Determination of L‐Ascorbyl 6‐Palmitate in Bread Using Reverse‐Phase High‐Performance Liquid Chromatography (HPLC) with Electrochemical (EC) Detection

Abstract

ABSTRACT L‐Ascorbyl palmitate (AP) was stable for up to 5 hr at 25°C in an extracting medium consisting of 90% dimethylsulfoxide (DMSO) with 0.12% metaphosphoric acid and 0.05% L‐ascorbic acid (AA). When the DMSO‐acid medium was used with reverse‐phase, high‐performance liquid chromatography (HPLC) to determine 0.6–4.8 mg AP/g dry dough or bread, AP was base‐line resolved on the chromatograms. Reverse‐phase HPLC with electrochemical detection was also used to obtain base‐line resolution of AA extracted from bread using 3% aqueous metaphosphoric acid. Fresh bread after cooling 1 hr retained 50.7% of AP and 58.1% of AA added at the dough stage (150 mg of AP or 63.8 mg of AA per 100g flour). During storage of the bread in polyethylene bags at 25°C, AA was lost approximately three times faster than AP. AA could not be detected in the bread after 10 days, whereas 30% AP remained. Bread baked with 0.15% AP in the formula retained 9% of the adult RDA for vitamin C after 3 days of bagged storage, and 6% RDA after 10 days; in a nitrogen atmosphere the bread retained 90% AP after 5 days.