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ABSTRACT:
In this study, changes in an extra virgin olive oil treated with lycopene during storage were analyzed. Pure lycopene (0.5 and 1.0 mg) obtained from tomato was added to two separate bottles, each containing 100 mL of extra virgin olive oil, while another bottle containing the same oil was stored without any treatment. Samples enriched with pure lycopene showed PV remarkably lower than the sample without lycopene, and the total phenol contents were higher in treated oil samples than in the reference sample. In addition, a good correlation (r^sup 2^ = 0.969) between total phenol content and antioxidant power calculated as Trolox Equivalent Antioxidant Capacity (TEAC) was observed. The concentration of added lycopene decreased very slowly; after about 8 mon its residual value was over 60% with respect to the initial concentration.
Paper no. J11390 in IAOCS 83, 933-941 (November 2006).
KEY WORDS: Antioxidant properties, β;-carotene, carotenoids, HPLC-MS, lycopene, peroxide value, polyphenols, TEAC, α-to-copherol.
(ProQuest Information and Learning: ... denotes formulae omitted.)
Carotenoids such as lycopene and β-carotene (Scheme 1 ) are principally responsible for the colors of vegetables and fruits. Like other carotenoids, lycopene, which provides the red color of tomatoes (Lycopersicon esculentum), is fat-soluble. In certain plants and microorganisms, lycopene serves as an accessory light-gathering pigment and as a protection against the toxic effects of oxygen and light (1). Lycopene may also protect humans against certain disorders, such as prostate cancer and perhaps some other cancers, and coronary heart disease (2-4).
As well as in tomatoes and tomato-based products, such as ketchup, pizza sauce, tomato juice and tomato paste, lycopene is found in watermelon, papaya, pink grapefruit, and pink guava. Furthermore, new lycopene-containing products have been placed on the market over the past years, including a reduced-fat margarine to which lycopene and lutein are added to produce a functional product. The lycopene in processed tomato products is more readily available to the body than that in fresh tomatoes. The average daily intake of lycopene is approximately 25 mg, with 50% in the form of processed tomato products (5,6). Various authors studied the correlations between oxidative stability and minor constituents of virgin olive oil (7) as well as the deterioration of natural antioxidant species of edible vegetable oils under deep-frying conditions...