Rice and quinoa starches are modified with short-chain fatty acids (SCFA) with different SCFA acyl chain lengths and levels of modification. This work is aimed to investigate the impact of modifying rice and quinoa starches with short-chain fatty acids (SCFAs) on various physicochemical properties, including particle size, protein and amylose content, thermal behavior, pasting characteristics, and in vitro digestibility. Both native and SCFA-starches showed comparable particle sizes, with rice starches ranging from 1.58 to 2.22 μm and quinoa starches from 5.18 to 5.72 μm. SCFA modification led to lower protein content in both rice (0.218-0.255 %) and quinoa starches (0.537-0.619 %) compared to their native counterparts. Esterification led to the reduction of gelatinization and pasting temperatures as well as the hardness of the paste of SCFA-starches were reduced while paste clarity increased. The highest level of modification in SCFA-starch was associated with the highest amount of resistant starch fraction. Principal component analysis revealed that modification levels exerted a greater influence on starch properties than the types of SCFA used (acetyl, propionyl, and butyryl). These findings is importance in considering the degree of substitution or level of modification when tailoring starch properties through SCFA modification, with implications for various applications in food applications.
Acetylated, propionylated and butyrylated rice and quinoa starches at different levels of modification and starch concentrations, were used to stabilize oil-in-water starch Pickering emulsions at 10% oil fraction. Short-chain fatty acid modified starch Pickering emulsions (SPEs) were characterized after emulsification and after 50 days of storage. The particle size distribution, microstructure, emulsion index, and stability were evaluated. An increase in starch concentration led to a decrease of emulsion droplet sizes. Quinoa starch has shown the capability of stabilizing Pickering emulsions in both the native and modified forms. The emulsifying capacity of SPEs was improved by increasing the chain length of SCFA. Modified quinoa starch with higher chain lengths (i.e. propionylated and butyrylated), at higher levels of modification, showed higher emulsion index (>71%) and stability over the entire 50 days storage. At optimized formulation, SCFA-starch particles have the potential in stabilizing emulsions for functional foods, pharmaceutical formulations, or industrial food applications.
Rapeseed protein is not currently utilized for food applications, although it has excellent physicochemical, functional, and nutritional properties similar to soy protein. Thus, the goal of this study was to create new plant-based extrudates for application as high-moisture meat analogs from a 50:50 blend of rapeseed protein concentrate (RPC) and yellow pea isolate (YPI) using high-moisture-extrusion (HME) cooking with a twin-screw extruder to gain a better understanding of the properties of the protein powders and resulting extrudates. The effects of extrusion processing parameters such as moisture content (60%, 63%, 65%, 70%), screw speed (500, 700, and 900 rpm), and a barrel temperature profile of 40-80-130-150 °C on the extrudates' characteristics were studied. When compared to the effect of varying screw speeds, targeted moisture content had a larger impact on textural characteristics. The extrudates had a greater hardness at the same moisture content when the screw speed was reduced. The specific mechanical energy (SME) increased as the screw speed increased, while increased moisture content resulted in a small reduction in SME. The lightness (L*) of most samples was found to increase as the target moisture content increased from 60% to 70%. The RPC:YPI blend was equivalent to proteins produced from other sources and comparable to the FAO/WHO standard requirements.