Effect of inclusion of soluble and insoluble fibres into extruded breakfast cereal products made with reverse screw configuration

Five dietary fibre rich ingredients were used at 5%, 10% and 15% replacement levels in a white flour cereal base to produce an extruded cereal product. The inclusion of the dietary fibres into the flour bases had no significant effect on the expansion ratio of the products. However, the bulk density of the extruded products increased with inulin addition. The pasting properties of the raw flour and fibre base as well as the extruded products were altered with the incorporation of dietary fibre, with guar gum enriched products showing elevated peak and final viscosity readings. This appeared to be related to moisture manipulation and hence the regulation of gelatinisation. In vitro starch hydrolysis of the raw bases and the extruded samples illustrated that the extrusion process significantly increased the availability of carbohydrates for digestion. Additionally, the inclusion of dietary fibres in the raw bases significantly reduced the rate and extent of carbohydrate hydrolysis of the extruded products. As such the addition of dietary fibres to extruded products reduced the amount of readily digestible starch components of breakfast products, and increased the amount of slowly digestible carbohydrates.     

The Relationship Between Wheat Flour and Starch Pasting Properties and Starch Hydrolysis: Effect of Non‐starch Polysaccharides in a Starch Gel System

Non‐starch polysaccharides (NSPs) and celite (used as inert filler) were incorporated into wheat flour and wheat starch paste preparations at levels of 1, 2.5, and 5% in both addition and replacement modes. Pasting properties of gums were compared using a Rapid Visco Analyser. Use of guar gum and locust bean gum elevated the peak and final viscosities of the resulting pastes (when used in either addition or replacement modes), whereas arabic gum significantly reduced the peak and final viscosity properties of the pastes. Samples which comprised wheat starch yielded higher peak and final viscosity characteristics compared to wheat flour containing samples, however higher breakdown and setback values were observed for samples using wheat flour as a base compared to wheat starch. The firmness of the gels (as determined using a texture analyser) increased with the use of wheat starch compared to wheat flour. Little significant difference was observed between NSP used and mode of application (replacement or addition). In vitro starch degradation was conducted on the wheat flour gels. Guar gum and locust bean gum reduced the amount of starch degradation in these gels, whereas arabic gum and celite increased the amount of starch hydrolysis (or were similar to the control). The rate of starch hydrolysis appears to be related to the viscosity altering behaviour of the NSPs in a starch‐rich system. The results indicate that selection of NSPs is important as gum arabic has the potential to increase starch hydrolysis compared to the control.     

Amaranth,millet and buckwheat flours affect the physical properties of extruded breakfast cereals and modulates their potential glycaemic impact

Three non‐traditional pseudo‐cereal flours (amaranth, buckwheat and millet) were used in the manufacture of extruded breakfast cereal products as a replacement for wheat and maize flour. The use of these flours altered the physical and nutritional quality of extruded breakfast cereals. Extruded products made using the flours exhibited an increased product and bulk density. However the extruded products were not significantly different compared to the control sample in terms of expansion ratio (excepting Amaranth at the 65% inclusion rate). All of the extruded products made with the inclusion of pseudo‐cereals showed a significant reduction in readily digestible carbohydrates and slowly digestible carbohydrates compared to the control product during predictive in vitro glycaemic profiling. The results illustrate the potential use of these non‐traditional cereal flours in lowering the glycaemic response to the ingestion of extruded breakfast cereals.     

Effect of guar gum content on some physical and nutritional properties of extruded products

The effect of guar gum (0-10%) added to flour (maize, potato, rice, and wheat) prior to extrusion on the microstructure, physical properties (texture, expansion, density, pasting) and nutritional properties (starch digestibility) was investigated. The inclusion of guar gum did not decrease starch digestibility; rather, at 10% guar gum rapidly digestible starch increased by 24%, 15%, 25% and 43%, in maize, potato, rice and wheat flour-based products, respectively. In general, increases in starch digestibility appear to be related to the weaker microstructure (i.e., lower textural hardness), larger matrix surface area, and lower viscosity (pasting properties) of extrudates containing guar gum. These results suggest that microstructural changes affect the starch digestibility of extrudates; nevertheless, probably other factors such as particle size during digestion may also play an important role.     

