Tomato Carotenoids Research Articles

HPLC Analysis of Carotenoids from Tomatoes Using Cross-Linked C18 Column and MS Detection

This study was conducted to analyze carotenoids from tomatoes by high-performance liquid chromatography using reversed-phase C18 silica having cross-linked end-capping with diode array and mass spectrometric detection. An efficient gradient elution system was developed to achieve good and reliable separation of both major and minor carotenoids as well as their isomers. Resolution of lycopene, β-carotene and their isomers was 0.91-3.97 and 1.02-2.86 with cross-linked and conventional C18 column, respectively. The % recovery for zeaxanthin, lycopene and β-carotene was found to be in the range of 89-97%. Limits of detection and quantification of 19.44 and 64.79 ng/mL for zeaxanthin, 15.6 and 52.4 ng/mL for lycopene and 8.28 and 27.61 ng/mL for β-carotene were determined. More carotenoid compounds could be separated and detected with the new method as compared with conventional C18 column. Hyphenation of HPLC with photodiode array and mass spectrometry detectors assisted in detection of tetra-dehydrocarotenoid and fatty acid diesters of xanthophylls in tomato products. Content of all-trans-lycopene, β-carotene and total carotenoid in different industrial tomatoes tested was found to range between 41.87 and 84.65, 0.89 and 1.50 and 53.22 and 112.60 µg/g fresh weight, respectively.

Effect of Simulated Thermo‐Degradation on the Carotenoids, Tocopherols and Antioxidant Properties of Tomato and Paprika Oleoresins

AbstractColor quality is the economical key factor for oily extracts, also referred to as oleoresins, obtained from carotenogenic fruits and vegetables for application in foodstuffs. However, this organoleptic property is not the only attribute as carotenoids develop some bioactive actions, which provide a beneficial effect on health. It has been suggested that reaching some oxidation level during processing enhances the antioxidant activity of phytochemicals, including carotenoids, so that knowledge of the impact of thermal processing in the redox state and antioxidant activity is significant. During thermal degradation of carotenoids in tomato and paprika oleoresins the coloring content, redox state and antioxidant capacity were evaluated. The lipid profile and tocopherol content were similar in both oily extracts but significant differences were observed on functional properties derived from carotenoid activity. The initial antioxidant capacity was similar for both carotenoid extracts, tomato oleoresin kept higher antioxidant capacity values (DPPH test) than paprika oleoresin, although the degradation rate was significantly higher for lycopene, while carotenoids of paprika oleoresin degraded slowly. Paprika oleoresin showed a higher antioxidant activity (hydrogen peroxide test) than tomato oleoresin. Carotenoid degradation products may participate on radical scavenging reactions but efficiency depends on the radical species and structure of degradation products produced during thermal degradation.

Hepatoprotective effects of lycopene against carbon tetrachloride-induced acute liver injury in rats

Lycopene, the major carotenoid in tomatoes, is a known antioxidant that may lower oxidative stress biomarkers by a mechanism that is not fully elucidated. The intoxication of rats with carbon tetrachloride (CCl4) resulted in significant histological hepatic degradation accompanied by a marked increase in reactive oxygen species (ROS) and in the number of apoptotic cells. The induced oxidative stress in turn results in a significant elevation of lipid peroxidation and H2O2 generation, together with a decrease in the concentration of reduced glutathione (GSH) and a significant reduction in activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S transferase (GST). CCl4-intoxicated rats, pre-treated with lycopene, showed strongly reduced cell damage and ROS generation. The level of markers for hepatic integrity in lycopene pre-treated rats was close to the controls in the absence of CCl4 treatment, indicating the protective effect of lycopene pre-treatment. In the same way, lycopene pre-treated rats significantly increased SOD, CAT, GPx, GST activities and GSH level. In addition, we measured an increased lipoxygenase (LOX) activity in CCl4-intoxicated rats. This activity was reduced in lycopene pre-treated rats to values close to those observed in the controls, suggesting a potential pharmacological application of this dietary carotenoid.

