Supplementation of extruded foams with wheat bran: Effect on textural properties

The objective of this study was to investigate the effect of wheat bran concentrations on the mechanical properties determining the texture of extruded carbohydrate matrices. For this wheat flour was extruded under different conditions with an increasing concentration of wheat bran. The mechanical properties were assessed using a threepoint bending test and the cellular structure was determined by micro-computed X-ray tomography. Regardless of the bran concentration, the stress at rupture of the extruded foams was positively correlated with their relative density according to the Gibson-Ashby model. At same relative densities and bran concentration, finer structures with higher density of small cells led to a higher mechanical strength of the foams. Expanded foams with added bran at an intermediate level showed increased mechanical strength. This was attributed to the finer cellular structures obtained.The effect of increasing the bran to a higher concentration on the mechanical properties was depending on the cell wall thickness and bran particle dimensions.     

Exploiting blackcurrant juice press residue in extruded snacks

Extrusion process was developed to exploit blackcurrant juice press residues from industrial side-streams. Press residues obtained from conventional enzymatic pressing, with high content of fiber and seed oil, and novel non-enzymatic juice processing, with high content of sugars, fruit acids and anthocyanins, were extruded with barley flour, oat flour or oat bran. The recipes consisted of blackcurrant press residues (30%), cereal materials (40%) and potato starch (30%) and small amount of sugar and salt. When compared to enzymatic press residue and oat bran, the novel non-enzymatic press residue extruded with barley or oat flour had higher expansion, lower hardness and density, higher redness (a*), lower pH, and higher contents of fructose, glucose and fruit acids, all contributing positively to liking of texture, appearance, and flavor as well as berry-like experience. These characteristics were obtained with more gentle processing parameters, consisting of a lower total mass flow, screw speed and barrel temperature. Female consumers gave lower ratings in flavor, appearance and overall pleasantness for blackcurrant snacks than males. The study presented a sustainable way of utilizing industrial press residues from different processes of berry juice pressing for production of healthy snacks and breakfast cereals.     

Determination of Neutral Detergent Fiber in Breakfast Cereals: Pentose, Hemicellulose, Cellulose and Lignin Content

Cereals are often promoted as important sources of dietary fiber. Ninety one breakfast cereals available in Canada and four unprocessed wheat brans were therefore analyzed for neutral detergent fiber (NDF) after rapid digestion with α-amylase from porcine pancreas. Many breakfast cereals contained less than 5% NDF. Wheat cereals contained 5–30% NDF, oat cereals contained 5% NDF, and corn and rice contained little NDF. Cereal NDF was predominantly hemicellulose (pentosans); pentose sugars liberated under hydrolysis represented up to 15% of processed bran cereals and 20–25% of unprocessed bran.     

挤压改性麦麸膳食纤维对饺子皮品质的影响

分析挤压改性麦麸膳食纤维对饺子皮品质的影响。饺子皮由挤压改性麦麸和饺子专用粉组成的混合粉制成,挤压改性麦麸含量为混合粉的0,1%,3%,5%;通过测试饺子皮的质构特性、蒸煮特性和感官评价,分析挤压改性麦麸对饺子皮品质的影响。结果表明,挤压改性麦麸含量的增加,提高了饺子皮质构特性中的硬度、胶黏性及咀嚼性,降低了蒸煮特性中蒸煮损失率,提高了饺子皮的吸水率;挤压改性麦麸虽可以改善饺子皮的口感,但会影响饺子皮的外观。研究表明当挤压改性麦麸含量为5%时,饺子皮具有良好的综合品质。此研究可为挤压改性麦麸膳食纤维在饺子皮中的应用提供参考。     

改性燕麦麸水溶性膳食纤维对发酵乳品质及抗氧化活性的影响

将微波改性制备、具有良好理化特性的燕麦麸水溶性膳食纤维(Soluble dietary fiber,SDF)添加到发酵乳中,研究改性燕麦麸SDF对发酵乳乳酸菌活菌数、稳定性、pH及酸度、凝乳时间、质构特性、感官品质、储能模量和损失模量、抗氧化活性的影响.结果表明:添加质量分数4％的改性燕麦麸SDF可显著提高发酵乳中乳酸...     

