Author
LOU, YANGCHAO - University Of Maryland | |
Wang, Thomas - Tom | |
TENG, ZI - University Of Maryland | |
Chen, Pei | |
SUN, JIANGHAO - Johns Hopkins University | |
WANG, QIN - University Of Maryland |
Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/28/2013 Publication Date: 8/1/2013 Citation: Lou, Y., Wang, T.T., Teng, Z., Chen, P., Sun, J., Wang, Q. 2013. Encapsulation of indole-3-carbinol and 3'3'-diindolylmethane in zein/carboxymethyl chitosan nanoparticles with controlled release property and improved stability. Food Chemistry. 139(1-4):224-30. Interpretive Summary: Indole-3-carbinol (I3C) and diindolylmethane (DIM) are two bioactive compounds from Cruciferous vegetables. However, they are not stable enough for pharmaceutical applications. To solve the problem, zein nanoparticles were used in this study to encapsulate I3C and DIM . The encapsulation efficiency of zein nanoparticles was greatly improved after coating with carboxymethyl chitosan (CMCS). The effects of encapsulation on stabilities of I3C and DIM have been systematically studied under UV-light exposure and thermal (37°C) treatments. Zein and zein/CMCS nanoparticles provided similar protection for both I3C and DIM against UV-light, attributed to the contribution of zein protein. Under thermal conditions, I3C control degraded and oligomerized to form DIM and other products after 24 h, but Zein/CMCS nanoparticles protected I3C from thermo degradation and inhibited the oligomerization to DIM and other products. It also showing significantly better protection than zein nanoparticles alone. Technical Abstract: Indole-3-carbinol (I3C) and diindolylmethane (DIM) are two bioactive compounds from Cruciferous vegetables. Their stabilities are the major challenges for their pharmaceutical applications. In this study, zein and zein/carboxymethyl chitosan (zein/CMCS) nanoparticles have been prepared to encapsulate I3C and DIM by liquid-liquid phase separation and ionic gelation method. The particle sizes of zein and zein/CMCS nanoparticles were around 250 and 100 nm, and zeta potential are around -10 and -20 mV, respectively. The encapsulation efficiency of zein nanoparticles was greatly improved after coated with CMCS. Both nanoparticle formulations provided the controlled release of I3C and DIM in PBS medium. The effects of encapsulation on stabilities of I3C and DIM have been systematically studied under UV-light exposure and thermal (37°C) treatments. Zein and zein/CMCS nanoparticles provided similar protection for both I3C and DIM against UV-light, attributing to the contribution of zein protein. Under thermal conditions, I3C control degraded and oligomerized to form DIM and other products after 24 h. Zein/CMCS nanoparticles not only protected I3C from degradation, but also inhibited the dimerization to DIM and other products, showing significantly better protection than zein nanoparticles. Based on our results, the encapsulation of hydrophobic bioactives in zein/CMCS nanoparticles is a promising approach to improve stabilities against harsh conditions, and may provide a possible way to dissect the efficacy of I3C and DIM. |