Quantitation and optimization of β-carotene and α-tocopherol in emulsion prototype with reversed-phase chromatography

Emulsion products that are rich in pro-vitamin A, vitamin E and antioxidants have been successfully formulated from red palm oil (FO-MSM), pumpkin (SLK), and dragon fruit (SBN). This study was aimed to determine the concentrations of β-carotene and αtocopherol in the prototype products of FO-MSM, SLK, and SBN by reverse phase chromatography and to determine the optimal deodorization time for FO-MSM on βcarotene and α-tocopherol levels. Optimal conditions for analysis of samples was with the mobile phase methyl dichloride: methanol: acetonitrile (2: 1: 3). The injection volume was 10 μL for β-carotene and 20 μL for α-tocopherol. Isocratic elution was carried out at a flow rate of 1.0 mL/min at room temperature (25±2°C). The mobile phase was first eliminated for 45 mins. The β-carotene and α-tocopherol peaks were identified by matching the peak retention times (Rt) of β-carotene and α-tocopherol in the sample with the standard Rt of β-carotene and α-tocopherol. The reverse-phase chromatography successfully determined β-carotene and α-tocopherol in prototype products of FO-MSM, SLK, and SBN. The developed emulsion prototype had 2044.5±196.1 ppm of β-carotene and 38.8±0.4 ppm of α-tocopherol. The content of β-carotene in the developed emulsion prototype was more than tenfold increase from the original prototype without sacrificing the product's taste. β-carotene showed no significant difference in reducing the deodorization time from 5 hrs to 1 hr, while the 2.5-fold increase of the α-tocopherol content was observed. Therefore, the optimal deodorization time for FO-MSM was determined based on the value of α-tocopherol and not by β-carotene. RP-18 was successfully used to determine β-carotene and α-tocopherol in FO-MSM, SLK, and SBN emulsion prototype products.