Minor project

My research question is the factors affecting preservative activity of reuterin can provide possibilities to apply reuterin in many kinds of food. Reuterin is an antimicrobial compound produced by the food grade lactic acid bacterium Lactobacillus reuteri. This substance has high potential as a broad spectrum food preservative. The issue is contested with some researcher saying reuterin can be apply as preservative in food and others saying it can be easily converted to inactive form which depends on environmental condition of food.

Researchers who have looked at this subject are El-Ziney et al. (1999) and Lüthi-Peng et al. (2002). The former encourages the use of reuterin produced from Lactobacillus reuteri as preservative for microbial decontamination in meat products and the latter found that reuterin can be easily transformed to other compounds that cannot exhibit antimicrobial activity.

El-Ziney et al. (1999) reported that Escherichia coli O157:H7 count on the surface of cooked pork meat with 100 AU/g of reuterin decrease by 5.0 log cfu/g after 1 day of storage at 7 °C. Reuterin at a concentration of 250 AU/g reduce 3.0 log cfu/g of Listeria monocytogenes after 1 week of storage at 7 °C. They suggest that reuterin could be used as food preservative, especially in cold stored food.

Lüthi-Peng et al. (2002) state that reuterin is less stable in milk and de Man, Rogosa and Sharpe (MRS) medium than in water. It can react with other components in the food or dehydrate to acrolein which is inactive form at higher temperatures above 20 °C.

Debate centers on the basic issue of environmental conditions in food that affect on stability and preservative activity of reuterin have to be investigated because there is no study has been done on this point.

My work will be closer to Lüthi-Peng et al. (2002) because I will elucidate a number of parameters, such as pH, salt, concentration, and temperature that influence on the stability and preservative activity of reuterin. Due to the applicability of reuterin in foodstuffs, an understanding of the factors that influence the stability and preservative activity will be determined.

Hopefully my contribution will provide a systematic investigation of the antimicrobial effect of reuterin under different conditions of concentration, temperature, salt and pH relevant to food products, and describe the interactions between these environmental factors and reuterin.

Reference list

El-Ziney, M.G., van den Tempel, T., Debevere, J.M., Jakobsen, M. (1999). Application of reuterin produced by Lactobacillus reuteri 12002 for meat decontamination and preservation. Journal of Food Protection, 62, 257-261.

Lüthi-Peng, Q., Schärer, S. and Puhan, Z. (2002). Production and stability of 3-hydroxypropionaldehyde in Lactobacillus reuteri. Applied Microbiology and Biotechnology, 60, 73-80