Intestinal absorption of lycopene from different matrices and interactions to other carotenoids, the lipid status, and the antioxidant capacity of human plasma

Summary Background: The bioavailability of carotenoids has been investigated in animal studies as well as in human studies, so far mostly for β-carotene. Only few results exist for lycopene. In recent studies, lycopene was significantly better available from processed tomatoes compared to raw tomatoes, when using daily intakes between 16.5 mg and 75 mg lycopene. Aim of the study In a comparative study the availability of a low oral lycopene dosage of 5 mg/d from different food matrices versus soft gel capsules containing tomato oleoresin was assessed. In addition to the plasma carotenoid content, the effect of lycopene ingestion on other plasma carotenoids, the lipid status parameters, and the antioxidant activitys was estimated. Methods Twenty-two female adults (20 – 27 y) were randomized in three groups and were advized to minimize their carotenoid intake for two weeks. After this initial period, two groups received a portion of tomatoes or tomato juice adjusted to a lycopene dose of 5 mg/d, the third group ingested the same dose comprized in soft gel capsules containing tomato oleoresin. During the test period of 6 weeks, the participants continued reducing the intake of carotenoids from food. Fasting blood samples were withdrawn prior to the study, before supplementation started, and then weekly while supplemented. Seven-day dietary records were prepared before the study started and after one week of supplementation. Carotenoids were analyzed by reversed phase HPLC with diode array detection. Dietary records were evaluated using the computer software EBIS 2.1. The plasma total cholesterol, HDL cholesterol, and triglycerides were determined enzymatically. In addition, the antioxidant activity of plasma was estimated by using the TEAC and the TRAP assays. Results The basal levels of lycopene in plasma were comparable for all groups (0.2 – 0.3 μmol/l) and decreased significantly during the two weeks of depletion to approximately 50 % of the basal values. Other plasma carotenoids such as β-carotene and β-cryptoxanthin decreased significantly, too, whereas lutein and zeaxanthin remained unchanged. After supplementation with tomato oleoresin capsules or tomato juice, the plasma lycopene increased significantly, while it remained unchanged during intake of tomatoes. Normal dietary habits were practized of all volunteers before and during the study except vitamin C whose intake was significantly lower during the study period, because the probands were recommended to reduce the intake of fruits and vegetables. Lycopene supplementation did not affect the lipid status parameters of the three groups. After ingestion of lycopene the antioxidant activity of the plasma was not altered. Mean TEAC values were estimated to 0.33 ± 0.05 mmol/l and TRAP values to 1.0 ± 0.1 mmol/l and showed no significant differences in all groups during the whole study period. Conclusions The bioavailability of lycopene varied significantly depending on the administered matrix. Lycopene from tomato oleoresin capsules and tomato juice (processed tomatoes) was better absorbed from the intestine than lycopene from raw tomatoes. The daily intake of 5 mg lycopene, an intake comparable to the usual daily carotenoid intake, did not affect cholesterol and triglycerides in plasma or its antioxidant capacity. Received: 1 March 1999, Accepted: 30 April 1999     

Lycopene--a natural antioxidant

Lycopene is a carotenoid found predominantly in tomatoes and tomato products. In contrast to beta-carotene it is not a precursor of vitamin A in humans. Lycopene is not destroyed during food processing, moreover its bioavailability improves. Lycopene is the most powerful antioxidant amongst carotenoids. Beside the antioxidant effect it influences the expression of various proteins (enzymes of biotransformation, cyclin D1, connexins). According to epidemiologic studies tomato lycopene may reduce the risk of prostate cancer and cardiovascular diseases. Positive effects are also hypothesized in case of other diseases such as osteoporosis, neurodegenerative diseases and hypertension. Neither adverse effects upon lycopene supplementation nor lycopene toxicity have been reported. Therefore, several arguments support the consumption of natural lycopene, whilst there are no contraindications according to the present knowledge.     

