High Levels Of Β-carotene Research Articles

Carotenoid and retinol composition of South Asian foods commonly consumed in the UK

The main aim of this study was to provide new and reliable food composition data on carotenoids and retinol in South Asian Foods for the United Kingdom's national database. A total of 38 commonly consumed foods were analysed using HPLC and accredited methods of analyses. Palak paneer (spinach and soft Indian cheese) contained the highest levels of β-carotene (4066μg/100g) followed by gajjeralla (carrot based sweet, 2324μg/100g) and saag (mixed green leafy vegetables), which contained 1514μg/100g, whilst retinol was present in only a few foods, with ghee being the major source (968μg/100g). Meat dishes contained higher amounts of lycopene (up to 1140μg/100g in chicken balti) than vegetable or dhal dishes (highest in palak paneer 317μg/100g), because of larger quantities of tomatoes used in meat curries. A variety of ethnic vegetables (green leafy vegetables and other coloured vegetables), namely legumes/dhal, tomatoes and coriander, were identified to be the major ingredients containing carotenoids. These new data can be used in future diet and nutrition surveys, as well as to identify carotenoid-rich foods for dietary programs.

Repeated measurements of serum carotenoid, retinol and tocopherol levels in relation to colorectal cancer risk in the Women's Health Initiative

Previous cohort studies examining the association of serum antioxidant levels and risk of colorectal cancer have used a single (baseline) measurement only. In the present study, we assessed the association of serum levels of eight antioxidant nutrients in relation to risk of colorectal cancer, using repeated measurements. Data on a subsample of women in the Women's Health Initiative with repeated measurements of serum retinol, α-carotene, β-carotene, β-cryptoxanthin, lutein+zeaxanthin, lycopene, α-tocopherol and γ-tocopherol during follow-up were included in the analysis. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CIs). Among 5477 women with baseline serum antioxidant values, 88 incident cases of colorectal cancer were identified over a median follow-up time of 12 years. Serum antioxidants measured at baseline generally showed no association with risk of colorectal cancer, although serum β-carotene at baseline showed a non-significant inverse association with colon cancer alone. Furthermore, using the repeated measurements of β-carotene, the average of all measurements was inversely associated with risk of both colorectal and colon cancer: HRs for highest vs lowest tertile 0.54, 95% CI 0.31-0.96, and 0.47, 95% CI 0.25-0.88, respectively. No associations were seen with other antioxidant nutrients in the repeated measure analyses. In this study, baseline levels of antioxidant nutrients were not associated with risk of colorectal or colon cancer; however, using repeated measures, a relatively high serum level of β-carotene (average of all measurements) was inversely associated with risk of colon and colorectal cancer in postmenopausal women.

The effect of artificial diets on gonad colour and biomass in the edible sea urchin Psammechinus miliaris

During two 12 week trials, groups of edible sea urchins, Psammechinus miliaris, were fed artificial diets containing carotenoid pigments. The aim was to improve both the biomass and the colour of the sea urchin gonad in terms of its acceptability as a human food-stuff in the European market place. The pigmented artificial diets, based on the formula used by Robinson et al. (2002), increased gonad index (GI), pigment deposition and improved gonad colour from that of the initial samples. In Trial I gonad β-carotene levels increased > 2 fold, echinenone and total carotenoid > 7 fold. Trial II showed greater increases. Diets containing high levels of β-carotene (500 mg per kg dry weight of diet) gave rise to the highest percentages of marketable gonad colours (61–73%), and GI of 17.87–19.81%, (Trial I and II respectively). There was some variation in the results for this particular diet treatment across the two trials presumably reflecting individual urchins varying capacity to ingest, deposit or express the carotenoids in their diet. Providing additional lipids in the diets gave no improvement to gonad colour (56% acceptable) or GI (15.95%) suggesting the lipid content of the basic formulation is adequate. Utilizing an esterified form of lutein and zeaxanthin as a pigment source gave no significant improvement in gonad colour (30–63% acceptable) suggesting that this form of xanthophyll cannot be assimilated by P. miliaris. Female urchins had acceptable gonad colouration more often than males. The dominant carotenoid in the successful diets was β-carotene and this was successfully metabolized into echinenone, the dominant carotenoid in all gonad samples. Total levels of echinenone positively correlated with acceptable gonad colour scores. This study demonstrates that 12 weeks is sufficient to effect the desired change in gonad biomass and colour in cultivated P. miliaris.

