Effect of Germination on Fatty Acid Composition in Cereal Grains

Sprouted grains are gaining popularity as functional food ingredients. This study aimed to evaluate the lipid and fatty acid composition of eight sprouted grains (millet, amaranth, quinoa, wheat, rye, barley, buckwheat, and oat). The method used was germination for up to 72 h at temperatures ranging from 19-23 °C. In general, the lipid content increased in the various grains sprouted, providing a rich source of polyunsaturated fatty acids. The % oil yield ranged from 1.17 ± 0.02% in sprouted rye to 5.71 ± 0.26% in sprouted amaranth. Germinated oat showed the greatest increase in fat content, 54.3%, compared to the control. Polyunsaturated fatty acids were more prevalent in whole grains (46.9-75.6%) than saturated fatty acids (10.1-25.9%) and increased with sprouting. The primary fatty acids detected in the grains, in order of abundance, were linoleic, oleic, palmitic, linolenic, and stearic acids. Millet sprouts contained the lowest total saturated fatty acids and the highest polyunsaturated fatty acids. Amaranth had the highest amount of saturated fatty acids, while buckwheat contained the lowest quantity of polyunsaturated fatty acids. The lowest omega-6/omega-3 ratio was 7 to 1 in sprouted rye and 8 to 1 in sprouted barley.

Analysis of Fatty Acid Composition in Sprouted Grains

A whole-grain diet is associated with the prevention of metabolic syndromes, including obesity, diabetes, and cardiovascular diseases. Sprouting improves the nutritional profile and bioactive properties of grains, which are important for use as raw ingredients in the food industry. The aim of this review was to examine the lipid and fatty acid composition of germinated grains. The methods discussed include germination and analytical procedures for determining fat and fatty acid contents of grains. The effects of sprouting on the fat content and storage stability of grains were also assessed. Lipid levels ranged from 1.43% to 6.66% in the sprouted grains. The individual fatty acid content of grains changed depending on the germination conditions (17-37 °C, 1-9 days). Limited findings showed that sprouting grains at higher temperatures (20-25 °C) and longer times generated a healthy balance of omega-6 and omega-3 fatty acids, which is beneficial to humans. Future studies are needed to determine the optimum incubation and germination periods specific to each grain to improve the omega-6/omega-3 ratio. Free fatty acids were produced more slowly and levels of oxidation products were lower in sprouted grains than in the raw ingredients when stored for a year. Additional studies are required to investigate the oxidative stability and shelf life of sprouted grains.

Identification of Phytochemical Compounds in Coffea arabica Whole Coffee Cherries and Their Extracts by LC-MS/MS

The current work assessed the phytochemical contents of Arabica whole coffee cherry (WCC) and its two commercially available extracts: a minimum 40% chlorogenic acid (CGA; WCCE-1) and 70% caffeine (WCCE-2). Mass spectrometry analyses tentatively identified 219 phytochemicals in the three coffee samples, which is, so far, the largest number of identifications in a single study. A new group of CGA derivative namely caffeoylvaleroylquinic acid (CVQA) was identified in the three samples. Moreover, three 5-hydroxytryptamide derivatives (C₂₀-5HT, C₂₂-5HT, and C₂₄-5HT) were identified in WCC but not in the extracts. Two groups of atractyligenin derivatives (carboxyatractyligenin and noncarboxyatractyligenin) were identified in the three samples. Furthermore, our results show that both extracts retained a large number of phenolic and other potentially bioactive compounds that were naturally present in whole coffee cherry (WCC).

Phytochemical composition and nutritional value of different plant parts in two cultivated and wild purslane (Portulaca oleracea L.) genotypes

Purslane (Portulaca oleracea) is a weed naturally found in driveways, lawns, and fields and edible in many regions of Europe, Asia, the Middle East, Africa, and Australia. The purpose of this study was to compare the nutritional and phytochemical components of cultivated and wild purslane. Omega-3 contents of both purslane genotypes were comparable with 189.16 ± 25.52 mg/100 g dry weight and 188.48 ± 6.35 mg/100 g dry weight in cultivated and wild purslane leaves, respectively. Omega-6/omega-3 ratio (1:1-1:3) were low in both genotypes. However, high levels of oxalic acid were observed. Cultivated contained greater amounts of amino acids and vitamins than wild purslane. Of the 184 compounds identified in both genotypes by LC-MS/MS, including phenolic acids, organic acids, flavonoids, alkaloids, and betanin, more than 80 showed greater than two-fold abundance in the wild compared to cultivated purslane. Purslane has the potential to be cultivated as a food ingredient for nutraceutical applications.

