Oat Products Research Articles

Detection of the lunasin peptide in oats (Avena sativa L)

We report the first discovery of lunasin in oats (Avena sativa L). Lunasin is a novel cancer preventive, anti-inflammatory and cholesterol-reducing peptide originally isolated from soy and later found in cereals (barley, rye, wheat, triticale). Lunasin was detected in oats using LC–MS/MS analysis. The chromatograms and mass spectra of lunasin isolated from five oat genotypes were compared with those of the synthetic lunasin peptide. We measured the lunasin content in harvests of two years and found that all tested oat genotypes contained the lunasin peptide. However, we observed genotype-related fluctuations in the lunasin content. Notably, the middle early oat variety ‘Ivory’ contained the highest and the most stable lunasin level at 0.197 ± 0.01 mg per g of grain in year 2010 and 0.195 ± 0.009 mg per g of grain in 2011. We also characterized the selected oat genotypes by measuring the contents of protein, β-glucans, fat, starch and moisture in the grains. However, we did not find correlation between lunasin and protein, and β-glucan content. Lunasin isolated from oat showed similar to the synthetic lunasin antioxidant effects. The detection of lunasin complements a list of bioactive compounds present in oats and strengthens recommendations to use oat products.

Evidence for a Whole Grains and Coronary Heart Disease Health Claim

A systematic review was undertaken to evaluate the evidence for a health claim about whole grain (WG) products and coronary heart disease (CHD). Studies were excluded if the American Association of Cereal Chemists International WG definition was not met or if foods with less than 51% WG ingredients were classified as WG. Seventeen of 26 clinical trials reported sufficient information to be included in the meta- analysis. Overall, pooled analyses suggested that WG products have total and LDL cholesterol-lowering effects. No effect remained when trials that tested single grains high in β-glucan fibre, such as oats, and poor quality studies were removed from the analysis. The cohort studies were too heterogeneous to calculate pooled risk estimates. Four of 6 cohort studies reported at least one improved CHD outcome in individuals who consumed more WG products. Two of the positive studies were poor quality; the remaining 2 were separate analyses of the same cohort. Health Canada concluded that the evidence to date was not sufficient to support a health claim about WG products in general and CHD. The effect of β-glucan fibre cannot be generalized to other grains, including wheat, the main grain consumed in Canada. Health Canada has already accepted health claims about oat and barley products and cholesterol-lowering.

Dietary Fiber and beta-glucan Contents of Oat Tarhana: A Turkish Fermented Cereal Food

Tarhana is a traditional Turkish fermented cereal based food, made from wheat flour, bakers’ yeast, yogurt and different vegetables. After fermentation, the tarhana dough is dried and milled. Tarhana powder is most often used in the form of soup. In this study, oat flour (OF) and steel cut oat (SCO) were used to replace wheat flour in the tarhana formulation (control) at the levels of 10, 20, 30 and 40% (w/w). Tarhana with 40% SCO had the highest insoluble dietary fiber (IDF), soluble dietary fiber (SDF) and total dietary fiber (TDF) values, followed by tarhana with 30 and 20% SCO. Control had the lowest beta-glucan content (0.13%) while tarhana with 40% SCO had the highest value (1.50%). As the levels of OF and SCO increased in formulations, beta-glucan contents increased. Results showed that OF and SCO additions improved the nutritional quality of tarhana by causing significant increases in dietary fiber and beta-glucan contents. All of the soups with oat products and control were comparable in terms of the sensory properties. Overall, acceptances of soups were found the best at the sample with 10% OF. It can be concluded that usage of OF and SCO in tarhana did not give negative results in terms of acceptability.

Oat β-Glucan Increased ATPases Activity and Energy Charge in Small Intestine of Rats

Dietary oat or oat products may potentially help to fight against high risk of cardiovascular diseases and β-glucan in oat was considered as a central player. The present study aimed to investigate the effects of dietary oat whole meal or β-glucan on insulin sensitivity and energy metabolism of rats. Rats were fed with control diet, oat whole meal based diet, or control diet with supplemented β-glucan for 4 weeks. Oat whole meal and β-glucan increased insulin sensitivity index. Interestingly, supplementation of oat whole meal or β-glucan induced increases in intestinal Na(+)K(+)-ATPase activity, Ca(2+)Mg(2+)-ATPase activity, and energy charge, particularly in the distal part of small intestine (ileum). Furthermore, amounts of Bifidobacterium and Lactobacillus in colon contents were elevated by oat whole meal or β-glucan. These findings provide an insight into that β-glucan increased insulin sensitivity and benefited intestinal health.

