Abstract:
Piperine is an alkaloid that is primarily responsible for the pungency of black pepper
and has gained significant attention for its potential health benefits and
pharmacological properties. This study aimed to select and optimize the best method
for piperine isolation using black pepper oleoresins using three techniques: ethanol
extraction (E1), methanol precipitation (E2) and chloroform precipitation (E3),
utilizing analytical grade solvents (ethanol, methanol, and chloroform respectively).
In each method, oleoresin was dissolved in ethanol (E1), methanol (E2) or chloroform
(E3). Each solution was treated with 10% KOH, while E3 was additionally treated
with 10% NaOH and 1% HCl. All solutions were then filtered and refrigerated at 4˚C
for 72 hours. The efficiency of piperine isolation was evaluated in terms of yield and
purity, while the physicochemical properties of piperine were also characterized.
According to the results, the piperine yield was greater (p<0.05) in the E2
[24.11±0.03% (w/w)] than in the E3 [12.02±0.03% (w/w)] or E1 [15.22±0.04%
(w/w)]. The purity of piperine was higher (p<0.05) in the E1 [97.58±0.39% (w/w)] in
comparison to the E2 [95.72±0.34% (w/w)] and E3 [92.53±0.41% (w/w)]. In this
study, E2, recognized as the best method, was further optimized to improve the
piperine yield by changing the factors such as oleoresin: solvent ratio [1:10, 1:15, and
1:20 (v/v)] and KOH concentration [8%, 10%, and 12% (v/v)] while maintaining
constant extraction time (72 hours) and temperature (4˚C). The optimal conditions for
the isolation of piperine were identified as oleoresin: solvent ratio of 1:20 (v/v) and a
KOH concentration of 12% (v/v). Optimizing the chemical isolation of piperine from
oleoresin can enhance its yield, purity, and commercial availability, thereby
increasing its applications in the food, medical, and cosmetic industries.
