Enhanced shelf life of jujube (Ziziphus jujuba Mill.) using aqueous chlorine dioxide

In this study, we aimed to determine the appropriate conditions for storage of jujube (Ziziphus jujuba Mill.). Jujube was treated with aqueous chlorine dioxide (10, 25, and 50 mg L-1 for 1, 5, and 10 min) and was stored at 0 +/- 0.3 degrees C (optimal storage temperature) and 90 +/- 5% relative humidity for six weeks. The weight loss rate of all samples increased during storage, but it was not significantly different among treatments. The percent of weight loss after six weeks of storage ranged from 0.4 to 1.4%. The colour change (.E) values, soluble solid content, and firmness of jujube were not significantly different among treatments. However, the sensory evaluation index was higher for chlorine dioxide-treated samples than untreated samples with regard to palatability, texture, and off-odor. The decay rate of all samples increased during storage, and after storage for six weeks it was the highest in the 10 mg L-1 - 1 min treatment group (50.0%) and was the lowest in the 50 mg L-1 - 5 min treatment group (23.0%). After six weeks of storage, the order of the treatments according to the number of yeasts and moulds present in the samples was: control (6.77 log CFU g(-1)) >50 mg L-1 - 1 min (6.73 log CFU g(-1)) > 10 mg L-1 - 1 min (6.53 log CFU g(-1)) > 25 mg L-1 - 1 min (6.37 log CFU g(-1)) > 10 mg L-1 - 5 min (6.33 log CFU g(-1)) > 25 mg L-1 - 5 min (6.00 log CFU g(-1)) > 25 mg L-1 - 10 min (5.90 log CFU g(-1)) > 10 mg L-1 - 10 min (5.70 log CFU g(-1)) > 50 mg L-1 - 5 min (4.80 log CFU g(-1)) > 50 mg L-1 - 10 min (4.63 log CFU g(-1)). These results suggest that aqueous chlorine dioxide treatment (particularly treatment at 50 mg L-1 for 5 min) improved microbiological characteristics and preserved the quality of jujube during storage.