Elastic properties of extruded starchy melts containing wheat bran using on-line rheology and dynamic mechanical thermal analysis

Addition of wheat bran reduces the expansion volumes of extruded cereals. This may be explained by the influence wheat bran has on the elastic properties of the melt. The elastic properties of extruded refined wheat flour supplemented with wheat bran were investigated using a complementary on-line and an off-line rheological technique. The Bagley pressure (end pressure), reflecting extensional properties of the melt, was measured on-line using the orifice die method (dies with different lengths). The storage modulus of the extruded samples was measured using dynamic mechanical thermal analysis (DMTA). Increasing the bran concentration to an intermediate level significantly increased the Bagley pressure likely due to a reduced mobility of starch molecules. Further increasing the bran concentration significantly decreased the Bagley pressure. This might be caused by physical rupture of the melt at the die exit due to the low adhesion properties between starch and bran particles. This change in Bagley pressure indicates that the elastic properties of the composite melt may be reduced by bran particles. The storage modulus measured by DMTA was decreased when increasing the bran concentration, further supporting a potential decrease of the elastic properties of the melt with bran.     

Comparative Effects of Particle Size Reduction on Physical Structure and Water Binding Properties of Several Plant Fibers

Reducing the particle size of AACC wheat bran decreased water-holding capacity, due, in part, to the collapse of its fiber matrix. Physical structure of commercial oat bran collapsed during manufacture and further grinding had limited effect. Physical structure of microcrystalline celluloses and guar gums did not differ between product types. The amount of water held by oat bran and microcrystalline cellulose was increased by reducing particle size. Water binding properties of guar gum were not affected. Physical structure of dietary fiber must be considered if water-binding properties are to be useful predictors of stool bulking efficiency.     

半固态酶解法改性挤压麦麸的制备及其对含麸馒头品质的影响

为提高麦麸中可溶性膳食纤维含量,改善含麸面制品食用品质,使用木聚糖酶对挤压麦麸进行半固态酶解改性处理,并将改性麦麸回添至面粉中制作含麸馒头,探讨改性麦麸最适添加量及其对含麸馒头的比容、质构和风味的影响。结果表明:当酶解时间4 h、木聚糖酶添加量1000 U/g麦麸、液料比1.0:1 mL/g时,改性麦麸中可溶性膳食纤维的含量达到6.24%,与原麦麸相比提高了89.09%;当改性麦麸添加量为7.5%时含麸馒头的比容达到最大（3.08 mL/g）,馒头品质最佳;与原麦麸相比,加入改性麦麸后,馒头的硬度和咀嚼性分别降低了41.19%和42.35%,比容升高了25.00%,均与空白组无显著性差异。麦麸的改性处理不仅有效增加了2-甲基吡嗪等令人愉快的挥发性风味成分浓度,同时降低了二乙二醇、二甲醚等原麦麸的不良风味。因此,挤压麦麸经过半固态酶解处理后,能有效改善含麸馒头的品质,同时使其具有浓郁的麦香味,为麦麸在主食面制品中的应用提供了新思路。     

燕麦麸皮与挤压燕麦麸皮特性比较

对燕麦麸皮和挤压燕麦麸皮进行碱法和酶法水解,并研究最优条件。通过碱解和酶解发现,燕麦麸皮的碱解液和酶解液中的蛋白质含量和β-葡聚糖含量都要高于挤压燕麦麸皮。另外通过傅里叶红外光谱及扫描电子显微镜对燕麦麸皮和挤压燕麦麸皮的微观结构进行分析,发现两者微观结构差别很大,燕麦麸皮的微观结构简单分散,表面平滑平整,而挤压燕麦麸皮的微观结构层次复杂,挤压特征明显,表面粗糙。最后对两者进行美拉德反应,对反应后的提取液进行气相色谱分析,发现燕麦麸皮含有28 种不同芳香物质,挤压燕麦麸皮含有29 种,二者主要芳香物质含量差别较大。     

Effect of Process on Physicochemical Properties of Oat Bran Soluble Dietary Fiber

ABSTRACT:  To evaluate the effects of processes on physicochemical properties of oat bran soluble dietary fiber (OSDF), the oat bran was processed by steam heating, superfine grinding, and extrusion, and extracted to obtain OSDF. The molecular weight distribution, monosaccharide composition, transparency, solubility, structure, and thermal and morphological properties of OSDF were investigated. The yield of OSDF increased after the processing compared to the untreated. The proportion of high molecular weight granules was higher in OSDF from extruded oat bran. The backbone of the OSDF was not changed, but the proportion of the residue linkages in OSDF was varied after the processing. Solubility and swelling power showed significant positive correlation with molecular weight distribution while transparency showed significant negative correlation with molecular weight distribution. Three processes had great impact on the physicochemical properties of OSDF. The OSDF from superfine ground oat bran showed some physical–chemical properties that might be of potential use in the food industry.     

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.     

