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.     

燕麦膳食纤维对胃肠道功能影响

除降低血脂和影响血糖反应外,燕麦膳食纤维还表现出其它生理功能,如影响肠道排空,减少营养素吸收,餐后延长饱腹感等;在大肠中,燕麦膳食纤维具有发酵能力,能产生短链脂肪酸,促进一些有益菌生长和增殖,该文综述以上几方面进展。     

Adsorption-isotherm and Effect of Gum Blends on Viscosity and Microstructure of Oat Gum (β-D-Glucan)

Interactions of oat β-glucan/oat gum (OG) in binary mixtures with other gums [xanthan (XG), locust bean (LBG), and guar (GG)] were studied by viscometry at ratios (50/50, 60/40, and 80/20) and concentrations (0.5 and 0.75%). Physical structure changes due to interactions were examined by scanning electron microscopy (SEM). Equilibrium moisture contents (EMC) were observed at relative humidities (RH), 10.5%, 22%, 33%, 44%, 76% and 93%. Water and oil uptake were determined. Viscosity enhancement occurred in OG/LBG (50/50 and 60/40; 0.5%) and OG/XG (60/40; 0.5%) blends, suggesting synergism. Micrographs depicted microstructural homogeneity (single bulk phase) in OG/LBG and OG/XG blends. EMC of OG and GG were 26.1 and 31.6%, respectively, at 93% RH for 2 wk. LBG showed high mold growth at 93% RH. Uptake of water and oil by OG were 2.6 and 2.0 mL/g, respectively.     

燕麦麸中β-葡聚糖的提取、测定及其在面条中的应用

以机械方法分离出含β-葡聚糖高的燕麦麸为原料，采用酶法测定燕麦麸中β-葡聚糖的含量。通过正交实验研究料液比、时间、温度和溶液的pH值对燕麦麸中β-葡聚糖提取率的影响，同时探讨添加燕麦麸对面条烹煮品质及感官品质特性的影响。结果表明：温度对提取率影响最大，其次为料液比、pH值，时间最小；添加适量的燕麦麸(8％～10％)生产功能性保健面条是可行的。     

Hypocholesterolemic Potential of Oat Bran Treated with an Endo-β-D-glucanase from Bacillus subfilis

Oat bran was treated with endo-β-D-glucanases to hydrolyze β(1 ± 3) (1 ± 4)-glucans. Hydrolysis of β-glucans reduced the in vitro viscosity of a suspension of oat bran. Untreated oat bran and hydrolyzed oat bran were incorporated into hypercholesterolemic purified diets and fed to rats for 4 wk; a diet containing cellulose was used as a control. Hepatic cholesterol accumulation was affected by dietary treatment and was less in the oat bran group than in the enzyme-treated oat bran or cellulose groups. Thus, functional properties of (1±3) (1±4)-β-D-glucan, such as viscosity, appear to be related to its hypocholesterolemic potential.     

稻米油对金黄地鼠胆固醇代谢的改善作用

该研究探讨了稻米油对金黄地鼠胆固醇代谢的改善作用。以金黄地鼠为实验对象,研究分别摄入猪油和稻米油对金黄地鼠肝脏中胆固醇代谢的影响,旨在为居民选用食用油提供科学的理论依据。实验选取30只叙利亚金黄地鼠,随机分为2组,分别饲喂15wt%脂肪供能猪油（Lard Oil,LD）和15wt%脂肪供能稻米油（Rice Oil,RD）。每周计算体质量、采食量,饲喂12周后解剖,分离血清后检测生化指标,并取主动脉和肝脏进行HE染色。用RT-qPCR检测肝脏组织中CYP27A1、LDLr、SR-BI、SLC27A5、sulfotransferase 2A1、和AQP8的mRNA表达水平。结果表明：与猪油组相比,稻米油组金黄地鼠血清中LDL-c浓度和肝脏中的TC浓度分别降低了46.78%和41.73%;稻米油能改善肝脏病理形态,降低肝脏的损伤,同时上调金黄地鼠肝脏组织中LDLr、SR-BI、CYP27A1、SLC27A5、sulfotransferase 2A1、AQP8等基因表达,其中LDLr、CYP27A1和AQP8的表达水平上升到2.04倍、2.14倍和2.83倍;这些基因与胆固醇和胆汁酸代谢相关,其表达升高可以降低机体的胆固醇和胆汁酸。结论：与食用猪油比较,稻米油能改善金黄地鼠血脂浓度、减少肝脏的损伤,抑制高胆固醇;稻米油降胆固醇的作用机制在于其能调控肝脏组织中胆固醇和胆汁酸代谢相关基因的表达。     

Characterisation of oat bran products with and without supercritical carbon dioxide extraction

