Processing and composition of wild oat groats (Avena fatua L.)

Wild oats, a common weed contaminant in commercial grain, were investigated as a potential food grain since large quantities are recovered in cleaning plants. Pure wild oats were separated effectively from mixed feed oat samples using thickness graders in combination with indent separators. The hulls were removed by impact hullers and air aspiration to yield an attractive groat which could be further processed into oat flakes or milled into flour and bran components.The wild groat contained over 20% protein, 8% lipid and 55% starch, and was rich in essential minerals and vitamins. The yield of flour to bran was 60:40 and their respective protein contents were about 16% and 25%. Since the wild oat proteins, like those in the common groat, contain nearly 4% of lysine and nutritionally adequate levels of other essential amino acids, the wild groat appears to be an excellent alternative source of dietary protein. Specific applications would be as a protein and energy constitutent in infant foods, breakfast cereals and low-allergenic diets, and as a source of oat bran for cardiac patients.     

燕麦研究进展

燕麦,一般分为带稃型皮燕麦和裸粒型裸燕麦两大类,燕麦营养成分包括蛋白质、脂肪、淀粉、膳食纤维、抗氧化物、维生素和矿物质等,现代营养学和医学研究表明,燕麦含有多种活性营养成分,具有降血脂、降血糖、减肥和美容等多种功能。目前有关燕麦研究主要集中在燕麦β-葡聚糖、蛋白、油脂等方面;该文主要讲述燕麦主要成分及其一些应用。     

Flavor chemistry

Abstract

Traditionally, the largest use of oats has been for animal feed. The beneficial nutritional and physiological effects of oat products has generated an increased demand for oats in human nutrition (e.g., reduction of serum cholesterol level by beta‐glucans and other dietary fiber components, high tocopherol and natural antioxidant level). The growing interest in the use of oats and its components for food purposes, together with the advantageous effects of some oat constituents in nutrition, resulted in an increased interest in the study of chemical composition of oats. Our knowledge concerning the oat constituents, particularly biologically active minor components, has rapidly increased. A summary of these results is given in this review.     

Replacement of barley with oats and dehulled oats: Effects on milk production,enteric methane emissions,and energy utilization in dairy cows fed a grass silage-based diet

Sixteen Nordic Red dairy cows, at 80 ± 4.6 d in milk and with an average body weight of 624 ± 91.8 kg, were used in a replicated 4 × 4 Latin square design to investigate the effects of different concentrate supplements on milk production, enteric CH₄ emissions, ruminal fermentation, digestibility, and energy utilization. The cows were blocked into 4 groups based on parity and milk yield and randomly assigned to 1 of 4 experimental concentrates: (1) barley, (2) hulled oats, (3) an oat mixture consisting of hulled and dehulled oats, 50:50 on dry matter basis, and (4) dehulled oats; canola meal was a protein supplement in all 4 concentrates. The cows were fed grass silage and experimental concentrate (forage-to-concentrate ratio 60:40 on dry matter basis) ad libitum. To compare the effects of barley and oats, the barley diet was compared with the overall mean of the hulled oat, oat mixture, and dehulled oat diets. To investigate the effects of gradual replacement of hulled oats with dehulled oats, linear and quadratic contrasts were specified. Milk and energy-corrected milk (ECM) yield were higher on the oat diets compared with the barley diet but were not affected by the type of oats. Concentrations of milk constituents were not affected by grain species or type of oats, except for protein concentration, which was lower on the oat diets than on the barley diet. Feeding the oat diets led to higher milk protein yield and higher milk urea N concentrations. Feed efficiency tended to be higher on the oat diets, and linearly increased with increased inclusion of dehulled oats. Methane emissions (g/d) and CH₄ yield (g/kg of dry matter intake) were unaffected by grain species but increased linearly with increasing inclusion of dehulled oats in the diet. Because of higher ECM yield, CH₄ intensity (g/kg of ECM) was on average 5.7% lower from cows on the oat diets than on the barley diet. Ruminal fermentation was not affected by dietary treatment. Total-tract apparent digestibility of organic matter, crude protein, and neutral detergent fiber was unaffected by grain species but linearly increased with increasing inclusion of dehulled oats. Gross energy content was higher on the oat diets and linearly increased with increasing inclusion of dehulled oats. Feeding the oat diets led to a lower ratio of CH₄ energy to gross energy intake, greater milk energy and heat production but no change in energy balance. Gradual replacement of hulled oats with dehulled oats linearly increased gross energy digestibility, CH₄ energy, metabolizable energy intake, heat production, and energy balance. We observed no effect of dietary treatment on efficiency of metabolizable energy use for lactation. In conclusion, replacing barley with any type of oats increased milk and ECM yield, which led to a 5.7% decrease in CH₄ intensity. In addition, dehulling of oats before feeding is unnecessary because it did not significantly improve production performance of dairy cows in positive energy balance.     

