Effect of beta-cyclodextrin in improving the correlation between lycopene concentration and ORAC values

Area of Science:

• Biochemistry
• Nutritional Science
• Analytical Chemistry

Background:

• Lycopene, a lipophilic antioxidant, is vital for human health, potentially protecting against cardiovascular disease, cancer, and boosting immunity.
• The Oxygen Radical Absorbance Capacity (ORAC) assay is a standard for measuring antioxidant activity but is not validated for fat-soluble compounds like lycopene.
• Beta-cyclodextrin enhances the water solubility of lipophilic compounds, making them amenable to aqueous assays.

Purpose of the Study:

• To validate the ORAC assay for quantifying the antioxidant activity of lycopene.
• To investigate the effect of beta-cyclodextrin on the correlation between lycopene concentration and ORAC values.
• To expand the applicability of the ORAC assay to include fat-soluble antioxidants.

Main Methods:

• Lycopene was extracted from Lyc-O-Mato 6% extract using a standard spectrophotometric assay.
• Beta-cyclodextrin was added at concentrations of 0%, 0.4%, 0.8%, and 1.6% to enhance lycopene solubility.
• Antioxidant activity was measured using the ORAC assay, with experiments conducted in quadruplicate and analyzed for statistical correlation.

Main Results:

• A strong correlation (R2 = 0.99) was observed between ORAC and ascorbic acid, validating the assay method.
• In the absence of beta-cyclodextrin, lycopene concentration showed a poor correlation with ORAC (R2 = 0.33).
• Correlation improved with increasing beta-cyclodextrin concentrations (R2 = 0.58 at 0.4%, R2 = 0.91 at 0.8%), but decreased at 1.6%.

Conclusions:

• The inclusion of beta-cyclodextrin significantly improves the correlation between lycopene concentration and ORAC values.
• This study successfully validates the ORAC assay for measuring the antioxidant capacity of lycopene, a key fat-soluble antioxidant.
• The findings expand the utility of the ORAC assay for evaluating a broader range of antioxidants, including lipophilic compounds.