Morphology, starch structures and thermal and pasting properties of oat bran concentrate (OBC) and Nutrim‐OB (NOB), a jet‐cooked oat bran product, with or without supercritical carbon dioxide extraction (SCD) were studied. Oil composition was analysed. OBC had three thermal transitions, starch gelatinisation and two amylose–lipid complex transitions. NOB only had amorphous amylose–lipid transition. SCD significantly decreased gelatinisation temperatures of OBC. Pasting properties, showed NOB had significantly higher peak viscosity and breakdown, with significantly lower final viscosity, setback and pasting temperature compared with OBC. SCD increased peak viscosity for NOB and final viscosity for OBC. Thermogravimetric analysis showed NOB had higher water‐holding capacity (WHC) than OBC, while SCD decreased WHC. Amylopectin molecular weight was 3.4 × 10⁸ for OBC and was significantly lower for NOB (1.4 × 10⁸). Predominant fatty acids were oleic (41%), linoleic (38%) and palmitic (16%). Study showed NOB had different properties from OBC thereby expanding industrial applications.     

裸燕麦麸皮蛋白的提取工艺及理化性质研究

采取裸燕麦麸皮为原料,优化了蛋白提取的工艺条件,并测定了蛋白质的等电点、黏度、热力学性质及原子力形貌观察。在裸燕麦麸皮的蛋白提取工艺中,以NaOH浓度、料液比、提取时间、提取次数、提取温度为单因素进行实验,并用考马斯亮蓝法对蛋白含量进行测定,根据单因素实验结果做正交实验,得蛋白质的最佳提取条件为0.15%的NaOH溶液,料液比1:8,50℃提取4次,每次提取20 min。该条件下,蛋白质的提取率为74.43%,所提取的蛋白质的等电点为4.8。特性黏度为10.22 g/mL,变性温度为61.49℃,原子力显微镜观察呈球状颗粒均匀分布,部分分子抱团聚集,高度为4 nm左右,最高处可达到19 nm。     

燕麦β-葡聚糖对小鼠肠道菌群的影响

目的:研究了两个不同分子量的燕麦β-葡聚糖对小鼠肠道菌群的影响。方法:选用90只昆明种小鼠,随机分成五组(对照组和1～4四个实验组),每组18只;实验1、2组灌胃给予分子量2.6×106的燕麦β-葡聚糖0.25g/kg·d和0.5g/kg·d,实验3、4组给予分子量为3.7×105的燕麦β-葡聚糖的相应剂量,对照组给予等体积生理盐水,灌胃期28d。分别于实验的第14d、第28d和停止灌胃后一周(35d)分析各组小鼠结肠、盲肠、直肠和粪便菌群变化,并在实验结束时观察各组小鼠体重。结果表明:和对照组相比,随着灌胃时间的延长,各实验组均可使小鼠肠道和粪便中的双歧杆菌和乳酸杆菌增值,使大肠杆菌数量减少(p<0.05),相同剂量不同分子量组间差异不大(p>0.05),同一分子量高低剂量组有差异(p<0.05),灌胃28d可使实验组动物体重有所下降。说明燕麦β-葡聚糖具有调节小鼠肠道菌群的作用。     

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。     

Composition and Physicochemical Properties of Chevon Patties Containing Oat Bran

Chevon (goat) meat-based patties were formulated with oat bran (15–50% w/w) and evaluated for nutrient content and physicochemical properties. Moisture, fat, and protein decreased with increased oat bran. Patties containing oat bran had higher concentrations of unsaturated fatty acids and lower cholesterol. Additions of oat bran also reduced sodium and zinc. Soluble and insoluble fiber content of patties increased, while cooking loss and shear force of patties decreased with increased oat bran. Nutritional value of patties was enhanced with minimal composition and texture changes at 15 or 20% oat bran addition.     

燕麦、大麦中β-葡聚糖的酶法测定

用从纤维酶中提纯的β-葡聚糖酶测定了燕麦、大麦样品中的β-葡聚糖。和控制样品的示值相差不超0．1％：和用AOAC方法测定的结果相比，相差不超过0．2％，本文介绍的方法具有和标准方法相比拟的准确度，且费用较少。     

Optimizing Cholesterol Removal in Cream Using β-Cyclodextrin and Response Surface Methodology

Average cholesterol reduction increased as β-cyclodextrin concentration increased, regardless of other factors. The process was optimized using RSM. When β-cyclodextrin addition was 10%, the effect of stirring speed was more noticeable than that of stirring time. When stirring speed was at 1,600 rpm, 94.2% of cholesterol was reduced in 30 min. When stirring time was 20 min, the cholesterol was reduced 97.99% using 15%β-cyclodextrin. When stirring speed was 1,200 rpm, the effect of β-cyclodextrin addition was greater than that of stirring time. Although the percentage of cholesterol reduction varied with different factors and conditions, about 94% of cholesterol was removed from cream.     