Effect of 6 weeks' consumption of β-glucan-rich oat products on cholesterol levels in mildly hypercholesterolaemic overweight adults

Several regulatory bodies have approved a health claim on the cholesterol-lowering effects of oat β-glucan at levels of 3·0 g/d. The present study aimed to test whether 1·5 g/d β-glucan provided as ready-to-eat oat flakes was as effective in lowering cholesterol as 3·0 g/d from oats porridge. A 6-week randomised controlled trial was conducted in eighty-seven mildly hypercholesterolaemic ( ≥ 5 mmol/l and < 7·5 mmol/l) men and women assigned to one of three diet arms (25 % energy (E%) protein; 45 E% carbohydrate; 30 E% fat, at energy requirements for weight maintenance): (1) minimal β-glucan (control); (2) low-dose oat β-glucan (1·5 g β-glucan; oats low - OL) or (3) higher dose oat β-glucan (3·0 g β-glucan; oats high - OH). Changes in total cholesterol and LDL-cholesterol (LDL-C) from baseline were assessed using a linear mixed model and repeated-measures ANOVA, adjusted for weight change. Total cholesterol reduced significantly in all groups ( - 7·8 (sd 13·8) %, - 7·2 (sd 12·4) % and - 5·5 (sd 9·3) % in the OH, OL and control groups), as did LDL-C ( - 8·4 (sd 18·5) %, - 8·5 (sd 18·5) % and - 5·5 (sd 12·4) % in the OH, OL and control groups), but between-group differences were not significant. In responders only (n 60), β-glucan groups had higher reductions in LDL-C ( - 18·3 (sd 11·1) % and - 18·1 (sd 9·2) % in the OH and OL groups) compared with controls ( - 11·7 (sd 7·9) %; P = 0·044). Intakes of oat β-glucan were as effective at doses of 1·5 g/d compared with 3 g/d when provided in different food formats that delivered similar amounts of soluble β-glucan.

Hypoglycemic Effects and Biochemical Mechanisms of Oat Products on Streptozotocin-Induced Diabetic Mice

Oat products are abundant in β-glucan, which could lower the glycemic index of products or foods. A low glycemic index is beneficial in the control of postprandial glycemia. The study examined the hypoglycemic effects of oat products that had the same percentage of oat β-glucan and were added into the diet fed to streptozotocin-induced diabetic mice for 6 weeks, and potential mechanisms are discussed here. Oat products significantly decreased fasting blood glucose and glycosylated serum protein (p < 0.05), but the hypoglycemic effect was not more than that of metformin (p > 0.05). Oat products increased glycogen, hormone, and nuclear receptor levels (p < 0.05), decreased free fatty acid content and succinate dehydrogenase activity (p < 0.05), and inhibited pancreatic apoptosis (p < 0.05). The results showed oat products had hypoglycemic effects. Hypoglycemic effects of oat products might be regulating glucose and fat metabolisms, stimulating hormone secretion, activating the nuclear receptor, and protecting organ function.

Survey of T-2 and HT-2 toxins by LC–MS/MS in oats and oat products from European oat mills in 2005–2009

T-2 and HT-2 toxins were analysed in oats (n = 243), oat flakes (n = 529), oat meal (n = 105) and oat by-products (n = 209) from 11 European mills during 2005–2009 by high-performance liquid chromatography with a triple quadrupole mass spectrometer. Limits of quantification were 5 µg kg−1 for both T-2 and HT-2 toxins in oats. The incidence of T-2 + HT-2 (>5 µg kg−1) in oats, oat flakes, oat meal and oat by-products was 93, 77, 34 and 99%, respectively. The mean values of T-2 + HT-2 were 94, 17, 11 and 293 µg kg−1 for oats, oat flakes, oat meal and oat by-products, respectively. T-2 and HT-2 occurred together and the T-2 level was 52% of HT-2 in oats. Maximal T-2 and HT-2 concentration in oat flakes and oat meal were 197 and 118 µg kg−1. The toxins were reduced by 82–88% during processing, but increased 3.1 times in oat by-products.

