Espina Laura, Monfort Silvia, Alvarez Ignacio, García-Gonzalo Diego, Pagán Rafael
Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain.
Int J Food Microbiol. 2014 Oct 17;189:119-25. doi: 10.1016/j.ijfoodmicro.2014.08.002. Epub 2014 Aug 9.
The production of microbiologically safe liquid whole egg (LWE) by industrial ultrapasteurization is restricted by the high thermal sensitivity of LWE components. This research proposes an alternative treatment based on the application of pulsed electric fields (PEF) and mild heat, in the presence of natural essential oils (EOs) or their individual components (ICs). The obtained results indicate that the successive application of PEF (25kV/ and 100kJ/kg) followed by heat (60°C during 3.5') to LWE added with 200μL/L of lemon EO would reach 4log10cycles of inactivation of Salmonella Senftenberg 775W and Listeria monocytogenes, when any of these barriers acting alone inactivated less than 1.5log10cycles of either bacteria. Therefore, the synergism between lemon EO and the successive application of PEF and heat would provide a safety level similar to that of ultrapasteurization treatment for Salmonella Senftenberg 775W and L. monocytogenes, but at a lower temperature. To a lesser extent, synergism with the successive application of PEF and heat was also observed in the presence of 200μL/L of carvacrol, citral, (+)-limonene, or mandarin EO, reaching about 3.5log10cycles of inactivation in Salmonella Senftenberg and 3.0log10cycles in L. monocytogenes, respectively. A sensory test on LWE containing 200μL/L of each additive in the form of omelets and sponge cakes revealed that this concentration of mandarin EO, lemon EO, or (+)-limonene did not decrease the sensory acceptability of the LWE-containing products, and lemon EO and mandarin EO even increased the hedonic acceptability of sponge cakes. In conclusion, this process could be applied in the food industry to obtain microbiologically safe LWE, which could be used to produce egg-based products without decreasing (and even increasing) their sensory appeal.
工业超高温瞬时灭菌法生产微生物安全的全蛋液（LWE）受到LWE成分高热敏感性的限制。本研究提出了一种基于脉冲电场（PEF）和温和加热的替代处理方法，该方法在天然香精油（EOs）或其单个成分（ICs）存在的情况下进行。所得结果表明，向添加了200μL/L柠檬EO的LWE中依次施加PEF（25kV/和100kJ/kg），然后加热（60°C持续3.5分钟），可使肠炎沙门氏菌775W和单核细胞增生李斯特菌的灭活达到4个对数周期，而当这些屏障单独作用时，对任何一种细菌的灭活都不到1.5个对数周期。因此，柠檬EO与依次施加PEF和加热之间的协同作用可为肠炎沙门氏菌775W和单核细胞增生李斯特菌提供与超高温瞬时灭菌处理相似的安全水平，但温度较低。在200μL/L香芹酚、柠檬醛、（+）-柠檬烯或柑橘EO存在的情况下，也观察到了与依次施加PEF和加热的较小程度的协同作用，分别使肠炎沙门氏菌的灭活达到约3.5个对数周期，单核细胞增生李斯特菌的灭活达到3.0个对数周期。对含有200μL/L每种添加剂的煎蛋卷和海绵蛋糕形式的LWE进行的感官测试表明，这种浓度的柑橘EO、柠檬EO或（+）-柠檬烯不会降低含LWE产品的感官可接受性，柠檬EO和柑橘EO甚至提高了海绵蛋糕的享乐可接受性。总之，该工艺可应用于食品工业，以获得微生物安全的LWE，可用于生产蛋类产品而不降低（甚至提高）其感官吸引力。
