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Hydrophobic curcumin in temulawak extract and hydrophilic betacyanin in red dragon fruit extract are high-value bioactive compounds with extensive applications in functional food. In this study, these extracts were encapsulated in water-in-oil-in-water (w/o/w) nanoemulsions as a delivery system using a two-step high-energy emulsification method. PGPR and Span 20 were used as lipophilic emulsifiers for the primary w/o emulsion. The most stable w/o/w formulation with the least oil phase separation of 5% v/v consisted of w/o emulsion (15% w/w) and Tween 80 (1.5% w/w) as hydrophilic emulsifier. The formulation was characterized by a 189-nm mean droplet diameter, 0.16 polydispersity index, and –32 mV zeta potential. The freeze–thaw stability may be attributed to the combination of low w/o emulsion content and high Tween 80 concentration in the outer water phase of the w/o/w nanoemulsions used in this study. The IC50 values of the nanoemulsion and the red dragon fruit extract were similar. It means that the higher concentration of curcumin in the nanoemulsions and the lower IC50 value of temulawak extract ensured sufficient antioxidant activities of the w/o/w nanoemulsions. 相似文献
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Niken Taufiqurrahmi Abdul Rahman Mohamed Subhash Bhatia 《Journal of nanoparticle research》2011,13(8):3177-3189
Nanocrystalline zeolites with crystal size smaller than 100 nm are potential replacement for conventional zeolite catalysts
due to their unique characteristics and advantages. In this study, the synthesis of nanocrystalline zeolite Y (FAU) and nanocrystalline
zeolite beta (BEA) under hydrothermal conditions is reported. The effect of crystal size on the physico-chemical characteristics
of the zeolite, Y (FAU), and beta (BEA) is reported. The properties of nanocrystalline zeolites Y and Beta with crystal size
around 50 nm are compared with the microcrystalline zeolite Y and microcrystalline zeolite beta, respectively. The performance
of the nanocrystalline zeolite as a catalyst was investigated in the cracking of used palm oil for the production of biofuel.
The nanocrystalline zeolite catalytic activity was compared with the activity of microcrystalline zeolite in order to study
the effect of crystal size on the catalytic activity. Both nanocrystalline zeolites gave better performance in terms of conversion
of used palm oil as well as selectivity for the formation of gasoline fraction. The increase in surface area and improved
accessibility of the reactant in nanocrystalline zeolites enhanced the cracking activity as well as the desired product selectivity. 相似文献
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