Hygienic Quality and Incidence of Histamine-forming Lactobacillus Species in Natural and Processed Cheese in Taiwan
HSIEN-FENG KUNG1, YUNG-HSIANG TSAI1*, CHIU-CHU HWANG1, YIING-HORNG LEE2, JIEH-HORNG HWANG3, CHENG-I WEI4 AND DENG-FWU HWANG5
1. Department of Food Science and Technology, Tajen Institute of Technology, Pingtung, Taiwan, R.O.C.
2. Kaohsiung District Agricultural Improvement Station, Pingtung, Taiwan, R.O.C.
3. Department of Pharmacy, Tajen Institute of Technology, Pingtung, Taiwan, R.O.C.
4. College of Human Environmental Sciences, Oklahoma State University, Stillwater, Oklahoma, U.S.A.
5. Department of Food Science, National Taiwan Ocean University, Keelung, Taiwan, R.O.C.
(Received: February 3, 2004; Accepted: October 8, 2004)
ABSTRACT
Thirty-one natural cheese and 39 processed cheese products were collected from food markets in Taiwan and analyzed for bacterial content and histamine-related quality. The natural cheese samples had <1 to 6.84 log colony forming unit (CFU)/g of aerobic plate count (APC) and <3 to 60 most probable number (MPN)/g of total coliform (TC). On the other hand, the processed cheese products had <1 to 4.57 log CFU/g of APC and <3 to 30 MPN/g of TC. None of the tested samples contained Escherichia coli. Only 2 of the natural cheese and 2 of the processed cheese products contained more than 10 MPN/g of TC, which is beyond the regulatory limit of hygienic quality. The tested natural cheese products had an average histamine content of 7.9 mg/100 g, while 17 of them (54.8%) had histamine content greater than the 5 mg/100 g limit set by the U.S. Food and Drug Administration for scombroid fish and/or product. In contrast, only 6 processed cheese products (15.4%) had histamine levels greater than this limit. The average content of the other 8 biogenic amines in all tested samples was lower than 2 mg/100 g. Among the 37 presumptive histamine-forming bacterial colonies isolated from the natural cheese products, 15 produced histamine, ranging from 6.4 to 16.4 ppm, in MRS broth supplemented with 0.25% L-histidine. These histamine-producing bacteria were identified as Lactobacillus spp. Of the 7 L. brevis identified, one produced 71.2 ppm of tyramine in histidine-supplemented MRS broth.
Key words: cheese, histamine, biogenic amine, hygienic quality, histamine-forming bacteria