Physicochemical characterization and oxidation stability of Sacha inchi oil encapsulated by spray drying

Abstract

In this study, we propose to assess the physicochemical characteristics of the maltodextrin and sodium caseinate capsules used to protect Sacha inchi oil (SIO) and their oxidative stability during storage using a secondary oxidation compound as an indicator. Various indicators of oxidation, including peroxide value (PV), malondialdehyde (MDA), and p-inside (p-AN), were evaluated. Three distinct oil-in-water emulsions were prepared and subsequently subjected to spray drying, utilizing a constant concentration of SIO at 10% v/v. These emulsions were formulated using a combination of maltodextrin and sodium caseinate at three different ratios: 1:1 (T1), 3:1 (T2), and 1.7:0.2 (T3), equivalent to 20% w/v of the emulsion. Fourier transform infrared spectroscopy revealed the absence of chemical interactions between the oil and the capsule materials, and thermogravimetric analysis indicated that all three SIO treatments exhibited notable thermal stability. Our data suggest that the formulation employed in T3 effectively maintained the oxidative stability of the encapsulated oil when contrasted with the other treatments: pansidine values for T1, T2, and T3 were 2.19 ± 0.13; 4.46 ± 0.12 and 1.43 ± 0.11 respectively and TBARS value for T1, T2, and T3 were 6.51 ± 0.41; 4.98 ± 0.16 and 2.62 ± 0.22 respectively, at 15 days storage, highlighting its potential as a superior choice for enhancing the oxidative stability of sacha inchi oil microencapsulation. Since SIO is a rich source of polyunsaturated fatty acids, this study represents a significant advancement in developing strategies to extend its shelf life. By enhancing its stability, the oil can be more effectively incorporated into consumers’ diets and utilized to prepare other functional foods.