Supercritical CO2 extraction of lycopene from pink grapefruit (Citrus paradise Macfad) and its degradation studies during storage

Lycopene was extracted from pink grapefruit using SC-CO2 and rice bran oil as co-solvent. Response surface methodology was employed to evaluate the individual and interactive effects of three process parameters varied at five levels i.e. pressure (250, 300, 375, 450 & 500 bar), temperature (55, 60, 70, 80 & 85 degrees C), and extraction time (60, 90, 135, 180 & 210 min). Single optimum point for multiple response variables was achieved at 325 bar, 64 degrees C, and 143 min with overall desirability of 0.92 at which 70.52 +/- 3.65% (lycopene extraction efficiency) and 11154 +/- 148 ppm (gamma-oryzanol) were predicted. Extraction temperatures of more than 80 degrees C and time beyond 180 min led to the isomerization of lycopene. Lycopene storage at 3 degrees C, 10 degrees C, & 25 degrees C showed average k and half-life values as 0.018, 0.030, & 0.075 and 40, 23, & 9 days, respectively for first-order degradation kinetics; depicting faster degradation at higher storage temperatures.

Automated summary

Lycopene was extracted from pink grapefruit using SC-CO2 and rice bran oil as co-solvent, with a single optimum point achieved at 325 bar, 64 degrees C, and 143 min. Extraction at temperatures above 80 degrees C and times beyond 180 min led to isomerization of lycopene, demonstrating faster degradation at higher storage temperatures of 10 degrees C and 25 degrees C.