Original article: Influence of flour mill streams on cake quality

Wheat‐milling process generates different flour streams that differ in particle size, composition and functional and cake‐making properties. Particle size, composition and pasting properties of flour fractions (two from break and three from reduction system) obtained during milling of three wheats varying in protein content were determined. Shape, textural, colour and sensory analyses were performed on cakes prepared with the different mill streams. The final break and reduction streams had the highest protein and ash contents, pasting temperatures and the lowest starch percentage. Cakes prepared with the last streams showed higher batter density and lower volume. These results could indicate good air incorporation but deficient air distribution. Last streams cakes showed a darker, more reddish and yellowish crumb that was significantly related to flour colour characteristics. Because of these differences, such cakes obtained the lowest sensory scores. In this study, it has been verified that, to adapt flours to cake preparation, the final streams should be eliminated. The particle size of each stream is the most determinant parameter to obtain cakes with better volume and texture, being the flours with small particle size the most adequate.     

Use of wheat,triticale and rye flours in layer cake production

In this study, the capacity of obtaining high quality layer cakes from rye and triticale lines was analysed and compared to wheat lines. The samples were characterised considering grain hardness, flour composition and quality parameters as protein, pentosan, damaged starch, pasting viscosity and functional predictive test – solvent retention capacity test. Cakes were analysed in weight, symmetry, volume, volume index (VI) by measuring the height in different points of the cake, crust and crumb colour, crumb structure and texture. Wheat and triticale cakes showed similar characteristics. Rye cakes showed higher volume and lower weight than those with crumbs darker in colour, higher adhesiveness, springiness and resilience. The multiple regression analysis was used to develop an equation for cake volume index prediction. The best‐fit linear regression model was: VI = 14.75 – 0.14 × protein + 0.93 × water soluble pentosan – 0.27 × total pentosan. Despite the differences, high quality cakes can be elaborated with rye, triticale and soft wheat cultivars.     

Hard Winter Wheat and Flour Properties in Relation to Breadmaking Quality of Straight-dough Bread： Flour Particle Size and Bread Crumb Grain

Samples of 12 hard winter wheats and their flours that produced breads varying in crumb grain scores were studied for 38 quality parameters including： wheat physical and chemical characteristics; flour ash and protein contents, starch damage, swelling power, pasting characteristics, and flour particle size distribution; dough properties determined by a mixograph; and breadmaking properties for pup loaves （100g flour）. Only two parameters, the protein content of wheat and the granulation of flour, showed significant correlations with bread crumb grain scores. Protein content of wheat ranging 12.9%- 14.5% determined by an NIR method showed a weak inverse relationship （r =-0.61, p〈0.05） with bread crumb grain score. Flour particle size distribution measured by both Alpine Air Jet Sieve and NIR methods revealed that the weight wt % of particles less than 38 μ m in size and representing 9.6% - 19.3 % of the flour weights was correlated positively （r =0.78, p 〈 0.01） with crumb grain score, whereas wt % of flour particles larger than 125μm had an inverse relationship （r =-0.60, p〈0.05） with crumb grain score.     

Effect of oat β‐glucan and its oxidised derivative on the quality characteristics of sponge cake

The objective of this study was to investigate the characteristics of sponge cakes containing native oat β‐glucan (BG‐B) and its oxidised derivative with TEMPO (2, 2, 6, 6‐tetramethyl‐1‐piperidine oxoammonium ion) (Oxi‐B). BG‐B and Oxi‐B were substituted at 1% (w/w) into a formulation, and then the effects of BG‐B and Oxi‐B addition on the pasting properties of wheat flour and the physicochemical and textural properties of sponge cakes were determined. The pasting parameters of wheat flour were increased by BG‐B, whereas they were decreased in wheat flour with added Oxi‐B. The cake containing Oxi‐B had a lower volume, and a higher symmetry and uniformity than the BG‐B cake. The Oxi‐B cake exhibited smaller L* and b* values and a higher a* value than the control in crumb and crust colour. According to texture profile analysis, the BG‐B cake had increased hardness, chewiness and gumminess, whereas the Oxi‐B cake had decreased hardness.     