Celiac disease, gluten-free diet, and oats

Oats in a gluten-free diet increase the diet's nutritional value, but their use remains controversial. Contamination with prolamins of other cereals is frequent, and some clinical and experimental studies support the view that a subgroup of celiac patients may be intolerant to pure oats. Thus, this issue is more complex than previously suggested. In order to produce oats that are safe for all celiac patients, the following topics should be addressed: selection of oat cultivars with low avenin content, research on such recombinant varieties of oats, development of assay methods to detect avenins in oat products, guidelines for the agricultural processing of oats and the manufacture of oat products, as well as guidelines for following up with celiac patients who consume oats.

The effects of steaming and roasting treatments on lipase activity and nutritional components of “oat rice” (OR): the peeled naked oat (Avena nuda) kernels

Peeled naked oat kernels, named “oat rice” (OR) by Chinese food scientists and processors, are novel oat products in China. This study exam-ined the effects of steaming and roasting treat-ments on the enzyme activities, nutritional con-tents, and flour pasting properties of OR kernels. Results showed that a peeling time of 20 s caused 16.13% β-glucan loss, while a peeling time 25 s caused 34.29% β-glucan loss in the kernels. OR kernels with a 20 s peeling treatment demonstrated significantly higher starch levels and kernel whiteness compared with normal oat kernels (P<0.01). It was also found that normal pressure steaming, autoclaved steaming and infrared roasting treatments could exterminate lipase activities in the OR kernels, and provide the OR kernels with significantly lower final viscosities and setback values than normal kernels (P<0.01).

Toxicity and risks with T-2 and HT-2 toxins in cereals

The trichothecenes T-2 and HT-2 toxins have during recent years been found frequently in cereals grown in Europe. They are mainly produced by Fusarium langsethiae. High concentrations of the toxins are most commonly found in oats, but they are also detected frequently at lower concentrations in barley. Wheat is only rarely contaminated. Yearly surveys of T-2 and HT-2 toxins in oats from Northern Europe have shown that the occurrence and levels have increased from 2002, with very high levels in 2005-2007, followed by a decrease in 2008-2009. Raw oats delivered to mills for processing to food have also been highly contaminated with T-2 and HT-2 toxins during the period 2006-2009. The processing of oats in the mills by sorting-sieving and dehulling reduce the toxin concentrations in the final food products, flakes and meals, with more than 80 % even at high levels in the raw oat. The concentrations of the toxins in the by-products from the process are instead increased. The by-products are mainly used as feed components. The toxic effects of T-2 and HT-2 toxins in animals and the toxicological information used in the risk evaluations are briefly described. Risk evaluations of the toxins in cereals for human consumption have been conducted by both EU-Scientific Committee on Food and by JECFA in 2001. Both evaluations resulted in the same temporary tolerable daily intake (t-TDI) for the sum of T-2 and HT-2 toxins. The group TDI for T-2 and HT-2 toxins, alone or in combination, became 60 ng/kg bw and day. The intake of T-2 and HT-2 toxins through oats is calculated from median concentrations in oat products and median consumption data from Norway. The intake was found to be 1.5-5.4 % of the t-TDI. The toxic effects studied or expected in farm animals, horses and ruminants, consuming high amounts of oat in their feed are described and discussed.

Aggressiveness of Fusarium langsethiae isolates towards wheat, barley and oats in an in vitro leaf assay

Aggressiveness of Fusarium langsethiae isolates towards wheat, barley and oats in an in vitro leaf assay Fusarium langsethiae has been identified as the primary producer of HT-2 and T-2 in European cereals. HT-2 and T-2 are considered as two of the most potent trichothecenes mycotoxins and a public health concern in Europe. There is currently no legislation on HT-2 and T-2, however, there is a discussion limit of 500 μg kg-1 in unprocessed oats, 200 μg kg-1 for oat products and 50 μg kg-1 for infant food. There are limited data regarding F. langsethiae's pathogenicity and mycotoxin production, but it is evident that its behaviour deviates from traditional trichothecene-producing Fusarium species. This experiment was aimed at assessing the aggressiveness (measured by lesion length) of 20 different F. langsethiae isolates on wheat, barley and oats using an in vitro detached leaf assay. There was a significant (P&lt;0.001) difference between lesion lengths formed by different F. langsethiae isolates used. Isolate Fl/2004/17(a) caused the shortest lesion on all cereals and this was significantly (P&lt;0.001) different from that caused by isolate Fl/0/08/009/1 which caused the longest lesion on all cereals used. A highly significant difference (P&lt;0.001) was also observed between lesions on the different cereals (wheat, barley and oats). Lesions on oats were the longest, followed by barley with wheat showing the shortest lesions.