Abstract 3769: Use of combined levels of dietary intake from FFQ and plasma biomarkers to assess association between antioxidant exposures and prostate cancer risk

Abstract Epidemiologic studies evaluating the relation between specific nutrients and risk of disease typically rely either on questionnaire-based or on biomarker-based measures of exposure; however both of these approaches may be affected by systematic error. In this study, we aim to improve assessment of antioxidant exposure through a combined measure reflecting both plasma measurements and food frequency questionnaire (FFQ)-derived levels of intake. This combined measure of exposure is examined in relation to risk of prostate cancer. In this community-based case-control study, dietary intake was assessed through the validated Block FFQ that allowed estimating daily intakes of various antioxidants. Archived plasma samples were analyzed using high performance liquid chromatography to determine circulating levels of carotenoids (lycopene, α-carotene, β-carotene, lutine, and β-cryptoxanthin), retinol (vitamin A), and α-tocopherol (vitamin E). Cases and controls were categorized as having “high” or “low” for each antioxidant's dietary intake and plasma level based on the median value among controls. Each participant was then included into one of the following four categories: (1) low dietary intake and low plasma level; (2) low dietary intake and high plasma level; (3) high dietary intake and low plasma level; and (4) high dietary intake and high plasma level. The combined measurements of high dietary intake and high plasma levels of lycopene, β-cryptoxanthin, and α-tocopherol demonstrated a statistically significant association with prostate cancer risk with adjusted odds ratios of 0.46 (0.23-0.91), 0.43 (0.22-0.84), and 0.32 (0.14-0.72), respectively. The combined measurements of high dietary intake and low plasma levels of β-carotene also demonstrated a statistically significant association (aOR = 0.43; 95% CI=0.20-0.91) with prostate cancer risk. These results tended to be stronger than the corresponding results for each measure of exposure considered individually. These findings provide evidence that the use of combined levels of dietary intake from FFQ and plasma biomarkers can improve the assessment of antioxidant exposure compared to use of either FFQ or plasma biomarkers separately. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3769.

Abstract B123: Sequence variants in inflammatory genes, plasma antioxidants, and prostate cancer risk

Abstract Background: Presence of xenotropic murine leukemia virus-related virus and chronic inflammation in prostate tumor tissue suggests that inflammation plays a role in prostate cancer etiology. This study thus investigated whether variants in genes involved in inflammation influence alone or interact with plasma antioxidants to influence prostate cancer risk in a population-based case-control study in Central Arkansas. Methods: Cases (n=193) were men, ages 40–80 years, diagnosed with prostate cancer in three major hospitals in 1998–2003, and controls (n=197) were matched to cases by age, race, and county of residence. Results: After adjustment for confounders, polymorphisms in COX2 (rs689466) and IL-8 (rs4073) were not significantly associated with prostate cancer risk. However, significant interactions were observed between these genetic variants and plasma antioxidants on the risk of this malignancy. The protective effect of the mutant allele of the COX polymorphism was more pronounced among subjects with high plasma levels of β-cryptoxanthin, lycopene, β-carotene, or selenium (≥median) [e.g., OR (95% CI): 0.37 (0.15–0.86) (AG/GG vs. AA) for β-cryptoxanthin]. Conversely, the promoting effect of the variant allele of the IL-8 polymorphism was more remarkable in subjects with low plasma levels of Lutein/zeaxanthin, β-cryptoxanthin, and β-carotene (<median) [e.g., OR (95% CI): 2.44 (1.08–5.75) (AT/TT vs. AA) for β-carotene]. Conclusions: We found that genetic variants in inflammatory genes interact with plasma antioxidants to modulate the risk of prostate cancer. The results obtained from our study need to be replicated in large epidemiologic studies. Citation Information: Cancer Prev Res 2010;3(1 Suppl):B123.

