Evaluation of Natural Antioxidants

This book relates the physicochemical properties of
phenolic compounds to their antioxidant activities.
It focuses on the partitioning of phenolic compounds
between hydrophilic and lipophilic environments and
the relevance this has to their in vivo health
effects. The partition coefficients (log P) of
phenolic antioxidants were measured by RP-HPLC.
The lipid Peroxidation Inhibition Capacity Assay
(LPIC), based on using liposomes to simulate a cell
membrane environment, was developed to measure the
activity of antioxidants with a broad range of
structures. The activities were correlated against
several physicochemical parameters and used to
derive a predictive model to calculate the LPIC
activity. The LPIC activities also correlated well
to published LDL inhibition activities but not to
measured ORAC activities. These findings suggested
that behaviours of antioxidants in the small
unilamellar vesicles of the LPIC assay were similar
to that in the LDL assay but not to the aqueous
phase based ORAC assay. The LPIC assay may
therefore be a better indicator of potential health
benefits of antioxidants in the human body.

Autorentext

Jingli Zhang received his PhD in 2004. During his PhD study, he investigated the health benefits of phytochemicals. Dr Zhang is currently working as a Senior Scientist at Plant & Food Research (New Zealand), where he investigates the health benefits of fruits and vegetables using chemical, cellular, animal and human models.

Klappentext

This book relates the physicochemical properties of phenolic compounds to their antioxidant activities. It focuses on the partitioning of phenolic compounds between hydrophilic and lipophilic environments and the relevance this has to their in vivo health effects. The partition coefficients (log P) of phenolic antioxidants were measured by RP-HPLC. The lipid Peroxidation Inhibition Capacity Assay (LPIC), based on using liposomes to simulate a cell membrane environment, was developed to measure the activity of antioxidants with a broad range of structures. The activities were correlated against several physicochemical parameters and used to derive a predictive model to calculate the LPIC activity. The LPIC activities also correlated well to published LDL inhibition activities but not to measured ORAC activities. These findings suggested that behaviours of antioxidants in the small unilamellar vesicles of the LPIC assay were similar to that in the LDL assay but not to the aqueous phase based ORAC assay. The LPIC assay may therefore be a better indicator of potential health benefits of antioxidants in the human body.