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.     

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。     

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.     

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.     

燕麦膳食纤维咀嚼片的工艺研究

以中国裸燕麦的麸皮为主要原料,采用多种现代食品新技术,经挤压膨化、超微粉碎等工艺加工后制成燕麦膳食纤维基料.将燕麦膳食纤维基料、麦芽糖醇、山梨糖醇和低聚异麦芽糖等主要原料,经混合、造粒、干燥、压片等工序加工后,制成低热量,具有调节血脂、血糖,改善肠道环境和润肠通便等保健功能的燕麦膳食纤维咀嚼片.     

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。     

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。     

Changes of phosphorus and trace elements species in rye and oat flakes and oat porridge induced by simulated digestion

Fractionation of chemical species of phosphorus, manganese, iron, nickel, copper, zinc and molybdenum in rye and oat flakes and porridge made of oat flakes was studied by size exclusion chromatography coupled to inductively coupled plasma mass spectrometry. The effect of in vitro simulated digestion of the samples was elucidated by comparison of the digestates and the extracts of the samples (in the Tris–HCl buffer solution, pH = 7.5). The procedure of simulated digestion included two steps: the pepsin-catalysed hydrolysis in diluted hydrochloric acid (pH = 1.7) followed by the pancreatin-catalysed hydrolysis at pH = 7.5. The enzyme-catalysed digestion of the samples results in alteration of iron, copper and zinc species distribution. The species of phosphorus in original cereal samples are distributed between two fractions: a medium-molecular mass fraction (15 kDa) and a low-molecular mass fraction (2 kDa). This pattern is also kept basically in the sample digestates. In digested samples, the majority of soluble iron is bound in a medium-molecular mass fraction (20 kDa), while in the extracts only traces of iron were found in a high-molecular mass fraction. Approximately 90% of the soluble zinc in the digestates of cereal flakes is represented by non-bound zinc ions. The bound zinc is mostly concentrated in a low-molecular mass fraction (1–2 kDa) together with some copper and almost all nickel. The low-molecular mass fractions (1–2 kDa) of nickel, copper and zinc present in extracts of original samples correspond quite well to those in the respective digestates. Molybdenum species occurs in another low-molecular mass fraction.     

EFFECT OF PARTICLE SIZE ON THE WATER SORPTION PROPERTIES OF CEREAL FIBERS1

Six particle size fractions were prepared by grinding and sieving stabilized hard red wheat bran, oat fiber, and corn bran. Water adsorption indices (WAI's) and effective diffusion coefficients (D_eff) were measured for all size fractions. WAI's of wheat bran decreased with particle size. WAI's of oat bran increased as particle size decreased and the WAI's of corn bran fractions did not vary as much as the other fibers. The D_eff's of wheat increased, of oat decreased, and of corn were about the same as the particle size decreased. The wheat D_eff was less than that of corn which was less than that of oats. Monolayer moisture content and bulk moisture content at high A_w were determined from moisture sorption isotherms measured on the smallest particles. There was no difference in the monolayer moistures but both corn and wheat brans adsorbed much more water at high A_w than did the oat bran. Effect of particle size on water sorption and, by inference, some types of functionality cannot be generalized and must be determined for each type of fiber.     