Cytosolic and Plastoglobule-targeted Carotenoid Dioxygenases from Crocus sativus Are Both Involved in β-Ionone Release

Saffron, the processed stigma of Crocus sativus, is characterized by the presence of several apocarotenoids that contribute to the color, flavor, and aroma of the spice. However, little is known about the synthesis of aroma compounds during the development of the C. sativus stigma. The developing stigma is nearly odorless, but before and at anthesis, the aromatic compound beta-ionone becomes the principal norisoprenoid volatile in the stigma. In this study, four carotenoid cleavage dioxygenase (CCD) genes, CsCCD1a, CsCCD1b, CsCCD4a, and CsCCD4b, were isolated from C. sativus. Expression analysis showed that CsCCD1a was constitutively expressed, CsCCD1b was unique to the stigma tissue, but only CsCCD4a and -b had expression patterns consistent with the highest levels of beta-carotene and emission of beta-ionone derived during the stigma development. The CsCCD4 enzymes were localized in plastids and more specifically were present in the plastoglobules. The enzymatic activities of CsCCD1a, CsCCD1b, and CsCCD4 enzymes were determined by Escherichia coli expression, and subsequent analysis of the volatile products was generated by GC/MS. The four CCDs fell in two phylogenetically divergent dioxygenase classes, but all could cleave beta-carotene at the 9,10(9',10') positions to yield beta-ionone. The data obtained suggest that all four C. sativus CCD enzymes may contribute in different ways to the production of beta-ionone. In addition, the location and precise timing of beta-ionone synthesis, together with its known activity as a fragrance and insect attractant, suggest that this volatile may have a role in Crocus pollination.

Transgenic carrot plants accumulating ketocarotenoids show tolerance to UV and oxidative stresses

Ketocarotenoids are strong antioxidant compounds which accumulate in salmon, shrimp, crustaceans and algae, but are rarely found naturally in higher plants. In this study, we engineered constitutive expression of an algal beta-carotene ketolase gene (bkt) in carrot plants to produce a number of ketocarotenoids from beta-carotene. These included astaxanthin, adonirubin, canthaxanthin, echinenone, adonixanthin and beta-cryptoxanthin. Leaves accumulated up to 56 microg/g total ketocarotenoids and contained higher beta-carotene levels but lower levels of alpha-carotene and lutein. The photosynthetic capacity of transgenic plants was not significantly altered by these changes. However, when high-expressing transgenic plants were exposed to UV-B irradiation, they grew significantly better than the wild-type controls. Similarly, leaf tissues exposed to various oxidative stresses including treatment with H(2)O(2) and methyl viologen showed less injury and retained higher levels of chlorophyll a+b. Total carotenoid extracts from transgenic leaves had higher antioxidant and free-radical scavenging activity in vitro compared to control leaves. Transgenic tissues also accumulated lower amounts of H(2)O(2) following exposure to oxidative stresses, suggesting that free radical and reactive oxygen species were quenched by the ketocarotenoids.

Characterization of cDNA of lycopene β-cyclase responsible for a high level of β-carotene accumulation inDunaliella salina

Lycopene beta-cyclase (Lyc-B) is the key enzyme in the catalysis of linear lycopene to form cyclic beta-carotene, an indispensable part of the photosynthetic apparatus and an important source of vitamin A in human and animal nutrition. Studies showing that the microalga Dunaliella salina can accumulate a high level of beta-carotene are lacking. We hypothesize that D. salina is closely involved with the catalytic mechanism of Lyc-B and the molecular regulation of its gene. In this study, we used RT-PCR and RACE-PCR to isolate a 2475 bp cDNA with a 1824 bp open reading frame, encoding a putative Lyc-B, from D. salina. Homology studies showed that the deduced amino acid sequence had a significant overall similarity with sequences of other green algae and higher plants, and that it shared the highest sequence identity, up to 64%, with Lyc-B of Chlamydomonas reinhardtii. Codon analysis showed that synonymous codon usage in the enzyme has a strong bias towards codons ending with adenosine. Two motifs were found in the Lyc-B sequence, one at the N terminus, for binding the hypothetical cofactor FAD, and the other was a substrate carrier motif in oxygenic organisms shared by an earlier carotenogenesis enzyme, phytoene desaturase, and Lyc-B. A tertiary structure prediction suggested that the catalytic or binding site structure within LycB from D. salina is superior to that of both H. pluvialis and C. reinhardtii. The LycB protein from D. salina was quite removed from that of H. pluvialis and C. reinhardtii in the phylogenetic tree. Taken as a whole, this information provides insight into the regulatatory mechanism of Lyc-B at the molecular level and the high level of beta-carotene accumulation in the microalga D. salina.

