Comparative study on the use of rosemary bioactive for enhancing the oxidative stability of blended perilla seed oil: A multivariant kinetic approach

Abstract

Vegetable oils rich in polyunsaturated fatty acids (PUFA) are susceptible to lipid oxidation, which results in oxidative rancidity which can be prevented using natural antioxidant. This study investigated the oxidative stability and kinetics of blended perilla seed oil (BPSO) with different levels of rosemary bioactive as rosemary extract (RE) and rosemary oil (RO) under accelerated temperature using the rancimat method. The preliminary evaluation of perilla seed oil (PSO) exhibited higher peroxide value, acid value, p-anisidine and TOTOX value compared to palmolein (PO) and BPSO. The analysis of fatty acid composition revealed that blending of PSO with PO resulted in decrease in PUFA content of BPSO leading to balancing of its fatty acid composition. The kinetic parameters were estimated and results ranged from 85.38 to 109.17 kJ/mol for activation energies (Ea), 82.24–106.77 kJ/mol for activation enthalpies (∆H++), and -50.92 to 28.20 J/mol K for entropies (∆S++). Among all the oil sample, BPSORE1500 exhibited highest total phenolic content (3.12 mg GAE/100 g) and DPPH % inhibition (41.03 %). Multivariant analysis was conducted to classify blended oil samples on the basis of oxidative stability and kinetic parameters. The principal component analysis (PCA) and hierarchal cluster analysis (HCA) effectively screened the BPSO with RE (1500 mg/kg), exhibited better oxidative stability (IP110, shelf life at 25 °C) with a slower kinetic rate and can be used as functional oil with a desirable level of PUFA (omega-3).

Keywords

• Perilla seed oil
• Rosemary oil
• Rosemary extract
• Rancimat
• Oxidative stability
• Oxidation kinetics