Lycopene degradation and color characteristics of fresh and processed tomatoes under the different drying methods: a comparative study

Tomato is a potentially valuable source of bioactive compounds such as lycopene. The degradation/isomerization rate of lycopene can be highly enhanced by the drying process of tomato pulps. In this study, the dehydrated tomatoes by osmotic solutions were processed by drying methods of hot air (HA), vacuum-assisted hot air (VA-HA), sun-assisted hot air (SA-HA), and microwave-assisted hot air (MA-HA). The lycopene content and color characteristics ( L * , a * , b * , and ∆ E values) of the dried samples to determine the favorable processing were analyzed using HPLC and Hunter-Lab colorimeter systems, respectively. Results showed that the osmotic pretreatment with a significant decrease in drying time led to a better-preserved color by reducing the degradation rate of lycopene. The samples processed with MA-HA showed the highest drying rate with a drying time of 150 min ( p