Antioxidant Profiling of Native Andean Potato Tubers (Solanum tuberosum L.) Reveals Cultivars with High Levels of β-Carotene, α-Tocopherol, Chlorogenic Acid, and Petanin

The antioxidant profile of 23 native Andean potato cultivars has been investigated from a human nutrition perspective. The main carotenoid and tocopherol compounds were studied using high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD) and a fluorescence detector, respectively, whereas polyphenols (including anthocyanins in colored tubers) were identified by means of both HPLC-mass spectrometry and HPLC-DAD. Antioxidant profiling revealed significant genotypic variations as well as cultivars of particular interest from a nutritional point of view. Concentrations of the health-promoting carotenoids, lutein and zeaxanthin, ranged from 1.12 to 17.69 microg g(-1) of dry weight (DW) and from 0 to 17.7 microg g(-1) of DW, with cultivars 704353 and 702472 showing the highest levels in lutein and zeaxanthin, respectively. Whereas beta-carotene is rarely reported in potato tubers, remarkable levels of this dietary provitamin A carotenoid were detected in 16 native varieties, ranging from 0.42 to 2.19 microg g(-1) of DW. The amounts of alpha-tocopherol found in Andean potato tubers, extending from 2.73 to 20.80 microg g(-1) of DW, were clearly above the quantities generally reported for commercial varieties. Chlorogenic acid and its isomers dominated the polyphenolic profile of each cultivar. Dark purple-fleshed tubers from the cultivar 704429 contained exceptionally high levels of total anthocyanins (16.33 mg g(-1) of DW). The main anthocyanin was identified as petanin (petunidin-3-p-coumaroyl-rutinoside-5-glucoside). The results suggest that Andean potato cultivars should be exploited in screening and breeding programs for the development of potato varieties with enhanced health and nutritional benefits.

Consumer acceptability of yellow maize products in Zimbabwe

This study analyzes consumers’ awareness of and attitudes towards yellow maize products in Zimbabwe and suggests intervention strategies that will ensure increased production and consumption of the crop, which is rich in provitamin A to help prevent the incidence of vitamin A deficiency prevalent among vulnerable groups. Data from 360 randomly selected rural and urban households show that yellow maize is known to all but few are aware of its nutritional qualities or consume it. The main source of supply is imported food aid. Rich in oils, carotenoids and fructose, yellow maize easily undergoes chemical changes to produce unacceptable organoleptic properties (or bad taste) if poorly handled during importation. These two factors are responsible for it being perceived inferior to white maize by consumers. Quality assurance during importation can improve consumer confidence but a long-term strategy will be to vigorously promote domestic production of yellow maize varieties rich in high levels of β-carotene that meet the preferences of consumers. Drawing from a probit model regression analysis, nutritional education can potentially promote yellow maize consumption, especially if targeted at low income households. Domestic production and consumption of yellow maize will decrease vitamin A deficiency among vulnerable groups and improve food insecurity through reduced grain prices and increased incomes for farmers. These results draw attention to the need for policy makers in developing countries to review their agricultural policies to ensure that they do not undermine the local production and consumption of nutritionally valuable crops.

