Bioactive compounds in different citrus varieties. Discrimination among cultivars

Cultivars of Clementine mandarin (Arrufatina, Clemenpons, Clemenules, Fino, Hernandina Loretina, Marisol, Orogrande, Oronules and Oroval), Satsume mandarin (Avasa Pri-10, Avasa Pri-19, Okitsu and Owari), Hybrid mandarin (Fortune, Ortanique and Nova), Navel orange (Fukumoto, Lanelate, Navelate, Navelina, Navel Foyos, Newhall and Powell), Common orange (Salustiana and Valencia Late) and Pigmented orange (Sanguinelli) groups have been analysed for its content in narirutin, hesperidin and total vitamin C. Sweet orange groups presented the higher concentration in flavonoids and total vitamin C. The influence of variety on the content of bioactive constituents and its contribution to taxonomy at the varietal level is studied.     

Bioavailability is improved by enzymatic modification of the citrus flavonoid hesperidin in humans: a randomized, double-blind, crossover trial

Hesperidin is the predominant polyphenol consumed from citrus fruits and juices. However, hesperidin is proposed to have limited bioavailability due to the rutinoside moiety attached to the flavonoid. The aim of this study was to demonstrate in human subjects that the removal of the rhamnose group to yield the corresponding flavonoid glucoside (i.e., hesperetin-7-glucoside) will improve the bioavailability of the aglycone hesperetin. Healthy volunteers (n=16) completed the double-blind, randomized, crossover study. Subjects randomly consumed hesperetin equivalents supplied as orange juice with natural hesperidin ("low dose"), orange juice treated with hesperidinase enzyme to yield hesperetin-7-glucoside, and orange juice fortified to obtain 3 times more hesperidin than naturally present ("high dose"). The area under the curve (AUC) for total plasma hesperetin of subjects consuming hesperetin-7-glucoside juice was 2-fold higher than that of subjects consuming the "low" dose hesperidin juice [3.45+/-1.27 vs. 1.16+/-0.52 mmol/(L.h), respectively, P>0.0001]. The AUC for hesperetin after consuming the hesperetin-7-glucoside juice was improved to the level of the "high" dose hesperidin juice [4.16+/-1.50 mmol/(L.h)]. The peak plasma concentrations (C(max)) of hesperetin were 4-fold higher (2.60+/-1.07 mmol/L, P<0.0001) after subjects consumed hesperetin-7-glucoside juice compared with those consuming "low" dose hesperidin juice (0.48 +/- 0.27 mmol/L), and 1.5-fold higher than those consuming "high" dose hesperidin juice (1.05+/-0.25 mmol/L). The corresponding T(max) was much faster (0.6+/-0.1 h, P<0.0001) after subjects consumed hesperetin-7-glucoside juice compared with "low" dose (7.0+/-3.0 h) and "high" dose (7.4+/-2.0 h) hesperidin juices. The results of this study demonstrated that the bioavailability of hesperidin was modulated by enzymatic conversion to hesperetin-7-glucoside, thus changing the absorption site from the colon to the small intestine. This may affect future interventions concerning the health benefits of citrus flavonoids.     

Orange juice is a good folate source in respect to folate content and stability during storage and simulated digestion