Determination and Quantitation of Residual Solvents in Natural Food Ingredients Using a Static Headspace Gas Chromatography with Flame Ionization Detection and Mass Spectrometric Detection Method

The determination of residual solvents is critical for quality control in food production and manufacturing processes. A gas chromatographic and mass spectrometric detection (MSD) method was developed and validated to complement the static headspace flame ionization detection (FID) technique for identification, confirmation, and quantitation of solvent residues in botanicals, using Coffeeberry extract and pomegranate powder as test samples. Relative standard deviations (RSDs) of less than 12% were obtained for residual solvents in water and dimethyl sulfoxide. Coffeeberry extract supplemented with10 μg/g of Residual Solvents Class 3 Mix showed MSD and FID recoveries mainly of 91 to 121% and 77 to 110%, respectively, while those samples supplemented with 100 μg/g of Residual Solvents Class 3 Mix displayed MSD and FID recoveries of 105 to 123% and 87 to 112%, respectively. For pomegranate samples supplemented with 10 μg/g of Residual Solvents Class 3 Mix, MSD and FID recoveries of 95 to 124% and 72 to 151% were observed, respectively. Those samples supplemented with 100 μg/g of Residual Solvents Class 3 Mix exhibited MSD and FID recoveries of 109 to 135% and 97 to 127%, respectively. Thus, the developed procedure was demonstrated to be suitable for the analysis of residual solvents in natural food ingredients and is expected to find numerous industrial applications (e.g., process control and impurity detection in final products).

Occurrence of Ochratoxin A in Infant Foods in the United States

Ochratoxin A (OTA) is a possible human carcinogen and occurs frequently in cereal grain, soy, and other agricultural commodities. Infants and young children may be more susceptible to contaminants than adults because of their lower body weight, higher metabolic rate, reduced ability to detoxify food toxicants, and more restricted diet. The purpose of this study was to investigate the occurrence and levels of OTA in infant formula and infant cereal products available in the U.S. market. In the present study, 98 powdered infant formula (milk- and soy-based) samples and 155 infant cereal (barley-, rice-, oat-, wheat-, and mixed grain-based) products were collected from different retail locations in the United States over a 2-year period. OTA levels were determined by liquid chromatography-tandem mass spectrometry. Although OTA was not detected in any of the infant formula samples, 47 (30%) of 155 infant cereals were contaminated with OTA in the range of 0.6 to 22.1 ng/g. At present, there is no regulatory limit for OTA in the United States. However, all of the positive samples were above the maximum level set by the European Commission (0.5 ng/g) for OTA in baby foods. OTA was detected in all types of infant cereals, but the highest incidence and concentrations were found in oat-based infant cereals (59%), followed by mixed grain cereals (34%). Increased surveillance and monitoring of OTA levels in grains used in infant foods may be needed to reduce exposure of infants and young children to OTA from cereal products.

Method validation and proficiency testing for determination of total arsenic in apple juice by inductively coupled plasma/ mass spectrometry

A proficiency test (PT) program for determination of total As in apple juice samples was conducted by the Food Emergency Response Network (FERN) laboratories. An analytical method using inductively coupled plasma (ICP)-MS was validated for this project. The LOD and LOQ were determined to be 0.315 and 2.32 ng/g, respectively. A total of eight apple juice samples were sent to 38 FERN laboratories, and results were statistically evaluated according to ISO 13528:2005. The total As concentrations in the PT samples reported by the participating laboratories were very close to those obtained in the homogeneity and stability tests. The reproducibility, repeatability, interlaboratory, and intralaboratory variability results led to 69% of participating laboratories being rated as satisfactory using the widely accepted Izl score <or= 2 criterion. The percentage of laboratories with acceptable z scores (Izl scores <or=2) increased from 61 to 89% with the increase in As concentration in PT samples from 5.05 to 30.72 ng/g. This study demonstrated that the ICP/MS method was adequate for total As determination in fruit juice, and most of the participating laboratories were proficient in their analytical performance.