Neighborhood Deprivation Is Associated with Lower Levels of Serum Carotenoids among Adults Participating in the Third National Health and Nutrition Examination Survey

Objective This study tested the hypothesis that neighborhood deprivation will be associated with lower levels of serum carotenoids in comparison with wealthy residential areas. Design Cross-sectional, nationally representative survey data were used to assess the relationship between neighborhood level socioeconomic status and serum carotenoids. Subjects Seventeen thousand two participants aged 17 years and older from the Third National Health and Nutrition Examination Survey were linked with 1990 census data. Main outcome measures Serum levels of lycopene, β-carotene, α-carotene, lutein/zeaxanthin, and β-cryptoxanthin. Statistical analysis Multivariate linear regression was used to model the association of serum carotenoids and neighborhood deprivation, which is a summary index of 11 indicators for tract level socioeconomic status. Adjustments are made for individual level age, sex, years of education, household income, employment, race/ethnicity, body mass index, serum cotinine, alcohol use, physical activity, and serum cholesterol. Results Multivariate analysis revealed a negative and statistically significant association between high levels of neighborhood deprivation and β-carotene (β=−2.98 μg/dL [−0.06 μmol/L], P=0.00), α-carotene (β=−1.28 μg/dL [−0.02 μmol/L], P=<0.0001), lutein/zeaxanthin (−1.69 μg/dL [−0.03 μmol/L], P=0.00, β-cryptoxanthin (β=−1.34 μg/dL [−0.02 μmol/L], P<0.0001), and total carotenoids (β=−8.20 μg/dL, P=<0.0001). Lycopene was not related to neighborhood deprivation. Adjusted mean levels of carotenoids for high deprivation neighborhoods were lower than neighborhoods with low deprivation: β-carotene=8.72 μg/dL [0.16 μmol/L] vs 20.64 μg/dL [0.38 μmol/L], α-carotene=0.44 μg/dL [0.008 μmol/L] vs 5.56 μg/dL [0.10 μmol/L], lutein/zeaxanthin=13.79 μg/dL [0.24 μmol/L] vs 20.55 μg/dL [0.36 μmol/L], β-cryptoxanthin=4.57 μg/dL [0.08 μmol/L] vs 9.93 μg/dL [0.18 μmol/L], lycopene=22.07 μg/dL [0.41 μmol/L] vs 25.63 μg/dL [0.48 μmol/L], and total=49.56 μg/dL vs 82.36 μg/dL. Conclusions Neighborhood deprivation was associated with lower serum levels of carotenoids. There was a substantial disparity between low deprivation and high deprivation residential areas with respect to fruit and vegetable intake.

High-Level Production of Beta-Carotene in Saccharomyces cerevisiae by Successive Transformation with Carotenogenic Genes from Xanthophyllomyces dendrorhous

To determine whether Saccharomyces cerevisiae can serve as a host for efficient carotenoid and especially beta-carotene production, carotenogenic genes from the carotenoid-producing yeast Xanthophyllomyces dendrorhous were introduced and overexpressed in S. cerevisiae. Because overexpression of these genes from an episomal expression vector resulted in unstable strains, the genes were integrated into genomic DNA to yield stable, carotenoid-producing S. cerevisiae cells. Furthermore, carotenoid production levels were higher in strains containing integrated carotenogenic genes. Overexpression of crtYB (which encodes a bifunctional phytoene synthase and lycopene cyclase) and crtI (phytoene desaturase) from X. dendrorhous was sufficient to enable carotenoid production. Carotenoid production levels were increased by additional overexpression of a homologous geranylgeranyl diphosphate (GGPP) synthase from S. cerevisiae that is encoded by BTS1. Combined overexpression of crtE (heterologous GGPP synthase) from X. dendrorhous with crtYB and crtI and introduction of an additional copy of a truncated 3-hydroxy-3-methylglutaryl-coenzyme A reductase gene (tHMG1) into carotenoid-producing cells resulted in a successive increase in carotenoid production levels. The strains mentioned produced high levels of intermediates of the carotenogenic pathway and comparable low levels of the preferred end product beta-carotene, as determined by high-performance liquid chromatography. We finally succeeded in constructing an S. cerevisiae strain capable of producing high levels of beta-carotene, up to 5.9 mg/g (dry weight), which was accomplished by the introduction of an additional copy of crtI and tHMG1 into carotenoid-producing yeast cells. This transformant is promising for further development toward the biotechnological production of beta-carotene by S. cerevisiae.

