The Effects of Shriveling up Waste Watermelons in Different Solar Drying Systems on Withering and Relevant Microbial Parameters

This study aimed to examine the shriveling parameters and some aerobic microbial qualities of waste watermelons in a combined solar energy drying system (CDS) and an open sun drying system (OSDS). Results showed that the CDS was better than the OSDS in terms of the temperature, relative humidity, surface temperature, time, and speed of reaching the target humidity level of the air-shriveled watermelon slices. The number of mesophilic aerobic bacteria (log10 cfu/g) increased in the shriveled (P>0.05) silages compared to fresh watermelon slices in the CDS and OSDS groups and decreased in silages (P<0.05). Compared to fresh watermelon slices, yeast count (log10 cfu/g) decreased in the shriveled CDS group (P>0.05) and increased in the OSDS group (P>0.05) and was not detected in silages. No mold was determined in the fresh watermelon slices and silages in the CDS and OSDS groups. However, mold was found to be higher in the shriveled slices in the OSDS group than in the CDS group (P<0.05). Aflatoxin was not detected in the fresh, shriveled and silage watermelon slices. As a result, it was determined in this study that the CDS group was more advantageous in terms of slaking parameters compared to the OSDS group in the shriveling process of the waste watermelon slices, which had not been previously studied. It was observed that there was no significant difference between the two systems in terms of aerobic microbial quality determined during the wilting and ensiling process.