|SHOFRAN, BRIAN - NCSU
|PURRINGTON, S - NCSU
|BREIDT, F - NCSU
Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/21/1998
Publication Date: N/A
Interpretive Summary: Fresh vegetables such as cabbage, mustard, and horseradish contain sinigrin, which breaks down into various flavorful compounds when the vegetables are physically disrupted, as by cutting or chewing. One of the breakdown products, allyl isothiocyanate (abbreviated AITC), was found to inhibit many types of microorganisms, some of which are poisonous to people. AITC is largely responsible for the pungent flavor of horseradish. We found that AITC is more inhibitory to some food-poisoning bacteria than the traditional food preservative, sodium benzoate, particularly in non-acidic foods. A current study is underway to learn if AITC can be used in vegetable food products at sufficiently low concentration to be a preservative without resulting in objectionably strong flavor.
Technical Abstract: Sinigrin, a thioglucoside of Cruciferae plants, may be enzymatically hydrolyzed to yield up to four distinct aglycones when the plants are injured or mechanically disrupted. These aglycones, allyl isothiocyanate (AITC), allyl cyanide (AC), 1-cyano-2,3-epithiopropane (CETP), and allyl thiocyanate (ATC), were tested for their minimum inhibitory concentration (MIC) to nine species of bacteria and eight species of yeasts. Sinigrin, AC, and CETP at 1,000 ppm were not inhibitory to any of the bacteria or yeasts tested. The inhibitory activity of ATC was uncertain due to its gradual conversion to AITC. AITC had an MIC between 50 and 1,000 ppm for bacteria and between 1 and 4 ppm for non-xerotolerant yeasts. Against xerotolerant yeasts tested, however, AITC at 50 ppm retarded but did not prevent growth. AITC was 10 to 100 times more inhibitory than sodium benzoate against Escherichia coli and Staphylococcus aureus at pH values of 5, 6, and 7, and the effect by AITC was much less influenced by pH than was sodium benzoate.