Lycopene Content of Tomato Products: Its Stability,Bioavailability and In Vivo Antioxidant Properties

Lycopene is a bioactive carotenoid present in many fruits and vegetables. Tomatoes constitute the major dietary source of lycopene. Recent evidence shows lycopene to be associated with several health benefits. However, very little information is available about the stability of lycopene and its bioavailability. Because tomatoes undergo extensive processing and storage before consumption, a study was conducted to evaluate the stability, isomeric form, bioavailability, and in vivo antioxidant properties of lycopene. Total lycopene and isomers were measured by spectrophotometry and high-performance liquid chromatography, respectively. Lycopene content of tomatoes remained unchanged during the multistep processing operations for the production of juice or paste and remained stable for up to 12 months of storage at ambient temperature. Moreover, subjecting tomato juice to cooking temperatures in the presence of corn oil resulted in the formation of the cis isomeric form, which was considered to be more bioavailable. Lycopene was absorbed readily from the dietary sources. Serum lipid and low-density lipoprotein oxidation were significantly reduced after the consumption of tomato products containing lycopene.     

Comparison of lycopene and tomato effects on biomarkers of oxidative stress in vitamin E deficient rats

Background Cohort studies suggested that individuals with higher intake of tomatoes and tomato products have a lower risk of degenerative diseases. Lycopene, an antioxidant and antiproliferative carotenoid, has been hypothesized to be responsible for the health benefits of tomatoes. However, studies demonstrated a higher potential of tomatoes compared to lycopene to reduce oxidative stress or carcinogenesis. Aim of the study Our study aimed at distinguishing lycopene effect from that of tomato on oxidative stress, by using yellow tomato, a tomato variety devoid of lycopene. Methods Effects of feeding with none (control), 16% freeze-dried yellow tomato (YT), 16% freeze-dried red tomato (RT) or 0.05% lycopene beadlets (LB) were compared in a rat model with mild oxidative stress induced by low vitamin E diet (LVED). Four groups of 10 rats were fed ad libitum for 6 weeks. Physiological parameters such as ingesta, body, spleen and liver weights, cholesterol and triglycerides (TG) levels were assessed. Lycopene and vitamin E concentrations and oxidative stress biomarkers were measured in the plasma and/or liver and/or heart tissue of the rats. Results RT, YT, and LB had no effect on rats’ ingesta, body and spleen weights. RT, YT and LB had no effect on plasma cholesterol concentration. RT decreased TG level compared to control, YT and LB (P < 0.05). Rats fed RT or LB accumulated lycopene in plasma in contrast with rats fed YT. Heart level of thiobarbituric reactive species (TBARS) in rats fed RT or YT was lower than that in the control and the LB fed rats (P < 0.05). Despite similar concentrations of lycopene in plasma and liver, rats fed LB showed a significantly higher heart level of TBARS than rats fed tomatoes. RT increased erythrocyte superoxide dismutase (eSOD) activity compared with LB and nitric oxide (NO) level compared with control and LB. LB decreased ferric reducing ability of plasma (FRAP) level compared with control, RT and LB (P < 0.05). Conclusion Our study showed for the first time that tomatoes, containing or not containing lycopene, have a higher potential than lycopene to attenuate and or to reverse oxidative stress-related parameters in a mild oxidative stress context.     

Effect of domestic cooking on human bioavailability of naringenin,chlorogenic acid,lycopene and β-carotene in cherry tomatoes

Summary Background Epidemiological data showed that tomato and tomato product (sauce, paste) consumption is associated with a protective effect against the development of some chronic-degenerative diseases. Tomato antioxidant bioactive molecules such as carotenoids and polyphenols could be responsible, at least in part, for the healthy effect observed. The bioavailability of these compounds is an essential requirement to sustain their in vivo role. While it is well known that many factors can influence the bioaccessibility of carotenoids from the food matrix, there is little information about the factors affecting phenolic compounds bioaccessibility. Aim of the study This investigation was carried out to evaluate the effect of domestic cooking on the bioavailability in humans of antioxidant molecules after the administration of a test meal containing cherry tomatoes. Methods A cross-over design was conducted. Subjects (3 females and 2 males) consumed experimental meals containing fresh and cooked cherry tomatoes. Blood collection was performed at different time intervals (0, 2, 4, 6, 8 and 24 h). Results Carotenoid and phenol plasma concentrations were measured. Plasma levels of lycopene and -carotene were not significantly different with respect to the baseline after ingestion of both the test meals, while plasma concentrations of naringenin and chlorogenic acid increased significantly with respect to the baseline (P<0.05) after administration of cooked cherry tomatoes, but not after administration of fresh cherry tomatoes. Conclusions The present study indicated that domestically cooked tomatoes significantly increase naringenin and chlorogenic acid plasma levels. Considering that both naringenin and chlorogenic acid are widely studied for their potential healthy properties, evidence of their bioavailability and of the factors influencing their bioaccessibility is an important tool to sustain the possibility that these polyphenols play a biological role in human physiology.     

