Extraction and quantification of ethyl cellulose-coated vitamins C, B5, and B9

Ethyl cellulose is often used to encapsulate water-soluble vitamins to slow degradation during processing and storage of fortified foods; however, accurate quantification of EC-coated vitamins remains challenging due to the lack of effective de-encapsulation methods. The industry-standard boiling method consists of 60 min of boiling, threatening heat-labile vitamins leading to inaccurate quantification of vitamins. A newly developed and validated liquid-liquid extraction (LLE) method for the extraction and quantification of vitamins C (ascorbic acid), B5 (pantothenic acid), and B9 (folic acid) is presented in this study. The LLE method uses ethyl acetate to dissolve the EC coating and an aqueous extraction solvent (2 M NaCl at pH 10) to recover the vitamins from the organic phase for quantification with HPLC-DAD. Method performance was evaluated against the boiling method using extraction time, vitamin recovery, and precision. The LLE reduced sample preparation time by ∼50% and achieved ∼20% higher recoveries for vitamins C and B9 compared to boiling. The LLE method had improved reproducibility with a lower average %RSD than boiling. This study establishes LLE as a robust and efficient approach for accurate quantification of EC-coated vitamins.