Changes in kale (Brassica oleracea L. var. acephala) carotenoid and chlorophyll pigment concentrations during leaf ontogeny

Abstract There has been recent market interest in “baby” salad greens. However, little information exists on the nutritional differences between immature “baby” greens and produce traditionally sold at the fully mature stage. Kale ( Brassica oleracea L. var. acephala D.C.) contains high levels of lutein and β-carotene, which possess important human health properties. Kale was grown in a controlled environment and pigments were measured in young ( 4 weeks) leaves using high-performance liquid chromatography (HPLC). Significant differences were observed for all pigments during leaf development. Pigment accumulation followed a quadratic trend, with maximums occurring between the 1st and 3rd week of leaf age. The highest concentrations of lutein measured 15.1 mg/100 g fresh mass and occurred in 1–2 week old leaves. The remaining pigments reached maximum levels at 2–3 weeks (β-carotene at 11.6 mg/100 g; chlorophyll a at 251.4 mg/100 g; and chlorophyll b at 56.9 mg/100 g fresh mass). Mature fully expanded kale leaves accumulated higher carotenoid concentrations than immature or “baby” leaves, with senescent leaves having the lowest carotenoid concentrations. Harvesting kale leaves at a mature stage of development resulted in maximum carotenoid values. Cultural management practices that increase carotenoid concentrations would be expected to improve nutritional quality for fresh markets.

Quantitation of Carotenoids in Commonly consumed Vegetables in Japan

The carotenoid content, potentially an antioxidant, of 70 vegetables in Japan was determined by reversed-phase HPLC. α-Carotene was detected in 55 of 70 vegetable samples; β-carotene, in all 70; lycopene, in four types of tomatoes and Kintoki carrot; capsanthin, in only two types of sweet peppers; lutein, in 68 of the 70; zeaxanthin, in 30 of the 70; and β-cryptoxanthin in 12 of the 70 samples. All leafy vegetables contained relatively high levels of β-carotene and lutein. In contrast, fruits showed variable carotenoid compositions. A high content of lycopene was quantified in tomatoes and capsanthin was found only in red sweet peppers. In root crops, orange carrots contained high levels of α- and β-carotene, and a high level of lycopene was found in the Kintoki carrot. In other crops, such as head, beans, pods, inflorescences, and spears, carotenoid content was not found to be high in this study.

The CauliflowerOrGene Encodes a DnaJ Cysteine-Rich Domain-Containing Protein That Mediates High Levels of β-Carotene Accumulation

Despite recent progress in our understanding of carotenogenesis in plants, the mechanisms that govern overall carotenoid accumulation remain largely unknown. The Orange (Or) gene mutation in cauliflower (Brassica oleracea var botrytis) confers the accumulation of high levels of beta-carotene in various tissues normally devoid of carotenoids. Using positional cloning, we isolated the gene representing Or and verified it by functional complementation in wild-type cauliflower. Or encodes a plastid-associated protein containing a DnaJ Cys-rich domain. The Or gene mutation is due to the insertion of a long terminal repeat retrotransposon in the Or allele. Or appears to be plant specific and is highly conserved among divergent plant species. Analyses of the gene, the gene product, and the cytological effects of the Or transgene suggest that the functional role of Or is associated with a cellular process that triggers the differentiation of proplastids or other noncolored plastids into chromoplasts for carotenoid accumulation. Moreover, we demonstrate that Or can be used as a novel genetic tool to induce carotenoid accumulation in a major staple food crop. We show here that controlling the formation of chromoplasts is an important mechanism by which carotenoid accumulation is regulated in plants.