In vitro availability of minerals from oat products

The content of macroelements P, Mg and Ca and microelements Mn, Fe, Zn and Cu was determined in 10 commercially sold oat products made by different technological processes (dehulling, instantinising, extrusion, flaking). Phosphorus was the most prevalent of the macroelements (from 240.8 ± 2.2 to 845.5 ± 8.1 mg per 100 g), followed by magnesium (from 73.2 ± 0.7 to 271.9 ± 2.7 mg per 100 g) and calcium (from 30.69 ± 0.01 to 112.7 ± 0.3 mg per 100 g). The Ca/P ratio ranged from 1:5.3 in crushed oat to 1:8.2 in oat flakes. Regarding the microelements, manganese was present at the highest concentrations (from 2.62 ± 0.02 to 8.69 ± 0.01 mg per 100 g). The content of iron was similar and that of zinc not much lower, whereas the amount of copper was considerably smaller (from 0.23 ± 0.002 to 0.59 ± 0.002 mg per 100 g). The highest concentrations of mineral elements were found in instant oat bran flakes and the lowest in extruded oat and corn crisps containing 50% corn grouts. Samples of the products analysed were subjected to in vitro enzymatic digestion, simulating the digestive process occurring in the human alimentary tract. The supernatants thus obtained were analysed for their content of the previously determined mineral components; the percentage of minerals released from the products was calculated. The following sequence of mineral components released was observed: Cu (57.2–95.6%) > P (39.7–60.9%) > Ca (18.2–39.5%) > Mg (16.4–39.8%) > Mn (6.4–24.7%) > Fe (6.5–29%) > Zn (11–17.2%). The Ca/P ratio in the supernatant worsened from 1:8.2 in crushed oat to 1:23.3 in extruded oat and corn crisps. Crushed oat released the highest amounts of mineral elements during enzymatic hydrolysis, with oat grouts coming second. As regards the other products, it is difficult to establish their relative sequence in the release of minerals. © 2002 Society of Chemical Industry     

复合发酵助剂对燕麦大豆酸奶品质的影响

选用大豆作为主要原料,采用单因素试验和正交试验设计优化燕麦大豆酸奶配方,通过对其pH、酸度、可溶性固形物、持水 力及感官品质的评定,研究燕麦、发酵剂、稳定剂、低聚木糖添加量对大豆酸奶pH、可溶性固形物和感官等品质的影响。 结果表明,燕 麦添加量对结果影响最大,其次为发酵剂,且两水平间存在显著差异（P＜0.05）。 最佳燕麦大豆酸奶配方为燕麦添加量6 g/mL,发酵 剂添加量0.6 g/mL,稳定剂添加量1.8 g/mL,低聚木糖添加量4.2 g/mL。 在此条件下制成的燕麦大豆酸奶品质最佳,感官评分为90分。     

Oat Gum and β-Glucan Extraction from Oat Bran and Rolled Oats: Temperature and pH Effects

The extractability of oat gum from oat bran and rolled oats was studied using 12 treatment combinations in a factorial design (2x3x4x2) i.e. 2 oat products; 3 pH (8.0–10.5); 4 temperatures (5O–70°C); 2 replications. The extraction procedure involved: (a) alkaline treatment of flour and removal of starch residue; (b) isoelectric precipitation of protein residue [namely, protein concentrates (PC)]; (c) and alcohol precipitation of oat gum/β-glucan and collection of gum by centrifu-gation. Extracted oat gum ranged from 2.99–6.28% for oat bran and 1.82–5.24% for rollcd oats whereas β-glucan (in gum) ranged from 70–89% and 50–68%, respectively. Protein contents of the PC from oat bran was 69–91% and rolled oats 66–89%. Correspondingly, starch content of residues ranged from 30–63% and 61–47%. Oat gum/β-glucan extracted at pH 9.2/50°C or pH 10.5/50/55°C showed little or no starch contamination.     

Optimization of Viscozyme L-assisted extraction of oat bran protein using response surface methodology

The study investigated enzymatic pretreatment of oat bran, using Viscozyme L to enhance protein extraction. Response surface methodology (RSM) was used to study the effects of pretreatment variables of Viscozyme L concentration (6–30 FBG), pH (3.0–5.0), incubation time (0.5–2.5 h) and temperature (35–55 °C) on protein extraction from oat bran. The results indicated that the generated regression model represented the relationship between the independent variables and the responses. Protein extraction from oat bran was mainly affected by pH and incubation temperature. From the RSM-generated model, the optimum conditions of enzymatic pretreatment were identified as Viscozyme L concentration 30 FBG/10 g of oat bran, pH 4.6, incubation time 2.8 h and temperature 44 °C. Under the optimum conditions, the predicted protein extracted from oat bran was 55.7%, whereas, the experimental extracted protein was 56.2%. The RSM-predicted and experimental extracted proteins were not significantly different from each other. The enzymatic pretreatment method under the optimum conditions extracted significantly more protein (56.2%) than did the alkaline (pH 9.5) method (14.76%). Viscozyme L pretreatment of oat bran improved protein extraction.     

