Microencapsulation of Purple Mashua Extracts Using Andean Tuber Starches Modified by Octenyl Succinic Anhydride

Abstract

This work is aimed at optimising the spray drying conditions of the phenolic extracts of purple mashua microencapsulated with octenyl succinic anhydride (OSA) Andean tuber starches. Purple mashua extracts were obtained and spray dried using native and OSA starches of yellow oca, pink oca, and yellow olluco (140°C, 4% starch). The powders obtained were analysed by encapsulation efficiency of anthocyanin (EE), total phenol content, and antioxidant capacity to select the best starch for optimisation purposes. OSA pink oca starch was selected because the obtained powder presented the highest EE. The spray drying conditions optimised were obtained using a central composite rotatable design (CCRD) and response surface methodology. The encapsulant proportion of OSA pink oca starch (2-12%) and the inlet drying temperature (IDT, 120-160°C) were used as factors of the design. The optimised spray drying condition was 160°C IDT and 2% encapsulant; this condition maximised the EE, total phenol content, antioxidant capacity, and solubility and minimised the water activity and hygroscopicity of the powder. The OSA pink oca starch could be used as an encapsulating agent of phenolic extracts because it can produce powder with high antioxidant capacity and high EE.

Effect of Inlet Air Temperature and Quinoa Starch/Gum Arabic Ratio on Nanoencapsulation of Bioactive Compounds from Andean Potato Cultivars by Spray-Drying

“…It can be observed that an increase in temperature leads to a significant increase in polyphenols. This phenomenon can be attributed to the almost instantaneous formation of a protective layer of gelatinized starch on the nanocapsules due to a higher inlet temperature in the spray-drying process [4,60]. On the other hand, it can be seen that a higher percentage of encapsulants is associated with a significant decrease in the concentration of these compounds.…”

“…The increase in temperature could be attributed to the destabilization of the nanocapsule walls, facilitating the release of bioactive compounds [4]. However, increasing the concentrations of the encapsulating agents reduced the antioxidant activity, a behavior related to the decrease in the content of bioactive compounds due to the dilution effect of the matrix [60].…”

“…It can be observed that the higher the temperature and percentage of the encapsulant, the higher the yield obtained. High spray-drying temperatures improve the encapsulation efficiency of bioactive compounds by promoting rapid formation of the capsule wall [32,60]. Likewise, a higher concentration of encapsulating material increases the retention of the active nucleus due to a greater matrix thickness [4,30].…”

“…It can be seen that the higher the temperature and percentage of the encapsulant, the lower the water activity. It is known that increasing spray-drying temperatures promotes the rapid evaporation of water, reducing the water activity in the powders obtained [60]. Also, higher concentrations of encapsulating agents can form more homogeneous and stable matrices, limiting water availability [66].…”