Localization Analysis of Multiple Vitamins in Dried Persimmon (Diospyros kaki) Using Matrix-assisted Laser...

The drying process used for persimmon fruit (Diospyros kaki) can alter the composition of nutrients, and especially vitamins. We visually determined whether the amounts of vitamin A₁, vitamin B₆ and vitamin C vary after drying persimmon fruit, using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) imaging. Drying altered the amount of moisture between the fruit interior and surface. Vitamin A₁ is lipophilic and localized at the desiccated outer regions (pericarp) and not in the inner region (mesocarp and endocarp), and its concentration was increased 3.4 times in dried fruit compared with raw persimmon. Vitamin B₁ and B₆ are water-soluble and concentrated in the moist mesocarp. The vitamin C content of dried persimmon is decreased by drying in the sun. The drying process affected the localizations and amounts of all the vitamins. The observed opposite localization of vitamin A₁ compared to B₁ and B₆ was due to vitamin A₁ being lipophilic and B₁ and B₆ being water soluble. Multiplevitamin imaging using MALDI-MSI has great potential for enhancing commodity value and for visually investigating the effects of manufacturing processes.