Tomato-enriched oil could lead to elaborate functional foods
them to edible oils boosts the thermal of stability of olive and
sunflower oils, reports a new study.
The research, published online in the peer-review journal Food Chemistry by scientists in Algeria and Greece, taps into the trend of sourcing value-added ingredients from agri-industrial waste. "The enrichment of oils with tomato carotenoids and lycopene, in particular low quality oils like refined olive oils, might be an alternative approach to elaborate new functional foods," wrote lead author Amar Benakmoum from M'Hamed Bougara University of Boumerdes in Algeria. Interest is growing in plant-derived food additives as replacements to synthetic antioxidants like butylhydroxyanisole (BHA) and BHT to slow down the oxidative deterioration of food. Indeed, according to a 2003 report by Frost and Sullivan, the synthetic antioxidant market is in decline, while natural antioxidants, such as herb extracts (particularly rosemary), tocopherols (vitamin E) and ascorbates (vitamin C) are growing, pushed by easier consumer acceptance and legal requirements for market access. Benakmoum and co-workers extracted carotenoids from tomato by-products (peel and purée) and added them to refined olive oil (so-called low quality edible oil), and compared this to extra virgin oil and refined sunflower oil. They report that the addition of either the peel or purée did not negatively impact on the levels of acidity or levels of peroxide of the oils, except for the refined sunflower oil where an increase in peroxide levels was recorded. In addition to lycopene and beta-carotene, the researchers also noted that the flavonoids rutin and naringenin were detected and attributed to the tomato purée or peel. "Interestingly, tomato peel incorporation in refined olive oil was more efficient to enhance its content on lycopene and beta-carotenoids as compared to tomato purée," "Moreover, tomato purée incorporation induced leaching of phenolic compounds, while tomato peel permitted to overcome this problem and enhance significantly the total phenol content of the refined olive oil," they added. "All in all, the results of this study show that the incorporation of tomato peel, as agro-industrial tomato waste, is an efficient means to extract carotenoids and phenolics into the fatty substrate, to enhance their bioavailability, thus upgrading low quality edible oils," concluded Benakmoum and co-workers. Added health benefits Tomatoes are a valuable source of nutrients, including beta-carotene, vitamins C and E, and lycopene, a potent antioxidant that gives the fruit its characteristic red colour. Epidemiological evidence has suggested that tomato-based foods can protect men from prostate cancer. One study found that men eating four to five tomato based-dishes per week were 25 per cent less likely to develop prostate cancer compared to men eating tomatoes only rarely. Such findings are boosting the lycopene market, with growth rates forecast at over 100 per cent by Frost and Sullivan, albeit from a low base of around €27m ($34m) in 2003. However, doubts have been raised about the benefits of the carotenoid after the FDA reported finding no credible evidence supporting lycopene intake and a reduced risk of prostate, lung, colorectal, gastric, breast, ovarian, endometrial, or pancreatic cancer. Source: Food Chemistry (Elsevier) Published online ahead of print, doi: 10.1016/j.foodchem.2008.02.063 "Valorisation of low quality edible oil with tomato peel waste" Authors: A. Benakmoum, S. Abbeddou, A. Ammouche, P. Kefalas, D. Gerasopoulos