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A compilation of volatile N-nitrosamine levels in processed (e.g., cured, canned, smoked) meat and poultry products is presented. Over 1800 samples of processed meat products including bacon, ham, salami, sausage, and various other processed meat and poultry products have been examined for the presence of eight volatile N-nitrosamines. The database compiled from the literature is based on 25 references published for the period of 1985 to 2018 from 14 countries. N-nitrosodimethylamine (NDMA), N-nitrosopiperidine (NPIP), and N-nitrosopyrrolidine (NPYR), are the most frequently identified volatile N-nitrosamines occurring in processed meat and poultry products. N-nitrosodiethylamine (NDEA), and N-nitrosodibutylamine (NDBA) are also frequently observed to a lesser extent. The processed meat and poultry products with the highest levels of volatile N-nitrosamines were pork (fried, fat only eaten), poultry (fried), poultry (spiced, grilled), and bacon (fried).

Background Executive function (EF) is considered an important mediator of health outcomes. It is hypothesized that those with better EF are more likely to succeed in turning their intentions into actual health behaviors. Prior studies indicate EF is associated with smoking cessation. Experimental and longitudinal studies, however, have yielded mixed results. Few studies have examined whether EF predicts post-treatment smoking behavior. Fewer still have done so prospectively in a large trial. We sought to determine if EF predicts quit attempts and cessation among community smokers in a large randomized trial evaluating the efficacy of motivational interventions for encouraging cessation. Methods Participants (N = 255) completed a baseline assessment that included a cognitive battery to assess EF (Oral Trail Making Test B, Stroop, Controlled Oral Word Association Test). Participants were then randomized to 4 sessions of Motivational Interviewing or Health Education or one session of Brief Advice to quit. Quit attempts and cessation were assessed at weeks 12 and 26. Results In regression analyses, none of the EF measures were statistically significant predictors of quit attempts or cessation (all ps > 0.20). Conclusions Our data did not support models of health behavior that emphasize EF as a mediator of health outcomes. Methodological shortcomings weaken the existing support for an association between EF and smoking behavior. We suggest methodological improvements that could help move this potentially important area of research forward.

Dietary exposures to the seven food, drug, and cosmetic (FD&C) colour additives that are approved for general use in food in the United States were estimated for the US population (aged 2 years and older), children (aged 2–5 years) and teenage boys (aged 13–18 years) based on analytical levels of the FD&C colour additives in foods. Approximately 600 foods were chosen for analysis, based on a survey of product labels, for the levels of FD&C colour additives. Dietary exposure was estimated using both 2-day food consumption data from the combined 2007–10 National Health and Nutrition Examination Survey (NHANES) and 10–14-day food consumption data from the 2007–10 NPD Group, Inc. National Eating Trends – Nutrient Intake Database (NPD NET-NID). Dietary exposure was estimated at the mean and 90th percentile using three different exposure scenarios: low exposure, average exposure and high exposure, to account for the range in the amount of each FD&C colour additive for a given food. For all populations and all exposure scenarios, the highest cumulative eaters-only exposures in food were determined for FD&C Red No. 40, FD&C Yellow No. 5 and FD&C Yellow No. 6. In addition, the eaters-only exposure was estimated for individual food categories in order to determine which food categories contributed the most to the exposure for each FD&C colour additive. Breakfast Cereal, Juice Drinks, Soft Drinks, and Frozen Dairy Desserts/Sherbet (also referred to as Ice Cream, Frozen Yogurt, Sherbet (including Bars, Sticks, Sandwiches)) were the major contributing food categories to exposure for multiple FD&C colour additives for all three populations.