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。     

基于亲水胶体改性和混料设计优化传统粘豆包的配方

目的 用亲水胶体改性和混料设计来优化传统粘豆包的配方, 改善其食用品质。方法 选用3种食品工业中常用的亲水胶体, 卡拉胶、黄原胶和瓜尔豆胶, 对糯玉米与糯大黄米淀粉进行改性, 通过快速粘度分析仪和质构仪比较回生值和硬度的变化, 筛选出复配糯玉米粉和复配大黄米粉作为粘豆包的制作原料, 然后利用混料设计优化粘豆包配方。结果 卡拉胶、黄原胶、瓜尔豆胶对糯性谷物淀粉有着良好的抗老化作用, 回生值都明显变小, 尤其瓜尔豆胶效果最明显; 通过混料设计发现当糯大黄米为33%, 糯玉米粉为24%, 红豆馅为43%时感官评分最高。结论 利用混料设计优化传统粘豆包的生产配方, 感官评分高, 传统粘豆包品质得到改善。     

Protein nutritional value of extrusion-cooked wheat flours

The effect of extrusion cooking on the protein nutritional value of wheat flour and whole-grain wheat flour was studied. Amino acid analysis showed lysine retention between 63 and 100%. The retention was positively affected by an increase in feed rate, and negatively by an increase in screw speed. The prominent lysine damage under severe conditions was probably due to formation of reducing carbohydrates through hydrolysis of starch. The loss of other amino acids was small. The BV of extruded wheat flours was significantly reduced in the products showing the most prominent lysine loss. However, no effect was seen in TD. In contrast, a decrease in BV of extruded whole-grain flour was accompanied by a significant reduction in TD. Extrusion cooking of wheat starch did not affect the nitrogen balance in rats given casein/starch diets containing raw or extruded starch.     

改良剂对面团流变学性质的影响

为了探讨小麦粉改良剂对面团流变学性质的影响,以宁麦15面粉为原料,分别加入不同比例的谷元粉、瓜尔豆胶和变性淀粉,用粉质仪和拉伸仪研究其对面团流变学特性的影响,以期生产出符合市场需求的面条专用粉。利用响应面法中心组合试验设计,采用综合加权评分法评估改良剂对多指标流变学性质的影响。结果表明:各因素对综合加权评分值的影响程度为谷元粉>变性淀粉>瓜尔豆胶,两两因素之间存在相互作用。适宜配粉条件为:谷元粉1.4%、瓜尔豆胶1.5%,变性淀粉2.2%。在此条件下流变学指标的综合加权评分预测值为0.869,验证值为0.856,与预测值的相对误差为1.5%。表明添加适量的改良剂能够显著提高宁麦15面粉的品质特性。     

Maize bran/oat flour extruded breakfast cereal: A novel source of complex polysaccharides and an antioxidant

A maize bran/oat flour extruded breakfast cereal was developed as a novel source of an antioxidant and complex polysaccharides. Six levels of maize bran/oat flour were formulated (0, 10, 20, 30, 40 and 50%, w/w). The breakfast cereal containing 30% maize bran was the most accepted by consumers. A 100 g serving of this cereal formulation provides 0.2 g of ferulic acid, and 8 g of complex polysaccharides, which includes 1.2 g of β-glucans and 6.8 g of arabinoxylans. This cereal breakfast could be an alternative to maize bran, which is a by-product scarcely used for human consumption.     

Wheat (Triticum aestivum L.) Bran in Bread Making: A Critical Review

Wheat bran, a by‐product of the industrial roller milling of wheat, is increasingly added to food products because of its nutritional profile and physiological effects. Epidemiological data and scientific studies have demonstrated the health benefits of consuming bran‐rich or whole‐grain food products. However, incorporation of wheat bran in cereal‐based products negatively affects their production process. Furthermore, the organoleptic quality of the obtained products is mostly perceived as inferior to that of products based on refined wheat flour. This review summarizes the current knowledge on the impact of wheat bran on bread making, provides a comprehensive overview of the bran properties possibly involved, and discusses different strategies that have been evaluated up till now to counteract the detrimental effects of wheat bran on bread making.     

Nutritional and physicochemical characteristics of wholemeal bread enriched with pea flour

In this work, wholemeal bread enriched with hydrated and nonhydrated pea flour was investigated. Moreover, hydrocolloids, such as hydroxypropylcellulose, agar‐agar and guar seed flour, were added to the bread to improve its organoleptic properties. The bread samples were analysed from the nutritional, microstructural and textural properties point of view, and their correlations were also evaluated. Results showed that guar gum at 2% gave the better results. In particular, the overall quality of the bread enriched with hydrated pea flour and guar gum was statistically similar to that of the CTRL reference sample (7.70). The fibres and ash content of all pea‐enriched bread samples were significantly higher compared with the CTRL sample; moreover, all functional bread samples recorded significantly lower glycaemic response with respect to the CTRL sample. In addition, the mixture of both guar gum and hydrated pea flour significantly improved the dough properties and reduced the firmness of the bread.     