Sorption of copper,zinc and cobalt by oat and oat products

We determined copper, zinc and cobalt sorption by oat and its products under variable pH conditions as well as the content of neutral dietary fiber (NDF) and its fractional composition. Adsorbents in a model sorption system were: oat, dehulled oat, oats bran and oats flakes. Three various buffers (pH 1.8, 6.6 and 8.7) were used as dispersing solutions. Results collected during this study indicate that copper, zinc and cobalt sorption is significantly affected by the type of cereal raw material. Zinc and copper ions are subjected to higher sorption than cobalt ions. Examined metal ions were subjected to high sorption under conditions corresponding to the duodenum environment (pH 8.7( regardless of the kind of adsorbent. A little lower sorption capacity is observed under conditions close to the neutral environment, while the lowest one is found in environment reflecting conditions of stomach juice (pH 1.8). Zinc ions are bound intensively by dehulled oat, while oats flakes bound mostly copper and cobalt, independently on environmental conditions. Contents of dietary fiber in oat, dehulled oat, oat bran and oat flakes were: 40.1, 19.3, 20.3 and 14.3%, respectively. The dominating fraction in all oat products was the fraction of hemicelluloses. The content of remaining fractions varies in dependence on the product.     

Sorption of copper,zinc and cobalt by oat and oat products

We determined copper, zinc and cobalt sorption by oat and its products under variable pH conditions as well as the content of neutral dietary fiber (NDF) and its fractional composition. Adsorbents in a model sorption system were: oat, dehulled oat, oats bran and oats flakes. Three various buffers (pH 1.8, 6.6 and 8.7) were used as dispersing solutions. Results collected during this study indicate that copper, zinc and cobalt sorption is significantly affected by the type of cereal raw material. Zinc and copper ions are subjected to higher sorption than cobalt ions. Examined metal ions were subjected to high sorption under conditions corresponding to the duodenum environment (pH 8.7), regardless of the kind of adsorbent. A little lower sorption capacity is observed under conditions close to the neutral environment, while the lowest one is found in environment reflecting conditions of stomach juice (pH 1.8). Zinc ions are bound intensively by dehulled oat, while oats flakes bound mostly copper and cobalt, independently on environmental conditions. Contents of dietary fiber in oat, dehulled oat, oat bran and oat flakes were: 40.1, 19.3, 20.3 and 14.3%, respectively. The dominating fraction in all oat products was the fraction of hemicelluloses. The content of remaining fractions varies in dependence on the product.     

果蔬燕麦食品营养与开发利用进展

燕麦片是一种营养丰富、方便快捷、易于携带的食品。燕麦食品能基本满足人体所需能量,但维生素和矿物质等成分相对不足,不能满足机体一餐的全部营养需求。果蔬是人体获取维生素、矿物质和膳食纤维的主要来源,与人体健康密切相关,早餐合理摄取一定量的果蔬是身体健康的重要保证。果蔬燕麦食品的开发,能更好地满足人体对营养的需要,为人们提供了更好的早餐选择。本文综述了燕麦的营养保健功能、果蔬燕麦片的开发优势,并对其未来发展趋势进行了阐述,以供果蔬燕麦食品的研究和开发提供参考。     

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.     