Cholesterol Reduction in Liquid Egg Yolk using β-Cyclodextrin

A process to reduce cholesterol in liquid egg yolk using β-cyclodextrin (CD) was optimized by response surface methodology, based on cholesterol reduction and yield. The most important factors influencing cholesterol reduction were dilution of egg yolk to a defined water:solid ratio and CD concentration. In the final process, egg yolk was adjusted to pH 10.5, diluted to a water:solid ratio of 2.9, heated to 50°C, and CD added at a CD:cholesterol molar ratio of 4.0. The slurry was mixed for 6.5 min at 1800 rpm, cooled to 4°C and centrifuged. Cholesterol in the supernatant was reduced by 89.2%. The yield, cholesterol and CD in the final product were adjusted by varying centrifugal force and CD concentration.     

乳酸菌在燕麦基质中生长特性的研究

非乳益生菌食品已成为益生菌食品发展的重要趋势,以燕麦为基质的益生菌食品具有高膳食纤维、低脂肪和无乳糖不耐症等优点。文中研究了乳酸菌在燕麦基质中生长的可行性,并以瑞士乳杆菌(Lactobacillushelveticus)为研究对象,考察了基质的预处理和基质浓度等对乳酸菌生长的影响。研究结果表明,不同的乳酸菌在燕麦基质中的生长能力具有较大差别。利用富含多种营养物和酶的麦芽对燕麦成分进行适当的水解可以促进瑞士乳杆菌的生长。向燕麦糊(燕麦7%,质量分数)中添加1%(质量分数)的麦芽,在60℃水解30 min后,以燕麦为基质,37℃发酵4 h,瑞士乳杆菌生长可达到稳定期,菌体浓度可提高2个数量级,达到108 CFU/mL。发酵后的燕麦糊在4℃下保藏21 d后,活菌数可保持107 CFU/mL。     

燕麦麸添加量对燕麦麸猪肉丸品质的影响

为采用燕麦麸糊替代猪肉丸中部分脂肪以开发最佳的低脂肉丸,本实验对不同燕麦麸添加量对传统猪肉丸的感官品质、色泽、质构、基本成分、风味物质及氧化程度的影响进行研究,从而为低脂燕麦麸猪肉丸的开发提供可行性建议。结果表明：当燕麦麸添加量为3.09%时,燕麦麸猪肉丸感官总评最高。随燕麦麸添加量增加,燕麦麸猪肉丸硬度、咀嚼性显著降低;亮度逐渐减小,红度与黄度增加;脂肪含量显著减少,粗纤维、蛋白质、水分含量增加。根据电子鼻及气相色谱-质谱分析发现,5 组样品的风味差异明显且脂肪氧化产物的含量降低;高效液相色谱分析显示,燕麦麸猪肉丸核苷酸含量并无显著差异,而氨基酸总量显著下降;过氧化值逐渐降低,但硫代巴比妥酸值却增加。综上,燕麦麸添加量对产品各方面的品质具有不同影响,因此,选择适当的燕麦麸添加量（3.09%）能保证燕麦麸猪肉丸综合品质最佳。     

燕麦β-葡聚糖溶液流体性能及其协同增稠效应研究

采用动态流变仪和乌氏粘度计测定动态粘度方法,系统研究燕麦β-葡聚糖流体力学性能和与 其它增稠剂协同增稠效应。     

Effect of an oat beta-glucan-rich hydrocolloid (C-trim30) on the rheology and oil uptake of frying batters

ABSTRACT:  C-trim30, a new β-glucan-rich hydrocolloid containing 32%β-glucan, was obtained by steam jet-cooking and fractionating oat bran concentrates. It was then incorporated into batter formulations to investigate the rheological effects of C-trim30, which were correlated with batter attributes. In steady shear measurements, the use of C-trim30 led to the increase in batter viscosity, while it did not show significant effects on the shear-thinning pattern of batters. Moreover, the increase in the dynamic viscoelastic properties was observed with more contribution to elastic properties because of the high water-holding properties of C-trim30. These rheological characteristics could be correlated with the adhesive properties of batters to a food matrix. In addition, C-trim30 was shown to produce a sample with increased batter pickup, less moisture loss, and reduced oil content. Even, the oil content was reduced by up to 40% when 4% C-trim30 was used in the batter formulations. The combined effects of elevated viscosity, great batter pickup, and reduced moisture loss by the use of C-trim30 contributed synergistically to the reduction of oil content in fried foods.