Flavor deterioration of Mandarin juice during storage by MDGC-MS/O and GC-MS/PFPD

Commercial mandarin juice often exhibits flavor deterioration during storage. The changes in volatile flavor profiles were investigated in mandarin juice stored under three different temperature conditions (4 degrees C, 25 degrees C, and 40 degrees C). The application of multidimensional gas chromatography-mass spectrometry/olfactometry (MDGC-MS/O) coupled with aroma extract dilution analysis (AEDA) identified 31 odorants in stored mandarin juice, including seven off-flavor contributing compounds: methanethiol (unpleasant, repulsive), dimethyl sulfide (sulfur, cabbage), methional (cooked potato), p-cymene (solventy), 4-vinylguaiacol (medicine), terpinen-4-ol (wood), and a-terpineol (floral, mint). 4-Vinylguaiacol was also identified in mandarin juice for the first time. In addition, 64 volatile compounds determined by GC-MS/pulsed flame photometric detector (GC-MS/PFPD) were classified as alcohols, terpenes, volatile sulfur compounds (VSCs), aldehydes, esters, ketones, and phenols. Volatile compound differences were observed in mandarin juice under different storage conditions by heat-map generation and principal component analysis (PCA). The results revealed that high-temperature storage led to a rapid increase in the concentration of total alcohols and VSCs. Furthermore, the flavor deterioration markers a-terpineol and dimethyl sulfide were identified based on off-flavor contribution and variable importance in projection (VIP) (score >1) values in the PLS-DA model. These two compounds are valuable for marker-assisted flavor deterioration analysis in mandarin juice during storage.

Automated summary

This study investigated the changes in volatile flavor profiles of mandarin juice stored under different temperature conditions, revealing that high-temperature storage led to rapid increases in total alcohols and volatile sulfur compounds concentration. Additionally, two flavor deterioration markers, α-terpineol and dimethyl sulfide, were identified, providing valuable insights for flavor control during mandarin juice storage.