Optimization of Gluten-Free Bread Prepared from Cornstarch, Rice Flour, and Cassava Starch

ABSTRACT: The proportions of cornstarch, cassava starch, and rice flour were optimized for production of gluten-free bread (with 0% and 0.5% soy flour) to maximize specific volume (Y₁,Y₁'), crumb-grain score (Y₂,Y₂'), and bread score (Y₃,Y₃'). A central composite design involving cornstarch/cassava starch ratio (X₁) and rice flour/cassava starch ratio (X₂) was used, and 2nd-order models for Y₁ and Y₁' were employed to generate response surfaces. The maxima of response surfaces for crumb-grain score and bread score indicate that optimal gluten-free bread can be prepared from 74.2% cornstarch, 17.2% rice flour, and 8.6% cassava starch. Addition of soy flour at the 0.5% level also improved bread texture.     

Comparative study on composite buckwheat dough and steamed bread modified by transglutaminase and ascorbic acid

The effects of transglutaminase (TGase) and ascorbic acid (AA) on the processing properties of composite buckwheat dough (CBD) and composite buckwheat steamed bread were investigated in this study. Both TGase and AA significantly enhanced the peak and trough viscosity of CBD. With the addition of TGase or AA, storage modulus (G′) and viscous modulus (G″) of CBD increased first and then decreased, which was corroborated by data on protein secondary structure. Results revealed TGase and AA promoted protein crosslinking, and that TGase led to a more continuous, smoother dough structure than did AA. TGase and AA strongly affected hardness, adhesiveness and cohesiveness of CBD with a positive aspect. Compared with the steamed bread made with pure buckwheat, that made with composite buckwheat flour with TGase or AA had significantly lower hardness and gumminess rates within 30–60 min but no significant results were noted within 0–30 min.     

乳化剂改善无麸质面包焙烤特性的研究

研究了乳化剂对无麸质面包(米粉、红薯淀粉)比容、硬度、色泽及感官品质的影响。结果表明,添加硬脂酰乳酸钠、蔗糖脂肪酸酯、大豆卵磷脂、分子蒸馏单甘酯可改善无麸质面包的品质,面包比容增大,结构松软,气孔更加均匀,硬度降低,色泽改善,感官品质提高。综合来看,添加0.5g/100g的分子蒸馏单甘酯无麸质面包品质改善最为明显,比容增加16.9%,硬度降低46.9%(24h),面包色泽明显改善,感官品质最好。     

酸性面团对普通面包和豆渣面包品质的影响

利用活性酸奶乳酸菌发酵制作酸性面团，在普通面包与豆渣面包中分别加入30％～40％(以面粉计)的这种酸性面团后，面包体积、口感、风味、保鲜期和营养品质得到了明显改善。     

Physicochemical Properties of Partbaked Breads

In this current study eight partially-baked breads were studied and compared in terms of a number of physicochemical characteristics: moisture distribution, density, RVA patterns, starch gelatinization, and retrogradation, amylose lipid complex formation and X-ray diffraction patterns. The samples were different in terms of total moisture content (from 32 to 38%) and moisture distribution in the cross section of the samples, starch retrogradation level (from 0.9 to 4.5 (J/g)) and RVA patterns. DSC experiments were carried out to determine the level of starch gelatinisation. The results showed that all starch granules in the eight partbaked breads were fully gelatinized under the conditions used and there was no intact starch granules left in the systems. Therefore, the second phase of baking will not be of great importance in terms of setting the structure and texture of the crumb of a product made from partbakaed bread. The role of the second phase of baking will be to a large extent the generation of flavor, crust, and coloration in the bread.     