Background Estimated average folate intake in Sweden is less than 55% of the recommended daily intake (RDI) for women of childbearing age (Becker and Pearson in Riksmaten 1997–1998 Kostvanor och n?ringsintag i Sverige. National Food Administration, Uppsala, pp 34, 44, 121, 2002). Because a good folate status reduces the risk of neural tube defects, mandatory folic acid fortification is discussed in some European countries. This however, could lead to exposure to unintentionally high amounts of folic acid for some population groups, therefore targeted folic acid fortification could be an alternative. Aims To (1) determine natural folate content in three popular brands of orange juice sold in Sweden, (2) determine stability of natural folate and folic acid fortificant during shelf life in a folic acid/iron fortified orange juice, (3) determine folate stability in four juices during simulated household consumption for one week and (4) determine the in vitro bioaccessibility of natural folate in one brand of orange juice using the TNO gastroIntestinal Model (TIM). Methods Natural folate content in juices was determined using RP-HPLC-FL. To determine folic acid content and confirm RP-HPLC-FL values LCMS was used. Stability during shelf life was determined in unopened bottles of a folic acid/iron fortified juice and for one week in four popular juices under household consumption conditions with reopening of bottles daily. For an in vitro folate bioaccessibility experiment in orange juice the TNO TIM Model was used. Results 5-CH₃-H₄folate was the dominant natural folate form in the juices with contents ranging from 16–30 μg/100 g. Shelf life losses of folic acid fortificant were 1–4%. During one week simulated household consumption 5-CH₃-H₄folate content decreased by up to 7% (n.s). Bioaccessibility of natural folate in orange juice was almost 100%. Most folate was released for absorption in jejunum between 60–120 min after trial start. Conclusion Orange juice may be considered a good source of natural folate in respect to content and stability during storage and simulated digestion. Moreover, added folic acid fortificant in a folic acid/iron fortified orange juice was stable during shelf life.     

Problems with folacin status with use of orange juice substitutes in a geriatric institution

An increased range of orange drinks is now available with varying proportions of orange juice. These have begun to appear in institutions for the care of elderly people. With evidence of folacin deficiency in such elderly people, we evaluated the effect of either 100% orange juice or an orange drink (at least 5% juice) on folacin status in 19 institutionalized elderly people over a 13-week period. Serum folacin increased from 8.5 ± 0.8 to 13.2 ± 0.8 nmol/l ( P < 0.001) in 13 weeks, with 100 ml orange juice daily, but did not change from baseline (8.9 ± 0.8 nmol/l) to 13 weeks (8.5%± 0.7 nmol/l) with orange drink. By 6 weeks the difference between orange juice (11.0 ± 1.0 nmol/l) and orange drink (8.6 ± 0.7 nmol/l) was significant. Thus, not only is the choice of orange drink important, but small regular orange juice supplements can produce a significant increase in biochemical folacin status.     

Controlling for sugar and ascorbic acid, a mixture of flavonoids matching navel oranges significantly increases human postprandial serum antioxidant capacity

Fruit and vegetable consumption reduces the risk for cardiovascular disease development. The postprandial state is an important contributor to chronic disease development. Orange flavonoids may reduce postprandial oxidation. It was hypothesized that a mixture of orange flavonoids would reduce postprandial oxidation better than a single orange flavonoid or orange sugar and ascorbic acid, but not as well as orange juice, when consumed with a typical breakfast. A placebo-controlled crossover trial (16 male and female participants, 4 treatments, 4 visits) was carried out. Treatments were placebo (ascorbic acid and sugar equivalent to orange juice); placebo plus hesperidin; placebo plus hesperidin, luteolin, and naringenin (mixture; found to have synergistic antioxidant properties in vitro in previous work); and orange juice (positive control). Serum oxygen radical absorbance capacity (ORAC), total plasma phenolics (TP), and serum lipoprotein oxidation (LO) were measured after a 12-hour baseline fast and at 1, 2, and 3 hours after sample consumption. The placebo plus mixture and orange juice groups were significantly increased in ORAC and LO lag time. Data for TP were inconsistent with ORAC and LO. Contrary to previous studies attributing the protective postprandial effect to fructose and ascorbate in other fruit trials, orange phenolic compounds contribute directly to the postprandial oxidative protection of serum, despite an inconsistent change in serum TP.     

