Ronald R. Eitenmiller

Histamine food poisoning: Toxicology and clinical aspects

Histamine poisoning can result from the ingestion of food containing unusually high levels of histamine. Fish are most commonly involved in incidents of histamine poisoning, although cheese has also been implicated on occasion. The historic involvement of tuna and mackerel in histamine poisoning led to the longtime usage of the term, scombroid fish poisoning, to describe this food-borne illness. Histamine poisoning is characterized by a short incubation period, a short duration, and symptoms resembling those associated with allergic reactions. The evidence supporting the role of histamine as the causative agent is compelling. The efficacy of antihistamine therapy, the allergic-like symptomology, and the finding of high levels of histamine in the implicated food suggest strongly that histamine is the causative agent. However, histamine ingested with spoiled fish appears to be much more toxic than histamine ingested in an aqueous solution. The presence of potentiators of histamine toxicity in the spoiled fish may account for this difference in toxicity. Several potentiators including other putrefactive amines such as putrescine and cadaverine have been identified. Pharmacologic potentiators may also exist; aminoguanidine and isoniazid are examples. The mechanism of action of these potentiators appears to be the inhibition of intestinal histamine-metabolizing enzymes. This enzyme inhibition causes a decrease in histamine detoxification in the intestinal mucosa and results in increased intestinal uptake and urinary excretion of unmetabolized histamine.

Could the Dumas Method Replace the Kjeldahl Digestion for Nitrogen and Crude Protein Determinations in Foods

Increased demand for determinations of nitrogen (N), and hence crude protein (CP), has led to wider use of the Dumas method in place of the traditional Kjeldahl methods. Although Kjeldahl N (KN) and Dumas N (DN) represent different N fractions, published studies on infant formula, animal feed and meat products have indicated that DN could replace KN with little practical impact on the reliability of the N values obtained. This study was conducted to establish whether DN determination could replace that of KN in a broader range of foods for CP calculation. Statistical analysis was performed on in-house assayed KN and DN values together with published KN and DN values for selected food products. In the range 0.05-6.8% N, KN may be estimated from DN with the equation : KN = 1.00 (P<0.01) x DN - 0.09 (P=0.50) (n = 101, R 2 = 0.98, P-regression < 0.01). Because N levels in individual groups of food did not span the entire range of N contents, KN : DN ratios were calculated for each food group. KN : DN ratios differed significantly (R 2 = 0.25, P <0.01) from group to group. Ratios of 1.01 for dairy, 1.00 for oilseeds, 0.99 for feed, 0.98 for infant formulas, 0.95 for cereals, 0.94 for meats, 0.89 for vegetables, 0.80 for fish and 0.73 for fruits were valid for the estimation of KN and CP using DN data. CP was independently calculated as CP1 = H x KN or CP2 = H x KN : DN x DN, where H is the nitrogen to protein conversion factor for the food group. Mean differences between CPI and CP2 values were 0% for dairy, oilseeds, feed, infant formulas and baby foods, cereals, meat and meat products, vegetables and vegetable products and fruit, and 1% for fish. These results suggest that DN may replace KN for the determination of N and CP in selected food groups when appropriate coefficients are used.

Analysis of tocopherols in vegetable oils by high-performance liquid chromatography: comparison of fluorescence and evaporative light-scattering detection

A comparison of the responses of an evaporative light-scattering detector (ELSD) and a fluorescence detector for tocopherols in vegetable oils by high-performance liquid chromatography is presented. The tocopherols were separated from acylglycerols by gel-permeation chromatography (GPC). The tocopherol fraction was collected off a set of four GPC columns with a mobile phase of methylene chloride before separation on a normal-phase silica column with a mobile phase of hexane/isopropanol, 99.7∶0.3 (vol/vol). An internal standard of 5,7 dimethyltocol, which was detected by both the ELSD and fluorescence detector, was used to obtain quantitative data. The fluorescence detector was ten times more sensitive than the ELSD. γ-Tocopherol was the major tocopherol detected in the vegetable oils studied and ranged from 24.1–93.3 mg/100 g. The amounts of tocopherols found in the vegetable oils agreed favorably with the literature values.

Tocopherols in runner and Virginia peanut cultivars at various maturity stages

Alpha-, beta-, gamma-, and delta-tocopherol (α-T, β-T, γ-T and σ-T) were determined in peanut (Arachis hypogaea L.) cultivars Florunner, Sunrunner, Southern Runner, AT-127, GK-7, NC-7, NC-9 and GK-3. There were significant differences in tocopherol content among runner- and virginia-type peanut cultivars, and these differences were affected by the degree of maturation. α-T decreased with maturation for all of the cultivars except Florunner. γ-T increased with maturation for GK-7, NC-9 and GK-3 but decreased for Florunner. For the mature nuts, Florunner and NC-9 had the highest levels of α-T while GK-3 and Southern Runner had the lowest levels. GK-7 and Sunrunner had the highest levels of γ-T, while the lowest levels were in Florunner and GK-3.