不同粒径分布对全籽粒玉米粉糊化特性的影响

分析不同粒径大小分布对不同淀粉含量全籽粒玉米粉糊化特性的影响,为其品质分析和加工提供参考依据。选取淀粉含量66%~77%的玉米,通过小型实验磨研磨得到不同粒径的全籽粒玉米粉,研究粒径大小分布、主要成分、损伤淀粉等指标对糊化特性的影响。结果表明,玉米粉的粒径大小和分布对其糊化能力、凝胶特性影响明显,特别是小颗粒粒径大小影响明显,但对回生老化特性影响不显著。平均粒径和小颗粒粒径越小、颗粒表面积越大时,越容易糊化,峰值黏度也越大,玉米粉间糊化能力差异越显著,总淀粉越多、脂肪和蛋白越少也越容易糊化,峰值黏度也越大;小颗粒粒径越小、比表面积越大,凝胶抗剪切能力越差,玉米粉间凝胶特性差异越明显,总淀粉和损伤淀粉含量升高、脂肪和蛋白质降低,也降低凝胶抗剪切能力;粒径大小与分布对玉米粉回生老化特性影响不显著,总淀粉和直链淀粉增加、脂肪减少,提高凝胶回生能力。     

Influence of Flour Particle Size on Quality of Gluten-Free Rice Cakes

There is a growing interest in developing gluten-free bakery products in recent time. In cake making, gluten network formation is not essential, but hardly any information exists about the influence of the gluten-free flour characteristics affecting the final cake product. This study analyses the influence of two different rice cultivars (short and long) with different flour particle size in batter characteristics (specific volume, viscosity and internal structure) and in sponge and layer cake formulas (volume, shape, texture and colour). During starch gelatinization, the finest flours (median particle size finer than 100 μm) increased their viscosity and reached the peak viscosity (RVA) later than the coarsest flours. Moreover, the finest flours gave batters with lower specific volumes but with an air distribution in smaller and uniform bubbles in both formulas. These flours also produced higher volume and lower firmness in sponge cakes and greater symmetry index both in sponge and layer cakes. The rice type also influenced batter and cakes characteristics but in a lesser extent. The different results obtained depending on the rice flour particle size, type flour and cake formulation indicate the need to define them both in industrial specifications and in research studies.     

Effects of wheat flour particle size on physicochemical properties and quality of noodles

The effect of particle size on the physicochemical and noodle quality of wheat flours was investigated. Granular wheat flour was ground by adjusting the distance between the rolls (0.02, 0.04, 0.06, 0.08, and 0.1 mm) of the flour mill to obtain wheat flour in five different particle sizes. The results showed that milling intensity significantly reduced the particle size and increased the damaged starch content and sedimentation value, but there were no significant differences in protein or ash contents. The reduction of wheat flour particle size significantly decreased the peak viscosity, trough viscosity, final viscosity, breakdown, and setback of the blends, while there were no significant differences in pasting temperature. Stress relaxation characteristics indicated that as the particle size of wheat flour decreased, dough hardness increased. The noodles made from wheat flour with a smaller particle size had a higher water absorption rate and cooking loss rate. Textural profile analysis parameters showed that as the particle size of wheat flour decreased, the hardness, chewiness, recovery, and adhesiveness of noodles showed increasing trends, and there was no significant difference in elasticity. In summary, it is found that the quality of the noodles made by sample C (D₅₀: 78.47 µm) is better.     

Quality variations in flours used for pretzel manufacturing

Research on the flour properties and their influence on pretzel characteristics is scarce. In the first part of the study, flour protein quantity and quality, flour pasting properties and solvent retention properties of 108 flour samples were investigated to help profile the flour properties used by the pretzel industry. Four different flours with a wider protein range than what was revealed in the flour evaluation were selected to produce pretzels and to determine the relationship between flour properties and the final product quality. Pretzel hardness, colour and pasting properties were used as a measure of pretzel quality. Results indicated that hard wheat flour would produce a harder pretzel but would not affect the surface colour of final product. However, soft wheat flour with a lower damaged starch, low water absorption levels and lower water binding powers during operations is desired for making hard pretzel.     