Effects of water-saving superabsorbent polymer on antioxidant enzyme activities and lipid peroxidation in oat (Avena sativa L.) under drought stress

BACKGROUND: Drought stress significantly limits oat (Avena sativa L.) growth and productivity. Thus an efficient management of soil moisture and study of metabolic changes in response to drought are important for improved production of oat. The objective was to gain a better understanding of drought tolerance mechanisms and improve soil water management strategies using water‐saving superabsorbent polymer (SAP) at 60 kg ha^?1 under three irrigation levels (adequate, moderate and deficit) using a new type of hydraulic pressure‐controlled auto irrigator. RESULTS: The results showed that the relative water content and leaf water potential (ψ₁) were much higher in oats treated with SAP. Although the SAP had little effect on plant biomass accumulation under adequate and moderate irrigation, it significantly increased the biomass by 52.7% under deficit irrigation. Plants treated with SAP under deficit irrigation showed a significant decrease in superoxide dismutase, catalase, peroxidase, ascorbate peroxidase and glutathione reductase activities in leaves compared with control plants. CONCLUSION: Our results suggested that drought stress leads to production of oxygen radicals, which results in increased lipid peroxidation and oxidative stress in the plant, and the application of SAP could conserve soil water, making same available to plants for increased biomass accumulation and reduced oxidative stress especially under severe water stress. Copyright © 2010 Society of Chemical Industry     

Phenols in spikelets and leaves of field‐grown oats (Avena sativa) with different inherent resistance to crown rust (Puccinia coronata f. sp. avenae)

BACKGROUND: Avenanthramides, health‐beneficial phenols in oats, are produced in response to incompatible races of the crown rust fungus, Puccinia coronata, in seedlings of greenhouse‐grown oats. This study aimed to elucidate whether avenanthramides and/or other phenolic compounds, together with the activities of phenylalanine ammonia lyase (PAL), phenoloxidase (PO) and the avenanthramide biosynthetic enzyme hydroxycinnamoyl‐CoA:hydroxyanthranilate‐N‐hydroxycinnamoyl transferase (HHT), are associated with crown rust infection in mature field‐grown oats. Nine oat (Avena sativa L.) genotypes with wide variation in crown rust resistance were exposed to naturally occurring fungal spores during the growth period. RESULTS: In the spikelets avenanthramides as well as HHT activities were more abundant in the crown rust resistant genotypes, whereas p‐coumaric and caffeic acids were more abundant in the susceptible ones. In the leaves avenanthramides were not associated with resistance. Instead two unknown compounds correlated negatively with the rust score. Phenols released by alkaline hydrolysis and PAL and PO activities were not related to rust infection, either in spikelets or in the leaves. CONCLUSION: Because grains of crown rust‐resistant oat genotypes seemed to have higher endogenous levels of health‐promoting avenanthramides, use of resistant oats may contribute to a food raw material with health‐beneficial effects. Copyright © 2009 Society of Chemical Industry     

Malted and unmalted oats in brewing

Using oats as a raw material in brewing has recently become the focus of increased interest. This is due to research findings that have shown that oats can be consumed safely by coeliac sufferers. It is also a response to consumer demand for products with novel sensory properties. In this study, beer was produced entirely from oat malt, from barley malt and from oat and barley malts mixed with various quantities of unmalted oats. Compared with barley wort, wort made from malted oats provided a lower extract content and had a higher protein content, but a lower free amino nitrogen content (FAN). The oat wort also showed increased viscosity and haze. The addition of unmalted oats during wort production produced significant changes in the physico‐chemical parameters of both oat and barley worts and beers. Unmalted oats caused an increase in wort viscosity and haze, and a reduction in total soluble nitrogen and FAN. Unmalted oats also contributed to lowering the concentration of higher alcohols and esters. Beer made from 100% oat and barley malts exhibited a similar alcohol content. The use of an oat adjunct in both cases resulted in a lower ethanol content. The introduction of enzyme preparations during the production of wort with oat adjunct had many benefits: increased extract content and FAN; a higher volume of wort; and a lower viscosity that led to faster wort filtration. This research suggests that the use of enzymes is necessary to make production using a high proportion of oats in the grist profitable. Copyright © 2014 The Institute of Brewing & Distilling     