Isolation and characterization of folate-producing bacteria from oat bran and rye flakes

The aim of this research was to identify endogenous bacteria in commercial oat bran and rye flake products in order to study their folate production capability while maintaining the soluble dietary fibre components in physiologically active, unhydrolyzed form.Fourty-two bacteria were isolated from three different oat bran products and 26 bacteria from one rye flake consumer product. The bacteria were tentatively identified by sequence analysis of the 16S rRNA genes. The identification results revealed up to 18 distinct bacterial species belonging to 13 genera in oat bran, and 11 species belonging to 10 genera in rye flakes. The most common bacterial genus in oat bran was Pantoea, followed by Acinetobacter, Bacillus, and Staphylococcus. Pantoea species dominated also in rye flakes. The extracellular enzymatic activities of the isolates were studied by substrate hydrolysis plate assays. Nearly 80% of the isolates hydrolyzed carboxymethylcellulose, whereas starch-degrading activities were surprisingly rare (10%). Beta-glucan was hydrolyzed by 19% of the isolates. Protease, lipase or xylanase activity was expressed by 24%, 29%, and 16%, respectively, of the isolates. Representatives of the genera Bacillus, Curtobacterium, Pedobacter, and Sanguibacter showed the highest diversity of enzymatic activities, whereas members of Janthinobacterium and Staphylococcus possessed no hydrolytic activities for the substrates studied. Production capability for total folates was analyzed from aerobic cell cultures at the stationary growth phase. The amount of folates was determined separately for the cell mass and the supernatant by microbiological assay. For comparison, folate production was also examined in a number of common lactic acid bacteria. The best producers in oat bran belonged to the genera Bacillus, Janthinobacterium, Pantoea, and Pseudomonas, and those in rye flakes to Chryseobacterium, Erwinia, Plantibacter, and Pseudomonas. Supernatant folate contents were high for Bacillus, Erwinia, Janthinobacterium, Pseudomonas, and Sanguibacter. Compared to the endogenous bacteria, lactic acid bacteria were poor folate producers. The results of this work provide the first insight into the potential role of endogenous microflora in modulating the nutrient levels of oat and rye based cereal products, and pave way to future innovations of nutritionally improved cereal foods.     

瞬时高压作用对麦麸膳食纤维改性的研究

本文就瞬时高压作用(InstantaneousHighProcess)对采用酶-化学法制得的麦麸膳食纤维(oatbrandietaryfiber)的改性作用进行了研究。研究结果表明:经过IHP处理后,麦麸膳食纤维的持水力、膨胀率、结合水力都有不同程度的提高;悬浮溶液的表观粘度增大;可溶性膳食纤维(SDF)含量增加;麦麸膳食纤维的形貌特征发生了很大的变化。     

Effect of Heat Treatments on Chemical Analysis of Dietary Fiber

Apple fiber, corn fiber, oat bran and soy fiber were analyzed to study the effect of heat processing (autoclaving at 121°C/15 min, 100°C/30 min and microwave heating for 5/10 rain) on dietary fiber fractions. Samples were analyzed for insoluble (IDF), soluble (SDF), and total dietary fiber (TDF) by an enzymatic-gravimetric method. Autoclaving reduced IDF of apple fiber and TDF of apple fiber and oat bran. Microwave heating reduced TDF in apple fiber and oat bran and IDF in oat bran but increased the SDF of apple fiber. All treatments decreased the SDF in corn fiber. Effects on dietary fiber fractions depended on fiber type and processing method.     

