Effect of Iron Fortification on Physical and Sensory Quality of Gluten-Free Bread

The scope of the present study was to investigate the effects of different iron compounds on the physical and sensory characteristics of gluten-free breads (GFBs) that were iron fortified (40 mg/kg solid compound) using different iron compounds. Differences among unfortified and fortified samples were observed in colour, crust firmness, and in the following sensory attributes: pore number, smell of ‘moisture’, metallic taste and stickiness. Elemental iron was more stable and thus adverse changes to product by its addition were not noticed. The results are useful in understanding the limitations of iron fortification and thus help designing more acceptable iron-fortified GFBs.     

面包、饼干和蛋糕的铁、锌、钙含量

食品中矿物质的含量及吸收利用情况一直是食品加工和营养学工作者关注的一个热点问题.针对这一情况,本研究选择北京市场消费量较大的面包、饼干、蛋糕三类烘焙食品为研究对象,分析了这些烘焙食品中铁、锌、钙三种矿物质含量,并采用体外模拟人体消化道酶的作用,对三种矿物质的利用情况进行了评价.结果表明:从含量上看,主食面包的铁、锌的含量最高,钙含量也仅次于饼干.主食面包是一种矿物质含量非常丰富的食品,饼干是一种富钙的焙烤食品.从利用率来看,面包铁、锌、钙溶出率均较低,蛋糕的铁和锌的利用率最高,饼干的钙利用率最高.     

木聚糖酶对面包品质的影响效果

采用改良二次发酵法制作面包,将木聚糖酶以不同比例添加到面包基本配方中,观察酶对面包加工过程及面包品质的影响,并由贮存试验,考察酶对面包贮存品质的影响.结果表明,木聚糖酶添加量为15 mg/kg(以面粉为基准)时,面包加工品质及贮存效果最佳.     

麦胚对面包质量影响的研究

研究了全脂麦胚和脱脂麦胚对面团的流变学特性和面包质量的影响。结果表明,面团的筋力随麦胚量的增加而降低;脱脂麦胚比全脂麦胚的面包质量较好;脱脂麦胚的适宜加量为8％;麦胚能改善面包的皮色、风味和营养价值。     

添加猪油对馒头品质的改善

研究了猪油对酵母发酵性能,馒头品质及馒头老化的影响。实验结果表明,猪油能增加面团的膨发体积,改善馒头体积,色泽和组织结构,并在延缓馒头化方面起到了一定作用。     

小麦芽粉的应用对面包品质影响的研究

研究探讨了小麦芽粉的添加量对面包品质和面团粉质性能的影响以及小麦芽粉面包的生产工艺.实验结果表明:小麦芽粉的的使用对面包的品质具有一定的改善作用,经过烘烤处理的小麦芽粉在面包生产中的最适宜添加量为6%～8%;通过正交实验得出了麦芽面包的最佳生产工艺条件.     

复合面包的组成对其品质影响

选用玉米粉、木薯粉、大米粉、分别与小麦粉和大豆粉配合,制作了成本低廉、芳香可口、营养丰富的复合面包。实验结果表明,随着玉米粉、木薯粉、大米粉添加比例的逐渐增加,所制得复合面包的单位重量体积逐渐减少;相比之下,木薯粉复合面包的体积较大,玉米粉复合面包位中,大米粉复合面包的体积最小。     

麦麸膳食纤维添加对面包和馒头品质影响

将麦麸膳食纤维添加于面粉中制作面包和馒头,通过感官评价来研究麦麸膳食纤维添加量对面包和馒头品质的影响.实验结果表明,在面包或馒头中添加5%麦麸膳食纤维较适宜,不会明显降低面包和馒头的感官性状和内部品质,而且口感细腻.无麸皮干涩味,感官评分最高.     

Pectins as Breadmaking Additives: Effect on Dough Rheology and Bread Quality

The effect of two types of pectins with different degrees of esterification on dough and bread characteristics was analysed. A high methoxyl pectin (HMP) and a low methoxyl pectin (LMP) were assayed in dough without or with salt (2%) at levels ranging from 0.25% to 2.0%. Farinographic water absorption increased when pectins were incorporated in dough with salt, whereas this effect was not observed in dough without salt. Pectin addition diminished the stability of dough in all cases. Texture profile analysis showed that pectins softened the dough, particularly when salt was added. Cohesiveness was also higher in doughs with salt at the maximum level of hydrocolloid addition. In dough with salt, HMP decreased the elastic and viscous moduli, while the values for tan (δ) were increased with respect to control. SEM micrographs showed that dough with pectin has a filamentous structure. In the breadmaking process, dough with HMP showed a better performance, leading to higher specific volumes and softer crumbs both in fresh and stored bread.     