Studies on cake quality made of wheat–chickpea flour blends

Legume flours, due to their amino acid composition and fibre content are ideal ingredients for improving the nutritional value of bread and bakery products. In this study, the influence of the total or partial replacement of wheat flour by chickpea flour on the quality characteristics of two kinds of cake was analyzed. The effects of the chickpea variety and the kind of flour used (white or whole) were also considered. Volume, symmetry, chroma, and crust and crumb L^* diminished when increasing the amount of chickpea flour. The replacement of wheat flour by chickpea flour also induced an increase in the initial firmness but cohesiveness and resilience diminished, increasing the tendency to hardening. Among the studied varieties, Pedrosillano and Sinaloa produced cakes with the highest volume. Those varieties also gave layer cakes with the lowest firmness, gumminess and chewiness. White flours produced sponge cakes with higher volume and symmetry than whole flours. No significant differences, however, were observed in layer cakes between white and whole flours. In both layer and sponge cakes, white flour produced cakes with lower firmness, gumminess and chewiness than whole flours.     

糕点专用粉品质指标的研究

作者研究了国产小麦粉各品质因素对苏式杏仁酥和海绵蛋糕烘焙品质的影响,结果表明,面筋的质和量均有重要影响,α-淀粉酶活力对海绵蛋糕烘焙品质有影响,对苏式杏仁酥则无显著影响,破损淀粉含量对苏式杏仁酥烘焙品质有显著影响,对海绵蛋糕品质影响不大。由现行工艺生产的特一粉细度基本可适应要求。本文还明确了可以用面团流变学试验(Farinograph)中的形成时间、稳定时间、衰落度和评价计值等指标来评价糕点专用粉的品质。最后提出了杏仁酥和海绵蛋糕专用粉的品质控制指标。     

Contribution of lipid to physicochemical properties and Mantou-making quality of wheat flour

Defatted flours of wheat varieties Karl and Jagger, after removing lipids by chloroform, were used to investigate the contribution of lipid to physicochemical properties and Mantou-making quality by comparing microstructure and thermal properties. The results indicated that defatted flours tend to have more single starch granules, higher gelatinization enthalpy, more water absorption, longer pasting peak time, higher peak and hold viscosity, lower setback and breakdown than those of the control. Meanwhile, the defatted flours had improved cooking stability and better ability to withstand mechanical shear stress. The Mantou-making test showed that the volume of Mantou made from defatted flour did not change significantly. C-Cell analyses on the internal crumb grains of Mantou revealed a deterioration in crumb grain characteristics upon removal of lipids from the flours. The grain cells of Mantou became bigger with thicker cell walls upon removal of lipids.     

Cookie- Versus Cracker-Baking—What's the Difference? Flour Functionality Requirements Explored by SRC and Alveography

The many differences between cookie- and cracker-baking are discussed and described in terms of the functionality, and functional requirements, of the major biscuit ingredients—flour and sugar. Both types of products are similar in their major ingredients, but different in their formulas and processes. One of the most important and consequential differences between traditional cracker and cookie formulas is sugar (i.e., sucrose) concentration: usually lower than 30% in a typical cracker formula and higher than 30% in a typical cookie formula. Gluten development is facilitated in lower-sugar cracker doughs during mixing and sheeting; this is a critical factor linked to baked-cracker quality. Therefore, soft wheat flours with greater gluten quality and strength are typically preferred for cracker production. In contrast, the concentrated aqueous sugar solutions existing in high-sugar cookie doughs generally act as an antiplasticizer, compared with water alone, so gluten development during dough mixing and starch gelatinization/pasting during baking are delayed or prevented in most cookie systems. Traditional cookies and crackers are low-moisture baked goods, which are desirably made from flours with low water absorption [low water-holding capacity (WHC)], and low levels of damaged starch and water-soluble pentosans (i.e., water-accessible arabinoxylans). Rheological (e.g., alveography) and baking tests are often used to evaluate flour quality for baked-goods applications, but the solvent retention capacity (SRC) method (AACC 56-11) is a better diagnostic tool for predicting the functional contribution of each individual flour functional component, as well as the overall functionality of flours for cookie- and/or cracker-baking.     

Physicochemical and bread-making properties of air flow pulverized wheat and corn flours

The air flow pulverized grain flours were prepared from American wheat (AWF), Korean wheat (KWF), and corn (CRF) at 3 different grinding speeds, 9,000, 10,000, and 11,000 rpm. The effects of grinding speed on the physicochemical and bread making characteristics of resulting flours were investigated. Pulverization at low grinding speed produced the flour similar to those from conventional milling in particle size (80–100 μm). The higher speed grinding at 11,000 rpm produced grain flours with smaller particle sizes (20–30 μm) and higher amount of damaged starches. Accordingly, grinding speed increased water holding capacity, swelling power, and water solubility of the resulting grain flour, and also increased pasting properties. Gluten addition was needed for KWF (15% gluten) and CRF (30% gluten) to facilitate optimum bread making. The flour pulverized at high speed produced the KWF and CRF bread with the highest loaf volume and the lowest firmness.     

