| Lycopene, a carotenoid primarily from tomatoes that is responsible for their red color, has been linked to several health benefits. In plant tissues, lycopene is found almost entirely as the all-trans isomer. However, in animal tissues, the lycopene isomer ratio is about 50% all-trans and 50% cis isomers. One reason for this is that cis isomers may be more bioavailable than the all-trans lycopene. Lycopene is labile to heat, light and oxygen. Cis isomers are less stable than all-trans lycopene, and can undergo retro isomerism. In an attempt to stabilize lycopene containing primarily 13-cis and 9-cis isomers, we microencapsulated lycopene via spray drying. We find that loss of lycopene during spray drying is significant and cis isomer content decreased to a larger degree than all-trans lycopene during spray drying, as determined by HPLC. Therefore optimization of spray drying parameters is especially important when spray drying cis isomers. We find no clear evidence that lycopene encapsulated with medium chain triglycerides (MCT) and gum acacia was more stable than lycopene in MCT only, and the isomer profile could not be maintained by either approach. Lycopene encapsulated with maltodextrin and Tween 80 was found to be more stable than pure lycopene, but less stable than lycopene in MCT. All formulations experienced a change in the lycopene isomer profile. Further modifications to the encapsulation formula and procedures are needed to produce a spray dried microencapsulate that has good lycopene stability in terms of isomerism and degradation. |
