Search Results

You are looking at 71 - 80 of 355 items for :

  • "��-carotene" x
  • Refine by Access: All x
Clear All
Full access

Anusuya Rangarajan, Betsy A. Ingall, Michael D. Orzolek, and Lewis Otjen

This research was supported in part by USDA-Risk Management Agency, Research and Evaluation Division, Kansas City, Mo., project 99-EXCA-3-0711. Authors would like to Joseph Hillebrandt for carotene analysis.

Free access

Mark G. Lefsrud, Dean A. Kopsell, Robert M. Augé, and A.J. Both

Consumption of fruit and vegetable crops rich in lutein and β-carotene carotenoids is associated with reduced risk of cancers and aging eye diseases. Kale (Brassica oleracea L. var. acephala D.C.) ranks highest for lutein concentrations and is an excellent source of dietary carotenoids. Kale plants were grown under varied photoperiods to determine changes in the accumulation of fresh and dry biomass, chlorophyll a and b, and lutein and β-carotene carotenoids. The plants were cultured in a controlled environment using nutrient solutions under photoperiod treatments of 6, 12, 16, or 24 hours (continuous). Fresh and dry mass production increased linearly as photoperiod increased, reaching a maximum under the 24-hour photoperiod. Maximum accumulation of lutein, β-carotene, and chlorophyll b occurred under the 24-h photoperiod at 13.5, 10.4, and 58.6 mg/100 g fresh mass, respectively. However, maximum chlorophyll a (235.1 mg/100 g fresh mass) occurred under the 12-hour photoperiod. When β-carotene and lutein were measured on a dry mass basis, the maximum accumulation was shifted to the 16-hour photoperiod. An increase in photoperiod resulted in increased pigment accumulation, but maximum concentrations of pigments were not correlated with maximum biomass production.

Free access

Mark G. Lefsrud and Dean A. Kopsell

Controlled plant growing systems have consistently used the standard earth day as the radiation cycle for plant growth. However, the radiation cycle can be controlled using automated systems to regulate the exact amount of time plants are exposed to irradiation (and darkness). This experiment investigated the influence of different radiation cycle periods on plant growth and carotenoid accumulation in kale (Brassica oleracea L. var. acephala DC.). Plants were grown in a controlled environment using nutrient solutions under radiation cycle treatments of 2, 12, 24 and 48 hours, with 50% irradiance and 50% darkness during each cycle. The radiation cycles significantly affected kale fresh weight, dry weight, percent dry matter, and the accumulation of lutein, β-carotene, and chlorophyll a and b. Maximum fresh weight occurred under the 2-hour radiation cycle treatment, whereas maximum dry weight occurred under the 12-hour treatment. Maximum accumulation of lutein, β-carotene, and chlorophyll a occurred with the 12-hour radiation cycle at values of 14.5 mg/100 g, 13.1 mg/100 g, and 263.3 mg/100 g fresh weight respectively. Maximum fresh weight production of the kale was not linked to increases in chlorophyll, lutein, or β-carotene. Consumption of fruit and vegetable crops rich in lutein and β-carotene carotenoids is associated with reduced risk of cancers and aging eye diseases. Increased carotenoid concentrations in vegetable crops would therefore be expected to increase the value of these crops.

Free access

Mark G. Lefsrud, Dean A. Kopsell, David E. Kopsell, and Joanne Curran-Celentano

Crop plants are adversely affected by a variety of environmental factors, with air temperature being one of the most influential. Plants have developed a number of methods in the adaptation to air temperature variations. However, there is limited research to determine what impact air temperature has on the production of secondary plant compounds, such as carotenoid pigments. Kale (Brassica oleracea L.) and spinach (Spinacia oleracea L.) have high concentrations of lutein and β-carotene carotenoids. The objectives of this study were to determine the effects of different growing air temperatures on plant biomass production and the accumulation of elemental nutrients, lutein, β-carotene, and chlorophyll pigments in the leaves of kale and spinach. Plants were grown in nutrient solutions in growth chambers at air temperatures of 15, 20, 25, and 30 °C for `Winterbor' kale and 10, 15, 20, and 25 °C for `Melody' spinach. Maximum tissue lutein and β-carotene concentration occurred at 30 °C for kale and 10 °C for spinach. Highest carotenoid accumulations were 16.1 and 11.2 mg/100 g fresh mass for lutein and 13.0 and 10.9 mg/100 g fresh mass for β-carotene for the kale and spinach, respectively. Lutein and β-carotene concentration increased linearly with increasing air temperatures for kale, but the same pigments showed a linear decrease in concentration for increasing air temperatures for spinach. Quantifying the effects of air temperature on carotenoid accumulation in kale and spinach, expressed on a fresh mass basis, is important for growers producing these crops for fresh markets.

Free access

Dean A. Kopsell, Carl E. Sams, T. Casey Barickman, and Robert C. Morrow

blue wavelengths (455 to 470 nm) significantly increased sprouting broccoli ( Brassica oleacea var. italica ) microgreen shoot tissue β-carotene, violaxanthin, total xanthophyll cycle pigments, glucoraphanin, epiprogoitrin, aliphatic glucosinolates

Free access

J.O. Kuti

Flavonoid content and antioxidant activity in peel and pulp samples of four different cactus pear fruit varieties were investigated. Major cactus fruit flavonoids were quercetin, kaempferol, and isorhamnetin. Greater amount of quercetin was found in the pulp compared with the peel samples in all varieties examined. Both kaempferol and isorhamnetin were found in at least three of the varieties (Opuntia ficus-indica; O. lindheimeri; O. streptacantha) exclusively in the peel samples. Generally, pulp tissue samples of all the cactus fruit varieties contained greater ascorbic acid, glutathione, alpha-tocopherol and beta-carotene and antioxidant activities than the peel tissue samples. Total flavonoids correlated well with antioxidant activity (r 2 = 0.89). Ascorbic acid had the highest antioxidant activity, followed by glutathione, beta-carotene, and alpha-tocopherol on equimolar basis.

