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。     

无麸质大米面包加工技术研究进展

大米不含面筋蛋白并且产量巨大,是无麸质食品的主要原料之一。因大米粉无法形成面筋网络,从而无法形成黏弹性的面团,所以大米面包存在组织不均匀、易塌陷、比容小、老化速度快等问题。目前对于无麸质大米面包的研究贯穿整个面包制作过程,并且不断深入,使得面包的品质有较大的改善,但市售的产品仍存在种类少、价格高和营养价值低的问题。本文从大米原料选取及处理、辅料和添加剂、加工工艺、营养强化4个方面系统综述了目前无麸质大米面包加工技术研究进展,并在目前的研究基础上进行了展望。     

无麸质大米面包品质评价方法的建立及原料品种适用性研究

对7种不同品种大米制备的无麸质大米面包烘焙品质、质构品质、感官品质和气孔结构品质各项品质指标进行分析,利用主成分分析法建立无麸质大米面包品质评价模型,计算无麸质大米面包综合得分并进行聚类分析。结果表明：大米品种对不同品质指标影响程度不同,无麸质大米面包各品质指标间有部分相关性。根据累计方差贡献率提取出3个特征值大于1的因子,累计贡献率达80.055%,以此建立无麸质大米面包品质评价模型。根据样品相似性和欧式平方距离,用Ward法对7种大米制备的无麸质大米面包品质综合评分进行聚类分析,可将其分为两类：第一类综合得分较高,品质较好,包括五常大米、宁粳8号和南粳46制备的无麸质大米面包;第二类综合得分偏低,包括江苏丝苗籼米、家和籼米、金皖仙和宜春大米制备的无麸质大米面包。粳米更适合于无麸质大米面包的制作。     

无麸质面包品质改良研究进展

无麸质面包即完全不含任何麸质的面包,是专门针对麸质过敏人群而制作的面包。无麸质面包中缺乏面筋蛋白,使得无麸质面包存在持气性能较差,产品体积小,风味不佳等品质问题,导致面包的加工性能较差。为了满足消费者对于无麸质面包高品质的需求,需要对其品质进行改良。本文综述了当前国内外关于无麸质面包品质改良的最新研究进展,包括添加乳化剂、亲水胶体、蛋白质、酶等外源物质,酸面团发酵技术,发芽技术等传统技术以及非传统烘焙技术等新兴技术,同时对无麸质面包的发展前景进行了展望。     

荞麦无麸质面包研究进展

对荞麦无麸质面包配方、工艺及品质改良研究进展进行综述。荞麦粉作为优质无麸质原料,常与其他谷物粉或淀粉复配制作面包,添加量主要为10%～50%,多采用温水和面,发酵时间短;添加纤维或多糖可通过模拟面筋蛋白黏弹性和控制水分子移动来增加面团黏度、提高荞麦面团发酵性能和持气性,降低面包硬度,增加面包体积;酸面团发酵技术可降低荞麦面团和面包的pH,增加面包体积,延缓面包老化;酶处理技术可帮助形成蛋白质网络,增加荞麦面包咀嚼性;添加蛋白质可强化荞麦面团网络结构,增加面包体积;营养学评价显示添加荞麦粉可提高无麸质面包抗氧化能力和矿物质含量。但荞麦无麸质面包依然存在面团持气性差、操作性不佳,面包体积小、硬化快等问题。未来研究应关注原料预处理、多种酶或胶体协作、老化改善及产品免疫学验证。     

无麸质食品

面筋蛋白的摄入可引起某些特殊人群患乳糜泄等疾病.无麸质食品是专门为面筋过敏的人群生产的.制作无麸质食品的原料不含面筋,为了使外观和口感变得更佳,研究人员通过各种方法来改善无麸质食品的品质.主要对国内外无麸质食品的种类,所采用的原料(大米粉、荞麦粉、高粱粉以及不同种类的淀粉)、功能性添加剂(胶体、蛋白、酶等)和无麸质食品的保存方法进行了综述,以期为无麸质食品的发展提供参考.     

无麸质食品品质改良研究进展

无麸质食品主要是针对乳糜泻疾病患者等对面筋蛋白过敏人群而生产的食品。由于无麸质食品的原料中不含面筋蛋白,在食品制作过程中面团难以形成有效的网络结构,不易成型,持水性、持气性、弹性和内聚性差,老化速率高。主要介绍无麸质食品采用的原料及其营养成分,综述通过添加功能成分和控制工艺技术来改善无麸质食品品质的研究进展,以期为无麸质食品品质改良研究与生产提供参考。     

响应面优化无麸质大米面包复合改良剂配方的研究

针对无麸质大米面包制作时存在的成型难,品质差等问题,研究了沙蒿胶、单甘酯、羟丙基淀粉、乳清蛋白等改良剂对无麸质大米面包品质的影响,并在单因素实验的基础上,以面包的比容为响应值,选用响应面分析法优化其复合改良剂的配方.结果显示,沙蒿胶、单甘脂、羟丙基淀粉、乳清蛋白对无麸质大米面包的质构、比容及感官均有改善作用.最终确定无...     