Effect of the Addition of Different Dietary Fiber and Edible Cereal Bran Sources on the Baking and Sensory Characteristics of Cupcakes

The effect of successively replacing (10%, 20%, and 30%) wheat flour with dietary fiber (DF) from wheat, oat, barley, and maize or cereal bran (CB) from wheat, oat, and rice on cake batter, final cake quality parameters, as well as on product shelf-life was studied. Batter viscosity (control, 2.96; wheat fiber 30%, 20.21; rice bran 10%, 0.47 Pa sⁿ), cake-specific volume (control, 2.27; wheat fiber 20%, 2.83; rice bran 30%, 1.94 cm³/g), porosity (control, 0.75; wheat fiber 30%, 0.81; rice bran 30%, 0.69), and crumb moisture content (control, 20.07%,; wheat fiber 30%, 26.45%; oat bran 30%, 13.89%) increased significantly (P < 0.05) with DF addition but decreased with CB addition. Addition of DF resulted in softer crumb texture (Control, 4.20 N; wheat fiber 20%, 3.19 N), while CB addition increased crumb firmness (rice bran 30%, 10.84 N), respectively. Minor differences were observed in the crumb and crust color of the DF cakes with respect to the control. Addition of CB decreased the L values of crumb color significantly and the decrease increased with increased level of CB incorporation. DF addition led to cakes with greater acceptance by panelists than CB addition, similar to the control. DF cakes stored in polyethylene bags at 25 °C and 60% relative humidity for 6 days showed delayed moisture loss and lower firmness compared to CB cakes. The optimal level of incorporation based both on the objective and sensory characteristics results was found 20% for DF and 10% for CB, respectively. Concluding, by incorporating DF or CB properly, cakes with improved nutritional value can be manufactured.     

不同谷物麸皮对面团流变学特性及面筋蛋白结构的影响

本实验选用小麦麸皮、黑小麦麸皮、燕麦麸皮为原材料,探究在高添加量(质量分数30%)情况下不同谷物麸皮对面团流变学特性、面筋蛋白组成及结构的影响。结果表明,谷物麸皮含有丰富的膳食纤维,麸皮的加入使面团的吸水率、黏度崩解值显著增加,回生值显著降低,面团的形成时间、稳定时间虽与麸皮种类有关,但整体均呈上升趋势;添加麸皮的面筋蛋白中麦谷蛋白与麦醇溶蛋白比例增加了24.7%~73.0%、二硫键含量显著下降了26.0%~35.5%;面筋蛋白中的二级结构以β-折叠为主,小麦麸皮和黑小麦麸皮的加入使得面筋蛋白中的β-转角结构向β-折叠结构转化;扫描电子显微镜图显示麸皮的加入破坏了面筋蛋白原本均匀致密的微观结构。综上所述,谷物麸皮的加入改变了面筋蛋白的组成及二级结构,这些变化可能是导致面团流变学特性及面制品品质下降的原因。     

VARIOUS DIETARY FIBERS DECREASE THE RATE OF LIPASE-CATALYZED HYDROLYSIS OF OLIVE OIL IN VITRO

An in vitro method was used to evaluate the effect of different types of dietary fiber on the initial rate of hydrolysis of olive oil catalyzed by porcine pancreatic lipase. Lipolysis was measured at pH 6.5 and 37C while stirring at 20 rpm. Excellent recoveries of added known amounts of oleic acid were obtained in control and fiber-containing samples. Dietary fibers tested (all 3% by weight unless otherwise noted) were: red wheat bran, white wheat bran, oat bran, soyfiber, sugarbeet fiber, chitin, chitosan, cellulose, pectin-LM and psyllium seed (1.5%). All inhibited lipolysis (35–85%) except cellulose and pectin. The contribution of aqueous extracts of the insoluble fibers to the total inhibitory properties of the fibers were: 0% for the two wheat brans; 100% for oat bran, chitin, chitosan and sugarbeet fiber; and 63% for soyfiber.     

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。     

燕麦麸皮对馒头品质的影响

将不同比例的燕麦麸皮添加到小麦粉中,研究其对面团流变学特性和对馒头品质的影响。实验结果表明,向面粉中适量地添加燕麦麸皮,蒸制出的馒头其体积、质量和风味都有所增加,感官评分提高,表面变得光滑、对称、挺立,具有球形感,且内部气孔细小均匀。燕麦麸皮在不同添加量的条件下所制得的馒头感官评分结果为:燕麦麸皮添加量为5%时,馒头感官评价得分最高。相同添加量下的燕麦麸皮和小麦麸皮所制得馒头感官评分结果为:添加量为5%的燕麦麸皮所制的馒头感官评分结果高于添加量为5%的小麦麸皮所制的馒头感官评分结果。     