Inhibition of azoxymethane-induced colon cancer by orange juice

Previous research has shown that hesperidin, a flavanone glycoside in orange juice, inhibits colon carcinogenesis and that feeding double-strength orange juice delays the onset of chemically induced mammary cancer in rats. This study determined whether feeding single-strength, pasteurized orange juice would inhibit azoxymethane (AOM)-induced colon cancer in male Fischer 344 rats. Colon cancer was initiated by injecting AOM (15 mg/kg body wt) at 22 and 29 days of age. One week after the second AOM injection, orange juice replaced drinking water for the experimental group (n = 30). The rats were killed 28 weeks later, and tumors were removed for histological analysis. Feeding orange juice reduced tumor incidence by 22% (p < 0.05). Tumor reduction was associated with a decreased labeling index and proliferation zone in the colonic mucosa. Hesperidin, other flavonoids, limonin 17-beta-D-glucopyranoside, and other limonoid glucosides are potential chemopreventive agents in orange juice that could account for the decreased colon tumorigenesis associated with feeding orange juice.     

Bioavailability in humans of the flavanones hesperidin and narirutin after the ingestion of two doses of orange juice

OBJECTIVE: Flavanones are polyphenols specific of citrus fruits, where they are present in high amounts. Although citrus fruits and juices are widely consumed in the world, little information has been published on flavanone bioavailability in humans. The aim of the present study was to determine the nature of the circulating metabolites, the plasma kinetics and the urinary excretion patterns of the flavanones, hesperidin and narirutin. DESIGN: After an overnight fast, five healthy volunteers ingested 0.5 or 1 l of a commercial orange juice providing 444 mg/l hesperidin and 96.4 mg/l narirutin, together with a polyphenol-free breakfast. Blood was sampled at 10 different timepoints over a 24 h period. Urine was collected for 48 h, in five fractions. RESULTS: Flavanones metabolites appeared in plasma 3 h after the juice ingestion, reached a peak between 5 and 7 h, then returned to baseline at 24 h. The peak plasma concentration of hesperetin was 0.46+/-0.07 micro mol/l and 1.28+/-0.13 micro mol/l after the 0.5 and 1 l intake, respectively. It was lower for naringenin: 0.20+/-0.04 micro mol/l after the 1 l dose. The circulating forms of hesperetin were glucuronides (87%) and sulphoglucuronides (13%). For both flavanones, the urinary excretion was nearly complete 24 h after the orange juice ingestion. The relative urinary excretion was similar for hesperetin and naringenin and did not depend on the dose: values ranged from 4.1+/-1.2 to 7.9+/-1.7% of the intake. CONCLUSIONS: In case of a moderate or high consumption of orange juice, flavanones may represent an important part of the pool of total polyphenols present in plasma.     

High‐Fiber Orange Juice as a Nutrition Supplement in Women

Background: The daily consumption of dietary fiber is frequently below suggested recommendations. Using a double‐blind, controlled, randomized study, we assessed the efficiency and tolerance of a fiber‐enriched orange juice to supplement fiber intake in women. Materials and Methods: After 1 week of noninterventional observation, 192 healthy adult women ingested 400 mL of orange juice for 21 days, which either was not (placebo group) or was enriched with fiber (fiber group). Orange juice ingestion was registered daily and controlled for each week during the study period. Macronutrient, fiber, and energy intake were determined using a 3‐day food record, validated food chemical composition databases, and the “Pro Diet” software. Gastrointestinal symptoms were self‐evaluated daily by scoring 4 grades of symptom intensity and using a visual analog scale to grade pain severity. Results: No changes were observed for macronutrient and energy ingestion. For the placebo group (n = 97), the total fiber intake record was under the daily recommended value. In contrast, the fiber group (n = 95) displayed higher comparative values of total and soluble fiber consumption (P ≤ .001), achieving the daily recommended values of fiber intake. Both groups reported an increased frequency of slight bloating and rumbles over time (P ≤ .05). The fiber group also experienced a higher frequency of slight flatulence over time (P = .002). Conclusion: Consumption of fiber‐enriched orange juice was efficient to achieve the daily fiber intake recommendation for women, was not accompanied by intense adverse events, and may represent a suitable method to supplement fiber intake in woman.     