Effect of Temperatures on Fish Alkaline Protease, Protein Interaction and Texture Quality

The effect of the activity of fish alkaline protease and protein denaturation on texture changes in mullet muscle during heating were studied. The proteolytic enzyme and the urea denatured hemoglobin substrate were incubated at different pH values and various temperatures. The enzyme activity was optimal at pH 8 and at 65°C. The extent of protein-protein interactions in mullet actomyosin solutions increased with increasing temperature. The rate of protein-protein interactions increased sharply as temperature increased from 35°C to 45°C at pH 6. When mullet muscle was heated at various temperatures ranging from 55°-85°C, the shear force value increased (toughening) during the initial stage of heating and then decreased (softening). The toughening of fish flesh is probably due to muscle protein interactions, and the later tenderizing of fish flesh may be explained by alkaline protease activity (hydrolysis) masking the protein denaturation effect. When fish flesh was cooked at 100°C, no tenderizing effect was observed. This was probably due to loss of enzyme activity and only protein denaturation had significant effect on texture quality.     

Effect of Calcium Level on Bread Iron Utilization by Iron-Deficient Rats

Utilization of iron in bread containing variable amounts of calcium was examined using iron-deficient rats as the test model. Iron was added to the bread at the normal enrichment level. Calcium, however, was added at levels up to 9 times the normal level. Iron utilization efficiency (IUE) was calculated based on collective increases observed in hemoglobin and liver iron. Compared to a diet low in both calcium and phosphorus (IUE = 100%), IUE averaged 98% when the diet was high in calcium but moderate in phosphorous, and 78% when the diet was very high both in calcium and phosphorous. Viewed collectively, the data suggested that excessive intake of both calcium and phosphorus would adversely affect the utilization of iron in bread, but some excess of calcium alone would not.     

Effect of Mineral Gluconates on Quality Characteristics of Bread and Cookies

These studies examined the effect of expanded fortification (FNB, 1974), using gluconates of Fe, Zn, Ca, and Mg as the mineral source, on quality characteristics of white pan bread and chocolate chip cookies. Gluconates, including magnesium gluconate, did not affect the yeast activity, dough mixing time, proof time, or dough pH. The pH and subjective quality scores of the breads were also little affected by any of the gluconates. Fortification reduced the specific loaf volumes slightly and also caused, by day 6, a greater firming of the crumb. Gluconates did not affect the subjective quality scores or spread ratios of the cookies, although cookie pH was lowered somewhat. Used singly, test gluconates did not appreciably alter the bread or cookie flavor profile except that cookies containing Zn gluconate were consistently preferred.     

酶制剂对面团流变学特性和面包品质的影响

探讨不同添加量的酶制剂对面团流变学特性和面包品质的影响。结果表明:真菌淀粉酶和木聚糖酶可弱化面团的流变学特性,葡萄糖氧化酶、谷氨酰胺转氨酶和脂肪酶可不同程度地改善面团的流变学特性;真菌淀粉酶、木聚糖酶、葡萄糖氧化酶和脂肪酶能有效改善面包焙烤品质,增大面包的比容,改善面包的硬度和弹性,而谷氨酰胺转氨酶对面包品质的影响不明显。真菌淀粉酶、木聚糖酶、葡萄糖氧化酶和脂肪酶的最适添加量分别是5μL/kg、20mg/kg、30μL/kg、50mg/kg。     