Formulation of an oat‐based fermented product and its comparison with yoghurt

In an attempt to develop a fermented, non‐dairy product based on oats, a new kind of oat base, Adavena® M40, was fermented with two different yoghurt cultures. Adavena® M40 is a concentrated liquid (with a dry matter content of 16 or 18%) derived entirely from oats, with maltose as the main carbohydrate source and an intact β‐glucan content. The oat base was heat treated for 5 min at 85 °C prior to inoculation. Additives in the form of stabiliser, fat and flavours were used. Texture, syneresis, colour and sensory parameters were evaluated. Yoghurt was used as a control. The final product had an acidity and viscosity similar to those of yoghurt. Addition of xanthan gum (0.03% w/v) improved the texture and overall appearance of the product. The product had the same texture as yoghurt but showed less syneresis. The mixture was less white than the control. The oat‐based, yoghurt‐like product showed high acceptability in terms of acidity, texture and overall appearance. The addition of flavours resulted in a higher acceptance of the final products by the panellists. The β‐glucan content was still high after the fermentation process. The results indicated the potential for a new, fermentable, oat‐based product with high acceptance and a high final β‐glucan content. © 2001 Society of Chemical Industry     

Fundamental study on the effect of hydrostatic pressure treatment on the bread-making performance of oat flour

The use of sourdough in wheat and rye breads has been extensively studied; however, little is known about its potential effect when baking oat bread. Consequently, the impact of sourdough on oat bread quality was investigated. Two different sourdoughs were prepared from wholegrain oat flour without the addition of starter cultures, by continuous propagation at 28 (SD 28) or 37 °C (SD 37) until the composition of the lactic acid bacteria remained stable. The dominant LAB were identified by sequence analysis of the 16S rDNA isolated from pure cultures. LAB from SD 28 belonged to the species Leuconostoc argentinum, Pedicoccus pentosaceus and Weissella cibaria, while Lactobacillus coryniformis dominated SD 37. The isolated LAB were further used as starter cultures for the production of oat sourdoughs. Fundamental rheology revealed softening of the sourdoughs compared to non-acidified and chemically acidified controls, which could not be attributed to proteolytic activity. Incorporation of oat sourdough into an oat bread recipe resulted in significantly increased loaf-specific volume as well as improved texture, independent of addition level or sourdough type. Overall, the results of this study show that sourdoughs containing lactic acid bacteria isolated from oats have the potential to enhance oat bread quality.     

燕麦膳食纤维的制备工艺及物理特性研究

本文研究了以燕麦麸皮为原料制取燕麦膳食纤维,确定简单经济的的工艺路线,并着重分析了燕麦膳食纤维的物理特性。     

燕麦膳食纤维的制备工艺及物理特性研究

燕麦膳食纤维的制备的工艺要点包括燕麦麸的清理、酶水解处理、碱处理、洗涤、漂白及脱水干燥。提取工艺、碾磨颗粒大小及干燥方法对膳食纤维的物理特性都有影响。     

An electron spin resonance study of radicals induced by radiation in oat (Avena sativa L.)

A detailed electron spin resonance (ESR) investigation of the spectroscopic features and kinetic behaviours over a range of temperatures of the long‐life free radicals induced in a sample of ground oat that had been irradiated with γ‐radiation is reported. Unirradiated ground oat exhibited a weak, broad single‐line ESR spectra centered at g = 2.0048 ± 0.0008. The structure of this radical is unknown and is assigned as radical III in this work. The γ‐irradiation of oats yields radical III and other radical species. Although all these species are stable at 77 K, some of them are very unstable at room temperature. A model based on three radical species (designated I, II and III) was used to describe the room temperature spectra of their decay at room and at high temperatures. Annealing studies at six different temperatures were used to determine the kinetic behaviour and activation energies of the radicals induced by radiation. A dose–response curve was also constructed and it was concluded that ground oat is potentially a good dosimetric material. The presence of an ESR signal after a storage time of 90 days was interpreted as providing an opportunity to distinguish irradiated from unirradiated oats.     

Sensitivity Analysis in Predictive Models for assessing the Level of β-Glucan in Oats and Barley Cultivars Using Meta-Models

Oats and barley β-glucans are well-known for their many health benefits; this has encouraged the food industry to develop new functional foods containing oats and barley. This study aims to develop an advanced sensitivity analysis to analyse and evaluate the most significant model inputs contributing to uncertainty in assessing the level of β-glucan content in harvested oat and barley grains. Two methodologies, nominal value and regression method sensitivity analysis, were adopted. The nominal sensitivity analysis highlighted that cultivar selection is the predominant factor with a correlation coefficient 0.66 for hulled oats and barley cultivars, whereas the correlation was 0.80 and 0.77 for naked oats and hull-less barley, respectively. Advanced sensitivity analysis using regression modelling highlighted that cultivar selection, storage days and germination time (days) were the most important parameters in both the oats and barley model. Regression analysis using the response surface methodology shows that prediction models were found to be significant (P < 0.0001) with low standard errors and high coefficients of determination (R ²  > 0.94). This study shows that regression modelling is an effective tool to highlight the effect of key input variables and their interactive effects on the predictive response of β-glucan in harvested oats and barley cultivars.     

