Research Article
Long Nguyen PT, & Tu Nguyen HK
Abstract
Lactobacillus rhamnosus is commonly used in milks, yogurts, and probiotics for human. L. rhamnosus has been reported to produce histamine that caused a risk to human. In the study, L. rhamnosus produced histamine in milk, not in MRS. By TLC, HPLC analysis and chemical tests according to United State and British Pharmacopoeia, L. rhamnosus (107 CFU) produced histamine from 10.671±0.256 µg/ml to 12.639±0.517 µg/ml in glucose milk medium and 11.373±0.128 µg/mL to 13.622±0.169 µg/mL in free glucose milk medium after 12 day incubation and 30.206±0.417 µg/mL to 30.685±0.690 µg/mL in glucose milk medium and 30.099±1.295 µg/mL to 44.410±4.893 µg/mL in free glucose milk medium after 14 day incubation. The study suggested the milk products supplied with L. rhamnosus, like yogurts should be used as soon as preparation.