Introduction Despite limitations in evidence, the current Clinical Practice Guideline advocates Motivational Interviewing for smokers not ready to quit. This study evaluated the efficacy of Motivational Interviewing for inducing cessation-related behaviors among smokers with low motivation to quit. Design Randomized clinical trial. Setting/participants Two-hundred fifty-five daily smokers reporting low desire to quit smoking were recruited from an urban community during 2010–2011 and randomly assigned to Motivational Interviewing, health education, or brief advice using a 2:2:1 allocation. Data were analyzed from 2012 to 2014. Intervention Four sessions of Motivational Interviewing utilized a patient-centered communication style that explored patients' own reasons for change. Four sessions of health education provided education related to smoking cessation while excluding elements characteristic of Motivational Interviewing. A single session of brief advice consisted of brief, personalized advice to quit. Main outcomes measures Self-reported quit attempts; smoking abstinence (biochemically verified); use of cessation pharmacotherapies; motivation; and confidence to quit were assessed at baseline and 3- and 6-month follow-ups. Results Unexpectedly, no significant differences emerged between groups in the proportion who made a quit attempt by 6-month follow-up (Motivational Interviewing, 52.0%; health education, 60.8%; brief advice, 45.1%; p =0.157). Health education had significantly higher biochemically verified abstinence rates at 6 months (7.8%) than brief advice (0.0%) (8% risk difference, 95% CI=3%, 13%, p =0.003), with the Motivational Interviewing group falling in between (2.9% abstinent, 3% risk difference, 95% CI=0%, 6%, p =0.079). Both Motivational Interviewing and health education groups showed greater increases in cessation medication use, motivation, and confidence to quit relative to brief advice (all p d =0.36, 95% CI=0.12, 0.60). Conclusions Although Motivational Interviewing was generally more efficacious than brief advice in inducing cessation behaviors, health education appeared the most efficacious. These results highlight the need to identify the contexts in which Motivational Interviewing may be most efficacious and question recommendations to use Motivational Interviewing rather than other less complex cessation induction interventions. Trial registration This study is registered at www.clinicaltrials.gov NCT01188018.

4-Methylimidazole (4-MEI) is formed in caramel colours produced using ammonium compounds (Class III and Class IV caramel colours). 4-MEI can also form in food through Maillard reactions between reducing sugars and amino acids during cooking, roasting or dry-heating. The USFDA has analysed over 700 food and beverage samples collected from 2013 to 2015 for the presence of 4-MEI. These samples include foods containing added caramel colour and foods that are not labelled as containing added caramel colour, but which may contain 4-MEI resulting from thermal treatment. The 4-MEI levels in all food samples were quantified using LC-MS/MS. These data were used to develop a comprehensive dietary exposure assessment for 4-MEI for the U.S. population aged 2 years or more and several sub-populations, using two non-consecutive days of food consumption data from the combined 2009-2012 National Health and Nutrition Examination Survey and 10-14-day food consumption survey data for 2009-2012 from the NPD Group, Inc. National Eating Trends-Nutrient Intake Database. Dietary exposure estimates were prepared for each category of foods labelled as containing added caramel colour and of foods not labelled as containing added caramel colour, but which may contain 4-MEI from thermal treatment. Exposure to 4-MEI from consumption of foods containing added caramel colour was higher than that from foods that contain 4-MEI from thermal treatment for all population groups. Cola-type carbonated beverages were the highest contributors for most populations from foods containing added caramel colour. Coffee was the highest contributor for most populations from foods in which 4-MEI could be formed from thermal treatment. An overall combined exposure to 4-MEI was also estimated that included all foods identified as containing added caramel colour and foods in which 4-MEI could be formed by thermal treatment.

The dietary exposures of nitrite and nitrate from consumption of cured meat products were estimated for the U.S. population aged 2 years and older, and children aged 2 to 5 years, using both 2-day food consumption data from the publicly available combined 2009-2012 National Health and Nutrition Examination Survey (NHANES) and 10-14-day food consumption data from the 2009 and 2012 NPD Group, Inc. National Eating Trends-Nutrient Intake database (NPD NET-NID), and residual nitrite and nitrate levels in cured meat products available from the recent American Meat Institute Foundation/National Pork Board (AMIF/NPB) national market survey of the nitrite and nitrate levels in cured meat products in the U.S.A. The dietary exposure for consumers of cured meat products (eaters-only) was estimated at the mean and 90th percentile for three exposure scenarios: low exposure, average exposure, and high exposure, to account for the range in the amount of nitrite and nitrate in a given cured meat product category. In addition, a cumulative exposure that takes into account all cured meat product categories containing nitrite and nitrate was determined, and the relative percent contribution of each cured meat product category to the cumulative exposure was estimated. Cured, cooked sausages and whole-muscle brine-cured products were the two major contributing categories to dietary exposure of nitrite and nitrate for both U.S. population aged 2 years and older and children aged 2-5 years.

