Sala Trepat F J
Tecnología de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza.
Microbiologia. 1995 Mar;11(1):23-32.
Food preservation by combined processes is based on the combination of two or more existing preservation methods with the objective of developing milder preservation procedures. Currently two combined processes (CP) deserve a special attention, the preservation of food by high pressures (HP) and the preservation of food with the combined use of heat and ultrasounds under pressure (Mano-Thermo-Sonication). In the preservation by HP, the food, at room temperature or at very mild temperature, is held during relatively long periods under very high pressures (100-1000 MPa) to inactivate its enzymes and/or microorganisms. This procedure has proved to be effective to inactivate vegetative cells but much less effective to inactivate most enzymes and bacterial spores. Several kinds of food preserved by this method have already been launched into the market. In Mano-Thermo-Sonication (MTS Process) microorganisms and enzymes are inactivated by a combined heat/ultrasounds treatment under pressure. By this method, the lethality of heat treatments at the same temperature is highly increased. Therefore, the intensity of heat treatments can be drastically reduced. Heat resistance of spores is reduced by a factor of 1/10 and that of enzymes and vegetative cells is reduced by a factor of 1/50 approximately. The applicability of this procedure is currently being investigated.
联合工艺进行食品保鲜是基于两种或更多现有保鲜方法的结合，目的是开发更温和的保鲜程序。目前，有两种联合工艺值得特别关注，即高压（HP）食品保鲜和压力下热与超声联合使用的食品保鲜（手动热超声处理）。在高压保鲜中，食品在室温或非常温和的温度下，在非常高的压力（100 - 1000兆帕）下保持相对较长时间，以灭活其酶和/或微生物。该程序已被证明对灭活营养细胞有效，但对灭活大多数酶和细菌孢子的效果要差得多。通过这种方法保鲜的几种食品已经投放市场。在手动热超声处理（MTS工艺）中，微生物和酶通过压力下的热/超声联合处理而失活。通过这种方法，相同温度下热处理的致死率大大提高。因此，热处理的强度可以大幅降低。孢子的耐热性降低约1/10，酶和营养细胞的耐热性降低约1/50。目前正在研究该程序的适用性。
