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The effect of heat treatment below the gelatinization temperature on the susceptibility of corn, mung bean, sago, and potato starches towards granular starch hydrolysis (35°C) was investigated. Starches were hydrolyzed in granular state and after heat treatment (50°C for 30 min) by using granular starch hydrolyzing enzyme for 24 h. Hydrolyzed heat-treated starches showed a significant increase in the percentage of dextrose equivalent compared to native starches, respectively, with corn 53% to 56%, mung bean 36% to 47%, sago 15% to 26%, and potato 12% to 15%. Scanning electron microscopy micrographs showed the presence of more porous granules and surface erosion in heat-treated starch compared to native starch. X-ray analysis showed no changes but with sharper peaks for all the starches, suggested that hydrolysis occurred on the amorphous region. The amylose content and swelling power of heat-treated starches was markedly altered after hydrolysis. Evidently, this enzyme was able to hydrolyze granular starches and heat treatment before hydrolysis significantly increased the degree of hydrolysis.

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In the present work, the effect of the emulsifier type, namely Tween 80 (T80), lecithin, sodium caseinate and gum arabic, on the physicochemical properties of lycopene nanodispersions was investigated. A lycopene nanodispersion was produced by emulsification-evaporation method. The lycopene nanodispersion exhibited different physicochemical properties with different types of emulsifiers. The smallest particle size and the highest transmittance of lycopene nanodispersion were obtained by using Tween 80 followed by lecithin, sodium caseinate and gum arabic. The lycopene nanodispersion produced from lecithin was the most stable, exhibiting the lowest polydispersity (PDI) value, narrow and monomodal distribution and high zeta potential value. Sodium caseinate retained the highest lycopene concentration among all the emulsifier types. Transmission electron microscopy (TEM) micrographs revealed sphere-shaped lycopene droplets at different sizes depending on the types of emulsifier used. The results from this study provide useful information to produce desirable properties in lycopene nanodispersions for food applications.