Mesure de la résistance à la compression d'œufs d'esturgeons : application au caviar

Un dispositif de compression a été mis au point pour mesurer la résistance à la compression d'œufs d'esturgeons. Le capteur de force enregistre les efforts dans la gamme 0–500 mN, le capteur de déplacement enregistre les déformations de l'œuf au cours de l'essai. Un suivi par caméra est utile pour visualiser la déformation de l'œuf ainsi que l'endommagement de sa membrane externe. Le dispositif développé est suffisamment maniable et robuste pour être transporté sur les lieux de pêche ou en laboratoire. Ce dispositif permet de suivre l'évolution de la maturité de l'œuf ou les différentes phases de préparation du caviar de façon à maîtriser le processus de fabrication ou de conservation

Multi-pulsed high hydrostatic pressure treatment for inactivation and injury of Escherichia coli

Escherichia coli cells in peptone water were pressurized at 300 MPa at ambient temperature with no holding time (pulse series) and with a total holding duration of 300 s for single- (300 s × 1 pulse) and multi-pulsed (150 s × 2 pulses, 100 s × 3 pulses, 75 s × 4 pulses, 60 s × 5 pulses, 50 s × 6 pulses and 30 s × 10 pulses) high hydrostatic pressure (HHP) treatments. Multi-pulsed HHP treatment with no holding time indicated that as the pulse number increased the number of inactivated and injured cells also increased. Holding time had significant effect on the inactivation of E. coli. There was low inactivation difference between single- and multi-pulsed HHP treatments with holding time. Escherichia coli cells showed at least 1.6 log10 more reduction on selective medium than the non-selective medium indicating that more than 95 % of the survivors severely injured for both single- and multi-pulsed treatments with holding time. Although the inactivation difference was low between single- and multi-pulsed HHP treatments, storage at 4 °C revealed that there was less recovery from injury for multi-pulsed HHP treatment