PDF(Pubmed)
Abstract：
Eggs are a valuable source of nutrients, but they represent a food safety risk due to the presence of microbes. In this work, three types of egg liquids (albumen, yolk and whole egg) previously contaminated with E. coli were treated with ultrasound (US) and a combination of ultrasound and low (55 °C) temperature (US+H). The US treatment parameters were 20 and 40 kHz and 180 and 300 W power and a 30, 45 or 60 min treatment time. The ultrasonic treatment alone resulted in a reduction in the microbial count of less than 1 log CFU, while the US+H treatment resulted in a reduction in CFU counts to below detectable levels in all three egg liquids. Heat treatment and ultrasound treatment had a synergistic effect on E. coli reduction. For all measurements, except for the whole egg samples treated with US, the 20 kHz treated samples showed a significantly (>90% probability level) lower bactericidal effect than the 40 kHz treated samples. PCA and aquaphotometric analysis of NIR spectra showed significant differences between the heat-treated groups\' (H and US+H) and the non-heat-treated groups\' (US and control) NIR spectra. LDA results show that heat-treated groups are distinguishable from non-heat-treated groups (for albumen 91% and for egg yolk and whole egg 100%).
摘要：
鸡蛋是营养的宝贵来源，但是由于微生物的存在，它们代表了食品安全风险。在这项工作中,三种类型的蛋液(蛋白，用超声波（US）以及超声波和低温（55°C）（USH）的组合处理先前被大肠杆菌污染的蛋黄和全蛋）。US处理参数为20和40kHz以及180和300W功率和30、45或60min处理时间。单独的超声处理导致微生物计数减少少于1logCFU，而US+H处理导致CFU计数减少到低于所有三种蛋液的可检测水平。热处理和超声处理对大肠杆菌的还原具有协同作用。对于所有测量，除了用美国处理的整个鸡蛋样本，20kHz处理的样品显示出比40kHz处理的样品显著(>90%概率水平)更低的杀菌效果。近红外光谱的PCA和水光度分析显示，热处理组（H和USH）和非热处理组（US和对照）近红外光谱之间存在显着差异。LDA结果显示热处理组与非热处理组(对于蛋白91%,对于蛋黄和全蛋100%)是可区分的。
