Effects of modified atmosphere packaging and preservatives on the shelf-life of high moisture prunes and raisins.
The growth of Aspergillus niger and Zygosaccharomyces rouxii on high moisture prunes and raisins in the presence of preservatives and packed under modified atmospheres was determined. Prunes and raisins adjusted to an aw of 0.84-0.87 in the presence of carbon dioxide atmospheres (40 and 80% CO2) did not support growth of A. niger. However, Z. rouxii spoiled the fruit samples, both in air and under CO2 conditions. Addition of low levels of K-sorbate (186 ppm in prunes and 153 ppm in raisins) or Na-benzoate (176ppm in prunes and 158ppm in raisins) delayed outgrowth of Z. rouxii. The inhibitory effect of preservatives was higher in raisins than in prunes. Modified atmospheres (40% CO2-60% N2 or 80% CO2-20% N2) combined with the addition of 417 and 343 ppm K-sorbate or 383 and 321 ppm Na-benzoate accomplished complete growth inhibition of Z. rouxii and extended the shelf-life of high moisture prunes and raisins at 30 degrees C for at least 6 months.
Department of Food Sciences, Ecole Nationale d'Agriculture, Meknes, Morocco.
A
A
El Halouat
H
H
Gourama
M
M
Uyttendaele
J M
JM
Debevere
D000388:Air; D001234:Aspergillus niger / Q000254:growth & development*; D001565:Benzoates / Q000008:administration & dosage; D002245:Carbon Dioxide / Q000008:administration & dosage; D018857:Food Packaging; D005519:Food Preservation; D005520:Food Preservatives / Q000008:administration & dosage; D005638:Fruit / Q000382:microbiology*; D004718:Saccharomycetales / Q000254:growth & development*; D013011:Sorbic Acid / Q000008:administration & dosage
D001565:Benzoates; D005520:Food Preservatives; D002245:Carbon Dioxide; D013011:Sorbic Acid