The effect of osmotic dehydration and starch coating on the microbiological stability of apples

Abstract

This paper examines the effect of starch coating and the osmotic dehydration in sugar beet molasses on the microbiological stability of apples. One-half of the osmotically treated/untreated apples were protected by starch coating, resulting in four sample groups (namely the K, P, OD and OD+P sample groups). E. coli, Salmonella spp. and Listeria monocytogenes were not detected in any of the samples. Enterobacteria were present in the K and P samples in the first four days (indicating a downward trend), but were not subsequently detectable. The total number of microorganisms (TVC) was found to be uniform in each sample group. However, the TVC values were significantly higher in the K and P sample groups than those of the OD and OD + P samples. Yeasts and molds were detected in the K and P samples, whereas the presence of yeasts and molds in the OD and OD+P samples was confirmed only after four days of storage. The results obtained indicate that osmotic dehydration is a suitable method for maintaining microbial stability, whereas starch coating did not justify its purpose.

Keywords

• apple
• osmotic dehydration
• molasses
• starch coating
• microbial profile