无麸质面包加工技术改良新进展

无麸质面包是无麸质食品中最重要的组成部分,其品质因麸质蛋白的缺失而受到一定影响,但可以通过优化加工工艺有效改善其品质。优选廉价营养的原料搭配高效的添加剂是无麸质面包加工第一环,通过碾磨、热加工、微波、高压、发芽等原料预加工方式可以提升无麸质粉的加工适应性,酸面团发酵和化学膨松法则为面团制备增添新方案,真空焙烤、欧姆加热、微波辅助焙烤可为面包焙烤拓展新思路。本文以加工工艺流程为主线,对原料与添加剂的选择、原料预加工、面团制备、面包焙烤等无麸质面包品质改良技术进行了综述。     

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%。     

How Do Xanthan and Hydroxypropyl Methylcellulose Individually Affect the Physicochemical Properties in a Model Gluten‐Free Dough?

To better understand the physicochemical changes imparted by hydrocolloids on gluten-free dough, 2 hydroxypropyl methylcelluloses (HPMCs) and xanthan gum were added at 2%, 3%, and 5% to rice cassava dough without the addition of alternative proteins. The formulated doughs were analyzed using thermoanalytic and rheological techniques to determine the role of water and subsequent flow behavior upon hydrocolloid addition. The baked loaves were then measured for specific loaf volume and tensile strength to determine bread quality. Thermogravimetric analysis (TGA) results revealed that hydrocolloid-added dough held water more tightly than the rice cassava control with an additional water distribution at 85 to 88 °C. Rheologically, the increase of elastic moduli in the low methoxy HPMC and xanthan-added dough became more pronounced with gum addition; however, both HPMC formulations had increased viscous moduli allowing the gas cells to expand without collapsing. In the bread, the final specific loaf volume increased with high methoxy HPMC (2% to 5%) and low methoxy HPMC (2%) but was depressed with increased addition of low methoxy HPMC (5%) and xanthan (3% and 5%). Crumb hardness was decreased in high methoxy HPMC loaves but was increased significantly in low methoxy HPMC (5%) and xanthan (5%) formulations. From the gums studied, it was concluded that high methoxy HPMC was the optimum hydrocolloid in the rice cassava gluten-free dough. PRACTICAL APPLICATION: Two types of hydrocolloids, xanthan gum and HPMC, were individually added to a gluten-free rice cassava formulation. Based on the thermoanalytic and rheological studies on dough, as well as the bread quality studies, high methoxy HPMC at 5% addition was determined to optimally improve the bread quality when only gum addition was considered. This study indicates the potential use of high methoxy HPMC as an additive in gluten-free bread formulations prior to considering alternative proteins.     

Breadmaking performance of protein enriched,gluten-free breads

Soybean enriched, rice-based gluten-free breads were designed incorporating a structuring agent (hydroxypropylmethylcellulose, HPMC) and a processing aid (transglutaminase, TG). At dough level the effect of increasing amounts of soybean protein isolate (SPI), HPMC and water was studied in the Mixolab. Mixing and thermal characteristics showed the significant effect induced by water, soybean protein isolate, HPMC and TG, allowing the selection of the appropriate amounts for the breadmaking performance of enriched gluten-free breads. The single addition or in combination of 4% HPMC, 13% soybean and 1% TG produced significant changes in the physical properties of the rice-based gluten-free breads. The presence of SPI blended with rice flour produced a significant decrease in the specific volume of the bread, although this detrimental effect was partially counteracted by its combination with HPMC, decreasing also the crumb hardness. The micrographs of the crumb showed the beneficial effect of the HPMC, obtaining a more open aerated structure. Protein enriched, gluten-free breads can be obtained with a combination of SPI, HPMC and TG.     

Exploring the applicability of tamarind gum for making gluten-free rice bread

The present study explored the applicability of tamarind gum in making gluten-free rice bread. Hydration properties of gums and pasting properties of rice flour with the gums were analyzed with Rapid ViscoAnalyzer. Batter properties and bread quality characteristics of rice bread containing gums were analyzed. Except for guar and xanthan gum, the final viscosity after hydration of other gums and the pasting properties of rice flour with the gums were similar. The batter properties and the quality of rice bread containing tamarind gum were equivalent or superior to those containing other gums. Cross-sections of rice bread showed that addition of tamarind gum and pectin resulted in a fine appearance, but pectin may not be preferred due to its lower pH causing unpleasant sour taste and smell of the rice bread containing the gum. Therefore, tamarind gum can be a useful gum for applying to make gluten-free rice bread.     

Application of Response Surface Methodology to the Development of Rice Flour Yeast Breads: Objective Measurements

A gluten-free wheat bread replacement was developed from rice flour (80%) and potato starch (20%). Using objective measurements as responses, response surface methodology was utilized to find carboxymethylcellulose (CMC)-hydroxypropylmethylcellulose (HPMC)-water combinations which could successfully replace gluten in the rice flour yeast breads from each of three rice flours. CMC and water had the greatest effect on the responses measured; HPMC had the least. Rice bread formulations were found that resulted in breads which met wheat (white) bread reference standards for specific volume, crumb and crust color, Instron firmness and % moisture.     

