Liquid chromatographic method for the determination of carotenoids, retinoids and tocopherols in human serum and in food

Epler, K. S.; Ziegler, Regina G.; Craft, Neal E.

doi:10.1016/0378-4347(93)80444-9

Cited by 175 publications

(85 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Samples, drawn after overnight fasting and two days after ceasing any vitamin supplementation, were protected from light and air exposure and stored in liquid nitrogen. Plasma concentration of b-carotene was determined by reversed-phase high-performance liquid chromatography (HPLC) separation 20 . , and calculated the ratio of total energy intake to BMR.…”

Section: -Hour Recalls (Reference Method)mentioning

confidence: 99%

Validation and calibration of food-frequency questionnaire measurements in the Northern Sweden Health and Disease cohort

Johansson

Hallmans

Wikman

et al. 2002

Public Health Nutr.

270

281

View full text Add to dashboard Cite

Objectives: To evaluate the reproducibility of, and to compare and calibrate, diet measures by the Northern Sweden 84-item food-frequency questionnaire (FFQ) with measures from 24-hour diet recalls (24-HDR). Design: Randomly selected respondents ðn ¼ 246Þ from the EPIC (diet-cancer) and MONICA (diet -cardiovascular disease) study cohort in Northern Sweden were invited to answer the FFQ twice over a one-year interval (FFQ1 and FFQ2), and to complete ten 24-hour recalls (reference method) in the months between. Plasma b-carotene concentrations were determined from a subset of 47 participants. Setting: Västerbotten and Norrbotten, Northern Sweden. Participants: Ninety-six men and 99 women, who completed the study. Results: The reproducibility of the FFQ was high in terms of both mean energy and nutrient intakes and relative ranking of participants by intake levels (median Pearson correlation of 0.68). Moderately higher food intake frequencies were recorded by FFQ1 compared with 24-hour recalls for dairy products, bread/cereals, vegetables, fruits and potato/rice/pasta, whereas meat, fish, sweet snacks and alcoholic beverage intakes were lower. The median Spearman coefficient of correlation between FFQ1 and the average of ten 24-HDR measurements was 0.50. Daily energy and nutrient intakes were similar for FFQ1 and 24-HDR measurements, except for fibre, vitamin C, b-carotene and retinol (FFQ1 . 24-HDR) and sucrose and cholesterol ðFFQ1 , 24-HDRÞ: Pearson coefficients of correlation between FFQ1 and 24-HDR corrected for attenuation due to residual day-to-day variation in the 24-HDR measurements ranged from 0.36 to 0.79 (median 0.54). Adjustment for energy had only very moderate effects on the correlation estimates. Calibration coefficients estimated by linear regression of the 24-HDR on the FFQ1 measurements varied between 0.30 and 0.59 for all nutrients except alcohol, which had calibration coefficients close to 1.0. These low calibration coefficients indicate that relative risk estimates corresponding to an absolute difference in dietary intake levels measured by the FFQ will generally be biased towards 1.0. Plasma b-carotene levels had a Pearson coefficient of correlation of 0.47 with the 24-HDR measurements, and of 0.23 with FFQ1 measurements. Conclusions: The Northern Sweden FFQ measurements have good reproducibility and an estimated level of validity similar to that of FFQ measurements in other prospective cohort studies. The results from this study will form the basis for the correction of attenuation and regression dilution biases in relative risk estimates, in future studies relating FFQ measurements to disease outcomes.

show abstract

Section: -Hour Recalls (Reference Method)mentioning

confidence: 99%

Validation and calibration of food-frequency questionnaire measurements in the Northern Sweden Health and Disease cohort

Johansson

Hallmans

Wikman

et al. 2002

Public Health Nutr.