Effect of micronised oat bran by ultrafine grinding on dietary fibre,texture and rheological characteristic of soft cheese

The purpose of this research was to study the effect of micronised oat bran on dietary fibre, textural and rheological of soft cheese. The soft cheese was processed by using the different particle size oat bran as fibre supplement, and its dietary fibre content, rheological and textural properties were determined. The results show that the micronised oat bran with 5–30 μm particle size was prepared by ultrafine grinding and passed through 60–400 mesh sieves. The soluble dietary fibre content in micronised oat bran soft cheeses was higher than that of the control (untreated oat bran soft cheeses; P < 0.05), with a maximum of 2.65 g per 100 g cheeses when oat bran was ultrafine crushed and passed through 300 mesh sieves, while the content of insoluble dietary fibre was lower than that of the control (P < 0.05). The micronised oat bran soft cheese in fermentation is a typical non-newtonian fluid. G′, G″ and apparent viscosity of soft cheeses were increased with the reduction of oat bran particle size. The chewiness and springiness of micronised soft cheeses were increased with the reduction of oat bran particle size, and were higher than that of the control (P < 0.05). The hardness and cohesiveness of micronised soft cheese were decreased with the reduction of oat bran particle size, the hardness was lower, but the cohesiveness of micronised soft cheese was higher than that of the control (P < 0.05). The 1% micronised oat bran can obtain better processing characteristics and overall acceptability for cheese products.     

Binding of Zinc to Apple Fiber, Wheat Bran, and Fiber Components

Zinc ion binding to commercial brans, fiber, and fiber components was studied by equilibrium dialysis. Maximum initial concentration of zinc bound by 50 ma of apple fiber (AF) and wheat bran (WB) at pH 7.2 was 220 μg. AF and WB binding capacities were significantly lower for soluble fractions than for unfractionated materials. The water-soluble fraction's binding capacity was 90% lower for AF than for WB. Hemicellulase and phytase slightly increased AF binding capacity but reduced WB capacity. Pectinase increased both AF and WB capacity slightly. Binding capacities of commercially available individual fiber components decreased in the order: lignin > polypectin > pectin > gum > cellulose. Zinc-binding capacities of various dietary fiber types differ, accounting for different zinc bioavailabilties of some foods.     

酶法制备小麦麸皮膳食纤维及其功能性质的研究

采用酶法提取麦麸中的膳食纤维。研究发现,基于耐高温α-淀粉酶的去除麦麸附着淀粉的条件为:pH6.5,温度96℃,淀粉酶添加量2%,作用时间2h;筛选得到了1种水解麦麸蛋白质能力较强的商业蛋白酶:Alcalase2.4L,此蛋白酶的去除蛋白质的适宜条件为:pH7.5,温度60℃,蛋白酶添加量1.8%,作用时间3.5h,得到的麦麸膳食纤维纯度>90%,室温下用5%H_2O_2脱色3.5h,最终产品纯度为89.89%。对其功能性质进行进一步研究,结果显示,麦麸膳食纤维的持水力、膨胀力、吸油力随产品粒度的减小而减小,阳离子交换能力随粒度的变化不明显。     

Behaviour of oat globulins in lactic acid fermentation of oat bran

Oat bran fermentation (OBF) is used to produce non-dairy yogurt-type products. Such products may be designed being rich in probiotic bacteria and/or dietary-fibre. Oat bran is, however, also rich in proteins, especially 12 S globulins. Understanding the behaviour of globulins in OBF would thus offer a basis for further exploitation of proteins in the product design. The behaviour of oat globulins was monitored during a model OBF in order to study changes in protein solubility and possible protein hydrolysis. Proteins were extracted from OBF samples with a buffered and a non-buffered extraction procedure. The extracts were analyzed with SDS-PAGE and a Lowry assay. Combined effect of pH and NaCl-concentration on the solubility of oat globulin isolate was studied. The solubility of oat globulins decreased during OBF; this appeared as their shift from the salt-soluble fraction to the residual protein fraction. The shift in oat globulin solubility was due to the acidifying conditions present in OBF, which lead to the unfolding of globulins and also apparently induced protein aggregation. No major protein hydrolysis was observed during OBF.