Overexpression of a tomato carotenoid ɛ-hydroxylase gene alleviates sensitivity to chilling stress in transgenic tobacco

Chilling is one of the most serious environmental stresses that disrupt the metabolic balance of cells and enhance the production of reactive oxygen species (ROS). Lutein plays important roles in dissipating excess excitation energy and eliminating ROS to maintain the normal physiological function of cells. A tomato carotenoid epsilon-ring hydroxylase gene (LeLUT1) was isolated, and the LeLUT1-GFP fusion protein was localized in the chloroplast of Arabidopsis mesophyll protoplast. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that the expression of LeLUT1 was the highest in the leaves and was down-regulated by various abiotic stresses in tomato. The transgenic tobacco plants overexpressing LeLUT1 had higher lutein content, which was decreased in cold condition. Under chilling stress, the non-photochemical quenching (NPQ) values were higher in the transgenic plants than in the wild type (WT) plants. Compared with the WT plants, the transgenic plants showed lower levels of hydrogen peroxide (H2O2), superoxide radical (O2(·-)), relative electrical conductivity, and malondialdehyde content (MDA), and relatively higher values of maximal photochemical efficiency of photosystem II (Fv/Fm), oxidizable P700 of PSI, and net photosynthetic rate (Pn). Therefore, the transgenic seedlings were less suppressed in growth and lost less cotyledon chlorophyll than the WT seedlings. These results suggested that the overexpression of LeLUT1 had a key function in alleviating photoinhibition and photooxidation, and decreased the sensitivity of photosynthesis to chilling stress.

Abstract 3701: Tomato carotenoids and testosterone modulate mRNA and miRNA profiles during prostate carcinogenesis.

Abstract There is considerable evidence supporting the hypothesis that tomato carotenoids may contribute to prostate cancer prevention however the mechanisms remain uncertain. We propose that bioactive tomato components, such as lycopene, may impact testosterone signaling to inhibit prostate carcinogenesis. Four week-old C57/BL6 WT and TRAMP male mice were fed either control (AIN93G), 10% tomato powder or 0.25% lycopene beadlets. At eight weeks of age, mice were randomized among treatments: intact, castration, or castration + 2.5mg/kg testosterone repletion and animals sacrificed at 10 weeks of age. Prostate gene expression was quantified by Nanostring nCounter was used to quantify prostate gene expression with a 200 gene murine prostate carcinogenesis custom codeset and miRNA with codeset v1.1. Carotenoid analysis is by HPLC and proliferation (Ki67) by immunohistochemical evaluation. Feeding dietary tomato or lycopene increased serum lycopene, for example, in WT mice concentrations reached 335 +/- 33 nmol/L and 337 +/- 34 nmol/L in tomato and lycopene fed animals, respectively. As expected, the TRAMP genotype and testosterone stimulate proliferation with diet as a modulating factor. In the WT intact prostate, the tomato powder and lycopene diet decreased proliferation (p<0.009). The TRAMP genotype and endocrine status impacted the expression of multiple genes and miRNAs in several distinct patterns. For example, Birc5, Ki67, PCNA, BRCA1, ATM, Aurora kinase A / B, Cdc25c, Cyclin B2, cyclin E2, Fox M1,and miRs 15b, 16, 25, 200a, 200b, and 429 are increased in the TRAMP prostate, only when testosterone is present. Alternatively, TMPRSS2, CD31, CD34, Cox 2, nCad, Cyclin D1, Keratin 5, Shh, and p63, and miRs 145, 205, 328, and 423-5p are decreased in the TRAMP prostate in the presence of testosterone. Nkx3.1, miR 148a, and miR 375 are decreased upon castration whereas beta catenin, FGFR1 and TNF alpha are increased. Tomato and / or Lycopene modestly decreased expression of eCad, HIF 1 alpha, Paxillin, RxR alpha, Sca 1 and Vimentin and increased expression of CD133 and miR 22. These highly controlled in vivo studies document the strong interactions between genetic defects in the prostate, the hormonal environment, and diet in modulating early prostate carcinogenesis. Citation Format: Jennifer M. Thomas-Ahner, Lei Wan, Hsueh-Li Tan, Nancy E. Moran, Amy C. Elsen, Dennis K. Pearl, John W. Erdman, Steven K. Clinton. Tomato carotenoids and testosterone modulate mRNA and miRNA profiles during prostate carcinogenesis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3701. doi:10.1158/1538-7445.AM2013-3701

