Combination of hydrophilic or lipophilic natural compounds to improve the oxidative stability of flaxseed oil

Abstract

Oxidation of bulk oils involves radical molecules, transitions metals and association colloids, among other factors. Combining mechanistically different antioxidants is one possible strategy to improve oxidative stability of polyunsaturated fatty acids rich oils. However, antioxidant polarity may play a critical role in the oxidative protection efficacy. Thus, the objective of this study was to formulate a hydrophilic mixture (HM) containing sinapic, ascorbic and citric acid and a lipophilic mixture (LM) composed of α‐tocopherol, ascorbyl palmitate and citric acid, and apply these mixtures in crude and stripped flaxseed oils. The oxidative stability of crude oil samples containing HM and LM was comparable to that of artificial compounds mixture (ethylenediamine tetraacetic acid (EDTA) and terc‐butyl hydroquinone (TBHQ). HM was more effective than LM in crude oil, but not in stripped oil, suggesting a strong influence of minor components on antioxidant activity of natural compounds.

Practical applications: The increasing demand for foods containing polyunsaturated fatty acids (PUFA) brings the challenge of their chemical stabilization. Here, a strategic mixture of hydrophilic natural antioxidants was effective to stabilize flaxseed oil, with effectiveness comparable to that of artificial antioxidants. Therefore, this hydrophilic mixture constitutes a feasible and efficient option to be applied by food producers, especially in formulations that present a health claim.

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