Flaxseed and avocado oil blends: Physical and physicochemical characterization, nutritional quality and oxidative stability

Abstract

This research investigated the physical and physicochemical characteristics, nutritional quality, and oxidative stability of flaxseed oil (FO) and avocado oil (AO) and their blends. Five formulations, varying the mass ratio between AO and FO (AO: FO, 0 %:100 %; AO: FO, 25 %:75 %; AO: FO, 50 %:50 %; AO: FO, 75 %:25 %; AO:FO, 100 %:0 %) were analyzed by fatty acids composition, total content of chlorophylls and carotenoids, tocopherols content, antioxidant activity, physical properties, nutritional parameters, and quality parameters. The peroxide index (PI) and extinction coefficients (K232 and K270) were used to assess the oxidative stability. The results revealed that pure avocado oil presented an unbalanced ratio of ω6-ω3 fatty acids of 18.40:1. Flaxseed and avocado oil blends were able to balance ω6-ω3 fatty acids content and positively affected the atherogenicity and thrombogenicity index values. Adding avocado oil to flaxseed oil significantly increased the total content of chlorophyll and carotenoid and antioxidant activity. At the end of the oxidative stability analysis, a variation of the PI of 17.18 times was observed for pure flaxseed oil and 2.09 times for pure avocado oil. Variations of the PI remained below 1.7 times for all blends. Regarding K232 and K270, variations of 2.0 and 4.01 times were observed for pure flaxseed oil, respectively. On the other hand, values below 1.15 and 1.48 were verified for pure avocado and the blends, respectively. The increased oxidative stability could be related to increased monounsaturated and saturated fatty acids content (oleic, palmitic, and palmitoleic fatty acids) and natural antioxidants present in the oil blends.