Rapid method for the determination of multiple mycotoxins in wines and beers by LC-MS/MS using a stable isotope dilution assay

A "dilute and shoot" method for the liquid chromatography-tandem mass spectrometric (LC-MS/MS) determination of multiple mycotoxins (aflatoxins B1, B2, G1, G2, ochratoxin A (OTA), fumonisins (F) B1 and B2, zearalenone, deoxynivalenol, T-2 toxin, and HT-2 toxin) in wines and beers has been developed and validated. Separation was accomplished using ultrahigh-performance liquid chromatography (UHPLC) with <10 min analysis time. Mycotoxins were detected by dynamic multiple reaction monitoring (MRM) in positive electrospray ionization mode. Due to matrix effects, (13)C-uniformly labeled mycotoxins were added to the sample extracts prior to LC-MS/MS analysis. With external calibration, recoveries were 18-148% for white wines, 15-118% for red wines, and 20-125% for beers, at three spiking levels. The (13)C-labeled internal standards compensated for matrix effects effectively, with overall recoveries of 94-112% for white wines, 80-137% for red wines, and 61-131% for beers, with greater recoveries for FB1 and FB2, at three spiking levels. The relative standard deviation was <20% for all analytes in the wines and beers. This method was applied to a USDA-funded nationwide survey of domestic and imported wines and beers for the determination of OTA and extended to include other mycotoxins.

Reduction of pesticide residues in tomatoes and other produce

There is interest in reducing pesticide residues in fruits and vegetables in order to minimize human exposure. The objectives of this study were to (i) determine the effect of various washing treatments with and without sonication on pesticide removal from tomatoes and (ii) assess the effectiveness of a water wash on select samples using a produce-washing flume. In the first set of experiments, tomatoes were contaminated with acephate, malathion, carbaryl, bifenthrin, cypermethrin, permethrin, cyhalothrin, chlorothalonil, and imidacloprid and were dried overnight. Subsets of the tomatoes were then washed (10°C, 1 min) with one of the following: water, sodium hypochlorite (80 μg/ml, pH 7), peroxyacetic acid (80 μg/ml), or Tween 20 (0.1%) with and without sonication. In general, the effect of sonication depended on the washing treatment and on the pesticide. A separate experiment measured pesticide residues in contaminated samples before and after being washed in a flume (22°C, 1 min). Pesticide residues in contaminated produce were reduced from about 40 to 90% when washed for 1 min in the flume.

Multiresidue pesticide analysis of dried botanical dietary supplements using an automated dispersive SPE cleanup for QuEChERS and high-performance liquid chromatography-tandem mass spectrometry