Effect of thermal processing on the profile of bioactive compounds and antioxidant capacity of fermented orange juice

Previously, we reported that alcoholic fermentation enhanced flavanones and carotenoids content of orange juice. The aim of this work was to evaluate the influence of pasteurization on the qualitative and quantitative profile of bioactive compounds and the antioxidant capacity of fermented orange juice. Ascorbic acid (203?mg/L), total flavanones (647?mg/L), total carotenoids (7.07?mg/L) and provitamin A (90.06 RAEs/L) values of pasteurized orange beverage were lower than those of fermented juice. Total phenolic remained unchanged (585?mg/L) and was similar to that of original juice. The flavanones naringenin-7-O-glucoside, naringenin-7-O-rutinoside, hesperetin-7-O-rutinoside, hesperetin-7-O-glucoside and isosakuranetin-7-O-rutinoside, and the carotenoids karpoxanthin and isomer, neochrome, lutein, ζ-carotene, zeaxanthin, mutatoxanthin epimers, β-cryptoxanthin and auroxanthin epimers were the major compounds. Pasteurization produced a decrease in antioxidant capacity of fermented juice. However, TEAC (5.45?mM) and ORAC (6353?μM) values of orange beverage were similar to those of original orange juice. The novel orange beverage could be a valuable source of bioactive compounds with antioxidant capacity and exert potential beneficial effects.     

Effects of orange juice and proline betaine on glycine betaine and homocysteine in healthy male subjects

Background Proline betaine (PB), a glycine betaine (GB) analogue found in citrus foods, increases urinary GB loss and plasma total homocysteine (tHcy) concentrations in rats. Its presence in human plasma is associated with increased GB excretion. Aim To compare the effects of dietary levels of PB on GB excretion, and on plasma tHcy and GB concentrations in healthy volunteers. Methods In a randomized crossover study, eight healthy males (18–50 years) ingested either 750 mL orange juice (containing 0.545 g PB), a PB supplement (0.545 g PB dissolved in 750 mL apple juice), or 750 mL apple juice (control). Plasma PB, GB and tHcy, and urine PB, GB and creatinine concentrations were measured hourly for 6 h and at 24 h post-treatment. Results Plasma tHcy concentrations were not increased (relative to control) following ingestion of either orange juice or PB supplement. Both treatments produced a significant increase in plasma PB concentrations (P < 0.001), this effect being greater following orange juice compared with PB supplement (P < 0.05, 1–2 h). Urinary excretion of PB was greater than the control following both orange juice (P < 0.001) and PB supplement (P < 0.001), from 2 to 24 h post-treatment. This increase in PB excretion was significantly greater following orange juice compared with PB supplement with higher peak excretion (C _max difference, P = 0.008). GB excretion was significantly greater following ingestion of orange juice compared with PB in apple juice (P = 0.007) and apple juice control (P < 0.001) in the first 2 h post-ingestion. Conclusions PB administered in dietary doses had little effect on plasma tHcy concentrations in healthy humans. Ingestion of PB in orange juice compared with PB alone resulted in greater increases in the urinary excretion of PB and GB.     

Orange Juice Ingestion and Supplemental Vitamin C Are Equally Effective at Reducing Plasma Lipid Peroxidation in Healthy Adult Women

Objective: To directly examine the contribution of vitamin C to the antioxidant potential of fruits and vegetables, the antioxidant effect of orange juice consumption (8 and 16 fl. oz.) was compared to the antioxidant effect of supplemental vitamin C (dosage equivalent to that supplied by 8 fl. oz. of orange juice).

Methods: Subjects (n = 11; 28.6 ± 2.1 years) received each treatment in a 3 × 3 randomized crossover design, and each two-week treatment was preceded by a two-week washout. During the entire trial, subjects restricted fruit and vegetable consumption to ≤3 servings per day except the vitamin C-rich foods (items containing >20 mg/serving), which were restricted to ≤3 servings per week. A fasting blood sample was collected at the end of each washout and each treatment period.