Little is known about effective methods to recruit unmotivated smokers into cessation induction trials, the reasons unmotivated smokers agree to participate, and the impact of those reasons on study outcomes. A mixed-method approach was used to examine recruitment data from a randomized controlled cessation induction trial that enrolled 255 adult smokers with low motivation to quit. Over 15 months, 33% of smokers who inquired about the study were enrolled. Common recruitment methods included word-of-mouth, print advertisements and clinic referrals. Frequently mentioned reasons for participating included to: gain financial incentives (44.7%), learn about research or help others quit (43%), learn about smoking and risks (40%) and help with future quits (i.e. Quit Assistance, 23.9%). Separate regression models predicting study outcomes at 26 weeks indicated that smokers who said they participated for Quit Assistance reported higher motivation to quit (B 1.26) and were more likely to have made a quit attempt (OR 2.03) compared to those not mentioning this reason, when baseline characteristics were controlled. Understanding reasons for unmotivated smokers' interest in treatment can help practitioners and researchers design effective strategies to engage this population.

Clarified, debittered grapefruit juice concentrate (64.2 °Bx) was produced by membrane filtration, debittering, and an evaporation process. Debittering by an XAD-16 adsorption column removed more than 78% of bitterness in grapefruit juice, based on naringin content. Also, some of the non-bitter flavonoids, such as narirutin and hesperidin, were nearly completely removed. Other values, such as vitamin C, and total phenolics, based on absorbance at 325 nm, were also reduced (P

Changes in carotenoid pigment content and juice color due to thermal pasteurization of Valencia orange juices were studied. Total carotenoid pigment content loss was significant (P

Color changes in red grapefruit juice concentrates during storage at -23 degrees C for 12 months were studied. Concentrate (38 degrees Brix) was packed in both plastic (16 oz) and metal (6 oz) cans. Decrease in red intensity (CIE a) in juice color and slight increases in CIE L*, b*, and hue values from analysis of reconstituted juices were the characteristic color changes in concentrate during frozen storage. With respect to fresh concentrate, juice color in stored concentrate shifted toward the direction between negative DeltaC* and positive DeltaL*, indicating the color became slightly paler. A color difference seems to exist between the two containers, especially for the magnitude of DeltaE*; color changes were more pronounced in concentrates packed in plastic. There are significant changes (P < 0.05) in major carotenoid pigments (beta-carotene and lycopene) in the concentrates. More than 20% loss of lycopene and about 7% loss of beta-carotene occurred with plastic containers after a 12-month period. Regression analysis showed that the rate of decline was about 0.291 ppm per month (r = 0.990) for lycopene compared to 0.045 ppm (r = 0.817) for beta-carotene in concentrate stored in plastic. In the metal can, the same trends were observed but pigment losses were slightly smaller than those with plastic. An estimated shelf life for lycopene was 26.1 months in the metal can compared to 18 months in plastic. Shelf life for beta-carotene was more than 39 months, more than twice that of lycopene in plastic container.

High-performance liquid chromatography (HPLC) with photodiode array detection was applied for the characterization of anthocyanins in red-fleshed Budd Blood (Citrus sinensis) orange. More than seven anthocyanin pigments were separated within 30 min by using a binary gradient (0.1% H(3)P0(4) in water and 0.1% H(3)PO(4) in acetonitrile) elution on a Prodigy ODS column. Separations by reversed-phase HPLC and semipreparative HPLC on a Prodigy 10-microm ODS Prep column, and acid and alkali hydrolyses were used for identification of anthocyanins. The primary anthocyanins in Budd Blood orange grown in Florida were cyanidin-3-(6"-malonylglucoside) (44.8%) followed by cyanidin-3-glucoside (33.6%). Two other minor pigments were also acylated with malonic acid. Malonated anthocyanins represented the major proportion (>51%) of anthocyanins in Budd Blood orange. Total anthocyanin contents and juice color parameters (CIE L,a,b) were compared with six other Florida-grown blood oranges.