四种常见亲水胶体对面团特性的影响研究

采用粉质仪、快速黏度分析仪和流变仪研究添加黄原胶、κ-卡拉胶、魔芋胶和瓜儿豆胶对小麦粉粉质特性、糊化特性及面团流变特性的影响.研究结果表明,亲水胶体可以提高小麦粉的黏度,改善面团的黏弹特性,不同亲水胶体的作用效果存在差异,添加质量分数1%的黄原胶和魔芋胶后小麦粉吸水率分别增大了4.9%和7.9%,添加质量分数1%黄原胶、κ-卡拉胶和瓜儿豆胶后小麦粉糊的糊化温度分别降低了21.35℃、18℃、14.7 ℃,添加黄原胶和瓜儿豆胶能够显著地提高面团的稳定性,而添加魔芋胶能够延缓淀粉的重结晶特性.     

Preparation of resistant starch from starch–guar gum extrudates and their properties

Mixtures of starch, guar gum and citric acid were extruded at a temperature of 150 °C and screw speed of 180 rpm. Properties of the extrudates such as bulk density, expansion ratio, apparent viscosity and resistant starch content were measured with different concentrations of guar gum. Extrusion with citric acid influenced the physical properties and resistant starch content of the extrudate. Expansion ratios were lower for samples extruded with citric acid, and decreased as starch–gum concentration increased. The apparent viscosity of the extrudate increased with increasing guar gum concentration; however, citric acid at 2.0% concentration was found to lower the viscosity of the extrudate. Resistant starch content increased from 6.23% for extruded starch only to 14.21% for starch–gum extrudate, and further enhanced to 16.19% with the addition of 2.0% citric acid to the starch–gum extrudate. Resistant starch increased with increase of gum concentration and decreased with increase of starch–gum concentration from 7.5% to 12.5%.     

Novel use of Acacia senegal (Super Gum™) and Anogeisus latifolia (Gatifolia SD) as functional ingredients in extruded snack products: Their role in manipulating product characteristics and modulating the potential glycaemic response of snack foods

Acacia senegal (in the form of Super Gum™) and Anogeissus latifolia (in the form of gum Gatifolia SD) were used in the manufacture of ready to eat extruded cereal snack products. Inclusions rates were 0, 5, 10 and 15% w/w replacement levels for wheat flour from a control recipe. The inclusion of Super Gum™ and Gatifolia increased product expansion and reduced product density compared to a cereal flour based control snack product. Inclusion of the gum materials also decreased the hardness of the snack products whilst increasing the crispiness of the product (number of fracture peaks recorded during axial compression of samples). Glucose area under the curve (AUC) measurements obtained using in vitro digestion procedures illustrated that the potential glucose release of snack products was reduced by more than 30% by the inclusion of Gatifolia and Super Gum™ at 15% w/w compared to the control sample. Such a reduction in potential glucose release was not dose responsive. These results illustrate a potential nutritional benefit of the utilisation of Gatifolia and Super Gum™ in the ready to eat snack food sector of the food industry.     

Improving storage property of wheat bran by steam explosion

Steam explosion (SE) was exploited for stabilizing wheat bran (WB), and its effects on nutrients retention of WB were investigated. Result showed that SE could effectively inactivate lipase and peroxidase of WB at 0.8 MPa (170 °C) for 5 min while lipid and protein were not loss. Total flavonoids, phenolics contents, soluble dietary fibre content and DPPH radical scavenging activity in WB after SE increased by 198%, 83%, 27% and 21% respectively compared with those after conventional thermal sterilization (0.1 MPa (121 °C) for 20 min), while fatty acid value and peroxide value and insoluble dietary fibre content deceased by 21%, 75% and 24%, respectively. SE inhibited hydrolysis rancidity of wheat bran and reconstituted whole wheat flour (wholemeal) in the accelerated storage test. Therefore, SE may be a new efficient technology that could stabilize cereal bran and further promote its products development.     

Antistaling of rice starch in a gel model system and Korean rice cake: the role of wheat flour in retrogradation-retardation technology

This study focused on the mechanisms of retrogradation-retardation technology for applications in garaetteok (steamed and extruded cylinder-shaped rice cake) production. Based on the comparison of conventional and retrogradation-retardation methods, the addition of raw wheat flour was selected as a key process. The rheological properties of gelatinized rice starch pastes after treatment with raw or autoclaved wheat flour and Novamyl L were investigated. Among them, raw wheat flour and Novamyl L resulted in significantly lowered the elastic modulus. The textural properties of garaetteok treated with raw or autoclaved wheat flour were examined by texture profile analysis (TPA) during storage for 3 days at 4°C. The hardness of garaetteok made with raw wheat flour was maintained for up to three days. In contrast, autoclaved wheat flour did not affect elastic modulus or hardness. As a result, raw wheat flour effectively retards starch retrogradation through starch hydrolysis induced by amylase in wheat flour.     