Optimization of encapsulation of maltogenic amylase into a mixture of maltodextrin and beeswax and its application in gluten-free bread

In this work maltogenic amylase (MAase) was encapsulated into the mixture of maltodexrin and beeswax (BW) for retarding staling of gluten-free bread. The effects of maltogenic amylase (MAase) concentration (8.2, 45, and 82 mg/ml), maltodextrin with dextrose equivalent (DE) 4–7 (MD) (1, 2.5, and 4%) and, BW (1, 2.5, and 4%) on the encapsulation efficiency (EE) of encapsulated enzyme were optimized using RSM. The optimized formulation was MAase with 8.2 mg/ml, MD 4% and BW 1%, leading to the highest EE (79.35%), thus chosen for subsequent experiments. The prepared particles were 1,190.50 nm with PDI of 0.336 and zeta potential of −8.30 mV. Surface morphologies of produced particles were almost spherical with layered appearance. Batter with this formulation led to higher cross over point in frequency sweep than free enzyme-loaded batter. Lower weight loss, higher volume index, darker crust color, whiter crumb color, more aerated microstructure, less hardness in crumb, and higher sensorial acceptability on the first day and during storage period in the breads containing encapsulated MAase was observed.     

响应面法优化混合发酵制作冷冻面团馒头的复合食品添加剂配方

将酵母与酵子按4∶5的质量比混合,研究木聚糖酶、聚丙烯酸钠、双乙酰酒石酸单双甘油酯（diacetyltartaric acid ester of mono(di)glycerides,DATEM）、海藻糖4 种食品添加剂添加量对混合发酵剂制作冷冻面团馒头品质的影响。利用响应面分析法对4 种食品添加剂的配方进行优化。在单因素试验的基础上,进行Box-Behnken试验设计,得到了4 种添加剂对冷冻面团馒头感官总分影响的数学模型和最佳添加量。结果表明,4 种食品添加剂添加量对冷冻面团馒头品质影响顺序为：木聚糖酶＞聚丙烯酸钠＞DATEM＞海藻糖。冷冻面团馒头复合食品添加剂的最佳配方为：DATEM添加量0.15%、聚丙烯酸钠添加量0.05%、木聚糖酶添加量25.73 mg/kg、海藻糖添加量3.65%。在此条件下预期的酵子冷冻面团馒头的感官总分是84.646,实际得分为84±0.74。复合食品添加剂能够改善相同较高扫描频率条件下面团的流变学特性,增大其弹性模量（G’）和黏性模量（G”）。复合食品添加剂能够抑制冰晶的重结晶,减弱冰晶对混合发酵剂和面筋网络结构的破坏,从而提高了面团的加工品质和成品的质量。     

Effect of Carob Flour Addition on the Rheological Properties of Gluten-Free Breads

In this study, the rheological properties of gluten-free doughs from rice flour containing different amounts of carob flour were investigated. Water added changed in response to the carob amount. Dynamic oscillatory and creep tests were performed in order to gain knowledge on the rheological behaviour of doughs, which is essential for the control of the bread-making procedure and the production of high-quality bread. Simple power law mathematical models were developed in order to evaluate the effect of carob and water added in dough rheological behaviour. Creep data evaluation demonstrates that an increase in water content decreased the resistance of dough to deformation and, therefore, dough strength, whereas carob flour increased the elastic character and structure strength of the dough. This was also found in dynamic oscillatory tests. Increased amounts of carob flour led to an increase in bread dough elastic character since fibre addition elastifies and strengthens the dough structure. Moreover, doughs exhibited a solid-like viscoelastic character, with the storage modulus (G′) predominant over the loss modulus (G″). Dough rheological properties have an important effect on baking characteristics. Rheological experiments and applied mathematical models can provide us with good knowledge of rheological behaviour and dough viscoelasticity prediction. Therefore, dough samples containing carob-to-water ratios of 10:110 and 15:130 can be considered to possess a balance between the viscous and elastic properties compared to the other samples.     

