Protective effect of milk constituents and sublethal injuries limiting process effectiveness during PEF inactivation of Lb. rhamnosus

Impact of PEF treatment on quality parameters of white asparagus (Asparagus officinalis L.)

“…Reversible permeabilization is a useful tool to induce stress reactions on plant systems and stimulate the generation of secondary cell metabolites (Guderjan, Toepfl, Angersbach, & Knorr, 2005;Ye, Huang, Chen, & Zhong, 2004). Irreversible PEF treatment can be applied to inactivate microorganisms (Barbosa-Cánovas, Góngora-Nieto, Pothakamury, & Swanson, 1999;Heinz, Toepfl, & Knorr, 2003;Jaeger, Schulz, Karapetkov, & Knorr, 2009) or to facilitate mass transfer and improve the diffusion of intra and extra cellular liquids. Increased extractions efficiency of juice and cell compounds from food plants could be shown by several researchers (Eshtiaghi & Knorr, 2000;Schilling et al, 2008;Yin, Han, & Han, 2006).…”

Upscaling from benchtop processing to industrial scale production: More factors to be considered for pulsed electric field food processing

“…Another reason may be due to the tendency of microbial cells to form clusters in food components, such as pectin and fiber in liquid food that protects cells. Jaeger et al (2009aJaeger et al ( ,2009b reported that milk protein provides a protective effect and reduces the PEF processing effectiveness against Lb. rhamnosus in raw milk.…”

“…The main cause of the observed increase in microbial inactivation may be more uniformity of PEF treatments at higher flow rate. The use of a higher flow velocity in a given chamber (i.e., higher Re number), leads to a greater degree of mixing of the microbial suspension, producing a more homogeneous temperature distribution in the treatment chamber, thus providing a more uniform treatment and increasing PEF inactivation (Cook, 1973(Cook, , 1978Donsì et al, 2007;Elez-Martínez et al, 2006b;Jaeger et al, 2009aJaeger et al, ,2009bMañas et al, 2001;Matsumoto et al, 1991;Qin et al, 1995;Zhang et al, 1994).…”

Food Safety: Shelf Life Extension Technologies

“…On the other hand, sublethally injured fractions have a potential for subsequent complete inactivation by the application of additional hurdles, such as suboptimal storage conditions or the application of other inactivation methods, such as the application of antimicrobials or other food preservation technologies (Garcia et al, 2005;Jaeger et al, 2009b;Somolinos et al, 2008). Membrane damage and sublethal injury was found to be repairable under certain conditions and the extent to which cells repair their injuries was reported to depend on the treatment intensity, the microorganism, and the treatment medium pH.…”

“…This was partly attributed to the protective effect of some food compounds, such as xanthan (Ho et al, 1995), proteins (Jaeger et al, 2009b;Sampedro et al, 2006), or fat (Grahl and Märkl, 1996). This was partly attributed to the protective effect of some food compounds, such as xanthan (Ho et al, 1995), proteins (Jaeger et al, 2009b;Sampedro et al, 2006), or fat (Grahl and Märkl, 1996).…”