Spray-Drying, Oil Blending, and the Addition of Antioxidants enhance the storage stability at room temperature of omega-3-rich microcapsules based on chia oil

Abstract

Chia oil (CO) has gained popularity given its α-linolenic acid content (around 60%). Nonetheless, the susceptibility of polyunsaturated fatty acids toward oxidation represents a challenge for incorporating CO in different products, which justifies the need for exploring stabilization methods. To the best of the authors' knowledge, no reports about powders based on chia oil blends are published. Therefore, the objective of this research is to evaluate the stability at room temperature of microencapsulated CO blends [with virgin sesame (VSO) and wheat germ (WGO) oils] and microencapsulated CO with the addition of tert-butylhydroquinone (TBHQ). Spray-drying yielded powders with a better encapsulation efficiency, flowability, and stability, compared with freeze-drying. After a storage test performed during 3 months, the highest hydroperoxide content (>100 meq.O2 kg−1 oil) is observed for the microencapsulated CO/WGO 80/20 blend, despite its α and β-tocopherol contents and its antioxidant activity (>90% inhibition of DPPH radical). Notwithstanding, bulk and microencapsulated CO-TBHQ, CO/VSO 80/20, and 20/80 showed hydroperoxide contents <8 meq.O2 kg−1 oil. By the end of the test, the highest induction period is observed for the microencapsulated CO/VSO 20/80 blend (19.85 ± 0.18 h). Finally, the drying method and the core formulation greatly affect the stability of microcapsules. Practical Applications: Addition of antioxidants, oil blending and microencapsulation are technological solutions for the preservation of omega-3-rich oils, which are popular among healthy food consumers. This research studies and compares the microencapsulation processes by spray or freeze-drying in order to preserve chia oil blends (with virgin sesame and wheat germ oils) and chia oil with the addition of antioxidants, thereby taking the advantages of the three technological solutions mentioned above. Stable omega-3-rich powders, with a higher oxidative stability than pure chia oil, can be obtained as ingredients for the food industry. This ultimately allows the incorporation of the oil into different food products developed to satisfy specific market tendencies.