不同粒径小米粉对面团流变特性及馒头质构特性的影响

为研究小米粉添加对面团流变特性和馒头制品质构特性的影响,分别选取不同粒径的粳性和糯性小米粉,利用损伤淀粉测定仪、快速黏度分析仪等对不同小米粉的损伤淀粉含量和糊化特性进行分析,通过流变仪测定小米面团的流变学特性,结合扫描电镜观察小米面团微观结构变化,并利用质构仪测定小米馒头的质构特性。结果表明：随着小米粉粒径的减小,多数品种小米粉（除冀谷39和汇华金米）损伤淀粉的碘吸收率增加;受直支比的影响,相同目数下,粳性小米粉的峰值黏度、谷值黏度、最终黏度和回生值较糯性小米粉大。流变学研究表明,除汇华金米和冀谷39,储能模量与损耗模量随角频率增加总体上升。扫描电镜观察发现小米粉的添加使面团结构更加松散。小米粉的添加会对馒头质构性质中硬度、咀嚼性和弹性等有一定程度的负面影响。主成分分析表明馒头咀嚼性、损伤淀粉、峰值黏度、谷值黏度、最终黏度、崩解值和回生值可作为区分粳糯品种和馒头品质特征的指标。     

Effects of Enzymatic Hydrolysis of Protein on the Pasting Properties of Different Types of Wheat Flour

Abstract: As one of the most effective methods to modify proteins, enzymatic hydrolysis is used widely in the preparation of wheat products in the food industry. During the same process, starch pasting occurs frequently. The effects of wheat protein hydrolysis with papain, pepsin, and trypsin on the pasting properties of 3 different kinds of flour were investigated in 5 concentrations. Results showed that the peak viscosity, trough, final, and integral area of pasting curve of these flours decreased with increasing enzymatic hydrolysis of protein, and decreased significantly with the increasing enzyme concentrations. Medium‐gluten flour was the least sensitive to enzymatic activity and weak‐gluten the most sensitive. Downtrends appeared with increasing papain and trypsin concentrations in the form of breakdown. Enzymes had no significant different effect on the peak times of strong‐ and medium‐gluten flour, but prolonged peak time slightly in weak‐gluten flour. The pasting time and temperature of strong‐ and medium‐gluten flour were significantly increased in a concentration‐dependent manner. However, there were no significant effects on the pasting times of weak‐gluten flour. These results could supply a basis for utilization of enzymatic hydrolysis of wheat protein in food industry and for further studies into the interactions between hydrolyzed protein and starch in food or processing industries. Practical Application: Illuminating the effects of enzymatic hydrolysis of protein on the pasting properties of different types of wheat flour is very important in food industry. Flour viscosity decreases after enzymatic hydrolysis of protein/gluten. Enzymes have different effects on peak time, pasting time, and pasting temperatures for different types of flour. These results could supply a basis for utilization of enzymatic hydrolysis of wheat protein in food industry and for further studies into the interactions between hydrolyzed protein and starch in food or processing industries.     

Adequacy of wholegrain non-wheat flours for layer cake elaboration

Flours (white and wholegrain flours) from wheat, rye, triticale, barley and tritordeum were used to elaborate layer cakes. The pasting properties (RVA) and the water-absorption (doughLab) of flours were analyzed. The batter characteristics (density, G′, G″, tan δ, consistency and flow index), and the cake characteristics (cake volume, crumb and crust colour and texture after 1 and 7 days) were studied. A sensorial evaluation of the cakes was also performed. Wholegrain flours showed higher pasting temperature and water-absorption, but lower peak time and viscosity than white flours. Its batters showed lower density and consistency and higher G′, G″, tan δ and n values. Wholegrain cakes showed lower specific volume, symmetry, colour characteristics, and staling rate but higher initial firmness. Considering the different cereals, barley showed the most different behaviour in flour, batter and cake characteristics. DoughLab analysis was very interesting to understand the adequacy of flours to cake elaboration, since significant correlations were found between water-absorption and specific volume, symmetry and firmness. Little differences in the consumer test were obtained between wheat and non-wheat cakes. Wholegrain non-wheat cakes could be a good alternative to white flour wheat cakes, due to their adequate technological properties and their nutritional advantages.     