Increases in plasma lycopene concentration after consumption of tomatoes cooked with olive oil

Lycopene is the main carotenoid in tomatoes and it has been hypothesised to be responsible for reducing the risk of some cancers and heart disease. The cooking of tomatoes with olive oil is a characteristic combination in the Southern Mediterranean diet. Previous studies have shown that the absorption of lycopene is greater from processed tomatoes than fresh tomatoes, since the processing breaks down the tomato cell matrix and makes the lycopene more available. The aim of the present study was to determine whether consumption of diced tomatoes cooked with olive oil resulted in higher plasma lycopene concentrations than consumption of diced tomatoes cooked without olive oil. Plasma lycopene concentrations were measured after 5 days on a low lycopene diet and again after a five-day dietary intervention, in healthy subjects, who consumed one meal per day of tomatoes (470 g) cooked with or without extra virgin olive oil (25 ml olive oil). There was an 82% increase in plasma trans-lycopene (P< 0.001) and a 40% in cis-lycopene (P = 0.002) concentrations in the 11 subjects who consumed tomatoes cooked in olive oil. There was no significant change in trans-lycopene (P = 0.684) and a 15% increase in cis-lycopene (P = 0.007) concentrations in 12 subjects consuming tomatoes cooked without olive oil. We conclude that the addition of olive oil to diced tomatoes during cooking greatly increases the absorption of lycopene. The results highlight the importance of cuisine (i.e how a food is prepared and consumed) in determining the bioavailability of dietary carotenoids such as lycopene.     

Protective activity of tomato products on <Emphasis Type="Italic">in vivo</Emphasis> markers of lipid oxidation

Summary.Background: It has been suggested that regular consumption of tomato products improves antioxidant defenses due to their endogenous antioxidant compounds, notably lycopene.Aim of the study: We evaluated the effects of tomato consumption on parameters of lipid oxidation in healthy human volunteers.Methods: Twelve females (enrolled at T-7), after a one-week of carotenoid-poor diet (T0), were instructed to supplement the same diet with different tomato products (raw, sauce, and paste), thereby providing approximately eight mg lycopene/day for three weeks (T21). Blood samples were periodically collected in order to evaluate plasma carotenoid concentrations, plasma antioxidant capacity, and susceptibility of LDL to metal ion-induced oxidation. Furthermore, 8-iso-PGF₂, a marker of in vivo oxidative stress, was analyzed in the 24-hour urine.Results: Carotenoid concentrations decreased significantly during the carotenoid-poor diet (P < 0.05), while lycopene concentrations increased significantly after tomato consumption (P < 0.001). The antioxidant capacity of plasma did not vary during the study. Conversely, LDL oxidizability decreased after tomato consumption, as demonstrated by a shortening of the lag phase (P < 0.001). This parameter was significantly correlated with lycopene concentration (r = 0.36, P < 0.05). The excretion of 8-iso-PGF₂ in urine was also significantly lower (–53%, P < 0.05 compared with T0) after tomato supplementation.Conclusions: These results further support a role for tomato products in the prevention of lipid peroxidation, a risk factor of atherosclerosis and cardiovascular disease.     

Influence of lycopene and vitamin C from tomato juice on biomarkers of oxidative stress and inflammation

A human study was carried out to investigate whether tomato juice, rich in natural lycopene and fortified with vitamin C, is able to reduce several biomarkers of oxidative stress and inflammation and whether the effect can be attributed to lycopene, vitamin C or any other micronutrient. Following a 2-week depletion phase, volunteers were assigned randomly to ingest either tomato juice with (LC) or without (L) vitamin C fortification for 2 weeks (daily dose 20.6 mg lycopene and 45.5/435 mg vitamin C). Plasma and urine were analysed for carotenoids and vitamin C, lipid status, antioxidant capacity, thiobarbituric acid reactive substances (TBARS) and 8-epi-PGF2alpha, protein carbonyls, cytokines IL-1beta and TNFalpha and C-reactive protein (CRP). The consumption of tomato juice led to a reduction in total cholesterol levels (L: 157.6 v. 153.2 mg/dl, P = 0.008; LC: 153.4 v. 147.4 mg/dl, P = 0.002) and that of CRP (L: 315.6 v. 262.3 microg/l, P = 0.017; LC: 319.2 v. 247.1 microg/l, P = 0.001) in both groups. The vitamin C-fortified juice slightly raised the antioxidant capacity in urine and decreased TBARS in plasma and urine. All other markers were affected to a lesser extent or remained unchanged. Cholesterol reduction was correlated with lycopene uptake (P = 0.003), whereas the other effects could not be related with particular micronutrients. Any beneficial effects of tomato consumption for human health cannot be attributed only to lycopene and, as the additional supplementation with ascorbic acid indicates, a variety of antioxidants might be needed to optimize protection against chronic diseases.     

