Progress 09/15/00 to 09/14/05
Outputs
Genomic sequences for 24 enzymes in the carotenoid biosynthetic pathway and 2 enzymes in the anthocyanin pathway have been mapped on the carrot genome, and the relationship between these structural genes and major genes controlling carrot root color was compared. Two-way QTL analysis aided in identifying two-way epistatic interactions that control some of the variation for total and specific carotenoids in carrot roots. Complete genomic sequences for genes coding for enzymes in the carotenoid pathway were completed and we began an expression assay for the 24 carotenoid biosynthetic genes. High-pigment, high culinary quality genetic stocks and molecular markers for use by the production industry were developed with sweet, low harsh flavor. These populations were tested by the seed industry and their general release has been initiated. Purple carrots were characterized by five cyanidin-based anthocyanins as previously reported After carrot ingestion, intact anthocyanins
(except coururoyl derivative) anthocyanins appeared in blood within 30 minutes of ingestion. No metabolites of these compounds were observed in the blood or urine of study subjects, leading us to conclude that these compounds are not only absorbed but are also excreted intact. Acylation substantially inhibits anthocyanin bioavailability. Bioavailability of anthocyanins from purple carrots is saturated at large doses. Cooking increased recovery of non-acylated anthocyanins but not acylated anthocyanins in blood and urine of study volunteers. Lycopene and beta-carotene were found to be bioavailable from lycopene red carrots in humans and affected by carrot fiber. The high b-carotene carrot provides more beta-carotene per carrot than the typical store-bought variety without a change in flavor. Lutein from the yellow carrots was 65% as bioavailable as the lutein from the supplement. High-beta-carotene carrots may be an alternative source of vitamin A to typical carrots in areas of
deficiency. Secondly, phenolics including anthocyanins and phenolic acids in purple carrot do not interfere with the bioavailability of carotene from purple carrots. Growers and vegetable seed companies, nutritionists, and international agriculture groups were educated about nutritionally enhanced carrots. We collaborated with media and agricultural groups to disseminate project results and related information. A web site was developed for rapid access to project results and field days were conducted to display results of field tests of new germplasm. Field days allowed industry and other groups to provide direct feedback on short-term research results in one-on-one and group exchanges with researchers. The consuming public was educated about nutritionally enhanced carrots with extension materials and presentations to the general public.
Impacts
Nutritional impact of colored carrots was evaluated and all pigments were found to be bioavailable. Consequently we can conclude that carrots with unusual red, yellow, dark orange, and purple color provide consumers with novel sources of nutrients to enhance and diversify their diets. Furthermore, breeding for higher levels of beta carotene results in carrots which provide consumers with a higher bioavailable level of this pigment. Minor interaction among pigments was observed relative to bioavailability. Growing conditions, and to a greater extent stage of crop maturity, alter the profile of carotenoids and anthocyanins, and consequently the projected nutritional value. Three genes were found to condition differences between white, yellow and orange carrots, with at least one additional gene accounting for red color. One gene conditons accumulation of anthocyanins. The genetic mapping and cloning of 24 genes in the carotenoid pathway provides anchors for map
development and candidates for phenotypic genes. Information was widely distributed to vegetable growers (both large and small scale) and to consumers so that the merits and potential uses of unusually colored carrots is now better known. Unusual colored germplasm is being released to the seed industry and researchers for further use.
Publications
- Tanumihardjo, S.A. and Howe, J.A. Twice the amount of beta-carotene isolated from carrots is as effective as beta-carotene in maintaining the vitamin A status of Mongolian gerbils. J. Nutr. 135:2622-2626, 2005.
- Porter Dosti, M., Mills, J.P., Simon, P.W. and Tanumihardjo, S.A. Bioavailability of beta-carotene (beta C) from purple carrots is the same as typical orange carrots while high-beta C carrots increase beta C stores in Mongolian gerbils (Meriones unguiculatus) Brit. J. Nutr., 2005.
- Kurilich, A.C., B.A. Clevidence, S.J. Britz, P.W. Simon, and J.A. Novotny. Plasma and urine responses are lower for acylated vs. nonacylated anthocyanins from raw and cooked purple carrots. J. Agric. Food Chem. 53: 6537 -6542. 2005.
