Comparative elucidation of colour, volatile and phenolic profiles of black carrot (Daucus carota L.) pomace and powders prepared by five different drying methods

Black carrot pomace is a juice industry by-product that can be easily spoiled due to its high moisture content and usually considered as waste; however, it is a valuable product with high amount of bioactive compounds that can be recovered for further application in several industrial fields. Drying is an effective method for the preservation of this product. Thus, the influence of five drying methods (FD: freeze drying, MWD: microwave drying, CD: convective drying, VCD: vacuum/convective drying, CHD: conductive hydro drying) on colour, phenolics and volatiles of pomace were investigated. Findings revealed that drying process decreased the amount of anthocyanins, colourless phenolics and volatile compounds. CHD resulted in similar colour quality and yielded a better preservation of colour and phenolics while FD provided dried sample with an aroma quality similar to fresh sample. The shorter duration of the CHD makes it a better choice.

Automated summary

The study found that conductive hydro drying had the best preservation effect on the color and phenolic substances of black carrot pomace, while freeze drying provided samples with aroma quality similar to fresh samples. Therefore, conductive hydro drying is the better choice for preservation of these bioactive compounds.