Changes In Carotenoid Concentrations Research Articles

Resonant Raman Spectroscopy of Carotenoids in Aging of Extra Virgin Olive Oil.

This work uses resonant Raman spectroscopy (RRS) to investigate changes in carotenoid concentration in extra virgin olive oil (EVOO) as it oxidizes under accelerated thermal aging. Carotenoids are nutritious antioxidants and biomarkers that represent the general quality of olive oil. HPLC is the conventional method used to determine the concentration of carotenoids, but it is expensive, time-consuming, and requires sample handling. A simple optical technique for estimating carotenoid concentration in extra virgin olive oil is, therefore, desirable. This work shows that the normally weak carotenoid signal is strongly amplified when using the resonant Raman technique. The aging and oxidation of EVOO decreases the Raman intensities associated with carotenoids and increases the fluorescence and Raman intensities associated with fatty acids. From these quantities, two Raman intensity ratios are presented as indicators of the effects of aging.

Changes in Carotenoid Concentration and Expression of Carotenoid Biosynthesis Genes in Daucus carota Taproots in Response to Increased Salinity

Studying the changes of carotenoids in the taproot of carrots under salt treatment is helpful to probe the salt stress response mechanism of carrots. The carotenoid concentration and the expression profiles of 10 carotenoid-related genes were determined in two carrot cultivars with different taproot colors. Under salt stress, the biosynthesis of carotenoids in the taproot of both ‘KRD’ and ‘BHJS’ was activated. RT-qPCR manifested that the expression levels of DcPSY1, DcPSY2, DcZDS1, DcCRT1 and DcCRT2 increased significantly in both ‘KRD’ and BHJS’ under salt stress, but DcCHXE transcripts decreased and DcPDS transcripts maintained a basal level compared to that of the control. In the taproot of ‘KRD’, the expression level of DcLCYB, DcLCYE and DcCHXB1 climbed dramatically. However, there was no significant change in the taproot of ‘BHJS’. The study showed that salt stress can stimulate the biosynthesis of carotenoids. The accumulation of lutein in the taproots of ‘KRD’ and ‘BHJS’ may be mainly attributed to the variation in DcLCYE and DcCHXB1 transcripts. The increase in β-carotene accumulation is speculated to increase salt tolerance.

Effect of high-pressure microfluidization on nutritional quality of carrot (Daucus carota L.) juice.

In this study, the effect of high-pressure microfluidization on the colour and nutritional qualities of the orange carrot juice was investigated. The juice was processed at three different pressures (34.47MPa, 68.95MPa and 103.42MPa) with three different passes (1, 2 and 3 passes). After that, total phenolic content (TPC), antioxidant activity, carotenoids, color properties, and total soluble solids content of the processed carrot juice were evaluated. As a result, no specific trends in TPC and antioxidant activity of the juice were observed through the variations of processing conditions. However, microfluidization significantly (p < 0.05) improved the carotenoids content in carrot juice. With increasing number of pass, concentrations of β-carotene and lutein had increased significantly. Similarly, increasing process pressure initially increased carotenoid content significantly (up to 68.95MPa), further increase pressure to 103.42MPa did not cause significant changes in carotenoid concentration. Furthermore, color properties such as lightness, redness, yellowness, and chroma value were reduced significantly with the increase of pressure and the number of passes. The results indicated that high-pressure microfluidization could be used as a novel alternative nonthermal technology to heat pasteurization to improve the color and nutritional qualities in orange carrot juice, resulting in a desirable, high-quality juice for consumers.

The Effect of Air Pollution on Leaf Iron (Fe) Concentration and Activity of Fe-Dependent Antioxidant Enzymes in Maple

Iron (Fe) nutrition status and activity of Fe-dependent enzymes is suggested to be affected by air pollution. This study was aimed to investigate changes in leaf Fe, zinc (Zn), chlorophyll (a, b), and carotenoid concentration and activity of catalase (CAT) and peroxidase (POX) in the leaves of maple (Acer negundo L.) with distance from two major sources of air pollution, i.e., Oil Refinery of Shiraz (ORS) operations and urban traffic of Imam Hossein square (AS) in Shiraz, Iran. By increasing the distance from the ORS, Fe, Zn, and chlorophyll concentration in the maple leaves increased. These changes were associated with lower intensity of chlorosis symptoms on the leaves of maple trees with distance from the ORS. Leaf activity of CAT increased with increasing distance from the ORS. Changes in concentration of carotenoids and activity of POX did not follow a distinct trend with distance from both pollution sources. No regular pattern was observed for changes in the measured parameters with distance from the urban traffic of Imam Hossein square (AS), as another major source of air pollution in the studied region. This was due to irregular changes in the concentrations of air pollutants across the sampling pathway. According to the results, significant impairment in Fe nutritional status is expected for plants exposed to the air pollution, although further studies are needed to clarify the physiological reasons of Fe chlorosis under air pollution stress.