Free access

Peter J. Mes*, James R. Myers, and Balz Frei

A nutritional study was initiated to determine which carotenoids found in tomato result in decreased lipid oxidation ex vivo. To compare the carotenoids in a human diet without the use of purified supplements, tomatoes expressing nonfunctional enzymes in the carotenoid pathway were used. Tomato lines carrying the genes t, B, ogc, Del, or r were grown to produce fruit containing with high levels of prolycopene, beta-carotene, lycopene, or delta-carotene respectively, or low total carotenoids in r. Juices were processed from these lines and used in a dietary intervention study. Plasma samples were drawn before and after consumption of each juice. These samples were subjected to a battery of tests to analyze the contribution of carotenoids to the total lipid antioxidant status. Results of these tests are discussed.

Free access

Judith Zambrano and Willian Materano

Mango fruits (Mangifera indica L.) were harvested at the preclimacteric stage. Fruits were immersed in 38, 42, 46, 50, and 54°C heated water for 30, 60, and 45 min prior to storage at 5°C for 2, 4, or 6 weeks in carton boxes. After storage, they were kept at 20°C. Fruits were evaluated for pulp color, total soluble solids, titrable acidity, ß-carotene content, reducing sugars and visible symptoms of chilling injury. Heated water had no significant effect on pulp color parameters (lightness, hue, and chroma). Soluble solids concentration, ß-carotene content and reducing sugars were higher in heated than in nonheated fruit after ripening. The chilling index was three-fold lower in treated than nontreated fruit. During storage and after removal at 20°C, hot-water-treated fruits ripened faster than nontreated fruits. Results of this study indicate that mango tolerance to chilling temperatures may increase after prestorage heat treatments.

Free access

Gene E. Lester, John L. Jifon, and D. J. Makus

Netted muskmelon [Cucumis melo L. (Reticulatus Group)] fruit quality (ascorbic acid, β-carotene, total free sugars, and soluble solids concentration (SSC)) is directly related to plant potassium (K) concentration during fruit growth and maturation. During reproductive development, soil K fertilization alone is often inadequate due to poor root uptake and competitive uptake inhibition from calcium and magnesium. Foliar applications of glycine-complexed K during muskmelon fruit development has been shown to improve fruit quality, however, the influence of organic-complexed K vs. an inorganic salt form has not been determined. This glasshouse study investigated the effects of two K sources: a glycine-complexed K (potassium metalosate, KM) and potassium chloride (KCl) (both containing 800 mg K/L) with or without a non-ionic surfactant (Silwet L-77) on melon quality. Orange-flesh muskmelon `Cruiser' was grown in a glasshouse and fertilized throughout the study with soil-applied N–P–K fertilizer. Starting at 3 to 5 d after fruit set, and up to 3 to 5 d before fruit maturity at full slip, entire plants were sprayed weekly, including the fruit, with KM or KCl with or without a surfactant. Fruit from plants receiving supplemental foliar K had significantly higher K concentrations in the edible middle mesocarp fruit tissue compared to control untreated fruit. Fruit from treated plants were also firmer, both externally and internally, than those from non-treated control plants. Increased fruit tissue firmness was accompanied by higher tissue pressure potentials of K treated plants vs. control. In general, K treated fruit had significantly higher SSC, total sugars, total ascorbic acid, and β-carotene than control fruit. Fall-grown fruit generally had higher SSC, total sugars, total ascorbic acid and β-carotene concentrations than spring-grown fruit regardless of K treatment. The effects of surfactant were not consistent but in general, addition of a surfactant tended to affect higher SSC and β-carotene concentrations.

Free access

Parthiban Valnaickenpalayam Kumaresan, Prakasam Velappan, Prabakar Kuppusami, and Thangaraju Muthu

Carrot is a rich source of nutrients. Carrots contains carotene and lycopene, which gives bright color to the roots. The quality of the carrots was assessed based on the carotene, lycopene, and other biochemical constituents such as sugars, starch, and protein. To study the effect of various isolates of the Erwinia carotovora var. carotovora on the above biochemical constituents, the pathogens were inoculated and the contents were analyzed separately at 1, 2, 3, 4, and 5 days after inoculation. The contents of ß-carotene increased significantly due to all the three isolates of the pathogen and the Coimbatore isolate recorded highest of 36.03%. The same trend was also observed in the lycopene content, with 93.55% increase over control. The contents of total and reducing sugars were found to significantly increase due to inoculation with the pathogen. The starch content showed a decreasing trend in all the isolates tested. The maximum reduction of 62.98% was observed in the roots inoculated with Coimbatore isolate. The protein content showed a decreasing trend up to 5th day of inoculation, and further reduction of about 25.45% was recorded with Coimbatore isolate on the 5th day. The total phenol content in the roots of carrot decreased significantly, and reached the least on 5th day due to the infection by all the three isolates and the maximum reduction of 22.79% was observed in roots treated with Coimbatore isolate.