A Modelling Approach to Estimate the Level and Molecular Weight Distribution of β-Glucan During the Baking of an Oat-Based Bread

Oat and oat products containing β-glucans are associated with many health claims. Both the level and molecular weight of β-glucans play an important role in determining the physiological efficacy of β-glucan in terms of health benefits, including reducing blood cholesterol levels. The objective of this study was to develop a probabilistic model to investigate the effect of various process stages in bread making on the level of β-glucan (BG) and its molecular weight (Mw) distribution using Monte Carlo simulation techniques. Various composite flours were formulated by substituting wheat flour (WF) with oat whole flour (OWF), oat refined flour (ORF), oat bran (OB) or rolled oats (RO). The baseline model predicted an overall mean reduction of 49% in BG in baked bread. The mean Mw of β-glucan in all composite flours was reduced following processing and baking from 1.22 to 0.77 × 106 (g/mol) for OWF + WF, 1.07 to 0.68 × 106 (g/mol) for ORF + WF, 1.17 to 0.75 × 106 (g/mol) for OB + WF and 1.25 to 0.80 × 106 (g/mol) for RO + WF. In all formulated breads, high molecular weight β-glucan was observed to be more susceptible to degradation compared with medium molecular weight and to lower molecular weight. A sensitivity analysis highlighted the negative influence of WF on β-glucan content and the BG reduction with fermentation time. The scenario analysis showed a positive influence on the level of BG with increase addition of oat flour in all formulated breads. The model was validated with experimental data and values were found to be within the confidence interval of predicted BG levels. This model facilitates the optimisation of various steps in the bread making process and highlights the potential for oat flour to improve the nutritional quality of baked bread.

T-2 toxin and HT-2 toxin in grain and grain-based commodities in Europe: occurrence, factors affecting occurrence, co-occurrence and toxicological effects

This paper presents an overview of the occurrence of T-2 toxin and HT-2 toxin in cereals in Europe and derived food products, factors influencing the occurrence, co-occurrence with other trichothecenes, and toxicological effects of T-2 and HT-2 in human. Of all cereals, oats showed to be most susceptible to T-2/HT-2 contamination. Particularly, oats grown in Scandinavia and UK in the period 2003-2007 were highly contaminated. This contamination has reduced in 2008 and 2009. In raw cereals, T-2 and HT-2 levels were highly correlated with each other in most instances, with the HT-2 level being two to seven times higher than the T-2 level. The toxin levels showed not to be correlated with levels of deoxynivalenol and nivalenol. The occurrence of T-2 and HT-2 in the field varied between years, regions, cereal grain varieties, sowing time, and precrop. Organically produced cereals contained lower T-2 and HT-2 levels as compared to conventionally grown cereals. Little or no effects from using fungicides was seen. Processing cereals resulted in low T-2 and HT-2 levels in food products, although oat products contained some T-2 and HT-2. The by-products from food processing, often used for animal feeding, frequently were highly contaminated. T-2 and HT-2 showed to have high acute and subacute toxicity, as they caused haematotoxic, immunotoxic, cytotoxic, and dermal effects. Carcinogenicity of T-2 and HT-2 in human has not been proven. Outbreaks of human toxicosis caused by trichothecenes, including T-2 and HT-2, have been reported. The present overview is deemed to be valuable for risk assessments at the European level, planned to be held by EFSA. It also provides directions for further research, including the ecology of the fungi responsible for T-2 and HT-2, and agronomical practices to reduce the contamination in the field.

Accumulation of Oxygenated Fatty Acids in Oat Lipids During Storage

ABSTRACTOxygenated fatty acids were identified in oat grain by gas chromatography‐mass spectrometry. We hypothesized that most of these were the results of lipoxygenase activity. This hypothesis was tested by measuring concentrations of these compounds after hydrothermal treatments and storage of oat groats or oat flour for 22 weeks at 37°C and 65% relative humidity. Steam treatments inactivated lipases, whereas roasting at 106°C did not. Free fatty acids accumulated quickly in untreated or roasted flour, but not in steamed flour or groats. A total of six hydroxy and epoxy fatty acids were identified. Oxidized fatty acids were found in both esterified lipids and free fatty acids, indicating that lipase action was not necessary for lipid oxidation. More oxidation products were found in flour than in groats, and less were found in the steamed treatments. Lipoperoxygenase appeared to be involved in the formation of oxidation products, although nonenzymatic mechanisms may also operate. Hydroxy‐fatty acids are associated with strongly bitter flavors and are undesirable. Results indicate the importance of enzyme inactivation before storage of processed oat products.