Results: Following washouts, plasma vitamin C and lipid peroxidation (plasma TBARS) were similar by treatment group and averaged 25.4 ± 3.6 μmol/L and 3.82 ± 0.10 nmol/mL respectively. Plasma vitamin C concentrations were similar following each treatment period, 37.9 ± 8.1, 45.8 ± 9.4, and 38.3 ± 12.4 μmol/L for the 8 and 16 fl. oz. orange juice treatments and the supplement treatment, respectively. All intervention treatments reduced plasma TBARS as compared to pretreatment values: ?47% (p = 0.013), ?40% (p = 0.083), and ?46% (p = 0.015) for the 8 and 16 fl. oz. orange juice treatments and supplement treatment respectively.

Conclusions:These data indicate that the regular consumption of 8 fl. oz. orange juice or supplemental vitamin C (～70 mg/day) effectively reduced a marker of lipid peroxidation in plasma.     

Absorption, metabolism and excretion of flavanones from single portions of orange fruit and juice and effects of anthropometric variables and contraceptive pill use on flavanone excretion

Oranges are rich sources of flavonoids that are bioactive and may protect against age-related diseases. The absorption of orange flavanones may be affected by factors such as processing and subject anthropometric variables, and the bioactivity of the absorbed phytochemicals depends on how they are metabolised during absorption. In a randomised cross-over study, twenty subjects consumed a single portion of orange fruit (150 g) or juice (300 g) that contained the flavanones narirutin and hesperidin, and an additional 109 subjects across a broad age range (18-80 years) consumed the juice. Flavanone metabolites were measured in regularly collected samples of plasma and urine. After consumption of fruit or juice, flavanone conjugates, but not the aglycones, were detected in plasma and urine. The flavanone conjugates were shown to include the 7- and 4'-O-monoglucuronides of naringenin, the 7- and 3'-O-monoglucuronides of hesperetin, two hesperetin diglucuronides and a hesperetin sulfo-glucuronide, but no aglycones or rutinosides. Analysis of the plasma pharmacokinetic and urinary excretion data on a dose-adjusted basis indicated no difference in absorption or excretion of either flavanone between the fruit and juice matrices. In the extended urinary excretion dataset the individual variation was very large (range 0-59 % urinary yield). There was a small but significant (P < 0.05) decrease in the excretion of hesperetin (but not naringenin) with increasing age (P < 0.05), but the effects of sex, BMI and contraceptive pill use were shown not to be associated with the variation in flavanone excretion.     

Effect of UV-C light on anthocyanin content and other quality parameters of pomegranate juice

Pomegranate juice (PJ) was subjected to UV-C irradiation as a non-thermal technology and changes in major quality characteristics of juice such as anthocyanins, polymeric colour, antioxidant activity and total phenol content were determined. The results were compared with control (untreated) and heat treated (at 90 °C, 2 min) juice samples. UV-C treatment preserved the major quality characteristics of pomegranate juice better than heating process. After UV-C treatment, total monomeric anthocyanin content of pomegranate juice did not change significantly and decrease in individual anthocyanin pigments were between 8.1% and 16.3%. However, anthocyanin content of PJ was significantly affected by heat treatment (P < 0.05) and 15.4% and 28.3% of individual anthocyanin pigments were lost after this process. Also, differences between the control and UV-C treated PJ samples were small in terms of polymeric colour values (P > 0.05) while polymeric colour of PJ were significantly affected by heat treatment (P < 0.05). There were no significant changes in antioxidant capacity evaluated by trolox equivalent antioxidant capacity (TEAC) assay and total phenol contents of PJ after UV-C and heat treatments. The effectiveness of the UV-C system on the aerobic plate count, yeast and mould count and Esherichia coli ATCC 25922 as a surrogate microorganism of E. coli O157:H7 in PJ resulted in 1.8, 1.45 and 6.15 log reductions, respectively.     

