TY - JOUR
T1 - Development of an antimicrobial sachet containing encapsulated allyl isothiocyanate to inactivate Escherichia coli O157:H7 on spinach leaves
AU - Seo, Hyun Sun
AU - Bang, Jihyun
AU - Kim, Hoikyung
AU - Beuchat, Larry R.
AU - Cho, Seung Yong
AU - Ryu, Jee Hoon
N1 - Funding Information:
This study was carried out with the support of the “ Cooperative Research Program for Agricultural Science & Technology Development (project no. PJ007387 ),” Rural Development Administration, Republic of Korea. We thank the Korea University Food Safety Center and the Institute of Food and Biomedicine Safety for providing equipment and facilities.
PY - 2012/10/1
Y1 - 2012/10/1
N2 - A sachet releasing allyl isothiocyanate (AIT) vapor was developed and its effectiveness as an antimicrobial packaging system for fresh spinach was evaluated. AIT was encapsulated in calcium alginate beads (AIT beads) and the release of AIT as affected by temperature and relative humidity (RH) was determined. The release rate of AIT from beads increased with increased temperature, but was not significantly affected by RH. A low-density polyethylene (LDPE) sachet containing AIT beads (AIT sachet) was prepared and the rate of release of AIT as affected by film thickness and temperature was studied. The release of AIT from sachets increased significantly with decreased LDPE thickness and increased temperature. Finally, antimicrobial effects of the AIT sachet against Escherichia coli O157:H7 and molds and yeasts (MY) on fresh spinach leaves were determined. E. coli O157:H7 and MY had similar sensitivities to AIT vapor. The number of E. coli O157:H7 on spinach leaves (5.6. log. CFU/leaf) decreased by 1.6-2.6. log. CFU/leaf at 4. °C and 2.1-5.7. log. CFU/leaf at 25. °C within 5. days. The reduction of E. coli O157:H7 was significantly greater at 85% RH than at 43% RH. Reductions on control leaves (no AIT sachet) did not exceed 1.2. log. CFU/leaf under any of the test conditions. Results of the study will be useful when developing antimicrobial packaging systems to increase the microbiological safety and extend the shelf life of spinach and possibly other fresh produces.
AB - A sachet releasing allyl isothiocyanate (AIT) vapor was developed and its effectiveness as an antimicrobial packaging system for fresh spinach was evaluated. AIT was encapsulated in calcium alginate beads (AIT beads) and the release of AIT as affected by temperature and relative humidity (RH) was determined. The release rate of AIT from beads increased with increased temperature, but was not significantly affected by RH. A low-density polyethylene (LDPE) sachet containing AIT beads (AIT sachet) was prepared and the rate of release of AIT as affected by film thickness and temperature was studied. The release of AIT from sachets increased significantly with decreased LDPE thickness and increased temperature. Finally, antimicrobial effects of the AIT sachet against Escherichia coli O157:H7 and molds and yeasts (MY) on fresh spinach leaves were determined. E. coli O157:H7 and MY had similar sensitivities to AIT vapor. The number of E. coli O157:H7 on spinach leaves (5.6. log. CFU/leaf) decreased by 1.6-2.6. log. CFU/leaf at 4. °C and 2.1-5.7. log. CFU/leaf at 25. °C within 5. days. The reduction of E. coli O157:H7 was significantly greater at 85% RH than at 43% RH. Reductions on control leaves (no AIT sachet) did not exceed 1.2. log. CFU/leaf under any of the test conditions. Results of the study will be useful when developing antimicrobial packaging systems to increase the microbiological safety and extend the shelf life of spinach and possibly other fresh produces.
KW - Allyl isothiocyanate
KW - Antimicrobial packaging
KW - Escherichia coli O157:H7
KW - Spinach
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U2 - 10.1016/j.ijfoodmicro.2012.08.009
DO - 10.1016/j.ijfoodmicro.2012.08.009
M3 - Article
C2 - 23072699
AN - SCOPUS:84867602740
VL - 159
SP - 136
EP - 143
JO - International Journal of Food Microbiology
JF - International Journal of Food Microbiology
SN - 0168-1605
IS - 2
ER -