Wheat and gluten in South African food products

Individuals with allergies and intolerances to grain products rely on accurate food labelling to prevent potentially life-threatening reactions. The aim of this study was to evaluate a number of South African food products for gluten and wheat to ascertain whether these products may pose a risk to celiac and/or wheat allergic individuals. Twenty-five products were analysed, including spelt products, flours of buckwheat, barley, rye, rice, millet, maize, semolina, triticale, oats, porridges, rice- and maize-based cereals, and rye bread. The rye and barley flours and two oat products were shown to be contaminated with wheat. Ten out of 17 naturally gluten-free products contained gluten, although in 13 of these the levels were below 20 mg/kg. The labels of four products were found to be misleading in terms of the gluten and/or wheat claims made.

Development and characterization of an oat TILLING-population and identification of mutations in lignin and β-glucan biosynthesis genes

BackgroundOat, Avena sativa is the sixth most important cereal in the world. Presently oat is mostly used as feed for animals. However, oat also has special properties that make it beneficial for human consumption and has seen a growing importance as a food crop in recent decades. Increased demand for novel oat products has also put pressure on oat breeders to produce new oat varieties with specific properties such as increased or improved β-glucan-, antioxidant- and omega-3 fatty acid levels, as well as modified starch and protein content. To facilitate this development we have produced a TILLING (Targeting Induced Local Lesions IN Genomes) population of the spring oat cultivar SW Belinda.ResultsHere a population of 2600 mutagenised M2 lines, producing 2550 M3 seed lots were obtained. The M2 population was initially evaluated by visual inspection and a number of different phenotypes were seen ranging from dwarfs to giants, early flowering to late flowering, leaf morphology and chlorosis. Phloroglucinol/HCl staining of M3 seeds, obtained from 1824 different M2 lines, revealed a number of potential lignin mutants. These were later confirmed by quantitative analysis. Genomic DNA was prepared from the M2 population and the mutation frequency was determined. The estimated mutation frequency was one mutation per 20 kb by RAPD-PCR fingerprinting, one mutation per 38 kb by MALDI-TOF analysis and one mutation per 22.4 kb by DNA sequencing. Thus, the overall mutation frequency in the population is estimated to be one mutation per 20-40 kb, depending on if the method used addressed the whole genome or specific genes. During the investigation, 6 different mutations in the phenylalanine ammonia-lyase (AsPAL1) gene and 10 different mutations in the cellulose synthase-like (AsCslF6) β-glucan biosynthesis gene were identified.ConclusionThe oat TILLING population produced in this work carries, on average, hundreds of mutations in every individual gene in the genome. It will therefore be an important resource in the development of oat with specific characters. The population (M5) will be available for academic research via Nordgen http://www.nordgen.org as soon as enough seeds are obtained.[Genbank accession number for the cloned AsPAL1 is GQ373155 and GQ379900 for AsCslF6]

Characterization of the properties of Pediococcus parvulus for probiotic or protective culture use.

Pediococcus parvulus 2.6 (previously Pediococcus damnosus 2.6, here confirmed as P. parvulus by 16S DNA sequencing) displayed antibacterial activity toward several bacterial species, including isolates found as contaminants in oats, herein genetically identified as Bacillus cereus. No inhibition of Listeria monocytogenes was found under the conditions used. Antibacterial activity was retrieved after ammonium sulfate or acetone precipitation showed it to be peptide mediated. P. parvulus 2.6 has previously shown good technological properties in oat-based products. This, together with the currently found inhibition of food spoilage microorganisms like B. cereus, makes it suitable as a food protective culture. Survival trials of P. parvulus 2.6 at conditions mimicking the gastrointestinal tract were prompted by previously found cholesterol-lowering effects in humans after consumption of oat products cofermented by using P. parvulus 2.6 and Bifidobacterium spp. Viability was measured with in vitro, gutlike simulations at 37 degrees C. High survival was shown under two of three conditions (gastric juice, bile, and small intestine juice), defined as main obstacles of the gastrointestinal tract. The critical step was bile exposure. At a concentration of 20%, viability was low, but 0.3% bile (mean concentration in the intestine) did not have a major influence on growth. Viability of P. parvulus 2.6 was significantly decreased in gastric juice at pH 1.5 (with pepsin), but it was not significantly affected at pH 2.5, and was also improved at a lower pH in 20% oat milk. Viability was judged sufficient for colonization at gutlike conditions, qualifying the strain for further probiotic studies.