Effects of processing methods (rolling vs. pelleting vs. steam-flaking) of cool-season adapted oats on dairy cattle production performance and metabolic characteristics compared with barley

Several processing techniques can be used to slow the degradation rate in the rumen and thus provide more bypass crude protein (CP) and starch to the small intestine. The aim of this study was to evaluate the effects of processing methods on cool-season adapted oat grain compared with dry-rolled barley grain, when fed as total mixed ration (TMR) for lactating dairy cows. Eight lactating Holstein cows were used in a replicated 4 × 4 Latin square design with 21-d periods and fed TMR with 1 of 4 treatments: dry-rolled oats, steam-flaked oats, pelleted oats, or dry-rolled barley. Dry matter intake (DMI) ranged from 28.19 to 31.61 kg/d and was lower for rolled oats compared with pelleted oats. Despite the nutrient intake being higher for cows fed pelleted oats, those fed rolled oats had the highest milk production and milk fat percentage (49.23 kg/d and 4%, respectively). Ruminal fermentation characteristics were similar across treatments, with only significant differences in concentrations of acetate (lowest for pelleted oats) and total short-chain fatty acids (highest value for rolled barley) and a lower pH for flaked oats at the 9-h and 12-h points. Dietary treatments did not affect total-tract digestibility of dry matter, organic matter, or CP; digestibility of starch was the lowest for rolled barley (89.04%). Measured blood metabolites, urea, glucose, and β-hydroxybutyrate, were not affected by dietary treatment. Purine derivatives and microbial N supply were also unaffected by dietary treatments. Cows fed flaked oat–based TMR showed the lowest N excretion in milk; however, the lack of difference between diets with regard to urinary N and fecal N excretion resulted in no significant changes in N balance between diets. Therefore, rolled oats allow cows to have higher milk production with lower DMI compared with all other treatments in this study.     

Gluten contamination in oat products and products naturally free from gluten

Some countries now allow celiac patients to include oats in their gluten-free diet. Studies have shown that commercially available oats can be contaminated with gluten. The aim of the study was to analyse oat products and products naturally free from gluten to determine the degree of contamination. A total of 88 oat products and 22 products based on maize, rice, millet or buckwheat were analysed, using a commercially available enzyme-linked immunosorbent assay (ELISA) with a monoclonal antibody to gliadin. The ELISA is quantitative with a detection limit of 20 mg/kg gluten. Some of the positive samples were also analysed for the presence of DNA from wheat, barley or rye. Thirteen percent of the oat products had gluten content over 200 mg/kg. Of the products naturally free from gluten 14% had a gluten content over 200 mg/kg. There was a tendency for higher levels of contamination with increased processing. The risk of gluten contamination in oat products as well as in non-gluten cereals must be considered. The level of contamination was in most cases low. The results regarding oats can be compared to those of such cereals as maize, rice, buckwheat and millet.     

Ethnobotanical and phytochemical aspects of the edible herb Coriandrum sativum L.

Coriandrum sativum (coriander) is an edible herb in the family Apiaceae. The leaves, fruits, and stems of C. sativum have long been used as culinary spice due to their favorable odor. Traditional practitioners used this plant for treating different diseases like blepharitis, scabies, aphthous stomatitis, laryngitis, headache, and palpitation. In modern researches, coriander has demonstrated anxiolytic, anticonvulsant, antimigraine, neuroprotective, analgesic, diuretic, hypoglycemic, hypolipidemic, hypotensive, anticancer, and antioxidant activities. Coriander contains a wide range of bioactive phytochemicals among which phenylpropenes, terpenoids, isocoumarins, phytosterols, and fatty acids are the most important. This review provides information about the botanical and ethnobotanical aspects, chemical profile, therapeutic uses in Islamic traditional medicine (ITM), and recent pharmacological studies of coriander effects. The results have shown that coriander and its monoterpenoid compound, linalool, can be considered as potential drug candidates for treating metabolic syndrome and different inflammatory conditions especially neural and CNS diseases.