Dietary carotenoids may reduce testicular steroidogenesis through HMG‐CoA reductase in mice with altered carotenoid metabolism

Higher serum levels of lycopene are inversely associated with prostate cancer incidence. Previous work in our lab has demonstrated that, in mice lacking carotene‐15,15′‐ monooxygenase (CMO1), dietary tomato powder or lycopene reduces testicular and serum testosterone levels. We hypothesized that lycopene may reduce testicular steroidogenesis through HMG‐CoA reductase (HMGCoAr). Nine‐ to twelve‐week‐old male wild‐type (WT), CMO1−/−, and carotene‐9′,10′‐monooxygenase knockout (CMO2−/−) mice were fed AIN‐93G‐based diets containing 10% tomato powder (TP), lycopene beadlets matched for lycopene content (LYC), or control diets for four days. We examined testicular mRNA and protein expression of canonical steroidogenic enzymes and found no alterations which explained the observed hormonal changes. However, protein levels of HMGCoAr were significantly decreased (p<0.05) in WT and CMO1−/− mice fed TP or LYC, but not in CMO2−/− mice. HMGCoAr mRNA expression was unaltered, suggesting that control is through a post‐transcriptional mechanism. We also examined mRNA expression of a testicular cholesterol acquisition mediator, SR‐B1, and found no changes. In summary, LYC and TP decreased testicular HMGCoAr protein levels in a CMO2‐ dependent manner, suggesting that metabolites of lycopene or other tomato carotenoids, produced by CMO2 cleavage, may mediate this effect.Grant Funding Source: NIH grant PHS‐1‐RO1 CA125384

Correction to Coconut Oil Enhances Tomato Carotenoid Tissue Accumulation Compared to Safflower Oil in the Mongolian Gerbil (Meriones unguiculatus)

ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionORIGINAL ARTICLEThis notice is a correctionCorrection to Coconut Oil Enhances Tomato Carotenoid Tissue Accumulation Compared to Safflower Oil in the Mongolian Gerbil (Meriones unguiculatus)Lauren E. Conlon, Ryan D. King, Nancy E. Moran, and John W. Erdman, Jr.*Cite this: J. Agric. Food Chem. 2013, 61, 14, 3560Publication Date (Web):April 1, 2013Publication History Published online1 April 2013Published inissue 10 April 2013https://doi.org/10.1021/jf401056sCopyright © 2013 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views333Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (107 KB) Get e-Alerts Get e-Alerts

Lycopene; chemistry, biosynthesis, metabolism and degradation under various abiotic parameters

Lycopene, the predominant carotenoid in tomatoes, is among the major carotenoids in serum and tissues of humans. Epidemiological studies have proven the bioactive role and potential disease prevention property of carotenoids and their consumption has been associated with reduced risk of degenerative diseases. Lycopene is reported to have a variety of pharmacological and nutritional effects in animals and humans, on one hand and promising health benefits as an antioxidant on the other. However, a need exists for better exploration of its biosynthesis, metabolic aspects, tissue distribution and bioavailability. To contribute to this effort, this integrated review presents data on the physico-chemical aspects, biosynthesis and metabolism, with special focus on the stability and degradation under various abiotic parameters. Heat light and oxygen are the main factors which induce degradation of lycopene via trans-cis isomerization and oxidation and reduce its health benefits. The stability of lycopene is also varied in different food matrices. Controversy also exists on some issues such as bioavailability and absorption of this compound which needs to be explored further.

