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Soybean oil and palm oil comprise 50% of the world population's fat and oil consumption. Meanwhile, fats and oils accounted for more than 20% of the vitamin E in the US diet, with soybean oil as a major vitamin E source. As part of the group of antioxidant food components, vitamin E in the form of its homologs, tocopherols and tocotrienols, may help prevent the onset of several diseases, including cancer, cardiovascular diseases, and cataracts.

The relationship between vitamin E and the oxidative stability of raw and dry roasted peanuts was studied during storage at 21degree Celsius under air and vacuum. The result showed that in air, peroxide values (PVs) for roasted peanuts reached 47 by 12 wk, whereas that for raw peanuts was below 2 after 38 wk whereas under vacuum lipid oxidation was significantly retarded.

Abstract: The purpose of this study was to examine the effects of high-iron and low-vitamin E diets on lipid peroxidation and aberrant crypt foci (ACF) development in rats. In a 2 x 2 x 2 factorial design, male Sprague-Dawley rats were fed 45 or 450 mg Fe/kg diet (adequate and high iron, respectively) and 15 or 100 IU vitamin E/kg diet (low and adequate vitamin E, respectively)for three weeks, when they received saline or azoxymethane (15 mg/kg for 2 wk). Diets were continued for an additional six weeks. Serum a-tocopherol concentrations in rats fed tow-vitamin E diets were decreased to 30% of concentrations observed in rats fed adequate-vitamin E diets (p < 0.0001). Also, serum a-tocopherol concentrations tended to be lower in rats supplemented with iron (p < 0.08). Lipid peroxidation in liver was significantly elevated by high-iron diets after 3 and 10 weeks of treatment, but lipid peroxidation in colonic mucosa was not altered by dietary iron or vitamin E. The total number of ACF and number of large ACF (>/=4 aberrant crypts/focus) were not significantly altered by iron or vitamin E intakes. However, the size distribution of ACF was slightly altered, such that iron-supplemented rats had 12% more ACF with two cryptsper focus (p < 0.02) than rats fed adequate-iron diets. Our data suggest that high-iron diets enhanced oxidative stress in liver, but not colon, of rats fed low-vitamin E diets. Furthermore, a high-iron diet does not increase the total number of ACF, even when vitamin E status is low. [ABSTRACT FROM AUTHOR]

This two-year study compared the status of targeted nutrients in selected fresh and frozen fruits and vegetables. In addition, a novel third category was examined—a “fresh-stored” categorization intended to mimic typical consumer storage patterns of produce following purchase (five days of refrigeration). Broccoli, cauliflower, corn, green beans, green peas, spinach, blueberries, and strawberries of all three categories of freshness were analyzed for their concentrations of l -ascorbic acid (vitamin C), trans -β-carotene (provitamin A), and total folate. Analyses were performed in triplicate on representative samples using standardized analytical methods and included a quality control plan for each nutrient. In the majority of comparisons between nutrients within the categories of fresh, frozen, and “fresh-stored”, the findings showed no significant differences in assessed vitamin contents. In the cases of significant differences, frozen produce outperformed “fresh-stored” more frequently than “fresh-stored” outperformed frozen. When considering the refrigerated storage to which consumers may expose their fresh produce prior to consumption, the findings of this study do not support the common belief of consumers that fresh food has significantly greater nutritional value than its frozen counterpart. [ABSTRACT FROM AUTHOR]

BSTRACT: The relationship between vitamin E and the oxidative stability of raw and dry roasted peanuts was studied during storage at 21°C under air and vacuum. Lipid oxidation was monitored by peroxide values (PVs) and conjugated diene values (CDVs). In air, PV (meq/kg) for roasted peanuts reached 47 by 12 wk, whereas that for raw peanuts was below 2 after 38 wk. Under vacuum, lipid oxidation was significantly retarded ( P < 0.05). Tocopherols of raw and roasted peanuts exponentially decreased with increasing PV. After 12 wk, about 50% of α-tocopherol (α-T) was lost for roasted peanuts under vacuum compared with about 90% under air. For raw peanuts, more than 70% of each tocopherol remained after 38 wk under air and vacuum. In general, α-T showed the least stability in roasted peanuts compared with other tocopherols under the reported storage conditions. [ABSTRACT FROM AUTHOR]

