Effects of oil-droplet diameter on the stability of squalene oil in spray-dried powder

Abstract

Effects of the oil-droplet diameter and emulsification with polymerized sodium caseinate (PNC) on the stability of squalene oil (SQ) retention in spray-dried powder were investigated. The SQ droplet diameter significantly affected the stability of the oil in spray-dried powders. The degradation behavior of SQ powders at 105 C was correlated using the Avrami equation. This oxidation mechanism may occur because of the propagative transfer of radical oxidation between oil-droplet particles. SQ emulsified with 5 wt% PNC and small oil droplets had better oxidative stability when compared with 3 wt% sodium caseinate (NC).

New Trends in the Microencapsulation of Functional Fatty Acid‐Rich Oils Using Transglutaminase Catalyzed Crosslinking

“…Therefore, there is a reverse relationship between the surface or nonencapsulated oil and EE levels, so that the lower oil‐EE indicates the higher surface oil, and enhanced oxidation rate and off‐flavor intensity (Bao and others ; Wang and others ; Eratte and others ). As a general rule, microencapsulated powders obtained from oil‐droplets with larger diameters have a higher surface oil ratio and a lower EE value (Ghani and others ). It seems that the conversion of coarser emulsion droplets to finer ones with shear forces during emulsification process can lead to fast oil oxidation during storage as a result of oil accumulation on the particle surface (Pourashouri and others ; Ghani and others ).…”

“…As a general rule, microencapsulated powders obtained from oil‐droplets with larger diameters have a higher surface oil ratio and a lower EE value (Ghani and others ). It seems that the conversion of coarser emulsion droplets to finer ones with shear forces during emulsification process can lead to fast oil oxidation during storage as a result of oil accumulation on the particle surface (Pourashouri and others ; Ghani and others ). This fact also results in the development of fragile and dark‐colored powders by forming cracks and wrinkles on the surface structure of microcapsules (Pourashouri and others ; Ghani and others ).…”

“…In this two‐phase technique, emulsification is firstly conduced to payload PUFAs by applying a polysaccharide and/or protein based‐carrier substance and then the core material encapsulated during spray‐drying in the second step. Accordingly, determination of optimal conditions of oil emulsifying (oil loading, and emulsifier type and concentration), and homogenizing (pressure and process cycles) can provide the long‐term stability with ideal droplet size and rheological properties (Gharibzahedi and others ; Ghani and others ). Optimization of operating parameters involved in spray drying of stabilized emulsions such as inlet air temperature and flow rates of air, feed and aspiration can highly ensure excellent physicochemical attributes of microparticle powders like encapsulation efficiency (EE) and lipid oxidation.…”

“…TGase‐induced gelation was utilized for emulsion‐based spray drying microencapsulation of microalgal oil rich of DHA by SC and maltodextrin (MD) (Bao and others ), fish oil by fish gelatin and MD (Pourashouri and others , , ), omega‐3 fatty acids by MD and bovine or caprine casein (Mora‐Gutierrez and others ), and squalene oil by PSC, SC, and MD (Ghani and others ). The results demonstrated that TGase formulated in emulsions is able to stabilize powders encapsulating biologically active lipid‐based materials.…”

“…It seems that the conversion of coarser emulsion droplets to finer ones with shear forces during emulsification process can lead to fast oil oxidation during storage as a result of oil accumulation on the particle surface (Pourashouri and others ; Ghani and others ). This fact also results in the development of fragile and dark‐colored powders by forming cracks and wrinkles on the surface structure of microcapsules (Pourashouri and others ; Ghani and others ). Therefore, use of the suitable homogenizing speed and pressure are highly relevant in the reduction of surface oil content of microcapsules.…”