The Effect of Methyl Jasmonate Vapour on Some Characteristics of Fruit Ripening, Carotenoids and Tomatine Changes in Tomato (Lycopersicon esculentum Mill.)

Tomato ripening in normal red-fruited cultivar (Fiorin) was delayed by treatment with methyl jasmonate (JA-Me) vapour. A visual scoring system for describing tomato ripening was used. Surface of fruits exposed to JA-Me vapour, increased in yellow and decreased in red as determined by HunterLab colour meter. JA-Me significantly altered the firmness of fruits after 21 days storage. Vapour of JA-Me enhanced the level of β-carotene in outer part (peel with 3 mm pericarp tissue) of fruit, while it had no effect in peeled fruit pericarp. JA-Me treatment decreased the level of lycopene in outer part and pericarp tissue, however, in outer part lycopene content decreased at a higher rate than in pericarp. Amount of tomatine in fruits treated with JA-Me had enhanced four-fold in outer part and by 62% in peeled fruit pericarp as compared with the control.

Lycopene metabolism and its biological significance

The beneficial effects of a high intake of tomatoes and tomato products on the risk of certain chronic diseases have been presented in many epidemiologic studies, with the suggestion that lycopene (a major carotenoid in tomatoes) is a micronutrient with important health benefits. Within the past few years, we have gained greater knowledge of the metabolism of lycopene and the biological effects of lycopene derivatives. In particular, the characterization and study of β-carotene 9',10'-oxygenase has shown that this enzyme can catalyze the excentric cleavage of both provitamin and non-provitamin A carotenoids to form apo-10'-carotenoids, including apo-10'-lycopenoids from lycopene. This raised an important question of whether the effect of lycopene on various cellular functions and signaling pathways is a result of the direct actions of intact lycopene or its derivatives. Several reports, including our own, support the notion that the biological activities of lycopene can be mediated by apo-10'-lycopenoids. More research is clearly needed to identify and characterize additional lycopene metabolites and their biological activities, which will potentially provide invaluable insights into the mechanisms underlying the effects of lycopene in humans.

The tomato CAROTENOID CLEAVAGE DIOXYGENASE8 (SlCCD8) regulates rhizosphere signaling, plant architecture and affects reproductive development through strigolactone biosynthesis

Strigolactones are plant hormones that regulate both above- and belowground plant architecture. Strigolactones were initially identified as rhizosphere signaling molecules. In the present work, the tomato (Solanum lycopersicum) CAROTENOID CLEAVAGE DIOXYGENASE 8 (SlCCD8) was cloned and its role in rhizosphere signaling and plant physiology assessed by generating knock-down lines. Transgenic SlCCD8 plants were generated by RNAi-mediated silencing. Lines with different levels of strigolactone reduction--confirmed by UPLC-MS/MS--were selected and their phenotypes investigated. Lines exhibiting reduced SlCCD8 levels displayed increased shoot branching, reduced plant height, increased number of nodes and excessive adventitious root development. In addition, these lines exhibited reproductive phenotypes such as smaller flowers, fruits, as well as fewer and smaller seeds per fruit. Furthermore, we show that strigolactone loading to the xylem sap is possibly restricted to orobanchol. Infestation by Phelipanche ramosa was reduced by 90% in lines with a relatively mild reduction in strigolactone biosynthesis and secretion while arbuscular mycorrhizal symbiosis, apical dominance and fruit yield were only mildly affected. This demonstrates that reduction of strigolactone biosynthesis could be a suitable tool in parasitic weed management. Furthermore, our results suggest that strigolactones are involved in even more physiological processes than so far assumed.