High-performance liquid chromatography with photodiode array detection was applied for the separation and characterization of carotenoids from a red-fleshed navel orange (Cara Cara). Carotenoid pigments were extracted using hexane/acetone/ethanol and saponified using 10% methanolic potassium hydroxide. More than 29 carotenoid pigments were separated within 60 min using a ternary gradient (75% acetonitrile/25% methanol, methyl tert-butyl ether, and water) elution on a C(30) reversed-phase column. The presence of lycopene (3.9 +/- 1.1 ppm) and a relatively large percentage of beta-carotene were distinct differences in the pigment profile of this red navel orange juice as compared to the profile of standard navel orange juice. The juice color in the red navel was much deeper orange than that from navel orange; hue angle ranged from 84.1 to 89.4 for red navel compared to 98.2 to 100.5 for standard navel.

The developmental patterns of carotenoids in Hamlin, Earlygold (an early-maturing selection), and Budd Blood sweet orange juices were studied during the September to mid-January period of the 1996-97 and 1997-98 seasons. The carotenoid concentration of Earlygold increased by as much as 4.9 times during the color development compared to 3.9 times in Hamlin and 4.5 times in Budd Blood juice in the same period. For the profiles of carotenoid pigment, dramatic changes occurred among the pigments that were present in high concentrations at the beginning of the season, with lutein and violaxanthin noted as the predominant pigments in Hamlin fruit. A marked increase in the percentage of beta-cryptoxanthin allowed it to become a major pigment in the late stage of maturation. The color development in the new cultivar Earlygold was especially notable, reaching the 36 color number, which is grade A, by late October to mid-November whereas Hamlin juice did not reach this grade A color number until January. Budd Blood juice was similar in carotenoid pigment content and seasonal changes to Hamlin juice, but also, the development of red anthocyanin pigment in January significantly increased juice color.

Three hundred and six (306) commercial samples from 19 processing plants in Florida, composed of frozen concentrated orange juice, orange juice from concentrate, and pasteurized orange juice, were analyzed for their sugars content by HPLC. In addition, the sugar profile of fresh-squeezed juice from 9 different cultivars of sweet oranges, 2 tangors, and 4 tangelos grown in Florida are included. Sucrose, fructose, glucose, total sugars, glucose/fructose ratio, and myo-inositol contents are presented. Mean ± standard deviation sugar levels for 100 mL of frozen concentrated orange juice were 4.1 ± 0.5 g of sucrose, 2.1 ± 0.2 g of fructose, 1.9 ± 0.2 g of glucose, and 0.1 ± 0.1 g of myo-inositol, from juices processed in Florida. A review of the methodology for the detection of sugars by HPLC in citrus products is presented; most results having been acquired by HPLC analysis utilizing NH2 column and acetonitrile/water. A compilation of literature furnishing information on free sugar contents in orange and grap...

Changes in color due to thermal pasteurization of two cultivars of red grapefruit juice were studied. Juices were pasteurized at 91°C using a plate heat exchanger. Apparently, thermal pasteurization changed all three color parameters (CIE L * , a * , b * ) in the juice, causing a slight color shift towards lighter and brighter. Thermal pasteurization especially affected CIE b * value and chroma in juice. The reflectance spectrum in the visible region (400 nm to 700 nm) clearly showed changes in spectral distribution of light reflected from juice after pasteurization. There were no changes (P>0.05) in major carotenoid pigments (β-carotene and lycopene) in the juices after pasteurization.

A storage study of frozen, fresh squeezed, unpasteurized, polyethylene-bottled orange juice was conducted to determine vitamin C loss on a monthly basis over a period of 24 months. Vitamin C content declined from an initial value of 40.6 mg/100 ml to 32.8 mg/100 ml in the final analysis for a loss of 19.2% over the storage period. A regression analysis showed a decrease of about 0.34 mg/100 ml of the vitamin C per month at this condition. The estimated shelf-life of this juice to meet the label claim of vitamin C of 130% DV is about 22 months at −23°C.

The reduced form of vitamin C is referred to as L-ascorbic acid (AA), and the oxidized form is referred to as L-dehydroascorbic acid (DHAA). In humans, both forms are biologically active. The total vitamin C activity is defined as the sum of both forms. This review discusses HPLC methodologies for total vitamin C activity with references to their applications mainly in citrus juices and related drink products.