Abstract: The fatty acid profiles of commercially-grown Runner-type peanut cultivars (i.e., 10 cultivars, n =151) collected over two production years (2005 and 2006) were determined by gas–liquid chromatography. Eight major fatty acids were identified in the sample set including palmitic (C16:0), stearic (C18:0), oleic (C18:1, ω9), linoleic (C18:2, ω6), arachidic (C20:0), gondoic (C20:1, ω9), behenic (C22:0), and lignoceric (C24:0) acids. Based on the oleic to linoleic acid (O/L) ratio, these cultivars were denoted as normal, mid-, and high-oleic peanut types. Correlation coefficients (r) between the eight major fatty acids identified were generated and revealed an inverse association between oleic and linoleic acids (r =–0.997, P <0.001), while oleic acid and linoleic acid were positively correlated to gondoic acid (r =0.818, P <0.001) and palmitic acid (r =0.967, P <0.001), respectively. Principal component analysis (PCA) of the fatty acid data yielded three significant PCs (i.e., eigenvalues⩾1), which together account for 87.18% of the total variance in the data set; with PC1 contributing 60.45% of the total. Eigen analysis of the correlation matrix loadings of the three significant PCs revealed that PC1 was mainly contributed to by palmitic, oleic, linoleic, and gondoic acids; PC2, by behenic acid; and PC3, by lignoceric acid. The score plot generated between PC1 and PC2 successfully segregated normal, mid- and high-oleic peanut cultivars, while the PC1–PC3 plot segregated normal and the combination of mid- and high-oleic acid cultivars. [Copyright &y& Elsevier]

Abstract: Tocopherol and tocotrienol contents of raw fruits and vegetables and processed products were determined by saponification and normal phase liquid chromatography. All samples were either locally obtained or collected as part of the US Department of Agriculture''s National Food and Nutrient Analysis Program (NFNAP). All fruits, vegetables and processed products were selected from the USDA Key Foods list. The study included 32 raw and processed fruits, 22 raw vegetables, various tomato products, baked beans, cooked potatoes, frozen broccoli and frozen green peas. α-Tocopherol (α-T) was detectable in all products and usually represented the vitamin E form present in highest quantity. γ-Tocopherol (γ-T) was higher than α-T only in cantaloupes, figs, red raspberries, cauliflower, button mushrooms, lettuce, and green peas. α- and γ-Tocotrienols (α- and γ-T3) were measurable in several fruit and vegetables but at levels usually less than 0.1mg/100g. [Copyright &y& Elsevier]

Abstract: A method was developed to differentiate folic acid from total folate in enriched cereal products. By elimination of the protease and conjugase digestion steps from the trienzyme digestion used to measure total folate, folic acid can be directly quantified by the microbiological assay using Lactobacillus casei (ssp. rhamnosus) ATCC 7469. Determination of total folate by the trienzyme digestion together with assay of folic acid by the procedure reported here allows calculation of food folate and μg dietary folate equivalents (μg DFE). Recovery studies conducted at five concentration levels in a non-fortified wheat flour gave a mean recovery of 95.5 (RSD% 9.7) for folic acid and 98.5 (RSD% 5.0) for total folate. Recoveries from a variety of enriched cereal foods ranged from 88% to 99% for the folic acid extraction and 90% to 96% for the trienzyme digestion. Analysis of SRM 1846 Infant Formula gave means±s.d. of 123.5±6.9μg/100g of folic acid and 136.6±6.7μg/100g of total folate (reference concentration value=129±28μg/100g). Intermediate precision determined as intra-laboratory reproducibility(r) gave RSDr % values of 4.32 for the folic acid assay and 3.15 for the total folate assay. Microgram DFE values were determined for several enriched cereals by calculating food folate as the difference between total folate and folic acid and the formula μg DFE=μg food folate+(1.7×μg folic acid). The differential assay of folic acid and total folate is a simple and accurate procedure to determine μg DFE in enriched cereal-grains or foods containing enriched flour. [Copyright &y& Elsevier]

Cites a study on the validation of a liquid chromatographic (LC) analysis for the determination of total vitamin B^{6 in infant formula. Quantification of total vitamin B6 by converting the phosphorylated and free vitamers into pyridoxine; Determination of pyridoxine by ion pair reverse--phase LC with fluorescence detection; Manifestation of dietary deficiency of vitamin B6 in infants.}

Presents an interlaboratory verified, chromatographic method for the analysis of vitamin A and E in soy-based infant formula powder. Procedures for extraction; Procurement of the reference material; Analysis of the fortified samples.

Discusses an interlaboratory-verified method for the determination of vitamins A and E in milk and soy-based infant formula by liquid chromatography with matrix solid-phase dispersion extraction. Evaporation and filtration process; Recoveries of retinyl palmitate; Extraction and cleanup.