Comparison of the postprandial chylomicron carotenoid responses in young and older subjects

Summary. Background: The plant carotenoids may contribute to the beneficial health effect of fruits- and vegetables-rich diet. Epidemiological studies consistently associated high plasma carotenoids status with reduced age-related diseases. However, the data concerning the bioavailability of carotenoids in the elderly are scarce. Objective: To test whether there is an age effect on carotenoid bioavailability. Design: Eight young (20–35 y) and eight older (60–75 y) healthy adults ingested three different meals containing 40 g triacylglycerols (TG) and vegetable sources of carotenoids. These sources were either 188 g carrot purée which provided 30 mg betacarotene as the main carotenoid, or 61 g tomato purée providing 30mg lycopene, or 260 g cooked chopped spinach providing 30 mg lutein. TG and carotenoids were assayed in chylomicrons (CM) collected for 9 h postprandially. Results: There was no major effect of age on the postprandial CM/TG response (0–9 h area under the curve (AUC)). There was no major effect of age on the postprandial CM all-trans beta-carotene, cis betacarotene, alpha-carotene, and lutein responses.Adjustment of these responses by the CM TG responses did not reveal any age effect. While there was no significant effect of age on the CM lycopene response, the CM TG-adjusted lycopene response was significantly lower (–40 %) in the older than in the younger subjects (P < 0.04). The cis-trans ratios of CM betacarotene were not significantly different between the old and the young subjects. There was no significant effect of age on the ratio of CM retinyl-palmitate to the sum of alpha-carotene and beta-carotene measured after the carrot meal. Conclusions: The bioavailability of lycopene is apparently impaired in the old,while there is no major difference in the bioavailability of beta-carotene, alpha-carotene and probably lutein. There is also no major effect of age on the cis-trans isomerization of beta-carotene during absorption, and in the intestinal conversion of provitamin A carotenoids into vitamin A.This study has been carried out with financial support from the Commission of the European Communities, specific RTD program Quality of Life and Management of Living Resources, QLK1-CT-1999–00830. It does not necessarily reflect its views and in no way anticipates the Commissions future policy in this area.     

Extraction of lycopene from tomato sauce with mushrooms (Agaricus brasiliensis), determined by high-performance liquid chromatography

Lycopene belongs to the subgroup of non-oxygenated carotenoids with antioxidant and anti-carcinogenic properties that are comparatively more powerful than the majority of plasma carotenoids. When foodstuffs containing lycopene are processed, the cell wall breaks down during the thermal process--thus enabling the extraction of lycopene from chromoplasts, improving their bioavailability. Edible mushroom Agaricus brasiliensis stands out given its medicinal properties and antioxidant potential when used to treat heart diseases and to prevent cancer. Given the interest in lycopene-rich foods, the purpose of the present study was to determine the lycopene present in different types of tomato sauce with A. brasiliensis and/or its extract by high-performance liquid chromatography. The type of solvent (dichloromethane, hexane and ethanol) to remove water from the tomato sauce was tested before the extraction of carotenoids. Lycopene determination in tomato sauces, in tomatoes and in the A. brasiliensis extract was carried out via high-performance liquid chromatography. Findings show that when tomato sauce and raw materials underwent heat treatment, the type of treatment did not interfere with carotenoid and lycopene bioavailability--indicating that those sauces have a significant concentration of carotenoids and, in particular, their content in the lycopene proportion compared with total carotenoids.     