The rate of vitamin C degradation in clear orange juice concentrate (80.2 °Brix) produced by the combined membrane−evaporation technique was studied at storage temperatures of 4, 14, and 24 °C for 19 weeks. Absorption at 420 nm and CIE L*, a*, b* color parameters were determined to evaluate color changes due to nonenzymic browning during storage. Calculated values of reaction rate constants indicated that vitamin C degradation occurred slowly in clear orange juice concentrate at 4 °C. Rates of vitamin C degradation ranged from 4.79 × 10-4 to 3.13 × 10-2 per week. The activation energy for vitamin C degradation was on the order of 34.3 kcal/g·mol. Main color changes in stored clear orange juice concentrate in amber glass vials were due to increases in b* value and chroma. Keywords: Clear orange juice concentrate; vitamin C; color; browning, membrane

The distribution of sugars (sucrose, glucose, and fructose) and related enzymes between the stem and the blossom halves of `Valencia' oranges [Citrus sinensis (L.) Osbeck] was determined at three stages of fruit development. The blossom half contained significantly higher concentrations of sugars during later stages of development and maturation (12% and 20%, respectively). Neither the enzyme marker for sucrose synthesis [sucrose-phosphate synthase (SPS)] nor enzymes of CO2 fixation (NADP-malic enzyme, PEP carboxylase, and PEP carboxykinase) were significantly different between the halves. Sucrose synthase (SS), the enzymatic marker for sink strength, had significantly higher activity in the blossom half during later stages of fruit development when rapid sugar accumulation takes place. These data suggest that differential distribution of sugars between the stem and the blossom halves of citrus fruit is, in part, the result of differential sink strength.

Vitamin C content in citrus juices processed in Florida was studied. A total of 2299 samples from February 1986 through October 1995 (908 frozen concentrated orange juices, 401 orange juices from concentrate, 319 pasteurized orange juices, 213 pasteurized grapefruit juices, and 458 grapefruit juices from concentrate) were obtained from 21 Florida processors for analysis of vitamin C. Means, standard deviations of the means, and maximum and minimum values are presented for each product on the basis of milligrams of vitamin C per 100 mL of product. Variations are reported for month, year, and manufacturing plant for each type of juice. Keywords: Vitamin C; citrus juice; orange juice; grapefruit juice; Florida

Introduction Although studies have suggested that implicit attitudes may predict smoking-related decisions, evidence that changes in implicit attitudes toward smoking are related to changes in smoking behavior is lacking. Using data from a trial comparing interventions to induce quit attempts among unmotivated smokers, this study examined whether changes in implicit attitudes were associated with quit attempts and cessation after controlling for explicit motivation. Methods Daily smokers recruited from the community completed measures of implicit attitudes (Implicit Association Test) and explicit measure of motivation to smoke at baseline, mid-intervention (week 12 [W12]) and follow-up (week 26 [W26]). Quit attempts and cessation were assessed at follow-up, and cessation was biochemically verified. Results As hypothesized, Implicit Association Test scores became more negative from baseline to W12, a change that was sustained at follow-up. Logistic regression analyses in which implicit attitudes were used to predict smoking outcomes revealed that negative changes in implicit attitudes from baseline to W12 and from baseline to W26 were significantly related to quit attempts (OR = 0.71, 95% CI [0.52, 0.97], p < .05 for both) independent of explicit motivation. Negative changes in implicit attitudes from baseline to W26 were significantly related to cessation (OR = 0.50, 95% CI [0.25, 1.00], p < .05). Conclusions Negative changes in implicit attitudes were associated with positive changes in smoking behavior independent of explicit motivation. This result indicates that smoking cessation interventions may be enhanced by incorporating strategies to change implicit attitudes, and that changes in implicit attitudes are also potentially important intervention outcomes. Implications Smoking cessation interventions may be improved by going beyond the current focus on explicit psychological constructs and targeting automatic cognitive processes such as implicit attitudes. The results are encouragement to examine how best to manipulate smokers' implicit attitudes as well as to determine the effect on their smoking behavior.

