Influence of modified blanching treatments on inactivation of Salmonella during drying and storage of carrot slices.
Documented outbreaks of human illness associated with consumption of minimally processed produce have increased in recent years. This study evaluated the influence of modified treatments on inactivation of Salmonella during preparation, home-type dehydration (60 degrees C, 6h) and storage of carrot slices. Inoculated (five strains, 7.8 log cfu/g) slices were subjected to the following treatments: (i) untreated control, (ii) steam blanching (88 degrees C, 10 min), (iii) water blanching (88 degrees C, 4 min), (iv) blanching in a 0.105% citric acid solution (88 degrees C, 4 min), or (v) blanching in a 0.21% citric acid solution (88 degrees C, 4 min), dried for 6h at 60 degrees C (140 degrees F), and stored for up to 30 d. Bacterial populations were reduced by 3.8-4.1, 4.6-5.1 and 4.2-4.6 log cfu/g immediately following steam, water or citric acid blanching, respectively. After 6h of dehydration, total reductions were 1.6-1.7 (control), 4.0-5.0 (steam blanched), 4.1-4.6 (water blanched) and 4.9-5.4 (blanched in citric acid solution) log cfu/g. Populations continued to decrease throughout storage, but were still detectable by direct plating at 30 d on all samples except for those blanched in 0.21% citric acid. Results suggest that blanching carrot slices, particularly blanching in 0.21% citric acid, before drying should enhance inactivation of Salmonella during home-type dehydration and storage.
Dipersio
Patricia A
PA
Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, Colorado 80523, USA.
Kendall
Patricia A
PA
Yoon
Yohan
Y
Sofos
John N
JN
D019343:Citric Acid / Q000494:pharmacology; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D018552:Daucus carota / Q000382:microbiology*; D003681:Dehydration; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control*; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D006358:Hot Temperature; D006801:Humans; D012475:Salmonella / Q000187:drug effects / Q000254:growth & development*; D013997:Time Factors
D019343:Citric Acid