|Hwang, Cheng-an - Andy|
Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/22/2013
Publication Date: 1/1/2014
Publication URL: http://handle.nal.usda.gov/10113/58842
Citation: Shen, X., Sun, X., Xie, Q., Liu, H., Zhao, Y., Pan, Y., Hwang, C., Wu, V.C. 2014. Antimicrobial effect of blueberry (Vaccinium corymbosum L.) extracts against the growth of Listeria monocytogenes and Salmonella Enteritidis. Food Control. 35:159-165 doi.org/10.1016/j.foodcont.2013.06.040. Interpretive Summary: Listeria monocytogenes and Salmonella spp. are major foodborne pathogens. This study was conducted to evaluate the efficacy of extracts from four different blueberry cultivars against L. monocytogenes and S. Enteritidis and determine the inhibitory and bactericidal concentrations. Result showed that blueberry extracts at 112-900 mg/mL displayed significant antimicrobial activities and were more effective against L. monocytogenes than S. Enteritidis. Chlorogenic acid, ellagic acid, and quercetin-3-galactoside were identified as the antimicrobial compounds in the extracts. This study demonstrates that blueberry extract may be used in food products to improve microbiological quality.
Technical Abstract: We studied the antimicrobial effects of berry extracts obtained from four cultivars (Elliott, Darrow, Bluecrop and Duke) of blueberry (Vaccinium corymbosum L.) on the growth of Listeria monocytogenes and Salmonella Enteritidis. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the extracts against L. monocytogenes and S. Enteritidis in tryptic soy broth were determined. The contents of the total phenolic compounds and four individual phenolics (chlorogenic acid, ellagic acid, quercetin and quercetin-3-galactoside) of the extracts were determined using the Folin-Ciocalteau method and HPLC analysis, respectively. L. monocytogenes was significantly more sensitive to the extracts (112.5-900 mg/mL) than S. Enteritidis. Blueberry extracts displayed a potent and significant dose-dependent antimicrobial activity. The evaluation of the antimicrobial activity of four pure phenolic compounds found in blueberry fruits suggested that chlorogenic acid, ellagic acid and quercetin-3-galactoside were the active antimicrobial compounds in blueberry fruits. These in vitro data support the concept that blueberry fruits or their derived foods rich in phenolic compounds may be beneficial against pathogens. More studies on the benefits of blueberry consumption in human and use as a natural antimicrobial in food products are warranted.