|CHIEN, SHI-YUNG - National Taiwan University|
|Sheen, Shiowshuh - Allen|
|SHEEN, LEE-YAN - National Taiwan University|
Submitted to: Food and Bioprocess Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/4/2018
Publication Date: 11/23/2018
Citation: Chien, S., Sheen, S., Sommers, C.H., Sheen, L. 2018. Effects of combined treatments of high pressure processing, single-and multi-antimicrobial (Melissa officinalis extract)on the reduction of pathogenic Escherichia coli in ground beef. Food and Bioprocess Technology. 12:359-370. https://doi.org/10.1007/s11947-018-2211-5.
Interpretive Summary: High pressure processing (HPP), is a green and sustainable non-thermal intervention to reduce the levels of harmful bacteria in foods, and has been demonstrated to be an effective means for inactivating pathogenic Escherichia coli. Natural antimicrobial compounds are “consumer friendly” and can help sensitize E. coli to the HPP treatment. In this study the ability of HPP to inactivate the Shiga toxin-producing E. coli (STEC) including O111, O121, O128, O145 and O157 in meat, with and without essential oil as the natural antimicrobials, were determined. The combination of HPP and natural antimicrobials (e.g. Melissa officinalis leaf essential oils – multiple compounds) in ground beef facilitated the inactivation of STEC while maintaining food quality. These findings will help meat (e.g. beef) processors to achieve a 5 log reduction (100,000 E. coli/g of meat) and provide regulatory agencies with valuable information for control of STEC.
Technical Abstract: Shiga toxin-producing Escherichia coli (STEC) are commonly found in meat. In this study we investigated the survival of STEC serovars O111, O121, O128, O145 and O157 in ground beef after exposure to high pressure processing (HPP) and Melissa officinalis leaf essential oils (antimicrobials: MoEOs – natural and multiple compounds or their similar chemical constituents, CCs). MoEOs are citral, geraniol and caryophyllene in which the antimicrobial effect in meat was found citral > geraniol > caryophyllene. A 5-log CFU/g reduction was achieved with properly selected pressure and essential oil (EO) concentration. For example, 1% citral, 1% geraniol or 1% MoEOs with 350-400 MPa could reduce ca. 3-6 log CFU/g of STEC depending on the processing parameters. Their post-process growth and survival were determined at 4degrees C, 7 days storage. The inactivation potential continued to show effectiveness during the low temperature storage test (i.e. 4 degrees C, 7 days), in which cell counts were in fairly stable (400MPa) or decreased trend (300, 350MPa) to attain the 5-log lethality as time progressed. The cell structures affected or damaged by HPP and EOs were examined by scanning and transmission electron microscopy.