The dietary intake of industrially-produced trans fatty acids (IP-TFA) was estimated for the US population (aged 2 years or more), children (aged 2-5 years) and teenage boys (aged 13-18 years) using the 2003-2006 National Health and Nutrition Examination Survey (NHANES) food consumption database, market share information and trans fat levels based on label survey data and analytical data for packaged and in-store purchased foods. For fast foods, a Monte Carlo model was used to estimate IP-TFA intake. Further, the intake of trans fat was also estimated using trans fat levels reported in the US Department of Agriculture (USDA) National Nutrient Database for Standard Reference, Release 22 (SR 22, 2009) and the 2003-2006 NHANES food consumption database. The cumulative intake of IP-TFA was estimated to be 1.3 g per person per day (g/p/d) at the mean for the US population. Based on this estimate, the mean dietary intake of IP-TFA has decreased significantly from that cited in the 2003 US Food and Drug Administration (FDA) final rule that established labelling requirements for trans fat (4.6 g/p/d for adults). Although the overall intake of IP-TFA has decreased as a result of the implementation of labelling requirements, individuals with certain dietary habits may still consume high levels of IP-TFA if certain brands or types of food products are frequently chosen.

Anthocyanins are the red, blue and purple pigments responsible for the coloration of many plants. These pigments have been the subject of many studies due to their importance as a quality indicator in foods and as an important chemotaxonomic indicator for plants. Early work with anthocyanins employed paper chromatographic methods. More recently, high-performance liquid chromatography has been widely applied to the study of these pigments. The objective of this paper is to review the chromatographic methods that have been employed in the analysis of anthocyanins with emphasis on the more recent developments in high-performance liquid chromatographic analysis of anthocyanins as applied to food quality measurement.

The purpose was to develop a procedure that would examine time-related HPLC patterns and UV-vis properties of browning pigments formed in temperature-aged grapefruit juice. A secondary goal included an examination of the UV-vis properties of container-specific pigments

The method utilized a two-position, 10-port valve that enabled direct injection of filtered citrus juice into an HPLC system. separation was by reversed-phase ion-pair HPLC with selective amperometric detection. Treatment with a folate polyglutamate hydrolase enzyme provides evidence for the existence of 5-methyl-THFpolyglutamates in Citrus juices.

From February 1986 to January 1988, samples of several processed Florida citrus juice products—frozen concentrated orange juice, orange juice from concentrate, pasteurized orange juice, grapefruit juice, and grapefruit juice from concentrate—were surveyed regularly during production. Samples were assayed for sodium, potassium, ascorbic acid, thiamin, calcium, iron, folic acid, phosphorus, magnesium, zinc, and copper primarily for the purpose of nutrition labeling. Means, standard deviations of the means, and maximum and minimum values of each nutrient are expressed in mg/6 fl oz for each product. In addition, the estimated percentage of the U.S. Recommended Daily Allowance (U.S. RDA) for each nutrient claimable at time of packing is given. (To be claimed on a nutrition label, a nutrient must occur at a minimum level of 2% of the U.S. RDA per serving, according to U.S. Food and Drug Administration [FDA] regulations.) The estimated percentage of the U.S. RDA claimable for ascorbic acid ranged from 90% to 100% in the orange juice products and was 70% for the grapefruit juice products. These juices are all considered significant sources of vitamin C. In the orange juice products, the percentage of the U.S. RDA for thiamin ranged from 6% to 8% and was 8% for folic acid. Significantly smaller amounts of each vitamin were noted in the grapefruit juices. Small but claimable levels of magnesium, calcium, copper, and phosphorus were found in one or more of the products tested. Neither zinc nor iron was found at the U.S. RDA minimum level of 2%. Significant amounts of potassium, for which there is no established U.S. RDA, were found in all the citrus juice products. The sodium content of all the citrus juice products was negligible, qualifying each juice to be labeled "sodium free" according to FDA specifications. Significant variations in the mean amounts of certain nutrients were found in each of the products depending on the time of processing (month and year) and manufacturing plant.