The trienzyme digestion including protease, α-amylase, and conjugase (γ-glutamyl hydrolase) for the extraction of total folate from cereal grain products used in AOAC Official Method 2004.05 was optimized using response surface methodology. Digestion times of α-amylase (p < 0.05) and conjugase (p < 0.01) showed significant effects on the response (total folate). Digestion time for Pronase digestion was not significant (p > 0.1). Ridge analysis showed that total times required for the trienzyme digestions ranged from 6.1 h for buckwheat to 8.7 h for CRM 121 (wholemeal flour). The predicted maximal value for CRM 121 (51 μg/100 g) was close to the certified value (50 ± 7 μg/100 g). The optimized extractions for the four cereals suggest that a generalized trienzyme extraction for cereals of 1, 2.5, and 6 h for Pronase, α-amylase, and conjugase, respectively, could be used to approximate total folate in cereals and cereal products. These conditions provide data comparable to AOAC Official Method 2004.05 for the cereals included in this study and would be suitable to approximate total folate in most cereals and cereal products. Compared to the official method, the shortened digestion provides cost savings and minimizes the folate loss possible with prolonged digestions.

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.

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.

Response surface methodology was applied to optimize the trienzyme digestion for the extraction of folate from vegetables. Trienzyme extraction is a combined enzymatic digestion by protease, alpha-amylase, and conjugase (gamma-glutamyl hydrolase) to liberate the carbohydrate and protein-bound folates from food matrices for total folate analysis. It is the extraction method used in AOAC Official Method 2004.05 for assay of total folate in cereal grain products. Certified reference material (CRM) 485 mixed vegetables was used to represent the matrix of vegetables. Regression and ridge analysis were performed by statistical analysis software. The predicted second-order polynomial model was adequate (R2 = 0.947), without significant lack of fit (p > 0.1). Both protease and alpha-amylase have significant effects on the extraction. Ridge analysis gave an optimum trienzyme digestion time: Pronase, 1.5 h; alpha-amylase, 1.5 h; and conjugase, 3 h. The experimental value for CRM 485 under this optimum digestion was close to the predicted value from the model, confirming the validity and adequacy of the model. The optimized trienzyme digestion condition was applied to five vegetables and yielded higher folate levels than the trienzyme digestion parameters employed in AOAC Official Method 2004.05.

A liquid chromatographic (LC) method was validated for the determination of total vitamin B6 in infant formula. Total vitamin B6 was quantified by converting the phosphorylated and free vitamers into pyridoxine. Pyridoxine was determined by ion pair reversed-phase LC with fluorescence detection. The method was subjected to an AOAC collaborative study involving a factory-manufactured, milk- and soy-based infant formula. Each was spiked at 3 concentrations in the range of 0-1 microg/g and sent as blind duplicate to participant laboratories. Nine laboratories returned valid data which were statistically analyzed for outliers and precision parameters. The repeatability relative standard deviation (RSD(r)) ranges were 2.0-4.0 and 3.5-5.9% for fortified milk- and soy-based formulas, respectively. The reproducibility relative standard deviation (RSD(R)) ranges were 8.2-8.4 and 6.7-11.2% for fortified milk- and soy-based formulas, respectively. HORRAT values ranged from 0.42 to 0.53, indicating that the precision of the method is acceptable. The mean RSD(r):RSD(R) values were 0.60 and 0.55 for milk- and soy-based formulas, respectively. As expected, RSDs for the unfortified samples were higher, but their HORRAT values (0.81 and 2.06) helped define a realistic limit of quantitation as 0.05 microg/g. Recovery data were quantitative and varied between 81.4 and 98.0% (mean = 89.8%) for each of 6 spiked materials.

Retention of immunoglobulin A (IgA) and IgA specific for enteropathogenic Escherichia coli (EPEC) was determined in human milk that was processed and stored under refrigeration or frozen conditions. Human milk was subjected to three different processing conditions: (a) deaerated, vacuum packaged in metalized polyester bags and pasteurized (64°C for 6 min, 10 s); (b) vacuum packaged and pasteurized; (c) vacuum packaged. Samples were stored at 4°C for 7 d and at -20°C for 28 d. An enzyme-linked immunosorbent assay (ELISA) to detect antibodies to EPEC was developed and used to monitor these antibody levels, while radial immunodiffusion (RID) plates were used to provide information on total IgA of the milk samples. In addition, the dissolved oxygen content of the samples was monitored. It was found that pasteurization and deaeration did not adversely affect the IgA levels, and levels of total IgA and IgA specific for EPEC remained stable or increased slightly during storage in most samples regardless of the storage temperatures.