Studies of the quality of cakes made with wheat-lentil composite flours

Legume flours, due to their amino acid balance and their demonstrated nutritional benefits, are ideal ingredients to improve the nutritional characteristics of bakery products. We have studied the inclusion of lentil flour on layer and sponge cakes, and its effect on the characteristics of the batter and of the final product. The addition of lentil flours reduced the density of layer-cake batter but increased the density of sponge-cake batter. This effect was greater with the smaller flour-particle size. Adding lentil flour to the formula reduced layer-cake volume, symmetry index, cohesiveness and springiness and increased hardness. In sponge cakes, no clear tendencies were observed in volume or symmetry index, but the total substitution of wheat flour by lentil flour gave rise to harder and less cohesive cakes. The use of lentil flour with a fine particle size increased cake volume but reduced hardness, particularly in sponge cakes.     

半干法磨粉中润米时间对鲜湿米粉的影响

为考察半干法磨粉过程中润米时间对大米粉粉质特性及鲜米粉质量的影响,本研究选用了不同润米时间条件下的大米原料进行半干法磨粉并制备鲜米粉。以可以实现半干法磨粉的24 h润米时间作为阳性对照,分析和比较不同润米时间的大米粉粒径分布、破损淀粉含量、糊化特性等粉质特性以及鲜米粉的蒸煮损失、感官评价等制品品质特性,以确定获得同样效果的最短润米时间。研究结果显示:润米6 h后进行半干法磨粉可以获得与24 h润米时间同样的大米粉粒度分布、破损淀粉含量、最高粘度和最低粘度等粘度特性。用此大米粉制备的鲜湿米粉产品,获得了理想的蒸煮损失率和可接受的感官评分值。以上结果表明,润米6 h是获得如润米24 h同样的大米粉及鲜湿米粉品质特征的理想润米时间。     

萌动小麦生化指标及Mixolab糊化特性的变化

分析了萌动小麦游离氨基酸、蛋白质、水溶性糖类和破损淀粉含量及Mixolab面团糊化特性的变化。小麦萌动后游离氨基酸总量显著增加,蛋白质含量(干基)也增加,Mixolab仪测定的C2稠度谷值、C3淀粉糊化黏度峰值、C4淀粉糊化黏度谷值、C5淀粉回生终点值均减小。小麦萌动前后,水溶性总糖含量、Bacillus amyloliquefaciens蛋白酶(含内切和外切酶)降解产生的游离氨基酸含量对试验的6个品种差异不显著;除1个品种外,试验的其他5个品种水溶性还原糖含量及Aspergillus melleus蛋白酶(仅含内切酶)酶解产生的游离氨基酸含量显著增加。不同品种小麦萌动前后破损淀粉含量增减不一致。结论为小麦发芽后游离氨基酸总量增加、Mixolab面团蛋白质网络弱化程度加大、淀粉糊化峰值和谷值均降低,可以作为芽麦检测的参考依据。     

Effect of damaged starch levels on flour-thermal behaviour and bread staling

The effect of the amount of damaged starch in two different flours (wheat and triticale) on the bread quality and its behaviour during storage has been analysed. Two wheat and one triticale flour cultivars were milled in a disc mill to obtain different levels of damaged starch. Differential Scanning Calorimetry (DSC) and Rapid Visco Analyser (RVA) were used to characterize the flour properties and TA-XT2 textural analyses were made on breadcrumb. The effect of the damaged starch content on the bread firming, the amylopectin retrogradation and starch-pasting properties were studied in order to establish any relationship between damaged starch and bread staling. DSC analysis showed that the damaged starch content changed the thermal behaviour of flour–water mixtures: the higher the levels of damaged starch the lower the starch-gelatinization enthalpy and the higher the melting enthalpy of amylose–lipid complexes. The amount of amylopectin retrogradation and breadcrumb firming increased with the damaged starch content at the beginning of storage time; however, differences were decreasing at final storage time. The flour viscosity during pasting decreased as their damaged starch content increased.