An automated dispersive solid phase extraction (dSPE) cleanup procedure as part of the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method, coupled with liquid chromatography-tandem mass spectrometry using electrospray ionization in positive mode, was used for the simultaneous analysis of 236 pesticides in three dried powdered botanical dietary supplements (ginseng, saw palmetto, and gingko biloba). The procedure involved extraction of the dried powdered botanical samples with salt-out acetonitrile/water extraction using anhydrous magnesium sulfate and sodium chloride, followed by an automated dSPE cleanup using a mixture of octadodecyl- (C18) and primary-secondary amine (PSA)-linked silica sorbents and anhydrous MgSO4 and online LC-MS/MS analysis. Dynamic multiple-reaction monitoring (DMRM) based on the collection of two precursor-to-product ion transitions with their retention time windows was used for all of the targeted pesticides and the internal standard. Matrix-matched calibration standards were used for quantitation, and standard calibration curves showed linearity (r(2) > 0.99) across a concentration range of 0.2-400 ng/mL for the majority of the 236 pesticides evaluated in the three botanical matrices. Mean recoveries (average %RSD, n = 4) were 91 (6), 93 (4), 96 (3), and 99 (3)% for ginseng, 101 (9), 98 (6), 99 (4), and 102 (3)% for gingko biloba, and 100 (9), 98 (6), 96 (4), and 96 (3)% for saw palmetto at fortification concentrations of 25, 100, 250, and 500 μg/kg, respectively. The geometric mean matrix-dependent instrument detection limits were 0.17, 0.09, and 0.14 μg/kg on the basis of the studies of 236 pesticides tested in ginseng roots, gingko biloba leaves, and saw palmetto berries, respectively. The method was used to analyze incurred ginseng samples that contained thermally labile pesticides with a concentration range of 2-200 μg/kg, indicating different classes of pesticides are being applied to these botanicals other than the traditional pesticides that are commonly used and analyzed by gas chromatography techniques. The method demonstrates the use of an automated cleanup procedure and the LC-MS/MS detection of multiple pesticide residues in dried, powdered botanical dietary supplements.

Validation of a rapid lateral flow test for the simultaneous determination of β-lactam drugs and flunixin in raw milk

β-Lactam antibiotics are the most commonly used drugs on dairy farms. β-Lactam residues in milk are kept out of the human milk supply with good agricultural practices and mandatory truck screening performed by the dairy industry under Appendix N of the Pasteurized Milk Ordinance. Flunixin, a nonsteroidal and anti-inflammatory drug, appears in dairy cattle tissue residues with a frequency similar to the occurrence of penicillin G. This creates concern that flunixin residues could be in milk and would go undetected under current milk screening programs. A single test that combines mandatory β-lactam screening with voluntary flunixin screening is an economical approach for monitoring and controlling for potential flunixin or 5-hydroxyflunixin, the primary flunixin metabolite marker in milk. The objective of this study was to validate a β-lactam and flunixin rapid lateral flow test (LFT) and compare the results obtained with a liquid chromatography-triple quadrupole tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of flunixin and 5-hydroxyflunixin in raw milk with a limit of detection of , 1 ppb, equivalent to 1 ng/ml. Using the LFT, three combined manufactured lots of test strips detected penicillin G at 2.0 ppb, ampicillin at 6.8 ppb, amoxicillin at 5.9 ppb, cephapirin at 13.4 ppb, ceftiofur (total metabolites) at 63 ppb, and 5-hydroxyflunixin at 1.9 ppb at least 90% of the time with 95% confidence. The LFT also detected incurred flunixin milk samples that were analyzed with the LC-MS/MS and diluted to tolerance in raw milk. The detection levels for the LFT are lower than the U.S. safe levels or tolerances and qualify the test to be used in compliance with U.S. milk screening programs.

Effect of processing on recovery and variability associated with immunochemical analytical methods for multiple allergens in a single matrix: sugar cookies

Among the major food allergies, peanut, egg, and milk are the most common. The immunochemical detection of food allergens depends on various factors, such as the food matrix and processing method, which can affect allergen conformation and extractability. This study aimed to (1) develop matrix-specific incurred reference materials for allergen testing, (2) determine whether multiple allergens in the same model food can be simultaneously detected, and (3) establish the effect of processing on reference material stability and allergen detection. Defatted peanut flour, whole egg powder, and spray-dried milk were added to cookie dough at seven incurred levels before baking. Allergens were measured using five commercial enzyme-linked immunosorbent assay (ELISA) kits. All kits showed decreased recovery of all allergens after baking. Analytical coefficients of variation for most kits increased with baking time, but decreased with incurred allergen level. Thus, food processing negatively affects the recovery and variability of peanut, egg, and milk detection in a sugar cookie matrix when using immunochemical methods.