Rates of thermal destruction of Staphylococcus aureus were determined in mature human milk using a continuous flow high-temperature short-time pasteurization system. D and z values for inactiviation of S. aureus were determined from data on survivors capable of forming colonies in an appropriate selective medium. The effects of thermal injury on D and z values were assessed by survivor colony forming units (CFU) on Staphylococcus medium 110 (SMI 10), nutrient agar (NA), Trypticase Soy Agar (TSA), Trypticase Soy Agar with 7.5% NaCi (TSAS) and Baird-Parker medium (BP) (Difco Laboratories, Detroit, MI). D values for inactivation of S. aureus at 52, 58 and 60 and 62°C were used to predict D at 60°C of 15.3 s and 24.3 s when based on survivor CFU in SM 110 and nutrient agar, respectively. The z value was 4.9°C in either medium. D-values for inactivation of S. aureus at 60, 62, 64 and 67°C were used to predict D at 60°C of 41.2 s, 41.0 s and 34.7 s when based on survivor CFU in BP, TSA and TSAS, respectively. The z values were 6.5, 6.5 and 6.4°C, respectively.

A comparative review of the specificities of various B-vitamin analysis methods is presented. Methods of vitamin analysis employing protozoa, viz. Tetrahymena and Ochromonas , are compared to the commonly used methods of vitamin assay, including officially accepted methods. Since 1968 the protozoan techniques have routinely been used to evaluate clinical vitamin status. This is due to their more mammalian-like response to the various forms of the vitamins that occur in natural materials. Protozoa have more developed ingestive and digestive systems than bacteria and yeast, which allow them to respond to conjugated forms of the vitamins (e.g. thiamin pyrophosphate and folic acid polyglutamates). Also, fewer problems are encountered with non-specific stimulation (e.g. fatty acid stimulation of the Lactobacillus casei assay for riboflavin or the sparing of the vitamin B 12 requirement of Lactobacillus leichmannii by deoxyribosides). Application of the protozoan methods to analysis of foods indicate significantly lower levels of biotin and vitamin B 12 than official methods, while significantly higher levels of riboflavin, vitamin B 6 , niacin and pantothenic acid are found in low-acid foods. This review also summarizes extraction methods for the B-vitamins from food samples and indicates the importance of enzymatic hydrolysis in extract preparation.

The bacteriological profiles of human milk samples collected from individual donors under supervised conditions of collection were compared to pooled human milk samples obtained from a commercial human milk bank. Total aerobic counts and total coliform counts of individual donor samples were lower than those of pooled, banked human milk. All of the 200 isolates from ten individual samples were staphylococci with Staphylococcus epidermidis predominating (82%). Only 1% of the isolates was identified as Staphylococcus aureus . Forty-two percent of the 100 isolates from five pooled samples were staphylococci and all of these staphylococci were coagulase-negative. Three percent of the isolates from the pooled samples were Streptococcus faecalis . The remainder (55%) were gram-negative organisms. S. epidermidis was the microorganism that was isolated most frequently from either individual (9 of 10) or pooled (3 of 5) samples.

A continuous flow high-temperature short-time pasteurization system was used to determine kinetic parameters (D- and z-values) for thermal destruction of the bacterial pathogens, Escherichia coli and Klebsiella pneumoniae , in mature human milk. D-and z-alues of each bacterium were determined from data on survivors enumerated on both selective media, Violet Red Bile agar or MacConkey's, and on a non-selective medium, nutrient agar (NA). For E. coli , D-values were determined at 58, 60, 62 and 64°C. The predicted value of D at 60°C is 31.5 s. The z-value for E. coli is 3.2°C. D-values for K. pneumoniae were determined at 52, 56 and 58°C. Based on these data the predicted value of D at 60°C is 1.3 s. The z-value for K. pneumoniae , is 2.8°C. For both E. coli and K. pneumoniae , counts on NA tend to be higher than on selective media. This is undoubtedly due to the inhibitory nature of the selective media. This also suggests that some degree of thermal injury may occur for each organism.

Three composites of human milk samples were subjected to different processing conditions: (1) deaerated, vacuum packaged in metalized polyester bags and pasteurized at 56°C for 8 min; (2) vacuum packaged and pasteurized; (3) vacuum packaged. On days 0, 4, 7, 14, 28, 64, and 96 of storage, each treatment was analyzed for dissolved oxygen content and viable microflora. On days 0, 4, and 14, randomly selected isolates from each treatment were identified to the species level. Heat treatment of the milk samples reduced the number of viable microorganisms and resulted in a shift in the type of bacteria in the milk. Pasteurized samples contained primarily non-pathogenic skin commensals, while non-pasteurized samples were populated by species of Pseudomonas and other Gram negative microorganisms, including potential pathogens. Deaeration did not affect either the number or types of microorganisms surviving the heat treatment.