Oxidation of ascorbic acid in stored orange juice is associated with reduced plasma vitamin C concentrations and elevated lipid peroxides

Ascorbic acid oxidizes in refrigerated orange juice, but the physiological relevance of this deterioration is unknown. We compared changes in plasma vitamin C and total lipid peroxides (thiobarbituric acid-reactive substances, TBARS) in the 2-hour period following consumption of commercial orange juices on day 1 vs day 8 of storage (4 degrees C). The ascorbic acid content decreased significantly after storage in juice reconstituted from frozen concentrate (117+/-8 vs 89+/-8 mg/8 fl oz, P =.001), but did not change in chilled juice (69+/-5 vs 64+/-12 mg/8 fl oz.). The mean incremental TBARS value was less on day 1 vs day 8 for juice from frozen concentrate (-0.46+/-0.72 and 0.70+/-0.53, P =.046), but did not differ for chilled juice (0.00+/-0.49 and 0.54+/-0.89). The incremental values for plasma TBARS and vitamin C in the 2-hour postprandial period were inversely related (r=-0.48, P =.017). These data indicate that the loss of ascorbic acid in refrigerated juice may impact postprandial oxidative stress.     

Stability of vitamin C in frozen raw fruit and vegetable homogenates

Retention of vitamin C in homogenized raw fruits and vegetables stored under routine conditions prior to analysis was investigated. Raw collard greens (Brassica oleracea var. viridis), clementines (Citrus clementina hort. ex Tanaka), and potatoes (Solanum tuberosum) were chosen, being representative of foods to be sampled in USDA's National Food and Nutrient Analysis Program (NFNAP), and having different expected stability of ascorbic acid (AA). Samples were homogenized in liquid nitrogen, assayed immediately, then stored at ?60 °C and analyzed at time points up to 49 weeks. Vitamin C (as total AA after reduction of dehydroascorbic acid) was analyzed using a validated method with quantitation by HPLC/ultraviolet detection. An orange juice control sample was included in each run. Vitamin C concentrations were stable in clementines and the orange juice, but decreased in collards and potatoes [16.8 and 10.9 mg/100 g (14.7% and 30.4%), respectively, after 49 weeks]. Significant losses had occurred after 12 weeks. These results suggest similar matrices must receive careful attention to sample handling protocols before analysis or AA values may not reflect the concentration in the food as consumed. The control sample was critical to allowing assessment of storage effects independent of analytical variability. Fruits and vegetables for the NFNAP will be analyzed without storage until a practical stabilization protocol is validated.     

The effects of ascorbic acid and flavonoids on the occurrence of symptoms normally associated with the common cold.

A controlled study was made of the effects of natural orange juice, synthetic orange juice, and placebo in the prevention of the common cold; both natural and synthetic orange juices contained 80 mg of ascorbic acid daily. Three-hundred sixty-two healthy normal young adult volunteers, ages 17 to 25 years, were studied for 72 days with 97% of participants completing the trial. There was a 14 to 21% reduction in total symptoms due to the common cold in the supplemented groups that was statistically significant (P less than 0.05). Ascorbic acid supplementation also increased the number of "episode-free" subjects. However, the clinical usefulness of the results does not support prophylactic ascorbic acid supplements in the well-nourished adult. The results in this study with both natural and synthetic orange juice of physiological content of ascorbic acid, are similar to those obtained using a "megadose" of ascorbic acid.     

Nutrient composition and antimicrobial activity of sorrel drinks (soborodo)

Aqueous extracts (1,200 mL) of roselle calyx (40 g), fortified with either orange juice or pineapple juice as sweetener and lemon grass as flavorant (sorrel drink), were analyzed with regard to their mineral composition (Na, Fe, Zn, Cu, Pb, Mn, and Ca), vitamin C content, and sensory evaluation. While the medicinal potentials were determined with respect to their inhibitory effect on the growth of Bacillus sp., Pseudomonas aeruginosa, Lactobacillus sp., and Corynebacterium sp. The results revealed that the roselle extract fortified with orange juice had higher vitamin C content than did those fortified with pineapple juice, while those fortified with pineapple juice had the best general acceptability. Zn, Na, and Ca were generally high in all the drinks; however, fortification with either pineapple or orange juice reduced the mineral content of the roselle extract. However, Pb, Cu, and Mn (toxic metals) were not detected. The antimicrobial effect of the unfortified roselle extract was low against the entire organism; however, fortification with pineapple juice and lemon grass greatly enhanced the inhibition of the growth of those organisms. They all had their highest inhibitory effect on the growth of P. aeruginosa. In view of the high Zn, Ca, Fe, Na, and vitamin C content as well as the antimicrobial activity, this cheaply produced drink from purely local materials could serve as a good replacement for expensive carbonated drinks.     