复合菌发酵苦荞麸皮馒头的工艺优化

选取从酸面团筛选的酵母YCY5-2,ZKY7-1及乳酸菌YCL7-3,ZKL10-4进行组合发酵苦荞麸皮馒头,以馒头黄酮含量和感官评定分数作为指标,筛选出发酵苦荞麸皮馒头的最适菌种组合。实验采用响应面法对菌株比例,菌株接种量,发酵时间和醒发时间进行了优化。结果表明:最佳组合菌种为YCY5-2和ZKL10-4,苦荞麸皮添加量为20%,最佳工艺条件为YCY5-2∶ZKL10-4=2∶1,菌种添加量为3%,发酵时间为5 h、醒发时间40 min。此条件下苦荞麸皮馒头黄酮含量为（211.33±1.34）mg Rutin/100 g,感官评分为（82.2±2.30）。与安琪酵母发酵的苦荞麸皮馒头的黄酮含量（（189.70±3.66 mg）Rutin/100 g）,感官评价（77.1±1.4）及质构相比可知,复合菌馒头的功能和品质均比安琪酵母的好。结论:复合菌发酵的苦荞麸皮馒头具有开发利用的价值。      

Quality of Gluten-Free Bread Formulations Baked in Different Ovens

The objective of this study was to determine the effects of different tigernut flour/rice flour ratios (0:100, 5:95, 10:90, 15:85, 20:80, and 25:75) on quality of gluten-free bread formulations baked in infrared–microwave combination and conventional ovens. The degrees of the starch gelatinization of breads baked in different ovens were also compared. Conventionally baked breads prepared with tigernut flour/rice flour ratio of 10:90 and the infrared–microwave combination-baked breads prepared with tigernut/rice flour ratio of 20:80 had the most acceptable firmness and specific volume values. These breads had also similar color. Tigernut flour had significantly higher gelatinization temperatures and lower gelatinization enthalpy (ΔH_g) values than rice flour (p?≤?0.05). As rice flour was replaced with tigernut flour, lower ΔH_g values were observed in dough samples. Breads baked in both conventional and combination oven had sufficient starch gelatinization degrees ranging from 91% to 94% and from 84% to 85%, respectively.     

Effect of hydrocolloids on gluten‐free batter properties and bread quality

The objectives of this study were to assess the effect of the addition of different hydrocolloids on gluten‐free batter properties and bread quality and to obtain information about the relationship between dough consistency and bread quality. Breads were made of rice, corn and soy flours and 158% water. Following hydrocolloids were added: carrageenan (C), alginate (Al), xanthan gum (XG), carboxymethylcellulose (CMC) and gelatine (Gel). Batter consistency, bread specific volume (SV), crumb analysis, crust colour, crumb hardness and staling rate were determined. Hydrocolloids increased batter consistencies: the highest value was obtained with XG, which doubled that of control batter, followed by CMC. Breads with hydrocolloid presented higher SV than control, especially with XG whose SV was 18.3% higher than that of control bread. A positive correlation was found between SV and batter consistency (r = 0.94; P < 0.05). Crumbs with Gel, XG and CMC presented higher cell average size. XG and CMC crumbs looked spongier. Breads containing hydrocolloid evidenced lighter crusts. Crumb firmness was decreased by XG and CMC addition, and staling rate was slower. Overall, XG was the hydrocolloid that most improved gluten‐free bread quality. These results show that, in formulations with high water content, batter consistency is strongly associated with bread volume.     

Improving Carob Flour Performance for Making Gluten-Free Breads by Particle Size Fractionation and Jet Milling

