Transcriptomic Analysis and Volatile Profiling Reveals Regulatory Mechanism of Flavor Volatiles in Fresh-Cut Potatoes
The potato (Solanum tuberosum L.) is one of the most edible vegetables worldwide. The cutting process disrupts the internal structure of several volatile substances that prompt flavor changes in fresh-cut potatoes. Understanding the composition of volatiles along with their biosynthesis mechanism is important to preserve original potato flavor during processing technology. This study characterized the volatile profiles of fresh cut potato shreds at different time intervals, including zero hour CK and after 4 hours of storage CK4. Further transcript analysis was performed to identify the regulatory mechanism of flavor volatile formation at different time intervals. According to volatile profiling, Alkanes were found to be the most abundant volatiles at both time intervals, followed by alcohols, aldehydes, esters, furans, and quinone. The abundance level of these volatiles was reduced many fold in CK4 potato shreds except for specific alkenes such as hexane, 1,3-hexadiene, and 1,6-octadiene. The transcriptome analysis revealed 5961 differentially regulated genes among comparisons of both time intervals. An array of differential genes had functional annotations with biological responses to wounding, alcohol, water deprivation, and the molecular activity of acetyltransferase. In addition, most of these genes had pathway enrichment into the biosynthesis of secondary metabolites, alpha-linolenic acid metabolism, fatty acid biosynthesis, degradation, elongation, and metabolism. In particular, the many-fold differential regulation of the hydroperoxide pathway encoding genes probably yields different volatile profiles that cause flavor disorders even after storage of fresh cut potato shreds for a few hours. Our results characterized flavor volatiles profiling and identified important genes associated with the regulation of flavor volatiles in potato shreds. Furthermore, it will be useful to dissect the genetic mechanism of potato flavor in the future.