1,721,234 research outputs found
Functional foods: from theory to practice
No full textAmong Functional Foods there are many different "traditional" foods rich in specific compounds shown to produce an effect or modulate a function in our organism. However, in most cases, e. g. in tomato, the evidence has not been sufficient to obtain an official health claim. Nevertheless it is important to investigate further the effects of vegetables in our diet and to communicate correctly their advantages for health. Different works were performed in my laboratory on cruciferous vegetables which contain a lot of active compounds such as vitamins, minerals, carotenoids and glucosinolates. Glucosinolates are metabolised and absorbed as isothiocyanates that can affect the activity of enzymes involved both in the antioxidant defence system and in the detoxification from xenobiotics.. Promising are the preliminary results of human intervention studies demonstrating that the regular intake of broccoli for a relatively short period of time could significantly affect glutathione-S-transferase (GST) activity and cell protection against DNA damage. The entity of the protective effect registered seems also related to the genetic characteristic (GSTM1 polimorphysm) of the subjects considered. These results support the use of the nutrigenetic approach also to study functional foods (e. g. for specific groups of population)
Factors influencing the bioavailability of antioxidants in foods : a critical appraisal
No full textAn important aspect when studying the role of antioxidants in human health is the evaluation of their bioavailability from foods. This aspect is gaining increasing interest as food industries are continually involved in developing new products, defined as ‘‘functional’’ by virtue of the presence
of specific antioxidants or phytochemicals. The bioavailability of these substances is, however, not always well known.
Although, from a theoretical point of view, several
definitions of bioavailability have been suggested, the most appropriate seems to be as that fraction of an ingested nutrient or compound that reaches the systemic circulation and the specific sites where it can exert its biological
action. In this definition, three main steps are implicit: release from the carrier matrix, intestinal absorption and tissue uptake.
These aspects are discussed in the paper
Lymphocyte lycopene concentration and DNA protection from oxidative damage is increased in women after a short period of tomato consumption
No full textSeveral epidemiologic studies have suggested a role of tomato products in protecting against cancer and chronic diseases. In nine adult women, we evaluated whether the consumption of 25 g tomato puree (containing 7 mg lycopene and 0.3 mg β-carotene) for 14 consecutive days increased plasma and lymphocyte carotenoid concentration and whether this was related to an improvement in lymphocyte resistance to an oxidative stress (500 μmol/L hydrogen peroxide for 5 min). Before and after the period of tomato intake, carotenoid concentrations were analyzed by HPLC and lymphocyte resistance to oxidative stress by the Comet assay, which detects DNA strand breaks. Intake of tomato puree increased plasma (P < 0.001) and lymphocyte (P < 0.005) lycopene concentration and reduced lymphocyte DNA damage by ~50% (P < 0.0001). β-Carotene concentration increased in plasma (P < 0.05) but not in lymphocytes after tomato puree consumption. An inverse relationship was found between plasma lycopene concentration (r = -0.82, P < 0.0001) and lymphocyte lycopene concentration (r = -0.62, P < 0.01) and the oxidative DNA damage. In conclusion, small amounts of tomato puree added to the diet over a short period can increase carotenoid concentrations and the resistance of lymphocytes to oxidative stress
Determination of carotenoids in vegetable foods and plasma
No full textIn this paper a HPLC method for the determination of lutein, zeaxanthin, β-cryptoxanthin, α-carotene, β-carotene and lycopene in mixed vegetables and fruit and in human plasma is described. The carotenoids were well separated and the separation was achieved within fifteen minutes using a HPLC system consisting of a 5 μm Vydac 20ITP54 C18 column, an UV detector, methanol-tetrahydrofuran (95:5 v/v) as mobile phase and a flow rate of 1.0 ml/min. The validity of the separation method was determined by evaluating the linearity of the calibration graphs of each carotenoid (between 0.1 and 1.0 μg/ml for all compounds except lycopene between 0.1 and 0.8 μg/ml, r = 0.999) and the accuracy of the chromatographic response (CV < 10%). The re-producibility of the retention times was also good. In the foods samples the extraction procedure was very effective whereas, the saponification step significantly damaged some of the carotenoids. In the plasma the extraction and separation of these compounds were also effective and the qualitative data obtained comparable with those reported in literature. The use of echinenone as internal standard helped to improve quality control
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