrease for a* and maximum force, respectively, were observed during storage. This study can contribute for the understanding of the real effect of temperature and storage time on two important quality attributes of tomatoes, such as colour and firmness.
- Influence of blanching treatments on colour, texture, chlorophylls content and sensory quality of broccoli (Brassica oleracea L.)Publication . Gonçalves, Elsa M.; Pinheiro, Joaquina; Abreu, Marta; Brandão, Teresa R. S.; Silva, Cristina L. M.
- Degradation kinetics of peroxidase enzyme, phenolic content, and physical and sensorial characteristics in broccoli (brassica oleracea L. ssp. Italica) during blanchingPublication . Gonçalves, Elsa M.; Pinheiro, Joaquina; Alegria, C.; Abreu, Marta; Brandão, Teresa R. S.; Silva, Cristina L.M.The effects of water blanching treatment on peroxidase inactivation, total phenolic content, color parameters [-a*/b* and hue (h *)], texture (maximum shear force), and sensory attributes (color and texture, evaluated by a trained panel) of broccoli (Brassica oleracea L. ssp. Italica) were studied at five temperatures (70, 75, 80, 85, and 90 C). Experimental results showed that all studied broccoli quality parameters suffered significative changes due to blanching treatments. The vegetal total phenolic content showed a marked decline. Degradation on objective color and texture measurements and alterations in sensorial attributes were detected. Correlations between sensory and instrumental measurements have been found. Under the conditions 70 C and 6.5 min or 90 C and 0.4 min, 90% of the initial peroxidase activity was reduced. At these conditions, no significant alterations were detected by panelists, and a small amount of phenolic content was lost (ca. 16 and 10%, respectively). The peroxidase inactivation and phenolic content degradation were found to follow first-order reaction models. The zero-order reaction model showed a good fit to the broccoli color (-a*/b* and h *), texture, and sensory parameters changes. The temperature effect was welldescribed by the Arrhenius law.
- Descontaminação em hortofrutícolas inteirosPublication . Pinheiro, Joaquina; Alegria, C.; Abreu, Marta; Gonçalves, Elsa M.; Moldão-Martins, Margarida; Silva, Cristina L. M.
- Modelling the kinetics of peroxidase inactivation, colour and texture changes of pumpkin (Cucurbita maxima L.) during blanchingPublication . Gonçalves, E. M.; Pinheiro, J.; Abreu, M.; Brandão, Teresa R. S.; Silva, Cristina L.M.The effects of blanching treatment on peroxidase inactivation, colour and texture of pumpkin (Cucurbita maxima L.) were studied in the temperature range of 75–95 C. Peroxidase inactivation followed a first-order Arrhenius model, where the activation energy and rate of the reaction at a reference temperature of 85 C were 86.20 ± 5.57 kJ mol 1 and 0.27 ± 0.01 min 1, respectively. During blanching, pumpkin became darker and softer with processing time. The degradation of colour (evaluated throughout CIE L*a*b* colour system, with chroma index and total colour difference) and texture parameters (firmness and energy) showed a fractional conversion model kinetics, being the temperature effect on kinetic parameters well described by the Arrhenius law. The results of this work are a good tool to further optimise pumpkin blanching conditions.
- Heat treatment evaluation on quality and safety of whole tomato (Lycopersicum Esculentum l.) fruitsPublication . Pinheiro, Joaquina; Alegria, Carla; Abreu, Marta; Fernandes, Isabel; Gonçalves, Elsa M.; Silva, Cristina L. M.
- Temperature effect on stored tomato (Lycopersicum esculentum L.) quality parametersPublication . Pinheiro, Joaquina; Alegria, C.; Abreu, Marta; Gonçalves, Elsa M.; Silva, Cristina L. M.
- «
- 1 (current)
- 2
- 3
- »