Coconut Oil Enhances Tomato Carotenoid Tissue Accumulation Compared to Safflower Oil in the Mongolian Gerbil (Meriones unguiculatus)

Evidence suggests that monounsaturated and polyunsaturated fats facilitate greater absorption of carotenoids than saturated fats. However, the comparison of consuming a polyunsaturated fat source versus a saturated fat source on tomato carotenoid bioaccumulation has not been examined. The goal of this study was to determine the influence of coconut oil and safflower oil on tomato carotenoid tissue accumulation in Mongolian gerbils ( Meriones unguiculatus ) fed a 20% fat diet. Coconut oil feeding increased carotenoid concentrations among many compartments including total carotenoids in the serum (p = 0.0003), adrenal glandular phytoene (p = 0.04), hepatic phytofluene (p = 0.0001), testicular all-trans-lycopene (p = 0.01), and cis-lycopene (p = 0.006) in the prostate-seminal vesicle complex compared to safflower oil. Safflower oil-fed gerbils had greater splenic lycopene concentrations (p = 0.006) compared to coconut oil-fed gerbils. Coconut oil feeding increased serum cholesterol (p = 0.0001) and decreased hepatic cholesterol (p = 0.0003) compared to safflower oil. In summary, coconut oil enhanced tissue uptake of tomato carotenoids to a greater degree than safflower oil. These results may have been due to the large proportion of medium-chain fatty acids in coconut oil, which might have caused a shift in cholesterol flux to favor extrahepatic carotenoid tissue deposition.

Kinetics of temperature increase during tomato processing modulate the bioaccessibility of lycopene

The nutritional benefit of bioactive metabolites depends on their bioavailability, i.e. the proportion that leaves the food matrix, and crosses the enteral barrier to reach their cellular target. The present study focused on lycopene, the major and bioactive tomato carotenoid, the bioavailability of which is known to be enhanced in cooked products.To better understand how processing may facilitate lycopene release, we assessed whether hot-break (HB) or cold-break (CB) treatments influence the tomato lycopene bioaccessibility. HB and CB are used in the tomato industry to modulate texture of purees through endogenous cell-wall lytic enzymes activity. HB and CB processes were mimicked through microwave heating, leading to a differentiated temperature rise in the product. The HB and CB models led to the expected differences, i.e. more viscous puree for HB with low methanol. The ability of the tomato matrix to release lycopene was measured as the extractability of lycopene to oil under standardized mixing conditions. We expected that CB treatment, by enhancing cell-wall degradation, would lead to enhanced lycopene bioaccessibility.The opposite was observed: oil contained three times less lycopene when mixed by CB (around 0.3μgml−1; similar to results obtained with fresh purees) than when mixed by HB (around 0.9μgml−1), although HB caused more lycopene degradation. Kinetics studies indicated that the quick rise of temperature at the beginning of HB treatment was a key parameter.

Coconut oil facilitates tomato carotenoid tissue accumulation in the Mongolian gerbil (Meriones unguiculatus)

Tomato carotenoids have demonstrated anti‐cancer bioactivity, and co‐consumption of carotenoids with a polyunsaturated fat source has been shown to enhance bioavailability. To investigate the effect of fatty acid chain length and saturation on tomato carotenoid tissue accumulation, Mongolian gerbils (Meriones unguiculatus) were fed a 20% fat diet. Gerbils (n = 40) were fed control diets with safflower or coconut oil, or experimental diets containing 10% tomato powder and coconut oil or 10% tomato powder and safflower oil for 28 days. Coconut oil increased carotenoids among many compartments including total carotenoids in the serum (p = 0.0001), adrenal glandular phytoene (p = 0.047), hepatic phytofluene (p = 0.0001), testicular all‐trans lycopene (p = 0.01), and cis‐lycopene (p = 0.006) in the prostate‐seminal vesicle complex compared to safflower oil. Safflower oil‐fed gerbils had greater splenic lycopene (p = 0.006) compared to coconut oil fed gerbils. Coconut oil also increased serum cholesterol (p = 0.0001), and decreased hepatic cholesterol (p = 0.0003) compared to safflower oil suggesting a shift in the carotenoid‐rich LDL cholesterol flux that may have facilitated extrahepatic carotenoid tissue deposition. In summary, dietary fatty acid profiles may impact both lipid metabolisms and tissue carotenoid deposition.Grant Funding Source : Funded in part by the Khatchaturian family

