Pseudomonas graminis strain CPA-7 differentially modulates the oxidative response in fresh-cut ‘Golden delicious’ apple depending on the storage conditions

Evaluation of Pseudomonas graminis CPA-7 as a biopreservation method for fresh-cut pear: Physicochemical, enzymatic, and nutritional quality

“…In calcium-untreated fresh-cut pears, the presence of CPA-7 could reduce the PPO activity during the six-day storage period. However, Collazo et al (2018) reported that PPO activity of fresh-cut apples increased drastically in response to CPA-7 in MAP reaching almost eight-fold the activity showed by the non-inoculated control stored in the same conditions. Moreover, Plaza et al (2016) showed that after eight days of refrigerated storage at 5 C, fresh-cut melons inoculated with CPA-7 and packaged under MAP did not present significant changes with regard initial values.…”

“…The POD activity was significantly lower after storage in samples treated with P. graminis CPA-7 regardless of the calcium treatment. In the recent study carried out by Collazo et al (2018), POD activity was inhibited immediately Food Science and Technology International 25(4) after P. graminis CPA-7 inoculation in fresh-cut 'Golden delicious' apples. However, in that study after six days of storage time in MAP, POD activity increased in the P. graminis CPA-7 inoculated samples (2.6-folder higher) respect to control.…”

“…However, exogenous ascorbic acid is probably housed in a different location and is therefore more exposed to O 2 (Cocci et al, 2006), enzyme ascorbate oxidase or oxidizing enzymes such as POD (Martı´ns et al, 2016). Fresh-cut pears treated with antagonist P. graminis CPA-7 presented the lowest vitamin C content (0.12 AE 0.01 and 0.13 AE 0.01 g kg À1 ) after six days of storage at 5 AE 1 C. However, Collazo et al (2018) recently reported that vitamin C content remained constant along storage time (6 d, 5 C) and there were no differences between P. graminis CPA-7 inoculated and non-inoculated fresh-cut apples at any of the analysed sampling points (0, 1, 3 and 6 d). Moreover, in the study carried out by Plaza et al (2016), the application of P. graminis CPA-7 to fresh-cut melon had no effect on the vitamin C content.…”

Bioconservación frente a patógenos de transmisión alimentaria en frutas y hortalizas mínimamente procesadas

“…Sin embargo, la interacción con el antagonista en la matriz alimentaria durante el almacenamiento redujo significativamente la invasividad de ambos patógenos: en 1,3 unidades logarítmicas en el caso de Listeria monocytogenes y a niveles indetectables (< 5 ufc g -1 fruto) en el caso de Salmonella Enteritidis, sugiriendo la interferencia con la expresión de genes involucrados en los mecanismos de virulencia de estos patógenos como posible mecanismo de acción de CPA-7 (Collazo, Abadias, Colás-Medà et al, 2017). Otro posible modo de acción de CPA-7 puede ser la activación de la respuesta defensiva de la planta y la tolerancia al estrés oxidativo, ya que esta bacteria indujo la actividad de enzimas antioxidantes y retardó la reducción del contenido en compuestos antioxidantes en manzana mínimamente procesada a lo largo de seis días de almacenamiento a 5 °C, sin afectar negativamente a la calidad del fruto (Collazo et al, 2018).…”

Impact of Pseudomonas graminis strain CPA-7 on respiration and ethylene production in fresh-cut ‘Golden delicious’ apple according to the maturity stage and the preservation strategy

“…As a consequence of this process pseudomonads can delay ripening and senescence, promote growth, prime resistance mechanisms and alleviate deleterious ethylenemediated plant stresses (Eckert et al, 2014;Glick, 2005;Wang, Knill, Glick, & Défago, 2000). Belonging to this bacterial group is Pseudomonas graminis CPA-7, an apple epiphyte biopreservative strain which controls foodborne pathogens such as Listeria monocytogenes, Escherichia coli and Salmonella enterica on fresh-cut fruit (Alegre et al, 2013a(Alegre et al, , 2013bAbadias et al, 2014;Collazo et al, 2017) and modulate oxidative metabolism in fresh-cut apple (Collazo et al, 2018). In an attempt to clarify its mode of action we also investigated the possibility for CPA-7 to modulate the ethylene metabolism in fresh-cut apple thereby influencing the defense response and/or the senescence of this fruit.…”