Model systems were employed to determine the relative reactivity of sucrose, glucose, and fructose in the formation of 5-hydroxymethylfurfural (5-HMF) at pH 3.5. Fructose was the major reactant for formation of 5-HMF. Fructose was 31.2 times faster than glucose, whereas sucrose was 18.5 times faster than glucose in the rate of 5-HMF formation when averaged over three different sugar-catalyst systems. Accelerating effects of citric acid, minerals (calcium, magnesium, and potassium), and amino acids (alanine, aspartic acid, and γ-aminobutyric acid) in the formation of 5-HMF from sugars were evaluated. With fructose as the substrate, 5-HMF formed 5 times faster in the presence of citric acid and minerals than in the presence of HCl. Varying catalytic effects were noted with the three amino acids. Rates of 5-HMF formation from glucose and sucrose showed slight enhancement in the presence of the amino acids, whereas virtually no enhancement occurred when fructose was the substrate.

An interlaboratory study was carried out for the determination of benzoic acid in orange juice by liquid chromatography. The orange juice was fortified with 0.5–10 ppm benzoic acid. Statistical analysis of the results showed that relative reproducibility (RSDR) between laboratories ranged from 6.92 to 15.97% for juice fortified with 1-10 ppm benzoic acid; RSDr was 27.90% for juice fortified with 0.5 ppm benzoic acid. Mean recoveries ranged from 94.5% for 4 ppm benzoic acid to 114% for 0.5 ppm benzoic acid. Total variability increased with increasing fortification level as measured by standard deviation for reproducibility (SR).

A recently introduced hydrophilic end-capped C 18 column (GMC ODS-AQ) was tested for the analysis of the nonvolatile organic acids in orange juices. Ten carboxylic acids can be detected from Valencia orange juice by isocratic elution with 20 mM KH 2 PO 4 as the mobile phase with a flow rate of 0.7 mL/min and UV detection at 214 nm. Juice samples are purified through a disposable SCX (benzenesulfonylpropyl) extraction cartridge

High-performance liquid chromatography with photodiode array detection was developed for the separation and identification of carotenoids from a new sweet orange, Earlygold. Carotenoid pigments were extracted using hexane-acetone-ethanol and saponified using 10% methanolic potassium hydroxide. More than 25 carotenoid pigments were separated within 40 min using a ternary gradient (acetonitrile-methanol, methyl tert-butyl ether and water) elution on a C30 reversed-phase column. The carotenoid pattern of Earlygold was generally similar to the early season Hamlin but with some quantitative differences, especially with violaxanthin. Major carotenoids including violaxanthin, lutein, beta-cryptoxanthin, antheraxanthin, luteoxanthin, zeaxanthin, beta-carotene, and alpha-carotene were identified based on on-line spectral data obtained by a photodiode array detector, and comparison to the spectra of the standards and reported values. A numerical notation, the ratio of the peak heights between absorption bands, was also calculated to compare to the literature values.

The color properties (CIE Lab, hue, and chroma) of 90 red grapefruit juices were studied by tristimulus reflectance measurement for two growing seasons. Juices were prepared from six red grapefruit cultivars including Ruby Red, Rio Red, Star Ruby, Ray Ruby, Flame, and Marsh Red grown in Florida. Very wide varietal and seasonal variations on juice color were observed, and most notably, CIE a values varied widely from -1.41 to 9.06 (CV = 82.6%). Lycopene is the major colored pigment in red cultivars with lesser amounts of beta-carotene as determined by HPLC on a carotenoid C(30) column with gradient elution using MeOH and MTBE. The highest correlation coefficients (r = 0.963) found between CIE a values and lycopene contents in juices from all cultivars combined suggest the possibility that the CIE a value would be a good indicator for pigmentation in red grapefruit juice.

The anthocyanins in the skin of lychee fruit were isolated and purified by Sephadex G-25 and LH-20 gel column chromatography, and Sep-Pak C-18 cartridge. Further separation by HPLC on a C-18 column, on-line spectra by photodiode array detection, and acid and alkali hydrolyses were used for identification. Cyanidin-3-rutinoside was the major anthocyanin found. Cyanidin-3-gIucoside and malvidin-3-ace-tylglucoside were also identified. Polymerized anthocyanin pigment was also present, appearing to contribute to the brownish-red color.