膨化麦麸对面团特性及馒头品质的影响

研究了膨化麦麸不同添加量对面团特性、馒头质量及其货架期的影响。结果表明:麦麸经挤压膨化后,脂肪含量略有下降,淀粉、不溶性膳食纤维含量明显下降,可溶性膳食纤维含量显著提高,粗蛋白含量几乎没有发生变化,可溶性成分增多,麦麸的营养组分发生变化;添加适量的膨化麦麸,可改善面团的特性及馒头的品质,增加馒头的体积,提高馒头的含水量,改善馒头的质地,延长馒头的货架期,在本试验条件下膨化麦麸添加量不宜超过8%。     

辅料添加对挤压复配米外观结构、蒸煮食用品质及体外血糖生成指数的影响

本研究通过在原料粉中加入有降血糖功能的菊粉、大豆多糖及燕麦麸等辅料来制备复配米,探讨3 种辅 料添加对复配米的食用品质及体外消化率的影响。结果表明：菊粉可增加复配米的亮度,但当菊粉添加量大于5% 时其蒸煮损失率明显增大。大豆多糖和燕麦麸会降低复配米的亮度,但对其蒸煮损失率影响不显著。质构特性分 析发现复配米硬度均随辅料添加量的增加而降低,菊粉可显著降低复配米的黏性,3 种辅料均对弹性和内聚性影响 不大。3 种辅料添加均使其感官评分降低,其中燕麦麸对感官品质的影响最小。电子鼻检测结果发现,各辅料添加 量低于25%时,复配米气味变化不显著,但当辅料添加量为50%时,复配米气味差异显著。扫描电子显微镜结果表 明,菊粉会使复配米结构变得疏松有孔隙,而大豆多糖和燕麦麸仅在高添加量时使复配米结构出现孔隙。体外消化 测定结果表明,燕麦麸和菊粉添加量在50%,大豆多糖添加量大于35%时,所制备的复配米属于低血糖生成指数食 物。由此可见,不同辅料对复配米食用品质及血糖生成指数影响不同,要根据不同需求选择合适的辅料添加。     

挤压蒸煮加工米糠可溶和不溶膳食纤维对米淀粉性质的影响及其相互作用分析

研究未挤压、挤压蒸煮加工米糠可溶和不溶膳食纤维对米淀粉糊化性质、热性质、回生性质、结晶性质、微观结构的影响,并采用质构分析、核磁共振、傅里叶变换红外光谱等方法探究挤压蒸煮米糠膳食纤维与米淀粉之间的相互作用。结果表明：与未挤压蒸煮加工米糠膳食纤维相比,挤压蒸煮加工米糠可溶和不溶膳食纤维分别使米淀粉的崩解值显著增加了74.09%和128.36%,并均显著降低米淀粉的峰值黏度、谷值黏度、终值黏度、峰值时间、糊化温度。米糠经过挤压蒸煮加工后,米糠可溶膳食纤维使淀粉凝胶的自由水向强结合水转化,米糠不溶膳食纤维使淀粉凝胶的自由水向弱结合水转化。与未挤压蒸煮加工相比,挤压蒸煮加工米糠可溶和不溶膳食纤维分别使米淀粉的回生值降低了62.59%和44.81%,也均降低了米淀粉凝胶的回生率、相对结晶度、硬度、内聚性、回复性、胶黏性、咀嚼性、1 047 cm－1与1 022 cm－1处吸收峰的峰高比,添加挤压蒸煮米糠可溶、不溶膳食纤维的淀粉凝胶表面较光滑,凝胶结构出现较大的裂缝,说明挤压蒸煮加工米糠提高了米糠膳食纤维对米淀粉回生的抑制效果,且挤压蒸煮可溶膳食纤维比挤压蒸煮不溶性膳食纤维效果好。     

小麦麸皮的品质改良及含麸皮面包焙烤品质的研究

本研究采用微波辐照联合复合酶法对小麦麸皮进行改良,将改良后的小麦麸皮添加至高筋粉中得到不同小麦麸皮含量的含麸皮面粉并制作含麸皮面包。结果表明:改良后小麦麸皮中脂肪酶残余酶活和脂肪氧化酶残余酶活降低至0和10.34%、粗纤维含量降低至3.21%、还原糖含量上升至3.79 g/100 g。与改良前的全麦面包相比,改良后的全麦面包组织结构得以改善、全麦面包储藏7d后吸热焓值降低了14.70%、全麦面包中酮基、羰基、醛基含量增多。改良后的全麦面包比容增加了26.40%、硬度降低了32.90%、弹性增大了6.90%。随着改良麸皮添加量的增加,含麸皮面包组织结构变得粗糙多孔,含麸皮面包吸热焓值逐渐降低,酮基、羰基、醛基含量增多,含麸皮面包芯亮度逐渐变暗、比容逐渐降低、硬度逐渐增加、弹性逐渐减小、感官品质降低。与未稳定化麸皮含量16%的全麦面包相比,稳定化全麦面包的稳定性、贮藏性和质构得到明显提高。