A Randomized Crossover Intervention Study on the Effect a Standardized Maté Extract (Ilex paraguariensis A. St.-Hil.) in Men Predisposed to Cardiovascular Risk

(1) Background: Due to its richness in chlorogenic acids (CGAs), Maté (Ilex paraguariensis A. St.-Hil.) could be of interest in the prevention of cardiometabolic diseases, however clinical evidence are lacking. This trial aimed to evaluate the impact of maté CGAs, consumed in a daily dose achievable through traditional maté beverages, on parameters related to cardiometabolic risk. (2) Design: Thirty-four male volunteers aged 45–65 years and with at most one criteria of metabolic syndrome, were recruited for a randomized, double-blind, placebo-controlled, and crossover study. The volunteers were assigned to consume an encapsulated dry maté extract for four-weeks, providing 580 mg of caffeoyl quinic acid derivatives (CQAs) daily, or a placebo, with a two weeks washout between intervention periods. Anthropometric variables, blood pressure, plasma glucose, lipids, endothelial, and inflammatory biomarkers were measured in overnight-fasted subjects and after a glucose load. (3) Results: We found no significant effects of treatment on these parameters and the response to the glucose load was also similar between the two interventions. However, a significant decrease in fasting glucose was observed between day 0 and day 28 for the maté group only (−0.57 ± 0.11 mmol/L, p < 0.0002). In subjects with an intermediate to high Framingham risk score, consumption of maté extract induced a 10% increase of high-density lipoprotein (HDL)-c from baseline. In a subgroup representative of the study population, significant decreases in the C-reactive protein (CRP) (−50%) and interleukin-6 (IL-6) (−19%) levels were observed. (4) Conclusions: These clinical observations suggest that maté, naturally rich in CGAs, could improve some cardiometabolic markers in subjects with a higher predisposition to metabolic syndrome, even if that remains to be confirmed in new trials specifically targeting this population.     

Role of antioxidant lycopene in cancer and heart disease

Lycopene, a carotenoid without provitamin-A activity, is present in many fruits and vegetables; however, tomatoes and processed tomato products constitute the major source of lycopene in North American diet. Among the carotenoids, lycopene is a major component found in the serum and other tissues. Dietary intakes of tomatoes and tomato products containing lycopene have been shown to be associated with decreased risk of chronic diseases such as cancer and cardiovascular diseases in several recent studies. Serum and tissue lycopene levels have also been inversely related with the chronic disease risk. Although the antioxidant properties of lycopene are thought to be primarily responsible for its beneficial properties, evidence is accumulating to suggest other mechanisms such as modulation of intercellular gap junction communication, hormonal and immune system and metabolic pathways may also be involved. This review summarizes the background information about lycopene and presents the most current knowledge with respect to its role in human health and disease.     

Role of Antioxidant Lycopene in Cancer and Heart Disease

Lycopene, a carotenoid without provitamin-A activity, is present in many fruits and vegetables; however, tomatoes and processed tomato products constitute the major source of lycopene in North American diet. Among the carotenoids, lycopene is a major component found in the serum and other tissues. Dietary intakes of tomatoes and tomato products containing lycopene have been shown to be associated with decreased risk of chronic diseases such as cancer and cardiovascular diseases in several recent studies. Serum and tissue lycopene levels have also been inversely related with the chronic disease risk. Although the antioxidant properties of lycopene are thought to be primarily responsible for its beneficial properties, evidence is accumulating to suggest other mechanisms such as modulation of intercellular gap junction communication, hormonal and immune system and metabolic pathways may also be involved. This review summarizes the background information about lycopene and presents the most current knowledge with respect to its role in human health and disease.     

A Rapid and Cheap Method for Extracting and Quantifying Lycopene Content in Tomato Sauces: Effects of Lycopene Micellar Delivery on Human Osteoblast-Like Cells

Identifying and quantifying the beneficial molecules contained in nutraceuticals is essential to predict the effects derived from their consumption. This study explores a cheap and rapid method for quantifying lycopene content from a semi-solid matrix. In addition, it compares the in vitro effects of the extracts obtained from different tomato sauces available on the local market with Osteocol^®, a patented tomato sauce from southern Italy. We performed a liquid extraction of lycopene using suitable solvents. The lycopene extracted was encapsulated in surfactant micelles and finally tested in vitro on Saos-2 cells. The effects exerted by lycopene on ALP and Wnt/β-catenin pathways were investigated by Western blotting. Hexane was found to be the best solvent for lycopene extraction. Spectrophotometrical and HPLC analyses showed similar trends. Osteocol^® contained 39 ± 4 mg lycopene per 100 g of sauce, while the best commercial product contained 19 ± 1 mg/100 g. The Osteocol^® lycopene extract increased ALP and β-catenin protein expressions in a dose-dependent manner, also showing statistically significant results (p < 0.05 respectively). In conclusion, despite both techniques showing similar final results, UV/VIS spectrophotometer is preferable to HPLC due to its cheap, rapid, and accurate results, as well as for the opportunity to analyze lycopene-loaded micelles. The extraction and release of lycopene to bone cells positively influences the differentiation of osteoblasts and increases the expression of the ALP and β-catenin proteins. As a consequence, as a lycopene-rich sauce, Osteocol^® represents a useful supplement in the prevention of osteoporosis compared to its commercial competitors.     

