No. 87 Preparation of tomato cyclodextrin powder for the improvement of unfavorable characteristics of tomato lycopene
Lycopene (Fig. 1), which is a functional ingredient in tomato and watermelon, is known to have a powerful antioxidant effect and prevent various lifestyle-related diseases. In addition to lycopene, tomato also contains 13-oxo-9, 11-octadecadienoic acid (13-oxo-ODA), which has a fat burning effect 1). Thus, tomato is an attractive vegetable having some effective ingredients for health. But lycopene has some unfavorable characteristics like easily oxidizable, low water solubility and therefore low absorbability. We have found that ingestion of fat-soluble substance-γ-cyclodextrin (γ-CD) inclusion complex gives the absorption improvement of the fat-soluble substance. It is due to the formation of molecular bile acid micelle of the fat-soluble substance after releasing from γ-CD. (for further details, please refer to the "25th, 46th, 56th and 67th" research on our homepage). Therefore, in this study, for the purpose of improving the oral absorbability of lycopene in tomato, we prepared tomato CD powders and evaluated the solubility of lycopene in artificial intestinal fluid, which can be used as an index of absorbability.
2-1. Preparation of tomato CD powders
Tomato juice was weighed, and α, β, and γ-CD were added so that the weight ratio was 1:1 with respect to the solid content, and then mixed uniformly. Tomato CD powders were obtained by freeze-drying the resulted pastes.
2-2. Solubility evaluation of lycopene in artificial intestinal fluid from tomato CD powders
Each tomato powder was weighed, was added with artificial intestinal fluid, and the mixture was shaken at 37 ℃ for 2 hours. Then, lycopene in the filtrate obtained by centrifugation and filter filtration was analyzed by HPLC.
Results and discussion
The highest solubility of lycopene in artificial intestinal fluid was shown when tomato-γ-CD powder was evaluated in comparison with tomato powder without CD, tomato-α-CD powder and tomato-β-CD powder (Fig. 2). Therefore, it was anticipated from our previous studies using various fat-soluble substances that the oral absorbability of lycopene in tomato was improved by using γ-CD. Similar results can be expected with watermelon-γ-CD powder.
It is thought that tomato-γ-CD powder and watermelon-γ-CD powder can be useful for the development of new health foods and beverages in expectation of high absorbability of lycopene.
1) Haruya T. et al., Bioscience Biotechnology and Biochemistry, 75 (8), 1621-1624 (2011).