Plant cell culture strategies to increase 13C‐enrichment of lycopene for human metabolic tracing studies

The red tomato carotenoid lycopene (LYC) and/or its metabolites may contribute to anti‐cancer bioactivity. However, little is known regarding LYC metabolites that are endogenously‐produced or absorbed from foods. To better understand LYC metabolism, tracer LYC was 13C‐biolabeled using tomato cell cultures grown in 13C‐glucose‐ containing media. Biolabeling produces a mixture of 13C‐mass isotopomers. The goal of this work was to shift the enrichment of LYC (C40H56) toward the uniformly labeled ([U]‐13C‐LYC) isotopomer, in order to provide a strong signal for metabolite detection. ‘Ailsa Craig’ hp‐1 cell cultures were grown in 13C‐glucose‐containing media for 1, 2, or 3 serial growth cycles and mass isotopomeric distribution was quantitated by tandem high pressure liquid chromatography (HPLC)‐mass spectrometry. Serially culturing cells for 1, 2, or 3 growth cycles led to [U]‐13CLYC yields of 10, 38, 46 %, respectively, with no deleterious effect on total LYC yield (~5 mg LYC/L culture for each cycle). To optimize harvest timing, HPLC evaluation of media glucose utilization during the labeling cycle indicated 99% of media glucose was incorporated by day 12 of the growth period. These approaches greatly enhance production efficiency of highly enriched a 13C‐LYC tracer for human carotenoid metabolism research.Grant Funding Source : Pelotonia Postdoctoral Fellowship at OSU and NIH/NCCAM 5R21AT005166‐02

The impact of industrial processing on health-beneficial tomato microconstituents

The effect of industrial processing was investigated on the stability of tomato carotenoids, phenolic compounds and ascorbic acid. A deep insight in the processed products allowed the quantification of caffeic acid hexosides, which are far more important contributors than the well-known chlorogenic acid, dicaffeoylquinic acids and quercetin oligosaccharides (new feruloyl, sinapoyl and syringoyl derivatives of quercetin apiosylrhamnosylglucoside). (E)-β-Carotene and (E)-lycopene were also quantified along with different mono- and di-(Z)-isomers of lycopene which were tentatively assigned. Processing of fresh tomato into paste had an overall positive effect on the contents in phenolic compounds, no effect on lycopene and a slight and high detrimental effect on β-carotene and ascorbic acid, respectively. The balance between the increase in tomato matrix extractability and microconstituent catabolism was further observed in two contrasted transformations of paste into sauce. Overall, the nutritional quality of tomato-processed products, except for ascorbic acid, is mainly preserved through manufacture.

Differences in the carotenoid content of ketchups and gazpachos through HPLC/ESI(Li+)‐MS/MS correlated with their antioxidant capacity

Carotenoids are important antioxidant compounds in the human diet. Owing to their constrained polyene structure, carotenoids can exist in cis and trans isomeric forms that can be difficult to differentiate in natural samples. In ketchups and gazpachos, all-trans isomeric forms are predominant. However, during thermal processing, cis isomers are formed. Therefore the determination of carotenoid isomers is required for the assessment of the nutritional value of foods. The main carotenoid found in ketchups was trans-lycopene, whereas in gazpachos a higher contribution to the total carotenoid content was made by other carotenoids such as 5-, 9- and 13-cis-lycopene, lutein, β-carotene and α-carotene. Ketchups exhibited the highest lipophilic antioxidant content owing to their higher content of trans-lycopene, the main carotenoid in tomatoes. Direct analysis of carotenoids by electrospray ionisation mass spectrometry (ESI-MS) often produces poor results requiring offline time- and sample-consuming derivatisation techniques. Therefore in this work a simple ESI-MS approach is described for the direct analysis of carotenoids in ketchups and gazpachos using the post-column addition of lithium chloride to promote the cationisation of carotenoids. To the best of the authors' knowledge, this paper presents for the first time the identification of 5-, 9- and 13-cis-lycopene in ketchups and gazpachos.

