Synthesis, purification, and characterization of structured lipids produced from chicken fat

A structured lipid (SL) was synthesized enzymatically from chicken fat by incorporating a medium-chain length fatty acid (caprylic acid) into chicken fat triacylglycerols. Carica papaya latex was used as the biocatalyst. The optimal substrate mole ratio found was 1:2 (chicken fat fatty acids/caprylic acid). At this ratio of reactants, the incorporation of caprylic acid (C-8:0) at 65 degrees C was 23.4 mol%, whereas at 55 degrees C the incorporation of caprylic acid was 17.6 mol%. A packed-bed column bioreactor was designed for the synthesis of SL from chicken fat. In using ground crude C. papaya latex (a(w) < 0.1), 7.1 mol% of caprylic acid was incorporated into the chicken fat triacylglycerols after 117 min of reactor residence time. After purification of the SL, the acyl positional distribution of fatty acids on the glycerol backbone was determined by C-13 nuclear magnetic resonance (NMR) spectroscopy. From the NMR spectrum of the SL, it was determined that saturated fatty acyl residues at the 1,3-positions of the SL triacylglycerols increased to 62% over that of the starting chicken fat triacylglycerols, suggesting that caprylic acid was preferentially incorporated at the 1,3-positions. In addition, differential scanning calorimetry thermograms were obtained to compare the crystallization characteristics of the starting chicken fat with the SL prepared from it.