270

281

View full text Add to dashboard Cite

show abstract

“…In all the three experiments, the lycopene extraction was based on the methods described by Epler et al (1993), Konings and Roomans (1997) and García-Plazaola and Becerril (1999). The lycopene concentration was measured by High Performance Liquid Chromatography (HPLC) with an Alltima C18, 3 μm, 100 mm x 4.6 mm (Alltech) column at 25°C.…”

Section: Lycopene Extraction and Analysismentioning

confidence: 99%

Effects of Cutting and Maturity on Lycopene Concentration of Fresh-Cut Tomatoes During Storage at Different Temperatures

Lana¹,

Dekker²,

Linssen³

et al. 2005

Acta Hortic.

View full text Add to dashboard Cite

To investigate the changes in lycopene concentration of fresh-cut tomato during storage, tomato fruits at different stages of maturity were cut into 7 mm slices and stored at temperatures varying from 2°C to 16°C. To assess the effect of cutting, intact fruit were stored in an additional experiment at 5°C. Cutting did not change the accumulation of lycopene in fruit stored at 5°C, compared to intact fruit. The lycopene concentration of the tomato slices stored at different temperatures showed net increases of lycopene concentration for all maturity stages tested at temperatures of 8°C and higher. At lower temperatures no increases or small decreases were observed. The lycopene concentration was considered to be the net result of production and degradation of lycopene. Kinetic models for different pathways were tested. The reaction rate constant for lycopene formation at 8°C was estimated at 2.16 ± 0.24 · 10 -2 µg/mg.day. The estimated activation energy for the lycopene formation (92.4 ± 7.3 kJ/mol) indicates that this process is highly dependent on temperature. The degradation rate constant was estimated at 2.99 ± 0.61 · 10 -2 (1/day) and, over the temperature range studied, the degradation rate was not dependent on temperature.

show abstract

“…All triglyceride levels were Ͻ400 mg/dL. Serum carotenoids and retinol concentrations were determined by high-pressure liquid chromatography 30 in a subgroup of participants, the 34 individuals enrolled in the fourth feeding group. The reported run-to-run CV was between 0.6% and 5.1% for all analytes (retinol, lutein, zeaxanthin, cryptoxanthin, lycopene, ␤-carotene, and ␣-tocopherol).…”

Section: Other Assaysmentioning

confidence: 99%

Effect of Dietary Patterns on Measures of Lipid Peroxidation

1998

View full text Add to dashboard Cite

Background-Free radical-mediated oxidative damage to lipids is thought to be an important process in the pathogenesis of atherosclerosis. Although previous studies have demonstrated a beneficial impact of antioxidant vitamin supplements on lipid peroxidation, the effect of dietary patterns on lipid peroxidation is unknown. Methods and Results-During the 3-week run-in period of a randomized trial, 123 healthy individuals were fed a control diet, low in fruits, vegetables, and dairy products, with 37% of calories from fat. Participants were then randomized to consume for 8 weeks: (1) the control diet, (2) a diet rich in fruits and vegetables but otherwise similar to the control diet, and (3) a combination diet rich in fruits, vegetables, and low-fat dairy products and reduced in fat. Serum oxygen radical-absorbing capacity, malondialdehyde (an in vitro measure of lipid peroxidation), and breath ethane (an in vivo measure of lipid peroxidation) were measured at the end of run-in and intervention periods. Between run-in and intervention, mean (95% CI) change in oxygen radical-absorbing capacity (U/mL) was Ϫ35 (Ϫ93, 13) in the control diet, 26 (Ϫ15, 67) in the fruits and vegetables diet (Pϭ0.06 compared with control), and 19 (Ϫ22, 54) in the combination diet (Pϭ0.10 compared with control

show abstract

Liquid chromatographic method for the determination of carotenoids, retinoids and tocopherols in human serum and in food

Cited by 175 publications

References 18 publications

Validation and calibration of food-frequency questionnaire measurements in the Northern Sweden Health and Disease cohort

Validation and calibration of food-frequency questionnaire measurements in the Northern Sweden Health and Disease cohort

Effects of Cutting and Maturity on Lycopene Concentration of Fresh-Cut Tomatoes During Storage at Different Temperatures

Effect of Dietary Patterns on Measures of Lipid Peroxidation

Contact Info

Product

Resources

About