Constitutive changes in pigment concentrations: implications for estimating isoprene emissions using the photochemical reflectance index

The photochemical reflectance index (PRI), through its relationship with light use efficiency (LUE) and xanthophyll cycle activity, has recently been shown to hold potential for tracking isoprene emissions from vegetation. However, both PRI and isoprene emissions can also be influenced by changes in carotenoid pigment concentrations. Xanthophyll cycle activity and changes in carotenoid concentrations operate over different timescales, but the importance of constitutive changes in pigment concentrations for accurately estimating isoprene emissions using PRI is unknown. To clarify the physiological mechanisms behind the PRI-isoprene relationship, the light environment of potted Salix viminalis (osier willow) trees was modified to induce acclimation in photosynthetic rates, phytopigments, isoprene emissions and PRI. Acclimation resulted in differences in pigment concentrations, isoprene emissions and PRI. Constitutive changes in carotenoid concentration were significantly correlated with both isoprene emissions and PRI, suggesting that the relationship between PRI and isoprene emissions is significantly influenced by constitutive pigment changes. Consequently knowledge regarding how isoprene emissions are affected by both longer term changes in total carotenoid concentrations and shorter term dynamic adjustments of LUE is required to facilitate interpretation of PRI for monitoring isoprene emissions.

Resonance Raman and EPR spectroscopy studies of untreated spring wheat leaves

Leaves are the structures in plants that have evolved primarily to absorb sunlight and to convert this energy into carbohydrates, which is the essence of the photosynthesis process. In the current study Raman and electron paramagnetic resonance (EPR) spectroscopic methods were applied to investigate the drought stress occurring in the fresh wheat leaves immediately after cutting them off from the rest of the plant. Resonance Raman microspectroscopy mapping allowed us to visualize the changes in concentrations of carotenoids, playing an important role in the photosynthetic membrane, as well as quinones and carbohydrates in the selected areas in plant tissues. EPR spectroscopy was used to detect free radicals in the leaf tissue directly. Besides these very reactive, short lifetime species (monodehydroascorbate–ascorbate radical (MDA)), the long-living semiquinone and carbohydrate radicals have been also detected.

Positive Carotenoid Balance Correlates with Greater Reproductive Performance in a Wild Bird

BackgroundCarotenoids can confer somatic and reproductive benefits, but most evidence is from captive animal experimentation or single time-point sampling. Another perhaps more informative means by which to assess physiological contributions to animal performance is by tracking an individual's ability to increase or sustain carotenoids or other health-related molecules over time, as these are likely to be temporally variable.Methodology/Principal Findings In a field study of North American barn swallows (Hirundo rustica erythrogaster), we analyzed within-individual changes in carotenoid concentrations by repeatedly sampling the carotenoid profiles of individuals over the course of the breeding season. Our results demonstrate that carotenoid concentrations of individuals are temporally dynamic and that season-long balance of these molecules, rather than single time-point samples, predict reproductive performance. This was true even when controlling for two important variables associated with reproductive outcomes: (1) timing of breeding and (2) sexually selected plumage coloration, which is itself positively correlated with and concomitantly changes with circulating carotenoid concentrations.Conclusions/SignificanceWhile reproduction itself is purported to impose health stress on organisms, these data suggest that free-ranging, high-quality individuals can mitigate such costs, by one or several genetic, environmental (diet), or physiological mechanisms. Moreover, the temporal variations in both health-linked physiological measures and morphological traits we uncover here merit further examination in other species, especially when goals include the estimation of signal information content or the costs of trait expression.

Changes in pigment concentrations associated with sunburn browning of five apple cultivars. I. Chlorophylls and carotenoids

Peel disks were taken from the sunburned area (SB-2), the area around the sunburned area (halo), the area around the halo (OH), and the center of the sun-exposed side of non-sunburned (NB) ‘Fuji’, ‘Gala’, ‘Delicious’, ‘Golden Delicious’, and ‘Granny Smith’ apples ( Malus domestica Borkh). Chlorophyll a and b concentrations in SB-2 peels of all five cultivars were generally significantly ( P ≤ 0.05) lower than those in the halo, OH and NB peels. Significantly higher concentrations of β-carotene, violaxanthin, and antheraxanthin were observed in ‘Fuji’ and ‘Delicious’ SB-2 peel as compared to OH and NB peels. Lower concentrations of β-carotene and L were observed in ‘Granny Smith’ SB-2 and halo peels than in OH and NB peels, with no differences observed in violaxanthin and antheraxanthin concentrations. The results indicate uniform changes in chlorophyll concentrations as a result of sunburn, while changes in carotenoid concentration are cultivar specific.