Effect of chlorine dioxide gas on Salmonella enterica inoculated on navel orange surfaces and its impact on the quality attributes of treated oranges

Microorganisms, including pathogens of public health significance, have been shown to contaminate orange juice during the mechanical extraction of juice. The problem gets exacerbated when washed oranges have high initial microbial load, due to an insufficient postharvest treatment. The objective of this study was to investigate the reduction of Salmonella enterica on orange surfaces using ClO? gas treatments to achieve a 5 log reduction, consistent with the recommendations of the U.S. Department of Agriculture-National Advisory Committee on Microbiological Criteria for Foods. A mixed culture of four Salmonella strains, isolated from previous orange juice outbreaks, was spot inoculated onto orange skin surface areas. The oranges were then treated with 0.1, 0.3, and 0.5 mg/L ClO? gas for 2-14 minutes at 22°C and 90%-95% relative humidity. Surviving bacteria on treated areas were recovered and enumerated over treatment time on a nonselective medium, tryptic soy agar, followed by culturing onto a selective medium, xylose lysine deoxycholate agar. A >5 log reduction of Salmonella per sample of orange surface was observed with 0.1 and 0.3 mg/L ClO? gas treatments at 14 minutes and a similar log reduction was observed at 0.5 mg/L ClO? gas at 10 minutes. This result demonstrates that the treatment of oranges with ClO? gas is a promising technology that could be successfully employed for the treatment of whole oranges to reduce the risk of Salmonella outbreaks in orange juice.     

广东四会柑 桔 橙中微量元素含量分析

用火焰原子吸收分光光度法、可见分光光度法和阳极溶出伏安法对广东四会８ 个品种的柑、桔、橙进行２１ 种微量元素含量测定。各元素在８ 个品种中差别较大，Ｃｏ和Ｃｄ 在所有品种中均未检出。     

No influence of increased intake of orange and blackcurrant juices and dietary amounts of vitamin E on paraoxonase-1 activity in patients with peripheral arterial disease

BACKGROUND: Paraoxonase-1 (PON1) is an antioxidative enzyme associated with HDL and its serum activity is associated with risk of cardiovascular disease. The interindividual variation in PON1 activity is partly determined by genetic factors, such as polymorphisms in the PON1 gene, but also by dietary factors like the antioxidants. AIM OF THE STUDY: We examined the effect of antioxidant-rich orange and blackcurrant juices and vitamin E supplement on PON1 activity in patients with peripheral arterial disease. Furthermore, we studied whether genetic polymorphisms in the PON1 gene predicted the change in PON1 activity. METHODS: The study was designed as a cross-over trial with 48 participants who received two of the four possible treatments: (1) 250 ml orange juice and 250 ml blackcurrant juice; (2) 15 mg vitamin E; (3) 250 ml orange juice and 250 ml blackcurrant juice and 15 mg vitamin E; or (4) control/placebo (energy-equivalent sugar-containing beverage). The treatments were given for 28 days, separated by a 4-week wash-out period. RESULTS: The PON1 activity was not affected by juice or vitamin E supplement neither was there evidence of synergetic effects. However, a statistically significant interaction was observed between treatment and PON1 genotype, such that PON1 activity increased after juice alone in patients carrying the PON1 L55-allele. Results need to be interpreted with care since the study population was relatively small. CONCLUSION: Consumption of orange and blackcurrant juice and vitamin E supplement does not affect the activity of PON1 in patients with peripheral arterial disease. However, a gene-diet interaction may be present.