Investigation of food matrices and excipient foods on carotenoid bioaccessibility

Recently, increasing attention has been given to carotenoid bioaccessibility and bioavailability in the field of nutrition research. As a consequence of their lipophilic nature and their specific localization in plant-based tissues, carotenoid bioaccessibility and bioavailability is generally quite low in raw fruits and vegetables, since carotenoids need to be released from the cellular matrix and incorporated in the lipid fraction during digestion before being absorbed. However, the poor water-solubility, high melting point, and low oral bioavailability of lipophilic bioactive agents like carotenoids make them difficult to incorporate into many aqueous-based food products and may reduce their bioaccessibility within the gastrointestinal tract. Today's approach related to improve bioaccessibility is to design of food matrix. Recently, the newest approach, excipient food, has been introduced to improve the bioavailability of orally administered bioactive compounds. The main idea is combining food and another food (the excipient food) whose composition and/or structure is specifically designed to improve health benefits. In this study, carotenoid bioaccessibility in vegetables (tomato, carrot and spinach) rich in different carotenoids with various forms (such as crystalline, globular) depending on the morphology will be determined, and effects of food processing (grated, steamed, puree after steamed, and cooking at different times) and food matrix on carotenoid bioaccessibility and the addition of excipient foods on carotenoid bioaccessibility will be evaluated. Moreover, to gain insight into this subject we have assessed the impact of different excipient foods (olive oil, lemon juice, whey curd or lor cheese and dried artichoke leaves powder) on the carotenoids levels and bioaccessibility of carrot, spinach and tomato. The results demonstrated that the carotenoid content and carotenoid bioaccessibility was significantly affected by excipient food ingredients and food matrix (p < 0.05). The results show that addition of olive oil, lemon juice and whey curd to carrot puree had a marked positive effect on bioaccessibility of β-carotene in carrot samples. The highest carotenoid bioaccessibility (50.26%) was determined for carrot puree with olive oil, lemon juice and whey curd. Addition of excipient foods (olive oil, lemon juice and whey curd) and cooking (100°C, 2 min) had no effect on lutein bioaccessibility in spinach samples. Lycopene bioaccessibility was higher when the tomatoes were cooked (100 °C, 10 min) with excipient foods (20.27%) than when they were cooked alone (5.88%) and added excipient foods (14.95%).