Postpartum Relationship of Beta Carotene and Vitamin A between Placenta, Blood and Colostrum in Cows and their Newborns

Carotenoids are lipophilic compounds which are involved not only in scavenging reactive oxygen species but also in many important biochemical processes. Periparturient period is supposed to be connected with oxidative imbalance which can be detected in blood of mother and newborn. Colostrum contains antioxidants which should protect newborn from stressful conditions. The aim of present study was do evaluate the relationship of beta carotene and vitamin A concentration between placenta, blood and colostrum of cows and blood of their newborns. 12 pregnant, healthy cows and their newborns were included into study. The concentration of beta carotene and vitamin A were detected in homogenates of placental tissues obtained immediately after parturition as well as in blood of mother and newborn and colostrum. Additionally blood and colostrum samples were collected 24 hours after parturition. The determinations were performed by use of spectrophotometric method at 325 and 453 nm. The concentration of beta carotene was significantly higher in fetal as in maternal part of placenta. Plasma level significantly decreased during 24 h after parturition in cows but significantly increased in calves. Colostrum level remained relatively stable during examined time. The concentration of retinol was significantly higher in fetal as in maternal part of placenta. Plasma levels, significantly higher in cows as in calves, increased significantly during 24 h after parturition in mothers but remained unchanged in newborns. Colostral concentrations increased significantly during examined period of time. In conclusion, dynamic changes in carotenoid concentrations in placenta, blood of mother and newborn as well as in colostrum that occur during 24 h after parturition may indicate the importance of antioxidative defence at this time both for cow and calf.

Effects of mountain grassland maturity stage and grazing management on carotenoids in sward and cow's milk

Carotenoids are involved in the sensorial and nutritional values of dairy products. In grazing systems, both herbage maturity stage and grazing management may affect the amount of carotenoid ingested, thus these factors may affect carotenoid concentrations in milk. Two homoge- nous plots of mountain grassland (1.4 and 2.0 ha) were grazed during two cycles of growth by 6 dairy cows in mid lactation, in strip (SG) and rotational grazing (RG), respectively. We monitored the changes in carotenoid concentrations in sward and milk, measured by HPLC twice a week. Seven carotenoids were identified in the sward: violaxanthin, antheraxanthin, epilutein, lutein, zeax- anthin, s-carotene and 13-cis s-carotene. Forage quality decreased throughout the course of the first growth stage, but carotenoid concentration in sward did not significantly change. In early regrowth, forage quality was high and the concentration of s-carotene and xanthophylls also tended to be higher. Carotenoid concentrations in sward were not affected by grazing management, averaging 350 µg per g DM. The carotenoids identified in milk were β-carotene (75%) and lutein (25%). A significant decrease in s-carotene concentration in milk was observed throughout the course of the first growth stage, from 5.37 to 3.87 µg per g fat, whereas it increased to 4.91 µg per g fat in early regrowth. β-carotene concentration in milk was not affected by grazing management, averaging 4.72 and 5.03 µg per g fat for RG and SG, respectively. However, lutein concentration was slightly lower for RG than for SG, averaging 1.39 and 1.74 µg per g fat, respectively. It is concluded that carotenoids in milk were only slightly affected by herbage maturity stage, and to a lesser extent by grazing management. carotenoids / cow's milk / mountain grassland / maturity stage / grazing management

Effect of short-term grain feeding on bovine body-fat colour: a cautionary note

Seventeen Brahman steers were removed from pasture and fed a high grain diet for 8 weeks prior to slaughter. Carotenoid concentrations were determined in samples of serum and subcutaneous fat obtained either from live animals or at slaughter. At slaughter carcass fat colour was assessed according to AUS-MEAT specification. The concentrations of G-carotene in the serum of these animals fell rapidly (over 60%, P lt; 0.001) in the first 2 weeks on the grain diet and then plateaued. There was no change in either the concentrations of carotenoids in subcutaneous fat or in fat colour of these cattle during the whole period of grain feeding. The overall average liveweight gain was 0.59 kg/day. Failure to observe changes in concentrations of carotenoids was unexpected, and may be partly due to the fact that these cattle did not settle to the trial conditions in the feedlot, as indicated by the significantly higher cortisol concentration in their serum compared with the initial slaughter group. The implications of the outcome of this study are discussed.