Many different raw materials have been proposed for producing nutritious gluten-free breads, but rarely, there is a parallel analysis of the effect of physical treatment on those ingredients. The aim of this study was to incorporate carob flour fractions of varying particle size on rice gluten-free breads prepared with carob/rice (15:85) flour blends. Carob flour particle size was controlled by fractionation or jet milling application. Quality features of gluten-free breads containing carob flour and commercially available gluten-free breads were compared. Carob flour addition led to breads with improved colour parameters, crumb structure, retarded firming and lower moisture loss compared to rice bread. Further improvement in specific volume, crumb hardness, protein and ash content and estimated glycaemic index (eGI) could be obtained by a careful selection of the particle size distribution of the carob flour. Carob breads prepared either with the coarsest or the finest fraction prepared using jet milling led to end products with the highest specific volume (≈2.2 g/cm³) and the lowest crumb hardness (≈5.5 N), although they had lower specific volume and harder crumbs than breads from commercial blends (≈3–4 g/cm³, 0.6–3.8 N). Nevertheless, rice-based bread made with the finest carob flour was superior considering its slower firming, protein content and lower eGI. The incorporation of carob flour obtained by jet milling in rice-based gluten-free breads led to end products with quality characteristics and sensory acceptance resembling commercial breads and high nutritional value.     

无麸质大米面包研究进展

开发大米面包不但可以丰富中国大米类产品的花色品种,还能解决麸质过敏人群对饮食多样化的需求。由于无麸质大米面包中不含面筋蛋白,在制作过程中存在面团难以形成有效的网络结构、不易成型、品质差(持水性、持气性、弹性和内聚性)、老化速率快等缺点。近年来,研究人员通过改进工艺条件、添加品质改良剂等方法,对无麸质大米面包品质进行改善,文章简述了无麸质食品的相关标准和大米面包使用的原料,并介绍了其工艺和品质改良研究进展,以期为无麸质大米面包的产业化开发提供参考。     

Assessing Influence of Protein Source on Characteristics of Gluten-Free Breads Optimising their Hydration Level

Most gluten-free products have lower protein content than their counterparts with wheat flour. The addition of exogenous proteins could not only be a good option to compensate for this reduction but also a tool to create gluten-free products rich in protein. However, the different water-binding capacities of proteins modify dough rheology, which also affects bread volume. Therefore, this study aimed to analyse the incorporation of a high percentage (30%) of several proteins (rice, pea, egg white and whey protein) in gluten-free breads whose hydration levels were adjusted for each protein to achieve the maximum volume. In this way, the breads with vegetal proteins required a higher amount of water than the breads with animal proteins. Moreover, all enriched breads exhibited lower maximum volume values than control, and the ones with whey protein presented the lowest volumes overall. From these results, the rheological behaviour and characteristics (colour, texture and weight loss) of optimised doughs and breads were measured. The doughs with whey protein presented the highest G′ and G″ values due to their low hydration level, and the ones with egg white protein were very watery. Regarding colour, the addition of protein led to darker crusts, with the ones with whey protein being the darkest. With respect to the control, breads with animal proteins exhibited higher hardness, especially with whey protein, while the ones with vegetal proteins did not present significant differences.     

Sensory Analysis of Whole Wheat/Soy Flour Breads

ABSTRACT: Breads containing 0% to 40% defatted soy flour, 35% to 100% whole wheat flour, and 0% to 35% white bread flour were prepared. Beany or bitter flavor ratings for the yeast-leavened breads containing up to 30% soy flour were not significantly different from the control whole wheat bread. A high-quality yeast was the most important factor in reducing the beany taste of the bread. Addition of ascorbic acid significantly increased yeasty flavor, and there was a strong inverse correlation between beany and sweet flavors. These studies suggest that an appealing, nutritious bread containing up to 30% to 40% soy flour can be prepared in an easy and economical manner using equipment available in home or institutional kitchens.     