Chromosomal promoter replacement of the isoprenoid pathway for enhancing carotenoid production in E. coli

For metabolic engineering it is advantageous in terms of stability, genetic regulation, and metabolic burden to modulate expression of relevant genes on the chromosome rather than relying on over-expression of the genes on multi-copy vectors. Here we have increased the production of β-carotene in Escherichia coli by replacing the native promoter of the chromosomal isoprenoid genes with the strong bacteriophage T5 promoter (P T5). We recombined PCR fragments with the λ-Red recombinase to effect chromosomal promoter replacement, which allows direct integration of a promoter along with a selectable marker that can subsequently be excised by the Flp/FRT site-specific recombination system. The resulting promoter-engineered isoprenoid genes were combined by serial P1 transductions into a host strain harboring a reporter plasmid containing β-carotene biosynthesis genes allowing a visual screen for yellow color indicative of β-carotene accumulation. Construction of an E. coli P T5 -dxs P T5 -ispDispF P T5 -idi P T5 -ispB strain resulted in producing high titers (6 mg/g dry cell weight) of β-carotene. Surprisingly, over-expression of the ispB gene, which was expected to divert carbon flow from the isoprenoid pathway to quinone biosynthesis, resulted in increased β-carotene production. We thus demonstrated that chromosomal promoter engineering of the endogenous isoprenoid pathway yielded high levels of β-carotene in a non-carotenogenic E. coli. The high isoprenoid flux E. coli can be used as a starting strain to produce various carotenoids by introducing heterologous carotenoid genes.

USDA 02L1058 and 02L1059: Cherry Tomato Breeding Lines with High Fruit β-Carotene Content

More than 20 genes have been characterized from tomato (Lycopersicon esculentum Mill.) that infl uence the type, amount, or distribution of carotenoids in fruit and/or foliage (Stommel, 1992). Orange-fruited tomato genotypes containing high levels of β-carotene were fi rst identifi ed among segregants from a cross of a red-fruited tomato genotype and the green-fruited wild tomato species L. hirsutum Dunal (Lincoln et al., 1943). High β-carotene levels are conditioned by a single dominant gene, Beta, and subject to infl uence by a modifi er gene, Mo B (Tomes et al., 1954). Recent studies demonstrated that Beta and Mo B are linked on chromosome 6 and do not segregate independently as originally proposed (Zhang and Stommel, 2000). In the presence of the homozygous recessive Mo B Mo B , β-carotene accounts for >90% of colored carotenes. With the dominant Mo B + allele, β-carotene to lycopene ratios are reduced, resulting in red-orange pigmented fruit. Tomato fruit with high β-carotene content are suitable for specialty applications and provide a rich dietary source of provitamin A. Many studies have examined the relationship between vegetables, fruit, and human health (e.g., Steinmetz and Potter, 1996). Horticultural crops represent about one-third of the U.S. diet and are the main source of dietary carotenoids. β-carotene is an essential nutrient due to its retinoid activity and like other carotenoids, is an antioxidant and may protect against free radical damage. The role that β-carotene and vitamin A play in growth, reproduction, mortality and morbidity from infectious diseases has been reviewed (e.g., Ross, 1998; Tee, 1992). The Agricultural Research Service of the United States Department of Agriculture announces the release of two new cherry tomato breeding lines designated 02L1058 and 02L1059. These lines produce fruit with high β-carotene content and are intended for use as breeding material in the development of new specialty cherry tomato cultivars.

Human intestinal and lung cell lines exposed to β-carotene show a large variation in intracellular levels of β-carotene and its metabolites

Although in vitro models are often used in β-carotene research, knowledge about the uptake and metabolism of β-carotene in cell lines is lacking. We measured by HPLC the intracellular levels of β-carotene and its metabolites in 9 human intestinal and lung cell lines after exposure to 1 μM β-carotene during 2, 6, 30, 54 h, and 3 weeks. In three colorectal carcinoma cell lines only low levels of β-carotene could be detected and an apparent linear increase in intracellular β-carotene was observed during the whole exposure period of 3 weeks. The remaining cell lines (an SV40 transformed colon cell line, a small intestinal carcinoma cell line and several lung cell lines) had medium or high intracellular β-carotene levels. In these cell lines intracellular β-carotene quickly increased during the first 54 h of exposure and after 3 weeks no further increase was observed, suggesting a stable level of β-carotene after 54 h. Estimated intracellular concentrations at steady-state levels varied between 2 and 5 μM (low) or 9 and 55 μM (medium/high). Our results seem to indicate that an active uptake mechanism of β-carotene exists in at least a subset of cell lines. Seven different β-carotene metabolites were detected in the various cell lines ( cis-carotene, retinol, three epoxy-carotenes, and two retinyl esters). Metabolite levels were the highest in cells with medium or high β-carotene levels. Each cell line appeared to have a distinct metabolite profile. No intestinal or lung specific pattern could be found, but two epoxy-carotene metabolites were not detectable in the colon cell lines.