Effect of Extruded Wheat Germ on Dough Rheology and Bread Quality

Wheat germ, a by-product of the milling industry, has interesting nutritional properties. However, it has limited use due to a high risk of rancidity, which could be reduced by using certain thermal treatments such as extrusion. The aim of this study was to investigate how wheat germ extrusion affects the changes induced by its addition to bread dough. For this purpose, different quantities of extruded or raw wheat germ (2.5, 5, 7.5, 10, and 20?g/100?g flour) were added to bread dough. Rheological characteristics of the dough and final quality characteristics of the bread were analysed from both the physical and the sensory points of view. Wheat germ addition increased water absorption and development time but decreased stability after over-kneading, dough tenacity, extensibility, and dough alveographic strength. The addition of extruded wheat dough improved stability and decreased extensibility and strength. Bread made from dough with added wheat germ presented decreased volume, cohesiveness, and elasticity and increased firmness. However, extrusion increased the volume of breads with added wheat germ and improver and decreased firmness. All breads obtained positive acceptability scores in sensory analysis, although wheat germ addition (10?g/100?g flour) slightly decreased texture, appearance, and overall acceptability scores of breads. Germ extrusion therefore improves dough rheology and bread quality and constitutes a suitable treatment to stabilise wheat germ in bread dough.     

磷酸盐对馒头品质的影响

研究了磷酸盐对馒头品质的影响。通过改变加入面粉中磷酸盐,找出了磷酸盐加入量对馒头各项指标的影响关系,结果显示,磷酸盐对馒头的品质起到很好的改善作用。当磷酸氢二钠的添加量为0.6%时,馒头的品质达到最好。     

Effect of Ingredients on Rheological, Nutritional and Quality Characteristics of High Protein, High Fibre and Low Carbohydrate Bread

Effect of replacement of wheat flour with a combination of soy protein isolate, oat bran and chickpea flour (SPOBCP) at the levels of 20%, 40% and 60% and addition of combination of additives such as fungal ??-amylase, dry gluten powder, sodium stearoyl-2-lactylate, hydroxypropylmethylcellulose (CA) on the rheological and nutritional characteristics of bread was studied. Use of SPOBCP decreased farinograph dough stability, increased pasting temperature, decreased cold paste viscosity and overall quality score of bread. Scanning electron microscopy images showed higher degree of disruption of protein matrix in bread dough with 60% SPOBCP than 20% and 40% SPOBCP. Addition of 60% SPOBCP resulted in flat, uneven shaped bread with an overall quality score of 38 when compared with 54, 81 and 91 for breads with 40%, 20% and 0% SPOBCP, respectively. However, use of CA increased the strength of the dough and improved the overall quality of bread with 40% SPOBCP. Nutritional profile of bread with 40% SPOBCP?+?CA showed higher protein, in vitro protein digestibility, total dietary fibre, resistant starch, ??-glucan and lower starch hydrolysis index than control bread.     

油脂对馒头品质的影响

本文研究了不同类型油脂对馒头品质及老化的影响.发现,固态油脂（起酥油和精制猪油）的适量添加能够改善馒头的表面色泽和内部质构,增大了馒头的体积和延缓了馒头的老化.而液体油（一级豆油）不能对馒头的品质起到改良作用.     

Effect of Surfactant Gels on Dough Rheological Characteristics and Quality of Bread

Sodium stearoyl-2-lactylate (SSL), diacetyl tartaric acid esters of monoglyceride (DATEM), glycerol monostearate (GMS), and distilled glycerol monostearate (DGMS) surfactant gels were made with water and varying shortening contents. The effect of these gels on dough rheological characteristics and quality of bread was investigated. Overall, the surfactant gels improved the farinograph and extensograph characteristics of wheat flour, but the improvement reduced to some extent with the presence of shortening in the gels. Alveograph data indicated that dough properties improved with the addition of surfactant gels. Shortening in gels showed varying influence on the dough alveograph properties of wheat flour. The results indicated that the surfactant gels changed the rapid visco analyzer characteristics of wheat flour, and the presence of shortening in gels further altered the characteristics. All surfactant gels improved the volume, specific volume, texture, and overall quality scores of bread, but the improvement varied for different surfactants. By increasing the addition of shortening in gels, though the quality characteristics further improved, the response to surfactants reduced by increasing shortening content.     

醒发条件对北方馒头品质的影响

醒发是馒头的工业化生产中的关键环节。采用一次发酵法,以馒头比容、硬度以及均匀度为指标,研究了醒发条件如醒发温度、湿度、醒发时间对北方馒头品质的影响。结果表明,当醒发时间为35min左右、醒发温度在35℃左右、醒发湿度在80％左右时馒头的品质最佳。