Update on the Healthful Lipid Constituents of Commercially Important Tree Nuts

Uncharacteristic of most whole foods, the major component of tree nuts is lipid; surprisingly, information on the lipid constituents in tree nuts has been sporadic and, for the most part, not well reported. Most published papers focus on only one nut type, or those that report a cultivar lack a quality control program, thus making data comparisons difficult. The present study was designed to quantify the healthful lipid constituents of 10 different types of commercially important tree nuts (i.e., almonds, black walnuts, Brazil nuts, cashews, English walnuts, hazelnuts, macadamias, pecans, pine nuts, and pistachios) according to standardized, validated methods. The total lipid content of each nut type ranged from 44.4 ± 1.9% for cashews to 77.1 ± 1.7% for macadamias. As expected, the major fatty acids present in the tree nuts were unsaturated: oleic (18:1 ω9) and linoleic (18:2 ω6) acids. A majority of the lipid extracts contained <10% saturated fatty acids with the exceptions of Brazil nuts (24.5%), cashews (20.9%), macadamias (17.1%), and pistachios (13.3%). The total tocopherol (T) content ranged from 1.60 ± 1.27 mg/100 g nutmeat in macadamias to 32.99 ± 0.78 in black walnuts. The predominant T isomers in the nut types were α- and γ-T. Tocotrienols were also detected, but only in 6 of the 10 nut types (i.e., Brazil nut, cashews, English walnuts, macadamias, pine nuts, and pistachios). In most cases, total phytosterol contents were greater in the present study than reported in peer-reviewed journal papers and the USDA National Nutrient Database for Standard Reference, which is attributed to total lipid extraction and the inclusion of steryl glucosides in the analysis; the levels were highest for pistachios (301.8 ± 15.4 mg/100 g nutmeat) and pine nuts (271.7 ± 9.1 mg/100 g nutmeat). Minor sterols were also quantified and identified using GC-FID and GC-MS techniques.

Commercial Runner Peanut Cultivars in the United States: Tocopherol Composition

Tocopherols in commercially grown normal, mid- and high-oleic Runner peanuts from 2005 and 2006 were quantified to give accurate vitamin E contents. Tocopherols were extracted from raw peanuts by a direct solvent extraction procedure using 10% ethyl acetate in hexanes that provided percent recoveries of 105.4, 101.2, 103.9, and 102.8 for alpha-tocopherol (T), beta-T, gamma-T, and delta-T, respectively. No significant (P > 0.05) differences were noted in total tocopherol levels in normal- (22.4 mg/100 g), mid- (23.9 mg/100 g), and high-oleic (22.4 mg/100 g) Runner peanuts. alpha-T levels did vary significantly among the Runner cultivars classified by their oleic acid content (mid, 11.7 mg/100 g; normal, 10.9 mg/100 g; high, 9.8 mg/100 g). Cultivar effects were highly significant (P < 0.001) for alpha-, beta-, gamma-, and delta-T and total tocopherol contents, whereas production year effects were highly significant for alpha- and beta-T levels. Year x cultivar interactions were not significant (P > 0.05). Cluster analysis segregated the cultivars into two major groups represented by lower alpha-T and higher gamma-T levels (cluster A) and high alpha-T and low gamma-T levels (cluster B) (P < 0.05). The mean alpha-T level in Runner peanuts (151 samples) was 10.5 +/- 1.5 mg/100 g, which is 26.7% greater than the imputed value for peanuts, all types (NBD 16087) provided by the USDA National Nutrient Database for Standard Reference.

Calcium, phosphorus, and magnesium contents of human milk during early lactation.

Summary Early milk samples from 102 American mothers were examined for Ca, P, and Mg contents in relation to stage of lactation, intake of prenatal mineral supplements, maternal age, parity, and previous history of lactation. A total of 415 samples were collected at three stages of lactation: early transitional (4–7 days postpartum); transitional (10–14 days postpartum); and mature (30–45 days postpartum). No diurnal variations in element concentrations were observed in representative samples of late evening (PM) and early morning (AM) feedings collected during the transitional and mature stages. The mean concentrations for the major elements were highest in early transitional milk and in some cases decreased significantly (p < 0.05) as lactation progressed. Ca, P, and Mg contents (means ± SEM) were 26.3 ± 0.6, 14.6 ± 0.4, 5.3 ± 0.1 mg/100 g in early transitional milk and 26.2 ± 0.5, 13.3 ± 0.3, and 5.0 ± 0.1 in mature milk, respectively. Increasing uniformity in the elemental content of milk was noted among the mothers as lactation became established. No significant relationship was found between intake of dietary supplements containing Ca and Mg and levels of these elements in milk. Also, no significant correlations were found between maternal age, parity, or previous history of lactation and the elemental content of milk. From these data, it was estimated that fully breast-fed infants would receive approximately 33, 18, and 6.5 mg/kg/day of Ca, P, and Mg, respectively, during the neonatal period.