4-Vinyl guaiacol, a potent off-flavor compound in orange juice, was isolated by using a C-18 cartridge and analyzed by high performance liquid chromatography (HPLC) with fluorescence detection. The new HPLC method possessed a sensitivity of 10 ppb for 4-vinyl guaiacol and was at least 5 to 10 times more sensitive than previously reported gas-liquid chromatographic procedures. Storage of bottled orange juice for 18 wk yielded the following 4-vinyl guaiacol levels: 42 μg/L (20°C), 223 μ/L (30°C), and 778 μg/L (40°C). Concentration of 4-vinyl guaiacol increased with storage time at all storage temperatures; however, a noticeable decrease occurred after extended storage at 50°C.

Apples from Michigan, Washington, Argentina, Mexico, and New Zealand were processed into juice; the 8 samples included Golden Delicious, Jonathan, Granny Smith, and Mcintosh varieties. Liquid chromatography was used for quantitation of sugars (glucose, fructose, sucrose, and sorbitol), nonvolatile acids (malic, quinic, citric, shikimic, and fumaric), and phenolics (chlorogenic acid and hydroxymethylfurfural [HMF]). Other determinations included pH, °Brix, and L-malic acid. A number of compositional indices for these authentic juices, e.g., chlorogenic acid content, total malic - L-malic difference, and the HMF: chlorogenic ratio, were at variance with recommended standards. The phenolic profile was shown to be particularly influenced by gelatin fining, with peak areas decreasing by as much as 50%. The L-malic: total malic ratio serves as a better index for presence of synthetic malic acid than does the difference between the 2 determinations. No apparent differences in chemical composition could be attributed to geographic origin.

Effects of storage temperature and time on the quality of commercially canned grapefruit juice were investigated. The most noteworthy and reproducible trend observed by HPLC was a significant increase in concentration of 5-hydroxymethylfurfural and furfural with increased storage temperature. During storage over 50% of sucrose was hydrolyzed after 6 wk at 30 degrees C, and the reducing sugars increased in accordance with hydrolysis of sucrose. In the juice stored at 50 degrees C, more than 98% of the ascorbic acid, and about 9% of total sugars were lost. Lightness value of juice decreased continuously during storage.

The 13C:12C ratios of 8 authentic apple juice samples and their subfractions were determined by mass spectrometry. Apples from Argentina, Mexico, New Zealand, and the United States were processed into juice; pulp was collected from the milled fruit and seeds were collected from the press-cake. Sugars, nonvolatile acids, and phenolics were isolated from the juice by treatment with ion-exchange resins and polyvinylpyrrolidone (PVPP). The mean value for all juice samples was — 24.2%o which is close to the values reported by other investigators. Juice from apples grown in Argentina, Mexico, and New Zealand did not differ from U.S. samples. The isotopic composition of the subfractions ranged from -22.0 to -31.0%o. The values for the pulp were essentially the same as for juice. The sugar fraction was slightly less negative than the juice; the nonvolatile acid and phenolic fractions were more negative. The levels of nonvolatile acids and phenolics in apple juice are low, however, so these compounds contribute little to overall δ13C values in juice.

An isocratic high-performance liquid chromatographic (HPLC) method has been developed to determine benzoic acid, sorbic acid, and methyl and propyl esters of p-hydroxygenzoic acid (parabens) in orange juice. The HPLC system consists of a reversed-phase column (150 × 6.0 mm i.d.) packed with a rigid polystyrene-divinylbenzene gel, a solvent system of acetonitrile-0.05M KH2P04 (40:60) with flow rate of 1.0 mL/min and 230 nm detection. Including sample preparation, a complete determination can be accomplished in 30 min. The method recovered 93% or more of all preservatives with the exception of high concentrations (500 ppm) of parabens.

A rapid sample clean-up and chromatographic separation were devel- oped to determine both furfural and 5-hydroxymetbylfurfural (HMF) in citrus juices. Furfural and HMF were isolated by using a C-18 cartridge, and quantified by isocratic elution with acetonitrile/water (1Y85, v/v) as the mobile phase with a Radial-PAK C-18 column (100 × 8 mm i.d.). Detection was at 280 nm and the lower limit of detection for both compounds was 50 ppb. Recoveries between 94.0 and 101.2% were obtained for HMF added to orange juice. Recoveries of fmfural ranged between 96.8 and 103.9%.