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- Effect of ultrasonication, thermosonication and UV-C irradiation on the quality of strawberries (fragaria anannassa) and red bell peppers (capsicum annuum L.)Publication . Santos Pedro, Dora M.; Alexandre, Elisabete M. C.; Fundo, Joana F.; Brandão, Teresa R. S.; Silva, Cristina L. M.
- Influence of ozone pre-treatment on the quality of frozen strawberries (Fragaria ananassa D.)Publication . Alexandre, Elisabete M. C.; Fundo, Joana F.; Santos Pedro, Dora M.; Brandão, Teresa R. S.; Silva, Cristina L. M.
- Influence of disinfectant technologies on red bell peppers safetyPublication . Alexandre, Elisabete M. C.; Fundo, Joana F.; Santos Pedro, Dora M.; Brandão, Teresa R. S.; Silva, Cristina L. M.The development of innovative technologies, promoting fruits and vegetables safety to reduce the risk of related food-borne diseases, is an actual concern. Several sanitizing agents for washing fruits and vegetables may be used to reduce the risk of microbial contamination. Traditional washing technologies utilize chlorine and hydrogen peroxide as sanitizing agents for fresh produce. More recently, ozone is being used as an innovative food processing technology that guarantees product safety, also increasing shelf life of fruits and vegetables. Its main advantage, when compared to traditional disinfectant technologies, relies on its potent antimicrobial action and non-toxic products decomposition. The objective of this work was to study the effectiveness of three sanitizing agents (sodium hypochlorite - used in a commercial available solution AMUKINA, hydrogen peroxide and ozone in aqueous solutions), on the reduction of Listeria innocua inoculated on red bell peppers. Results showed that ozone treatment allowed bacteria reductions identical to the ones attained with the traditional disinfectant solutions. On average, aqueous ozone allowed a decimal reduction of 2 cycles in Listeria innocua counts.
- Study of the effect of non-thermal treatments on the safety of some fruits and vegetablesPublication . Alexandre, Elisabete M. C.; Santos Pedro, Dora M.; Fundo, Joana F.; Brandão, Teresa R. S.; Silva, Cristina L. M.
- Influence of ozone pre-treatment on the quality of frozen strawberries (Fragaria ananassa D.)Publication . Alexandre, Elisabete M. C.; Fundo, Joana F.; Santos Pedro, Dora M.; Brandão, Teresa R. S.; Silva, Cristina L. M.
- Influence of ozone pre-treatment on the quality of frozen red bell peppers (Capsicum annuum L.)Publication . Alexandre, Elisabete M. C.; Fundo, Joana F.; Santos Pedro, Dora M.; Brandão, Teresa R. S.; Silva, Cristina L. M.
- Effect of ultrasonication, thermosonication and ultraviolet irradiation on the quality of strawberies (fragaria anannassa) and red bell peppers (capsicum annuum L.)Publication . Santos Pedro, Dora M.; Alexandre, Elisabete; Fundo, Joana F.; Brandão, Teresa R. S.; Silva, Cristina L.M.The objective of this work was to study the effect of ultrasonication, thermosonication and UV-C irradiation on the quality attributes of strawberries (Fragaria anannassa) and red bell peppers (Capsicum annuum, L.). Thermosonication studies were carried out at 50ºC and 65ºC. Control water treatments at the same temperatures were conducted. The analysed quality factors were colour and texture for both products, in addition to anthocyanins content in the case of strawberries. Results showed that UV-C constituted a harmless treatment, with little or no effect on color, texture or anthocyanins content. Ultrasonication caused small colour changes and no significant effects on texture of both products. Thermosonication at 65ºC resulted in undesirable changes of color, anthocyanins and texture of strawberries, and color of red bell peppers. When compared to water treated samples, thermosonicated ones showed higher texture retention. This effect was much more pronounced on red bell peppers.
- Effect of non-thermal methods on the safety of strawberries (Fragaria anannassa) and watercress (Nasturtium officinale)Publication . Alexandre, Elisabete M. C.; Santos Pedro, Dora M.; Fundo, Joana F.; Brandão, Teresa R. S.; Silva, Cristina L. M.Innovative non-thermal technologies have been studied as an attempt to substitute thermal methods on fruits and vegetables processing. The objective was to study the effect of methods, such as ultrasonication, and its combination with a milder heat treatment (thermosonication), and UV-C irradiation on safety of strawberries and watercress. Thermosonication studies were carried out at 50ºC, 55ºC, 65ºC and room temperature. Control water washings, at the same temperatures, were also performed. Safety was assessed in terms of total mesophyles and total coliforms, respectively on strawberries and watercress samples. For total mesophyles, results showed that thermosonication carried out at 65ºC and water washing at 50ºC were the most efficient treatments in microbial reduction. Results from UV-C treatments were not conclusive. For total coliforms, the most efficient processes were thermosonication and water-washing at 55 ºC. Results from UV-C treatments were identical to the ones obtained by ultrasonication and water washing at room temperature.