Bioactive compounds,folates and antioxidant properties of tomatoes (Lycopersicum esculentum) during vine ripening

Bioactive compounds and their relationship with antioxidant activity were determined in three tomato cultivars (Ronaldo, Siena and Copo) during vine ripening. The lycopene, chlorophyll (total, a and b), total phenolic, flavonoid, vitamin C and folate contents, and the antioxidant activity, by the ferric reducing/antioxidant power assay and the β-carotene lineolate system, were determined in the samples. Tomato ripening involved the breakdown of chlorophylls, accompanied by a continuous increase in the lycopene content. Total phenolics, flavonoids and vitamin C increased significantly during ripening, whereas the folate content fell markedly as tomatoes turned from green to red. The lycopene and flavonoid content was highest in the Copo cultivar, vitamin C and folate highest in Ronaldo, and total phenolics highest in Siena. The antioxidant activity, as measured with the ferric reducing/antioxidant power assay, increased significantly during ripening in all extracts, and showed a positive correlation with the total phenolic and flavonoid contents. However, when measured with the β-carotene lineolate system, the antioxidant activity decreased significantly during ripening; perhaps due to the antioxidant activity of chlorophylls and the peroxidation activity of vitamin C.     

Tomato By-Products,a Source of Nutrients for the Prevention and Reduction of Malnutrition

Malnutrition is a global phenomenon that mainly affects children under five years old, the elderly and food insecure people. It can be linked to undernourishment or overnutrition. To prevent it, a healthy and balanced diet, rich in energy and micronutrients, is necessary. The objective of this study was to evaluate the nutritional composition and contribution of tomato by-products to prevent and reduce malnutrition. Thus, standard methods were used for proximate composition and bioactive compounds. Results showed that tomato by-products are rich in macronutrients and micronutrients capable of preventing undernutrition and reducing the incidence of the effects of overnutrition. The average carbohydrate, protein and lipid contents were 15.43%, 11.71% and 5.4% (DM) in peels and for seeds the contents were 58.75%, 15.4% and 22.2%, respectively. The average energy values were 280.47 kcal/100 g and 472.8 kcal/100 g DM for peels and seeds, respectively. The main minerals found were, in decreasing order, potassium, magnesium, sodium, iron and zinc. High contents of phenolic compounds, lycopene, β-carotene and vitamin C were also found in these by-products. They also presented important antioxidant activities. Due to their nutritional and bioactive compounds, tomato by-products may be included in functional food formulation programs to reduce the incidence of nutritional diseases.     

Carotenoid bioavailability in humans from tomatoes processed in different ways determined from the carotenoid response in the triglyceride-rich lipoprotein fraction of plasma after a single consumption and in plasma after four days of consumption

Tomatoes are the main dietary source of lycopene, and the bioavailability of lycopene from tomato paste is higher than that from fresh tomatoes. We investigated systematically the effect of mechanical homogenization and heating on the bioavailability of carotenoids from canned tomatoes. Further, we compared the carotenoid response in triglyceride-rich lipoproteins (TRL) after single consumption with the change in fasting plasma carotenoid concentrations after 4 d of daily consumption. In a split plot design, 17 men and women consumed tomatoes which had received minimal additional heating and 16 others consumed extensively additionally heated tomatoes (1 h at 100 degrees C). These tomatoes were not, mildly or severely homogenized. The tomato products were consumed daily (ca. 22 mg/d lycopene) for 4 d. Eleven participants provided postprandial blood samples on the d 1 and all gave fasting blood samples on d 1 and 4. Homogenization enhanced the lycopene response significantly (P<0.05) both in TRL [mean areas under the curves: 54.9, 72.0 and 88.7 nmol. h/L (SE 11.0) for not, mildly and severely homogenized tomatoes, respectively] and in plasma [mean changes: 0.19, 0.22 and 0.23 micromol/L (SE 0.009), respectively]. Additional heating also tended to enhance the lycopene responses in TRL (P = 0.14) and plasma (P = 0.17). Similar effects to those for lycopene were found for beta-carotene. We conclude that the intactness of the cellular matrix of tomatoes determines the bioavailability of carotenoids and that matrix disruption by mechanical homogenization and/or heat treatment enhances the bioavailability. The carotenoid response in plasma after 4 d intervention can be used to compare the bioavailability of carotenoids from different foods.     