Effect of water and guar gum content on thermal properties of chestnut flour and its starch

Thermal properties of chestnut flour and chestnut starch at several water content (40, 50, 60 and 95%, flour basis, f.b.) as well as the influence of guar gum (0.5, 1.0, 1.5 and 2.0%, f.b.) on both raw materials at fixed water content (50%, f.b.) were determined by differential scanning calorimetry (DSC). Thermal properties of guar gum–water systems at several guar content (0.5, 1.0, 1.5 and 2.0%, w/w) were also obtained by DSC. Results indicated that the water content and the presence of guar gum had a significant impact on the thermal properties of chestnut flour and its starch. For each endothermic curve, the values of onset (T_o), peaks (T_p1, T_p2) and final (T₁) temperatures decreased linearly with increasing water content. Experimental data were successfully (R² > 0.997) described following the Flory equation. A reverse trend was observed in the enthalpy values. Thermal properties of chestnut flour and chestnut starch were suppressed by the presence of guar gum even at the lowest concentrations employed (0.5%, f.b.). The guar gum addition to the assayed systems promoted a starch gelatinization delay and the enthalpy values showed a threshold content above 1.0% of guar gum. Analyses of aqueous guar gum mixtures showed that the existence of a second transition in chestnut starch systems can be successfully explained by means of hydrocolloid–starch interactions, whereas in the flour other interactions should be taken into account.     

Comparison of baking tests using wholemeal and white wheat flour

Production of whole-grain products can provide more variety in bakery products and might impact positive health effects due to fermentable soluble fibers. To assess technological quality, micro-scale methods using 10 g of white flour are usually carried out, in particular if amount of material or additives is limited. Using wholemeal flour for micro-scale testing might enhance use efficiency of raw material. Up to date, there is no information, whether micro-scale testing of wholemeal flour provides the same information on techno-functionality as classical methods. Two wheat varieties with the same protein concentration but different bread-making performance were used to analyze this aspect. Micro-scale baking test was optimized for wholemeal flour concerning dough consistency and fermentation time. Wholemeal flour reduced loaf volume, but optimization was successful. Although all processing steps of wholemeal baking test were adapted, differences in loaf volume between the two varieties were only present with white flour. Coarse particles in wholemeal flour may be responsible for reduced gas retention. Decreasing particle size of bran material might reduce adverse effects on loaf volume. A micro-scale baking test using wholemeal flour would have several advantages after correct implementation: lower price, less time and material required, direct measurement of quality aspects.     

复合米粉挤压膨化制品配方的研究

以大米为基料,面粉、糯米粉、玉米淀粉、马铃薯淀粉为辅料,采用挤压膨化工艺制作膨化制品,研究了大米粉进料颗粒度、各辅料添加量对膨化制品L值、b值、吸水性、水溶性、容重、硬度等品质指标的影响,筛选出了大米粉最佳进料颗粒度为60目。在此基础上设计正交试验,优选出最佳配方为以大米粉为基准(计为100),辅料配比为面粉25%、糯米粉20%、玉米淀粉15%、马铃薯淀粉15%;利用该配方制得产品的L值为59.69、b值为12.96、水溶性指数为30.95%、吸水性指数为5.08g/g、容重为126.72g/L、硬度为617.3g,产品感官品质优良。     

麦麸膳食纤维火腿肠的研制与营养价值评价

根据食物有机搭配可改善制品的营养、感官和质构品质的基本原理,综合肉类食品及麦麸膳食纤维原料的特点,开展麦麸膳食纤维在火腿肠中的应用研究,试制出了新型麦麸膳食纤维复合火腿肠,其主配方中猪瘦肉占62.7%,麦麸粉占7.5%,淀粉占4.4%.麦麸膳食纤维的添加改善了火腿肠的功能特性,由于同时使用了低钠食盐,与普通型火腿肠相比,麦麸膳食纤维火腿肠的脂肪含量降低了50%、热量降低了20%,氯化钠含量也有所降低,符合清淡(light)食品的第一定义.试制出的复合火腿肠在外观、组织结构、色泽和风味上均可接受,具有良好的质构.为开发利用小麦加工副产品、研制健康功能型肉制品开辟了新途径.