IgA, IgG, IgM and Lactoferrin Contents of Human Milk During Early Lactation and the Effect of Processing and Storage

The total IgA, IgG, IgM and lactoferrin concentrations in human milk from 89 donors were studied at three lactational stages: early transitional (3 to 8 d postpartum), transitional (10 to 14 d postpartum) and mature (30 to 47 d postpartum). The effects of processing and storage on these components in composite samples of mature human milk were determined. There were no significant diurnal variations in any of the four protective factors at either the transitional or mature stages. Concentrations of total IgA, IgM and lactoferrin decreased significantly as time postpartum increased, whereas the IgG content showed no significant changes. The total IgA, IgM and lactoferrin levels were significantly decreased by all heat treatments (62.5°C for 30 min, 72°C for 15 s, 88°C for 5 s, and 100°C for 5 min). Heating at 62.5°C for 30 min did not affect the IgG content; however, the other heat treatments significantly reduced IgG concentration. At the times and temperatures selected for this study, the two lower temperature treatments were less detrimental to the protective factors than the higher temperature treatments.

Commercial peanut (Arachis hypogaea L.) cultivars in the United States: phytosterol composition.

Phytosterols in commercially grown Runner, Virginia, and Spanish peanuts (n = 221) from 2005 and 2006 were quantified by a combination of acid hydrolysis and alkaline saponification steps followed by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry analysis of the trimethylsilyl derivatives. Δ(5)-Avenasterol, which partially degrades during acid hydrolysis, was quantified after alkaline saponification plus direct analysis of the steryl glucosides isolated by solid-phase extraction. β-Sitosterol, Δ(5)-avenasterol, campesterol, and stigmasterol were identified in peanut lipid extracts as the dominant sterols by retention time mapping and mass spectra with recoveries ∼99%. Clerosterol, Δ(5,24(25))-stigmastadienol, Δ(7)-sitosterol + cycloartenol, and one unidentified sterol were also present but at low levels. Free and esterified phytosterols accounted for ∼80% of the total sterols determined; the remainder was attributed to steryl glucosides. The total sterol level in Spanish market type peanuts (144.1 ± 5.3 mg/100 g) was significantly greater than both Runners (127.5 ± 6.3 mg/100 g) and Virginias (129.3 ± 6.9 mg/100 g) (P < 0.05). Tamspan 90 (146.9 mg/100 g) followed by OLIN (138.5 mg/100 g) showed the highest total sterol content among the cultivars examined. Cultivar effects were strongly significant (P < 0.001) for all phytosterols, whereas production year effects were strongly significant (P < 0.001) for Δ(5)-avenasterol, Δ(5,24(25))-stigmastadienol, and the combined quantities of Δ(7)-sitosterol + cycloartenol, which coeluted. Cultivar × year interactions were strongly significant (P < 0.001) in all sterols except for Δ(7)-sitosterol + cycloartenol (P < 0.01). Total phytosterol contents were markedly higher than those reported in the existing literature for Runner and Virginia type peanuts, partially attributed to the inclusion of steryl glucosides in the analysis.

Vitamin E Content of Margarine and Reduced Fat Products Using a Simplified Extraction Procedure and HPLC Determination

Abstract A liquid chromatographic method is described for the analysis of vitamin E in margarine and vegetable oil products (spreads). The tocopherol homologs (α, γ, δ-tocopherol) are extracted in hexane with anhydrous MgSO4 added to remove water. Complete resolution of the homologs is achieved on a normal phase column and a mobile phase of 0.9% isopropanol in hexane with fluorescence detection. Based on five repetitive assays the mean recoveries were 99.0±1.4, 97.4±2.2%, and 99.5±2.6% for α-, γ-, and δ-tocopherol, respectively. The method is rapid, specific, and accurate for the measurement of vitamin E in margarine and vegetable oil spreads. Further, the method avoids: (1) saponification techniques (2) emulsion forming organic solvent extractions and (3) the use of chlorinated solvents. The limit of detection for α-, γ-, and δ- tocopherol were 23.2, 2.96, and 1.98 μg/100g, respectively. The limit of quantitation for α-, γ, and δ- tocopherol were 39.8, 5.00, and 3.02 μg/100g, respectively. The vitamin E ...