Baroresistant buffer mixtures for biochemical analyses

Baroprotection of vegetative bacteria by milk constituents: A study of Listeria innocua

“…Survival of L. innocua following treatment at 500 MPa for 5 min when suspended in 0.1 m Tris-HCl (pH 6.6), a pressure-stable buffer (Morild, 1981;Quinlan & Reinhart, 2005), was 5.2 log, compared with 3.4 log in PBS (pH 6.6), which is less pressure-stable (Morild, 1981;Quinlan & Reinhart, 2005). This suggests that maintaining a constant pH under pressure reduced inactivation of this bacterium.…”

Impact of dissociation equilibrium shift on bacterial spore inactivation by heat and pressure

“…During the first phase of such basic inactivation studies buffer systems to obtain constant pH-values and medium properties are in common use. However, the dissociation equilibrium in water and buffer solutions varies with pressure and temperature (Bruins, Matser, Janssen, & Boom, 2007;Distèche, 1959;Hamann, 1982;Kitamura & Itoh, 1987;Marshall & Franck, 1981;North, 1973;Quinlan & Reinhart, 2005). This change of the pK a -value plays a major role in different sensitive reactions, but its behaviour has rarely been investigated.…”

“…Distèche (1959) developed one of the first pH electrodes up to 150 MPa. At present only few optical measurement methods during pressure treatment up to 250 MPa (Hayert, Perrier-Cornet, & Gervais, 1999;Quinlan & Reinhart, 2005) and 450 MPa (Stippl, Delgado, & Becker, 2002, 2004 were developed. However, these experimental methods are limited and not suitable for the investigation of combined thermal and pressure dependencies.…”

Ultrahochdrucktechnik für innovative Behandlungsverfahren von Lebensmitteln

“…Momentan ist es noch nicht möglich die Verschiebung des Dissoziationsgleichgewichtes direkt in festen Lebensmitteln zu messen, aber es wurden bereits einige optische Messmethoden für in-situ Messungen des pH-Wertes während der Hochdruckbehandlung bis 250 MPa [52,53] und 450 MPa [54,55] [58,59]. Als Ursache werden prooxidative Effekte von Metall-Ionen (Fe, Cu) genannt, die den antioxidativen Effekt des Druckes überlagern [60,61].…”