Effect of processing on recovery and variability associated with immunochemical analytical methods for multiple allergens in a single matrix: dark chocolate

Immunodetection of allergens in dark chocolate is complicated by interference from the chocolate components. The objectives of this study were to establish reference materials for detecting multiple allergens in dark chocolate and to determine the accuracy and precision of allergen detection by enzyme-linked immunosorbent assay (ELISA) before and after chocolate processing. Defatted peanut flour, whole egg powder, and spray-dried milk were added to melted chocolate at seven incurred levels and tempered for 4 h. Allergen concentrations were measured using commercial ELISA kits. Tempering decreased the detection of casein and β-lactoglobulin (BLG), but had no significant effect on the detection of peanut and egg. Total coefficients of variation were higher in tempered than untempered chocolate for casein and BLG, but total and analytical CVs were comparable for peanut and egg. These findings indicate that processing has a greater effect on recovery and variability of casein and BLG than peanut and egg detection in a dark chocolate matrix.

Effects of Consumer Food Preparation on Acrylamide Formation

Acrylamide is formed in high-carbohydrate foods during high temperature processes such as frying, baking, roasting and extrusion. Although acrylamide is known to form during industrial processing of food, high levels of the chemical have been found in home-cooked foods, mainly potato- and grain-based products. This chapter will focus on the effects of cooking conditions (e.g. time/temperature) on acrylamide formation in consumer-prepared foods, the use of surface color (browning) as an indicator of acrylamide levels in some foods, and methods for reducing acrylamide levels in home-prepared foods. As with commercially processed foods, acrylamide levels in home-prepared foods tend to increase with cooking time and temperature. In experiments conducted at the NCFST, we found that acrylamide levels in cooked food depended greatly on the cooking conditions and the degree of "doneness", as measured by the level of surface browning. For example, French fries fried at 150-190 degrees C for up to 10 min had acrylamide levels of 55 to 2130 microg/kg (wet weight), with the highest levels in the most processed (highest frying times/temperatures) and the most highly browned fries. Similarly, more acrylamide was formed in "dark" toasted bread slices (43.7-610.7 microg/kg wet weight), than "light" (8.27-217.5 microg/kg) or "medium" (10.9-213.7 microg/kg) toasted slices. Analysis of the surface color by colorimetry indicated that some components of surface color ("a" and "L" values) correlated highly with acrylamide levels. This indicates that the degree of surface browning could be used as an indicator of acrylamide formation during cooking. Soaking raw potato slices in water before frying was effective at reducing acrylamide levels in French fries. Additional studies are needed to develop practical methods for reducing acrylamide formation in home-prepared foods without changing the acceptability of these foods.

Migration of volatile degradation products into ozonated water from plastic packaging materials

Migration of volatile degradation products from poly(ethylene terephthalate) (PET) and high-density polyethylene (HDPE) bottles, polypropylene (PP) caps and ethyl vinyl acetate (EVA) liners into ozonated water was measured. Polymer strips were immersed in deionized and distilled water with ozone concentrations of 0.5, 2.5 and/or 5 mg kg(-1) inside 35-ml vials, which were clamp-sealed and stored at 40 degrees C for 10 days. A purge-and-trap unit was developed to extract volatile products from the ozonated water in vials. The extractables were trapped in an adsorbent tube and analysed using a GC-MS coupled with an automated thermal desorber (ATD). Mass spectra were interpreted by comparison with a NIST mass spectral library, and an internal standard method was used to quantify the extractables of interest. Several volatile compounds found in ozonated water that had been in contact with PP, EVA and HDPE polymers included butanal, pentanal, hexanal, heptanal, octanal, nonanal, 2,2-dimethyl propanal, 3-hexanone, 2-hexanone and heptanone. These compounds could cause off-taste and off-odour with a low organoleptic threshold. In general, the concentrations of these volatile compounds increased with an increased exposure to ozone. The highest concentration found was 14.1 +/- 0.6 microg kg(-1) for hexanal with a 5 mg kg(-1) ozone treatment of PP caps. Even at a treatment level of 5 mg kg(-1) ozone, which is greater than 10 times the current regulatory limits for bottled water, the extractables migrating from those polymers were within the levels permitted by the FDA. For the PET sample, no significant peaks were observed before or after ozonation. These results imply that PP caps containing EVA liners may be major sources of off-odour and taste in ozonated bottled water.