Elimination of Lactobacillus plantarum and achievement of shelf stable model salad dressing by pilot scale pulsed electric fields combined with mild heat

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• 作者：Li ; Si-Quan ; Zhang ; Howard Q. ; Jin ; Tony Z. ; Turek ; Evan J. ; Lau ; Ming H.
• 刊名：Innovative Food Science and Emerging Technologies
• 出版年：2005
• 出版时间：June, 2005
• 年：2005
• 卷：6
• 期：2
• 页码：125-133
• 全文大小：153 K

文摘

Model salad dressing inoculated with Lactobacillus plantarum 8014 was subjected to pulsed electric fields (PEF)-only processing and PEF followed by a mild heat treatment. More than 7 log inactivation was achieved by using PEF-only processing at 34 kV/cm for 45.7 μs with minimal heat contribution. Samples for shelf life evaluation were aseptically packed in 4-oz HIPS/EVOH/PE cups using a Benco® system. The PEF-treated samples were stable at 4 °C for the 8-week evaluation period. However, L. plantarum in the samples treated with PEF-only grew up to more than 10⁹ cfu/ml in 1 week at room temperature. PEF processing at 31.8 kV/cm for 45 μs followed by a mild heat processing at 67.273.6 °C for 24 s resulted in a shelf stable product with an initial L. plantarum load of 3.7×10³ cfu/ml. No L. plantarum 8014 recovered in the model salad dressing at room temperature for at least 1 year.

Industrial relevance

Pulsed electric field processing is on the verge of entering industrial scale processing. Consequently pilot scale data are essential for process scale up purposes. Increasing evidence is currently occumulated that PEF in conjunction with moderate heat treatment is not only an attractive minimal processing alternative but also interesting in terms of energy efficiency and low environmental impacts for pasteurization of foods. This paper is one example for such process development for food materials with low (10³ cfu/ml) initial microbial counts.