Rosemary extract as a natural antioxidant in structured lipid systems: A sustainable approach to enhance stability of Perilla seed oil based omega-3 fatty acid rich margarine

AISHWARYA DHIMANRajni Chopra^*

• National Institute of Food Technology Entrepreneurship and Management, Sonipat, India

This study explores the use of rosemary extract (RE) as a natural antioxidant to enhance the oxidative stability of omega-3 fatty acid rich margarine formulated with interesterified fat derived from perilla seed oil (PeO). It aims to mitigate the susceptibility of polyunsaturated fatty acids (PUFAs) to oxidation without relying on synthetic antioxidants which may pose health risks with prolonged consumption. The effectiveness of RE at concentrations of 500, 1000, 1500 and 2000 ppm was assessed under accelerated storage conditions by Schaal oven test. Oxidative stability was evaluated by analysing peroxide value, acid value, p-Anisidine value, TOTOX index, conjugated dienes, conjugated trienes and changes in fatty acid composition. The results of the study indicated that incorporation of RE significantly delayed lipid oxidation with reductions of about 40% observed in peroxide values compared to the control SLM (Structutre Lipid Margarine), particularly at 1500 ppm RE. The TOTOX value and conjugated diene and triene content were significantly reduced in RE incorporated samples, indicating enhanced protection against both primary and secondary oxidation. There was a reduction of 21.7%, 21.6%, 26.9%, 37.7%,and 29.3%, in p-Anisidine value of SLM, and SLM incorporated with RE at 500, 1000, 1500, and 2000 ppm respectively when compared to PeO. Antioxidant capacity of RE revealed a concentration dependent improvement, and exhibited superior antioxidant properties than TBHQ. Principal Component Analysis confirmed the effectiveness of RE at 1500 ppm which was comparable to TBHQ in structured lipid systems, validating its functional equivalence in oxidative protection. RE also contributed to a higher retention of PUFA during storage when compared to samples without antioxidants. The synergistic effect of enzymatic interesterification and natural antioxidant supplementation presents a dual and sustainable approach for stabilizing PUFA-rich lipid systems. These findings support the potential of RE as an effective sustainable and natural alternative to synthetic preservatives in functional fat-based food products.