Effects of Lycopene on the Initial State of Atherosclerosis in New Zealand White (NZW) Rabbits

BackgroundLycopene is the main carotenoid in tomatoes, where it is found in high concentrations. Strong epidemiological evidence suggests that lycopene may provide protection against cardiovascular diseases. We therefore studied the effects of lycopene on diet-induced increase in serum lipid levels and the initiation of atherosclerosis in New Zealand White (NZW) rabbits.Methodology/Principal FindingsThe animals, divided into four groups of 9 animals each, were fed either a standard diet, a high-cholesterol diet containing 0.5% cholesterol, a high-cholesterol diet containing placebo beadlets, or a high-cholesterol diet plus 5 mg/kg body weight/day of lycopene (in the form of lycopene beadlets), for a period of 4 weeks. We found significantly elevated lycopene plasma levels in the animal group treated with lycopene beadlets. Compared to the high-cholesterol and the placebo group, this was associated with a significant reduction of 50% in total cholesterol and LDL cholesterol serum levels in the lycopene group. The amount of cholesteryl ester in the aorta was significantly decreased by lycopene. However, we did not observe a significant decrease in the extent of aortic surface lipid accumulation in the lycopene group. In addition, no differences in the intima-media thickness among groups were observed. Endothelial-dependent and endothelial-independent vasodilation in isolated rabbit aortic and carotid rings did not differ among any of the animal groups.ConclusionsLycopene supplementation for 4 weeks increased lycopene plasma levels in the animals. Although we found strongly reduced total and LDL cholesterol serum levels as well as significantly lower amounts of cholesteryl ester in the aortae in the lycopene-treated group, no significant differences in initial lesions in the aortae were detected.

Rapid determination of lycopene and β‐carotene in tomato by liquid chromatography/electrospray tandem mass spectrometry

The tomato fruit is a dietary source of carotenoids, bioactive antioxidant compounds that play an important role in the prevention of degenerative diseases. Several extraction and detection techniques regarding carotenoids in tomatoes can be found in the literature, mainly based on high-performance liquid chromatography separation and ultraviolet-visible detection. The best extraction conditions and tandem mass spectrometry (MS) analysis were evaluated: lycopene and β-carotene were extracted in a cyclohexane/ethyl acetate mixture without the addition of antioxidants, next separated by liquid chromatography on a C(18) column and then determined through electrospray tandem MS. Ionic suppression by the matrix in negative ionisation mode did not allow the analysis of extracts, hence the positive ionisation mode was chosen. Validation parameters demonstrated the suitability for purpose of the analytical method: accuracy, precision, linearity and detection limits were adequate. The method was finally applied to different tomato samples, and differences could be easily highlighted. The method was simple, fast and appropriate for the purpose of analysing lycopene and β-carotene in tomatoes.

Ultra-performance liquid chromatographic separation of geometric isomers of carotenoids and antioxidant activities of 20 tomato cultivars and breeding lines

All-trans-lutein, lycopene, β-carotene and their 22 cis-isomers in 20 tomato breeding were separated and identified by a rapid and sensitive UPLC method using a 1.7μm C18 column and a new gradient mobile phase based on methanol–MTBE–water in 15min. All-trans-carotenoids were predominant, but 9-cis, 13-cis-lutein, 5-cis, 9-cis, 13-cis, 15-cis, di-cis-lycopene, 9-cis, 13-cis, 15-cis and di-cis-β-carotene were also found. The cis-isomers were identified using absorption around 330nm and the Q-ratio. The total antioxidant activities as evaluated by PCL and DPPH assays were found to correlate well with the total carotenoid content, but not with the individual carotenoid or its different isomers. This paper provides an efficient analytical method for obtaining a complete picture of carotenoids in tomatoes. It can be a valuable tool for plant breeders, food processors and researchers in developing designer tomatoes and tomato-products with unique carotenoid compositions, and functional properties.