- Tanumihardjo, S.A., Li, J. and Porter Dosti, M. Lutein absorption is facilitated with co-supplementation of ascorbic acid in young adults. J. Am. Diet. Assn. 105: 114-118, 2005.
- Surles, R.L., Weng, N., Simon, P.W. and Tanumihardjo, S.A. Carotenoid profiles and consumer sensory evaluation of specialty carrots (Daucus carota, L.) of various colors. J. Agric. Food Chem. 52: 3417-3421, 2004.
- Molldrem, K.L., Li, J., Simon, P.W. and Tanumihardjo, S.A. Lutein and beta carotene from lutein-containing yellow carrots are bioavailable in humans. Am. J. Clin. Nutr. 80: 131-136, 2004.
- Molldrem, K.L. and Tanumihardjo, S.A. Lutein supplements are not bioavailable in the Mongolian gerbil while consuming a diet with or without cranberries. Int. J. Vit. Nutr. Res. 74: 153-160, 2004.
- Horvitz, M.A., Simon, P.W. and Tanumihardjo, S.A. Lycopene and beta-carotene are bioavailable from lycopene red carrots in humans. Eur. J. Clin. Nutr. 58: 803-811, 2004.
- Tanumihardjo, S.A. Factors influencing the conversion of carotenoids to retinol: Bioavailability to bioconversion to bioefficacy. Int. J. Vitam. Nutr. Res. 72: 40-45, 2002.
- Santos, C.A. and P.W. Simon. QTL analyses reveal clustered loci for accumulation of major provitamin A carotenes and lycopene in carrot roots. Molec. Genet. Genomics 268: 122-129. 2002.
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Progress 10/01/03 to 09/30/04
Outputs
At the USDA, Beltsville, prior clinical study suggested no dose-response when comparing ingestion of 250 grams of purple carrot vs. 500 grams of purple carrot. Thus, we designed and conducted a follow-up dose response study at lower levels of ingested anthocyanin. Additionally, we have completed further analysis of data from a feeding study in which subjects consumed raw or cooked purple carrots. While four of the five carrot cyanidin derivatives were found in plasma, their recoveries differed. Recoveries of cyanidin derivatives with only sugar moieties did not differ from each other, and recoveries of cyanidin derivatives with a sinapoyl or feruloyl group did not differ from each other, but the presence of a sinapoyl or feruloyl group was associated with significantly lower recovery compared to cyanidin derivatives with only sugar moieties attached. This suggests that the sinapoyl and feruloyl groups may inhibit intestinal absorption. At the USDA, Wisconsin, attempts
were made to attain partial genomic sequences for genes coding for enzymes in the carotenoid pathway and their placement on the carrot linkage maps . The 24 putative genes are added to the map and can serve as anchor points on future carrot linkage maps and as candidate genes for pigment related-traits. We also generated the results of several QTL analyses performed with the updated linkage maps on specific and total root carotenoid accumulation. The system developed describes the mutants in terms of qualitative and quantitative expression of pigment biosynthesis genes. We began attempts to obtain full length cDNA sequences for many of the carotenoid biosynthetic genes. At the University of California - Riverside, field evaluation of commercial and experimental lines at Holtville (desert) and Bakersfield (inland) locations was performed. Data was collected and summarized. Samples from the Holtville site were sent forward for further breeding work, and for feeding studies. The
Bakersfield site field experiment was evaluated and documented. Final seed samples for the final year of these same two trials, will be planted in the next few months and then evaluated in 2005. At the University of Wisconsin, Department of Nutrition, vitamin A (VA) deficiency was noted as a world-wide public health problem. Biofortifying existing sources of b-carotene (bC) and increasing dietary bC could help combat the issue. Two studies were performed to investigate the relative bC bioavailability of a bC supplement to purple, high-bC orange, and typical orange carrots using Mongolian gerbils. Both orange and purple carrot diet resulted in higher liver VA compared to the supplement (P < 0.05). High-bC carrots resulted in more than 2 times higher bC and 1.1 times greater VA liver stores compared to typical orange carrots (P < 0.05). These results suggest that high-bC carrots may be an alternative source of VA to typical carrots in areas of VA deficiency. Secondly, phenolics
including anthocyanins and phenolic acids in purple carrot do not interfere with the bioavailability of bC from purple carrots.
