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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Publications at this Location » Publication #362968
Research Project: Characterization and Mitigation of Bacterial Pathogens in the Fresh Produce Production and Processing Continuum

Location: Environmental Microbial & Food Safety Laboratory

Title: Efficacy of natural fruit extracts in reducing Salmonella on whole cucumbers

Author
item BYUN, SUYEUN - US Department Of Agriculture (USDA)
item CHEN, CHI-HUNG - US Department Of Agriculture (USDA)
item HSIN-BAI, YIN - US Department Of Agriculture (USDA)
item Patel, Jitu

Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: 4/5/2019
Publication Date: 4/24/2019
Citation: Byun, S., Chen, C., Hsin-Bai, Y., Patel, J.R. 2019. Efficacy of natural fruit extracts in reducing Salmonella on whole cucumbers. BARC Poster Day. 8:23.

Interpretive Summary:

Technical Abstract: Salmonellosis outbreaks linked to the consumption of contaminated cucumbers have highlighted the need to develop effective interventions for improving microbial safety of cucumbers. The objective of this study was to evaluate the efficacy of fruit extracts namely lemon, yuzu, grapefruit (naringin), and grape (resveratrol) for reducing Salmonella on cucumbers. Fresh Persian cucumbers (N=128) purchased from local retailer were submerged in 70% ethanol for 1 min to remove surface wax. Each cucumber was marked with two 1 cm x 5 cm areas and spot-inoculated with 20 µl of 9 log CFU/ml of Salmonella cocktail (S. Newport, Poona, and Typhimurium) to obtain 5 log CFU/cm2 on cucumbers. After air-drying for 2 h, each inoculated area was sprayed with 1 ml treatment solution, including controls (water, 20% ethanol, and water adjusted to pH 3.0), 10% lemon, 10% yuzu, 1% naringin, or 1% resveratrol. After treatment, cucumbers were stored at 10°C or 22°C for 7 days. On days 0, 2, 5, and 7, each marked area was swabbed with cotton applicator; swab was pummeled for 2 min in 10 ml of tryptic soy broth, and then plated on XLT4 agars. Initial Salmonella populations on the cucumbers sprayed with water (4.5 log CFU/cm2) were not significantly different from controls. Salmonella recovered from lemon- or resveratrol-treated cucumbers stored for 5 days at 10°C were 1.2 log and 2.3 log CFU/cm2, respectively; and significantly lower from water control (3.4 log CFU/cm2). Resveratrol at 1% completely inactivated Salmonella on cucumbers stored at 22°C for 2 days and they were undetectable by enrichment. Overall, 10% lemon and 1% resveratrol exerted superior antimicrobial effects against Salmonella at both storage temperatures for 7 days. The results of this study reveal that fruit extracts could be potentially used to kill Salmonella on cucumbers.