Morphology and physicochemical properties of porous sago starch carriers produced by a variety of combination pre-treatment techniques

Abstract

Porous starch is a type of modified starch that recently gained interest and continuous innovation in food applications. It provides high surface area, great absorption, and protection for active compounds from degradation with controlled release ability. Porous starch is generally produced by different treatment including physical, chemical, enzyme, or their combination and various type of starches. However, production and characterization of porous sago starch is still scarce. This research aimed to, (i) produce porous sago starch using three different pre-treatment methods in combination with ultrasonic and enzymatic treatments, and (ii) characterize the morphology and physicochemical properties of porous sago starch produced by these methods. Microwave, heat moisture and freeze-thaw treatments were used to pre-treated native sago starch, followed by an ultrasonic and enzyme hydrolysis process. The application of freeze-thaw pre-treatment, ultrasonic treatment, and enzyme treatment (FT) resulted in the formation of pore structures on the surface of the granules and the disruption of the double helix bond, as indicated by the lowest value of 0.97 at a band ratio 995/1022 cm^− 1. Prior to pore formations, the FT sample had the highest absorption capacity for water and oil at 37.04% and 108.74%, respectively. The enthalpy of gelatinization (ΔH) is significantly lower in treated samples (range 2.98–3.13 J/g) compared to the native (3.32 J/g). Regardless of the variation treatments applied, the crystallinity value of all samples remained unchanged, which corresponds to the peak ratio 1047/1022 cm^− 1. The morphology and physicochemical experiments demonstrate that porous sago starch has significant potential as an active compound carrier and could be used in food packaging application.