Impacts
Nutritional impact of unusually colored carrots will be determined. Bioavailability of anthocyanins, provitamin A carotenoids, lycopene, and lutein will be measured and compared to other dietary sources of these compounds. Interaction with other nutrients will also be evaluated. The effects of growing conditions in the field will be measured. The genetic basis and genomic location of major genes will be determined. This information will be disseminated to growers, consumers, and researchers. This information will place the efficacy of unusually colored carrots as a source of nutrients.
Publications
- Surles, R.L., Weng, N., Simon, P.W. and Tanumihardjo, S.A. 2004. Carotenoid profiles and consumer sensory evaluation of specialty carrots (Daucus carota, L.) of various colors. J. Agric. Food Chem. 52: 3417-3421.
- Molldrem, K.L., Li, J., Simon, P.W. and Tanumihardjo, S.A. 2004. Lutein and beta-carotene from lutein-containing yellow carrots are bioavailable in humans. Am. J. Clin. Nutr. 80: 131-136.
- Molldrem, K.L. and Tanumihardjo, S.A. 2004. Lutein supplements are not bioavailable in the Mongolian gerbil while consuming a diet with or without cranberries. Int. J. Vit. Nutr. Res. 74: 153-160.
- Horvitz, M.A., Simon, P.W. and Tanumihardjo, S.A. 2004. Lycopene and beta-carotene are bioavailable from lycopene "red" carrots in humans. Eur. J. Clin. Nutr. 58: 803-811.
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Progress 10/01/02 to 09/30/03
Outputs
At the USDA, Beltsville, twelve subjects consumed each of three purple carrot treatments in a cross-over design. The treatments were 250 grams raw carrots, 250 grams cooked carrots, and 500 grams cooked carrots. Serial plasma samples were collected for 8 hours, and urine samples were collected for 24 hours. Anthocyanins from carrots were observed to be absorbed intact. Plasma and urinary appearances of anthocyanin were compared among treatment groups. No differences were observed for total anthocyanin when comparing raw vs. cooked or low-dose cooked vs. high dose cooked. However, cooking reduced the plasma and urinary appearance of one anthocyanin. At the USDA, Wisconsin, putative genomic sequences for 15 enzymes in the carotenoid biosynthetic pathway and 2 enzymes in the anthocyanin pathway have been mapped on the carrot genome, and the relationship between these structural genes and major genes controlling carrot root color is being compared. We have identified
putative genomic sequences corresponding to each of the enzymes in the carotenoid biosynthetic pathway and mapped them in at least one population. Using carotenoid biosynthetic genes as markers we have shown that this gene maps to a region on linkage group 5. We are also investigating the Y, Y1, Y2, and P1 loci in several carrot populations. At the University of California - Riverside, field evaluation of commercial and experimental lines at Holtville (desert) and Bakersfield (inland) locations was performed. Samples from the Holtville site were sent forward for further breeding work, and for feeding studies. At the University of Wisconsin, Department of Nutrition, three research studies were completed. Lycopene and b-carotene are bioavailable from lycopene red carrots in humans: These results show that lycopene and b-carotene are bioavailable from red carrots. The lycopene in the red carrot is about 44% as bioavailable as that from tomato paste. The difference in bioavailability of
b-carotene from three types of carrots: The serum carotenoid response in the white carrot group was always significantly lower than either orange carrot. The high b-carotene carrot provides more b-carotene per carrot than the typical store-bought variety without a change in flavor. The availability of high carotene carrots could readily increase consumption of b-carotene as well as impact the vitamin A status of those individuals who are deficient or at risk of depletion. Lutein is bioavailable in humans from lutein yellow carrot : The objective was to evaluate and compare lutein uptake and clearance from genetically selected yellow lutein carrots and from a lutein supplement. Lutein from the yellow carrots was 65% as bioavailable as the lutein from the supplement. Lutein from this novel food source is highly bioavailable in humans.
Impacts
Nutritional impact of unusually colored carrots will be determined. Bioavailability of anthocyanins, provitamin A carotenoids, lycopene, and lutein will be measured and compared to other dietary sources of these compounds. Interaction with other nutrients will also be evaluated. The effects of growing conditions in the field will be measured. The genetic basis and genomic location of major genes will be determined. This information will be disseminated to growers, consumers, and researchers. This information will place the efficacy of unusually colored carrots as a source of nutrients.
Publications
- No publications reported this period
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