Effects of oat bran, processed to different molecular weights of β-glucan, on plasma lipids and caecal formation of SCFA in mice

In the present study, we evaluated the cholesterol-lowering effects of different oat bran (OB) preparations, differing regarding their peak molecular weight (MWp) of beta-glucans (2348, 1311, 241, 56, 21 or < 10 kDa), in C57BL/6NCrl mice. The diets were designed to be atherogenic (0.8 % cholesterol and 0.1 % cholic acid), and they reflected the Western diet pattern (41 % energy fat). All OB preparations that were investigated significantly reduced plasma cholesterol when compared with a cellulose-containing control diet, regardless of the molecular weight of beta-glucan. Moreover, the difference in viscous properties between the processed OB (from 0.11 to 17.7 l/g) did not appear to play a major role in the cholesterol-lowering properties. In addition, there was no correlation between the molecular weight of beta-glucan and the amount of propionic acid formed in caecum. Interestingly, however, there was a significant correlation between the ratio of (propionic acid+butyric acid)/acetic acid and the MWp of beta-glucans: the ratio increased with increasing molecular weight. The results of the present study suggest that the molecular weights and viscous properties of beta-glucan in oat products may not be crucial parameters for their cholesterol-lowering effects.

Simultaneous determination of type A, B and D trichothecenes and their occurrence in cereals and cereal products

A sensitive LC–MS/MS method for the simultaneous determination of type A, B and D trichothecenes in cereals is presented. The limits of detection ranged between 0.1 and 0.7 µg kg−1 for all analytes. The method was applied to 289 representatively drawn samples of wheat, rye and oat products. Ninety-four percent of the wheat samples (n = 130), 95% of the rye samples (n = 61) and 100% of the oat samples (n = 98) were contaminated with the type A trichothecenes T-2 and HT-2 toxin. Median levels of T-2/HT-2 (sum of the toxins) were 0.91, 0.53 and 8.2 µg kg−1, respectively. Highest levels were found in wheat bran (24 µg kg−1), rye kernels (3.1 µg kg−1) and oat flakes (85 µg kg−1). All wheat and rye samples and 75% of the oat samples were contaminated with the type B trichothecene deoxynivalenol. Median levels of this toxin were 23, 15 and 0.53 µg kg−1, respectively. Highest levels were found in wheat bran (1160 µg kg−1), rye kernels (288 µg kg−1) and oat flakes (55 µg kg−1). The type B trichothecene nivalenol was detected in 67% of the wheat samples, in 3% of the rye samples and in 24% of the oat samples with highest levels in wheat bran (96 µg kg−1), rye kernels (1.8 µg kg−1) and in oat flakes (17 µg kg−1), respectively. Levels of other type A and B trichothecenes played a minor role, although the rates of contamination were often high. Neither macrocyclic type D trichothecenes (satratoxin G and H, verrucarin A, roridin A) nor diacetylverrucarol and verrucarol (type A trichothecenes), were detected in any of the samples.

The Green Oat Story: Possible Mechanisms of Green Color Formation in Oat Products during Cooking

Consumers occasionally report greenish colors generated in their oat products when cooking in tap water. Here we have investigated pH and ferrous (Fe(2+)) ion as possible mechanisms for this color change. Steel-cut oat groats can turn brown-green color when cooked in alkaline conditions (pHs 9 to 12). Extraction of this color with methanol, and high-pressure liquid chromatography indicated a direct association of this color with the phenolic acid or avenanthramide content of the oat. The presence of 50 mM NaHCO(3) in water will cause oat/water mixtures to turn alkaline when cooked as CO(2) is driven off, generating OH(-) ion. Although tap water rarely, if ever, contains so much bicarbonate, bicarbonate is used as a leavening agent in baking applications. Industrial interests using baking soda or alkaline conditions during oat processing should be aware of possible off color generation. We have also found that as little as 10 ppm Fe(2+) will turn oat products gray-green when cooked. The aleurone stained darker than the starchy endosperm. Other divalent cations, such as Ca(2+) or Mg(2+) had no effect on cooked oat color. As much as 50 ppm Fe(2+) may be found in freshly pumped well water, but Fe(2+) reacts quickly with oxygen and precipitates as Fe(OH)(3). Thus, some freshly pumped well water may turn oats green when cooked, but if the water is left under atmospheric conditions for several hours, no discoloration will appear in the cooked oats.