Improving gluten-free bread quality by enrichment with acidic food additives

An experimental design has been developed to improve gluten-free bread formulation, on the basis of rice flour and hydroxypropylmethylcellulose (HPMC) as alternative baking ingredients. In order to improve the quality of gluten-free bread, several levels of acidic food additives (acetic acid, lactic acid, citric acid and monosodium phosphate) have been tested. The influence of these compounds on the dough and on bread properties has been determined, including a hedonic sensory test of appearance, odour, taste and texture of bread. Results suggest that monosodium phosphate yields bread producing better texture scores, associated with the highest volumes of the loaf. Discussions are made on the basis of CO₂ transport pathway across the HPMC network and simultaneous interactions with acidic food additives present. Chemical properties of the acids justify the bread’s alveolus size and the preservative effects of acetic acid in the dough.     

Optimization of hydroxypropylmethylcellulose,yeast β-glucan,and whey protein levels based on physical properties of gluten-free rice bread using response surface methodology

Response surface methodology (RSM) was used to analyze effects of hydroxypropylmethylcellulose (HPMC), yeast β-glucan, and whey protein isolate (WPI) on physical properties of gluten-free bread baked from formulas based on rice starch. A Box–Behnken design with three independent variables (HPMC, yeast β-glucan, and WPI) and three levels was used to develop models for the different responses (physical properties). Individual contour plots of the different responses produced from the models were compared to the corresponding reference wheat bread data and were superimposed to locate gluten-free bread formulations that met the wheat bread standards for spread ratio, specific volume, hardness, cohesiveness, chewiness, and crumb color L∗ value. The optimal formulation, determined from the data, contained 4.35 g/100 g HPMC, 1 g/100 g β-glucan, and 0.37 g/100 g WPI, rice starch basis. Predicted values of the optimized bread were experimentally tested and compared with the experimental wheat bread data. A good agreement among these data was observed. Moreover, the optimized rice starch bread was found to be acceptable according to the results of sensory analysis.     

Sunflower protein concentrate: A possible and beneficial ingredient for gluten-free bread

The global demand for gluten-free products increased and resulted in a significant technological challenge for the bakery industries: producing gluten-free bread with similar quality to wheat bread. This study aimed to analyze the effects of different concentrations of sunflower protein concentrate (SPC) addition on the gluten-free bread quality parameters compared to the use of pea flour. The SPC flour was inserted at 5%, 10%, and 20% on a flour basis mixture (70% rice flour and 30% cornstarch). Some parameters as specific volume, color, and texture profile were evaluated during 21 days of storage. The obtained results showed that SPC has a significant potential to be used in gluten-free bread with high quality and sensory acceptability. The addition of this beneficial ingredient, in all concentrations, resulted in gluten-free bread with lower hardness after 21 days of storage and with a 100% increment in the protein content when compared to pea flour bread.     

Effect of HPMC on the quality of wheat-free bread made from carob germ flour-starch mixtures

Carob germ proteins have been shown to have functional properties similar to wheat gluten enabling formulation and production of yeast leavened gluten-free baked goods from a true dough rather than a stiff batter. The purpose of this research was to optimize the production of wheat-free bread containing carob germ flour, corn starch, NaCl, sucrose, hydroxypropyl methylcellulose (HPMC), and H(2)O. A key criterion was to formulate viscoelastic dough similar to wheat dough. To that end, response surface methodology (RSM) was used to determine optimal levels of carob germ flour, H(2)O, and HPMC. Components varied as follows: 4.94%-15.05% for carob germ flour, 0.05%-3.75% HPMC, and 65.25%-83.75% H(2)O (percents are on a flour basis, where carob germ flour in combination with maize starch equals 100%). Sucrose, NaCl, and yeast were held constant at 2%. Bread parameters evaluated were specific volume and crumb hardness, where the largest specific volume and the lowest value for crumb hardness were considered most desirable. The optimum formula as determined by RSM consisted of 7% carob germ flour, 93% maize starch, 2% HPMC, and 80% H(2)O with predicted crumb hardness of ~200 g of force and a specific volume of ~3.5 cm(3)/g. When proof time was optimized, a specific volume of ~5.6 ml/g and crumb hardness value of ~156 g of force was observed. Carob germ flour may be used as an alternative to wheat flour in formulating viscoelastic dough and high quality gluten-free bread. PRACTICAL APPLICATION: Celiac disease affects approximately 1% of the world's population. Sufferers of the disease must consume a gluten-free diet. Currently, gluten-free baked products are made from batters and lack the ability to be made from dough based systems which limits the overall processability and product variety. This research is aimed at the utilization of carob germ protein and its ability to form dough to produce an optimal gluten-free bread formulation. This will help to alleviate problems in processability and product variety associated with gluten-free baked goods.