title: Effects of bilimbi (Averrhoa bilimbi L.) and tamarind (Tamarindus indica L.) juice on Listeria monocytogenes Scott A and Salmonella Typhimurium ATCC 14028 and the sensory properties of raw shrimps.
abstract: The potential of using juice of bilimbi (Averrhoa bilimbi L.) and tamarind (Tamarindus indica L.) to reduce Listeria monocytogenes Scott A and Salmonella Typhimurium ATCC 14028 populations on raw shrimps after washing and during storage (4 degrees C) was investigated. The uninoculated raw shrimps and those inoculated with approximately 9 log cfu/ml of L. monocytogenes Scott A and S. Typhimurium ATCC 14028 were washed (dipped or rubbed) in distilled water (SDW) (control), bilimbi or tamarind juice at 1:4 (w/v) concentrations for 10 and 5 min. Naturally occurring aerobic bacteria (APC), L. monocytogenes Scott A and S. Typhimurium ATCC 14028 counts, pH values and sensory analysis of washed shrimps were determined immediately after washing (day 0), and on days 3 and 7 of storage. Compared to SDW, bilimbi and tamarind juice significantly (p<0.05) reduced APC (0.40-0.70 log cfu/g), L. monocytogenes Scott A (0.84-1.58 log cfu/g) and S. Typhimurium ATCC 14028 (1.03-2.00 log cfu/g) populations immediately after washing (0 day). There was a significant difference (p<0.05) in bacterial reduction between the dipping (0.40-0.41 log for APC; 0.84 for L. monocytogenes Scott A and 1.03-1.09 log for S. Typhimurium ATCC 14028) and rubbing (0.68-0.70 log for APC; 1.34-1.58 for L. monocytogenes Scott A and 1.67-2.00 log for S. Typhimurium ATCC 14028) methods. Regardless of washing treatments or methods, populations of S. Typhimurium ATCC 14028 decreased slightly (5.10-6.29 log cfu/g on day 7 of storage) while populations of L. monocytogenes Scott A (8.74-9.20 log cfu/g) and APC (8.68-8.92 log cfu/g) increased significantly during refrigerated storage. The pH of experimental shrimps were significantly (p<0.05) decreased by 0.15-0.22 pH units after washing with bilimbi and tamarind juice. The control, bilimbi or tamarind-washed shrimps did not differ in sensory panellist acceptability (p>0.05) throughout the storage except for odour (p<0.05) attributes at 0 day when acidic or lemony smell was noticed in bilimbi- and tamarind-washed shrimps and not in control shrimps.
authors.affiliation: School of Land, Crop and Food Sciences, University of Queensland, St. Lucia, Queensland 4067, Australia.
authors.forename: M N Wan
authors.initials: MN
authors.lastname: Norhana
authors.forename: Mohd Nor A
authors.initials: MN
authors.lastname: Azman
authors.forename: Susan E
authors.initials: SE
authors.lastname: Poole
authors.forename: Hilton C
authors.initials: HC
authors.lastname: Deeth
authors.forename: Gary A
authors.initials: GA
authors.lastname: Dykes
mesh_terms: D000818:Animals; D015169:Colony Count, Microbial; D004202:Disinfectants / Q000494:pharmacology; D004203:Disinfection / Q000379:methods; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D005638:Fruit / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000187:drug effects*; D019684:Magnoliopsida / Q000737:chemistry*; D033561:Penaeidae / Q000382:microbiology*; D010936:Plant Extracts / Q000494:pharmacology*; D012486:Salmonella typhimurium / Q000187:drug effects*; D012677:Sensation; D029861:Tamarindus / Q000737:chemistry*; D013696:Temperature
chemical_list: D004202:Disinfectants; D010936:Plant Extracts