Prediagnostic Levels of Serum Micronutrients in Relation to Risk of Gastric Cancer in Shanghai, China

Abstract Data on blood levels of specific carotenoids and vitamins in relation to gastric cancer are scarce. Little is known about the relationship between prediagnostic serum levels of carotenoids other than β-carotene and risk of gastric cancer especially in non-Western populations. Prediagnostic serum concentrations of α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein/zeaxanthin, retinol, α-tocopherol, γ-tocopherol, and vitamin C were determined on 191 cases and 570 matched controls within a cohort of 18,244 middle-aged or older men in Shanghai, China, with a follow-up of 12 years. High serum levels of α-carotene, β-carotene, and lycopene were significantly associated with reduced risk of developing gastric cancer (all Ps for trend ≤ 0.05); the odds ratios (95% confidence intervals) for the highest versus the lowest quartile of α-carotene, β-carotene, and lycopene were 0.38 (0.13-1.11), 0.54 (0.32-0.89), and 0.55 (0.30-1.00), respectively. Increased serum level of vitamin C was significantly associated with reduced risk of gastric cancer among men who neither smoked cigarettes over lifetime nor consumed ≥3 drinks of alcohol per day; the odds ratios (95% confidence intervals) for the second, third, and fourth quartile categories were 0.69 (0.28-1.70), 0.36 (0.14-0.94), and 0.39 (0.15-0.98), respectively, compared with the lowest quartile of vitamin C (P for trend = 0.02). There were no statistically significant relationships of serum levels of β-cryptoxanthin, lutein/zeaxanthin, retinol, α-tocopherol, and γ-tocopherol with gastric cancer risk. The present study implicates that dietary carotenes, lycopene, and vitamin C are potential chemopreventive agents for gastric cancer in humans.

Recovered lipids from prickly pear [ Opuntia ficus-indica (L.) Mill] peel: a good source of polyunsaturated fatty acids, natural antioxidant vitamins and sterols

Compositions and concentrations of fatty acids, lipid classes, sterols, fat-soluble vitamins and β-carotene were determined in extracted lipids from prickly pear [ Opuntia ficus-indica (L.) Mill] peel. Total lipids (TL) recovered were found to be 36.8 g kg −1 (on dry weight basis). The level of neutral lipids was the highest, followed by glycolipids and phospholipids, respectively. Among the TL, linoleic acid was the dominating fatty acid, while oleic and palmitic acids were estimated to be in relatively equal amounts. Compared with the neutral lipids, the polar fractions were generally characterised by higher percentages of saturated fatty acids and lower percentages of unsaturated fatty acids in all subclasses. Concerning trienes, γ-linolenic acid was present at 8.60% of TL, while α-linolenic acid was present at 0.69%. Recovered lipids were characterised by a high percentage of unsaponifiables (12.8% TL) and found to be a rich source of vitamin E and sterols. Free sterols accounted for ca. 29% of the total unsaponifiables, wherein β-sitosterol and campesterol were the major sterols. In terms of vitamin E, α-tocopherol constitutes about 80.0% of total vitamin E present, the rest being β-, γ- and δ-tocopherols in decreasing order. Moreover, lipids under investigation were characterised by a high levels of β-carotene and vitamin K 1. The information obtained in the present investigation is useful for characterising lipid of prickly pear peel and further chemical and nutritional investigations of prickly pear peel. The results are also important for industrial utilisation of the major by-product of the fruit.