HPMC、CMC对无麸质面包特性影响的研究

本文采用纯的米粉和红薯淀粉为原料来制作无麸质面包,研究了羟丙基甲基纤维素(HPMC)、羧甲基纤维素(CMC)对无麸质面包的比容、失水率、表皮颜色、硬度和弹性的影响,并从感官上对面包的品质进行了评价。实验结果表明:与空白样相比,添加2%CMC的面包比容增加最多为22%,添加2%CMC面包的黄色指数增加最多为37%,添加1%CMC面包的失水率减小了7%。面包放置24 h、48 h后,含1%CMC的面包硬度变化率减少最多分别为18%、21%,含1%HPMC的面包弹性变化率减少最多分别为18%、19%。     

Development of Gluten-Free Muffins made from Breadfruit and Unripe Plantain Flours

Inclusion of breadfruit (BF) and unripe plantain (UP) in gluten-free muffins was investigated along with a 1:1 BF/UP blend muffin and compared to controls made with gluten-free rice (RI) or traditional wheat (WH) flour. The alternative flours had a 10% higher fibre content than WH and 2%–4% higher than RI flours. Muffin batter viscosity of RI and WH was initially much lower (3-10 times) than UP, BF and BF/UP blend batter. Additionally, starch gelatinisation temperature was increased by 4%–14% for batter made from BF or UP flours, which can provide structural benefits to baked muffins. Muffins made with BF/UP were the hardest (34.7N), followed by BF (31.7N) and RI muffins (30.7N), with UP (28.4) and WH muffins (26.9N) being the softest. Interestingly, overall acceptability of gluten-free muffins showed that both BF/UP and BF flour muffins scored significantly higher than UP and RI muffins indicating their commercial potential.     

微波复热速冻馒头保水剂及其对质构的影响

以速冻馒头为研究对象,以海藻酸钠、结冷胶、硬脂酰乳酸钙(CSL)等几种改良剂为原料,研制了一种速冻馒头保水剂的配方,以提高馒头微波复热后的品质。响应面优化试验结果表明：速冻馒头保水剂的最佳配方为海藻酸钠0.37%、结冷胶0.15%、CSL 0.21%。验证实验表明,在此条件下速冻馒头微波复热后质量损失率为6.02%,接近预测值6.01%,说明该配方可靠。     

Changes in the Physicochemical Properties of Wheat- and Soy-containing Breads During Storage as Studied by Thermal Analyses

ABSTRACT: Adding soy ingredients to baked products influences textural and sensorial properties. The changes in physical properties of bread modified with soy flour during 7-d storage at ambient temperature were investigated using thermoanalytical techniques (differential scanning calorimetry and dynamic mechanical analysis). An increase in loaf density, moisture content, and FW content, and a decrease in amylopectin recrystallization were observed with increased addition of soy flour. Addition of soy shifted the main thermal transition (0 °C, mainly due to ice melting) to slightly lower temperatures (both in differential scanning calorimetry and dynamic mechanical analysis analysis) and decreased its temperature range (increased homogeneity). These observations suggest a role for soy in modulating bread staling.     

A Study on Staling Characteristics of Gluten-Free Breads Prepared with Chestnut and Rice Flours

The effects of chestnut flour and a xanthan–guar gum blend–DATEM mixture on staling of gluten-free rice breads baked in conventional and infrared–microwave combination ovens were studied. Staling properties of the bread were assessed using mechanical compression (TA), differential scanning calorimetry, X-ray diffraction, and fourier transform infrared spectroscopy (FT-IR). Hardness, moisture loss, and retrogradation enthalpy values for all bread samples increased significantly during storage. FT-IR spectra showed that the integrated area of peaks around 1,041 and 1,150 cm^?1 wave lengths, which are related to the structure of starch retrogradation, increased with storage time. The X-ray diffractograms of aged breads indicated a B-type structure with the appearance of peaks at around 17°, 19.5°, and 22°. An additional peak at 24° was observed in breads stored for longer periods. Higher values of hardness and lower moisture contents were obtained for breads baked in an infrared–microwave combination oven, but the use of infrared–microwave combination oven did not result in excessive hardness after storage. Retrogradation enthalpies and total crystallinity values of breads did not show significant differences with baking type.The replacement of rice flour with chestnut flour and addition of xanthan–guar gum blend–DATEM mixture in formulations significantly delayed staling of gluten-free breads by decreasing moisture loss, hardness, retrogradation enthalpy, and total mass crystallinity.