Characterization and evaluation of acid-modified starch of Dioscorea oppositifolia (Chinese yam) as a binder in chloroquine phosphate tablets

Chinese yam (Dioscorea oppositifolia) starch modified by acid hydrolysis was characterized and compared with native starch as a binder in chloroquine phosphate tablet formulations. The physicochemical and compressional properties (using density measurements and the Heckel and Kawakita equations) of modified Chinese yam starch were determined, and its quantitative effects as a binder on the mechanical and release properties of chloroquine phosphate were analyzed using a 2³ full factorial design. The nature (X1), concentration of starch (X2) and packing fraction (X3) were taken as independent variables and the crushing strength-friability ratio (CSFR), disintegration time (DT) and dissolution time (t80) as dependent variables. Acid-modified Chinese yam starch showed a marked reduction (p<0.05) in amylose content and viscosity but increased swelling and water-binding properties. The modified starch had a faster onset and greater amount of plastic flow. Changing the binder from native to acid-modified form led to significant increases (p<0.05) in CSFR and DT but a decrease in t80. An increase in binder concentration and packing fraction gave similar results for CSFR and DT only. These results suggest that acid-modified Chinese yam starches may be useful as tablet binders when high bond strength and fast dissolution are required

Heat-drying and size reduction-treated tapioca flour stabilized oil-in-water emulsion-loaded eugenol: Physical properties, stability, and in vitro gastrointestinal digestion

Native tapioca is strongly hydrophilic and hence not surface active in an emulsion. This research improved the functional properties of tapioca flour using physical modifications as heat-drying (HD) and combined heat-drying and ball milling (HD-Bmill) to act as a particle stabilizer in Pickering oil-in-water emulsions. The modified tapioca flour-stabilized emulsion was used to encapsulate eugenol (oil-soluble bioactive compound), and eugenol stabilities during storage and in vitro gastrointestinal digestion were investigated. Results showed that the HD and HD-Bmill treatments changed the morphology and physicochemical properties of the tapioca flour, especially by increasing the hydrophobicity and emulsifying ability, expressed as surface activity on the oil droplet surface. The HD and HD-Bmill-stabilized emulsion-loaded eugenol enhanced eugenol encapsulation efficiency (EE) compared to the control emulsion (without flour) and the emulsion containing native flour, resulting in higher antioxidant activity. The HD and HD-Bmill flours improved eugenol stability during storage at room temperature for 14 days compared to native flour. After the eugenol-loaded emulsions had passed through in vitro gastrointestinal digestion, the HD and HD-Bmill flours increased the release of free fatty acids, indicating an increase in lipid digestibility compared to native flour. The HD-Bmill flour also improved eugenol stability during digestion compared to native flour. HD-Bmill flour showed promise as an alternative non-chemical particle stabilizer for applications in functional emulsion foods that encapsulate oil-soluble bioactive compounds

Novel starch based emulsion gels and emulsion microgel particles: Design, structure and rheology

Novel starch-based emulsion microgel particles were designed using a facile top-down shear-induced approach. The emulsion droplets were stabilized using octenyl succinic anhydride (OSA) modified starch and incorporated into heat-treated and sheared native starch gels, forming emulsion gels. Using gelation kinetics and small deformation rheological measurements of sheared native starch gels and emulsion gels, OSA starch-stabilized emulsion droplets were demonstrated to act as “active fillers”. By varying native starch concentrations (15–20 wt%) and oil fractions (5–20 wt%), optimal concentrations for the formation of emulsion microgel particles were identified. Microscopy at various length scales (transmission confocal laser scanning and cryo-scanning electron microscopy) and static light scattering measurements revealed emulsion microgel particles of 5–50 μm diameter. These novel emulsion microgel particles created via careful combination of gelatinized native starch and OSA stabilised-emulsion droplets acting as active fillers may find applications in food and personal care industries for delivery of lipophillic molecules