Investigation of the antioxidant and synergistic activity of lycopene and other natural antioxidants using LAME and AMVN model systems

The antioxidant activity of lycopene and its cooperative interaction with vitamin E were studied in a homogenous solution of linoleic acid methyl ester (LAME). Antioxidant property of lycopene, β-carotene, vitamins C and E, individually or in combination, were assayed by measuring the inhibiting effect of individual or combination of antioxidants on the production of diene hydroperoxides from LAME oxidation induced by azo-initiator 2,2′-azobis (2,4-dimethylvaleronitrile) (AMVN). The lipophilic tomato extracts were also determined by the same assay. The lipophilic tomato extracts displayed greater inhibition on LAME oxidation compared to pure lycopene. The observed enhancement of inhibition on LAME oxidation by tomato lipophilic extracts might have results from the additive effect of individual antioxidants in the mixture and/or cooperative interaction between structurally different antioxidant. Combination of lycopene and vitamin E exhibited a greater inhibitory effect, in a concentration-dependent manner, than the additive effect of individual antioxidants, while the combination of β-carotene and vitamin E did not produce a similar synergistic effect. This study investigated the interaction between structurally different antioxidants.     

Passionflower fruit-a "new" source of lycopene?

Many population studies have established a link between dietary intake of the carotenoid antioxidant lycopene and a reduced risk of chronic diseases. Unlike most carotenoids, lycopene occurs in a few places in the diet. Besides tomatoes and tomato products, major sources of lycopene, other lycopene-rich foods include watermelon, pink grapefruit, pink guava, and papaya. Dried apricots and pureed rosehips contain relatively large amounts, too. In our study we found that passionflower fruit (skin and pericarp) contains a great amount of lycopene, whereas the content of other carotenoids is very low, and almost inexistent. This edible fruit could be an alternative source of a potential important nutrient for those people who do not eat tomatoes and tomato products.     

Effect of tomato product consumption on the plasma status of antioxidant microconstituents and on the plasma total antioxidant capacity in healthy subjects

OBJECTIVES: to identify the plasma antioxidant microconstituents mainly affected by tomato product consumption, to check whether tomato product consumption can affect antioxidant status, and to identify tomato-product antioxidant-microconstituents mainly involved in the effect of these products on oxidative stress. DESIGN: Medium-term dietary supplementation study. SETTING: Human Nutrition Laboratory, Clermont-Ferrand, France. SUBJECTS: Twenty healthy young (20 < years < 40), non obese (18 < BMI (kg/m2) < 25), females were recruited by advertisement. All of them completed the study. INTERVENTION: The usual diet of the subjects was supplemented for three weeks with 96 g/day tomato puree. The volunteers then avoided tomato-product-rich foods for a subsequent three-week period. Measures of Outcome: Fasting blood samples were collected the day before supplementation, the day after the supplementation period, and the day after the depletion period. The status of several antioxidant microconstituents (plasma microconstituent concentrations), and the antioxidant status (plasma total antioxidant capacity) were assessed. RESULTS: Supplementation with tomato puree significantly increased plasma lycopene, beta-carotene and lutein. Conversely it did not significantly affect plasma vitamin C and E, plasma antioxidant trace metals (Cu, Zn and Se), and plasma total antioxidant capacity. Avoidance of tomato-product-rich foods for three weeks significantly (p < 0.05) decreased plasma lycopene, beta-carotene, lutein and vitamin C, as well as plasma total antioxidant capacity. Plasma total antioxidant capacity, as measured by chemiluminescence, was positively related (p < 0.05) to the status of lycopene, vitamin C and beta-carotene. CONCLUSIONS: Tomato product consumption can affect not only the lycopene status, but also that of other antioxidant microconstituents (beta-carotene and lutein). Lycopene, but also beta-carotene, are apparently the main tomato microconstituents responsible for the effect of tomato products on antioxidant status.