Publications by authors named "Preenapha Tepkasikul"

3 Publications

  • Page 1 of 1

Dynamics of biogenic amines and bacterial communities in a Thai fermented pork product Nham.

Food Res Int 2019 05 24;119:110-118. Epub 2019 Jan 24.

National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand. Electronic address:

A traditional Thai fermented pork, nham, is a product popularly consumed in Thailand. Fermentation of the protein-rich product by uncontrolled bacterial community can result in high amounts of hazardous biogenic amines (BA). This study aimed to unveil dynamics of microbial community and its relation to BA accumulation in nham. Three batches of nham were analyzed for pH, lactic acid bacteria population, concentrations of organic acids and BA. Bacterial communities were analyzed by pyrosequencing of 16S rRNA gene amplicons. In all batches, pH dropped to the quality standard of nham (≤4.6) within 3-5 days by production of lactic acid and acetic acid. Initial BA levels varied batch-by-batch and increased with fermentation time. In the highest quality batch, levels of histamine, tyramine, and total BA were within the recommended safety limits (200, 100 and 1000 mg/kg, respectively) throughout the 10-days study. However, in other batches, unsafe levels of tyramine and total BA were found after 5 days of fermentation. The results indicated that over-fermentation and inferior conditions of ingredients increased risk due to high levels of BA. Lactobacillus, Lactococcus, Pediococcus and Weissella were prevalent and comprised >90% of total bacteria during fermentation. Weissella was predominant in the batch with low BA while Lactobacillus and Pediococcus were predominant in the higher BA batches. A negative correlation between Weissella dominance and total BA was observed (r = -0.90, p = .003). A 10% increase in dominance of Weissella was associated with 75-170 mg/kg decrease in total BA. W. hellenica was the species prevalent only in low BA batch. Therefore, W. hellenica isolates were suggested as subjects for future study to develop efficient starter culture securing safety of nham.
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http://dx.doi.org/10.1016/j.foodres.2019.01.060DOI Listing
May 2019

Water-based oligochitosan and nanowhisker chitosan as potential food preservatives for shelf-life extension of minced pork.

Food Chem 2014 Sep 13;159:463-70. Epub 2014 Mar 13.

The Petroleum and Petrochemical College, Chulalongkorn University, Soi Chula 12, Phyathai Rd., Pathumwan, Bangkok 10330, Thailand; Center for Petroleum, Petrochemicals, and Advanced Materials, Chulalongkorn University, Bangkok 10330, Thailand; Center of Innovative Nanotechnology, Chulalongkorn University, Bangkok 10330, Thailand. Electronic address:

Water-based chitosans in the forms of oligochitosan (OligoCS) and nanowhisker chitosan (CSWK) are proposed as a novel food preservative based on a minced pork model study. The high surface area with a positive charge over the neutral pH range (pH 5-8) of OligoCS and CSWK lead to an inhibition against Gram-positive (Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus) and Gram-negative microbes (Salmonella enteritidis and Escherichia coli O157:H7). In the minced pork model, OligoCS effectively performs a food preservative for shelf-life extension as clarified from the retardation of microbial growth, biogenic amine formation and lipid oxidation during the storage. OligoCS maintains almost all myosin heavy chain protein degradation as observed in the electrophoresis. The present work points out that water-based chitosan with its unique morphology not only significantly inhibits antimicrobial activity but also maintains the meat quality with an extension of shelf-life, and thus has the potential to be used as a food preservative.
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http://dx.doi.org/10.1016/j.foodchem.2014.03.019DOI Listing
September 2014

Biogenic amine formation in Nham, a Thai fermented sausage, and the reduction by commercial starter culture, Lactobacillus plantarum BCC 9546.

Food Chem 2011 Dec 11;129(3):846-53. Epub 2011 May 11.

Food Biotechnology Research Unit, National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Rd., Klong Luang, Pathumthani 12120, Thailand.

Biogenic amines are of concern for sausage due to their toxicological effects on nervous, blood pressure, gastric and intestinal systems. In this study, the influence of raw pork meat quality and starter culture inoculation on biogenic amines accumulation in Nham, a Thai traditional fermented pork, were studied. Before Nham processing, pork meat was stored at 30°C for 6h, and at 4 and -20°C for 2days. Formation of biogenic amines (cadaverine, putrescine, histamine and tyramine) was significantly higher in Nham processed from stored meat. Accumulation of these biogenic amines in Nham reduced significantly by the addition of Lactobacillus plantarum BCC 9546, a commercial Nham starter culture. The results highlight the importance of using fresh meat products and the inclusion of an appropriate starter culture to minimise the formation of biogenic amines during the process of Nham fermentation.
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http://dx.doi.org/10.1016/j.foodchem.2011.05.033DOI Listing
December 2011