Pulsed UV light as a postprocessing intervention for decontamination of hard-cooked peeled eggs

作者：Macias Rodriguez Braulio; Yang Wade^*; Schneider Keith; Rock Cheryl

来源：International Journal of Food Science and Technology, 2014, 49(11): 2472-2480.

DOI：10.1111/ijfs.12571

• Colour
• Escherichia coli K12
• hard-cooked eggs
• photophysical
• pulsed light
• scanning electron microscopy
• texture

The efficiency of pulsed UV light (PL) for inactivation of E.coli K12 on hard-cooked eggs was investigated. Temperature, colour and texture were recorded to determine adverse effects on quality. Distance from the quartz window (5.5, 9.5cm) and time (1-30s) was set as the experimental variables. Results indicated that E.coli K12 viability decreased at closer distances and increased time (P<0.05). Bacterial populations were reduced to 3.54 log CFU per egg and 3.23 log CFU per egg after 15 and 20s at 5.5cm and 9.5cm, respectively. Scanning electron micrographs revealed the existence of photophysical mechanisms, bacterial overlapping and internalisation interfering inactivation. Treated samples experienced slight thermal increases (6-9 degrees C) contributing to the preservation of colour and texture, not significantly different from untreated samples (P>0.05). Our findings support the use of PL to enhance the safety of hard-cooked eggs although bacterial shadowing may have significant implications on treatment efficiency.

• 出版日期2014-11