抗性淀粉对面团流变学特性的影响、应用及改良

主要研究小麦粉中加入不同比例的抗性淀粉(RS)后,对面团流变学特性以及焙烤食品(面包)品质的影响。结果表明,添加RS会影响面团的流变学特性,降低面包品质。为此,通过加入谷朊粉对混合粉(小麦粉+抗性淀粉)进行品质改良,研究表明,谷朊粉对混合粉面团流变学特性有明显改善作用。RS添加量控制在10%,只需添加3%的谷朊粉,面包品质就能明显改善。     

变性淀粉对冷冻面团面包品质的影响

以木薯淀粉为原料,主要研究了预糊化淀粉、羟丙基二淀粉磷酸酯和乙酰化二淀粉磷酸酯三种变性淀粉的物化特性与冻融稳定性,以及它们对冷冻面团面包比容及面包全质构的影响。实验结果表明:木薯淀粉经过不同方式的变性后,物化特性差异很大,其中,羟丙基二淀粉磷酸酯的冻融稳定性最好,预糊化淀粉的冻融稳定性最差;添加5%三种变性淀粉后均能显著延缓冷冻面团的下降趋势,并对冷冻面团面包的品质具有良好的改善作用。这一结果与变性淀粉冻融稳定性及冷冻面团面包比容变化趋势一致,进一步表明变性淀粉,尤其是羟丙基二淀粉磷酸酯可以有效抑制冷冻面团内部水分的迁移,降低冻藏过程中冰晶和重结晶的形成,从而改善冷冻面团面包的内部质构。     

变性淀粉对面团流变学特性和面包品质的影响

探讨不同添加量的马铃薯变性淀粉和木薯变性淀粉对面团流变学特性和面包品质的影响。结果表明:两种变性淀粉均可改善面团的流变学特性,增大面团的韧性、减小面团的延伸性,改善面团的筋力;与对照相比,马铃薯变性淀粉能有效改善面包的焙烤品质,明显增加面包的比容,有效改善面包的硬度和弹性,木薯变性淀粉对面包品质的影响不明显;马铃薯变性淀粉的最适添加量为0.8%～1.2%面粉。     

The impact of resistant starch on characteristics of gluten-free dough and bread

The study focused on partial replacement in gluten-free breads of corn starch with tapioca and corn resistant starch preparations. The use of resistant starch resulted in the increase of storage and loss moduli of the dough, and the lowering of loss tangent, which indicates its more elastic character. The incorporation of resistant starch reduced creep and recovery compliance and elevated zero shear viscosity. Modified doughs displayed higher starch gelatinization temperatures and lower viscosities that were proportional to the share of RS. It was found that the loaves baked with the share of resistant starch had less hard crumb than bread without RS addition. The crumb hardness diminished with the increasing amount of applied RS preparation. The addition of resistant starch raised total dietary fibre, by up to 89%, as compared to control (bread without RS addition). The most pronounced change was observed for insoluble dietary fibre (increase 137%), while only slight increase was found for its soluble fraction (18%).     

变性淀粉对冷冻面团面包焙烤特性的影响

探讨了醋酸酯马铃薯淀粉对冷冻面团面包焙烤特性的影响。面团中分别添加不同质量分数(0%、5%、7.5%、10%、12.5%、15%)的醋酸酯马铃薯淀粉,在冷冻不同天数后,解冻进行焙烤,并对比容和全质构等参数进行测定。结果表明:醋酸酯马铃薯淀粉增大了面包的比容,减缓了面包在冻藏过程中比容的下降趋势,改善了面包的品质。     

Effect of the addition of different fibres on wheat dough performance and bread quality

A good correlation has become evident between fibre consumption and the reduction of coronary heart-related diseases and diabetes incidence. However, fibre intake is commonly lower than recommended. In consequence, the development of foods with high fibre content should be desirable. The potential use of various commercial fibres (carob fibre, inulin and pea fibre), as fibre-enriching agents in breadmaking, is reported. The effects of the addition of these fibres to wheat flour on the viscoelastic properties of dough and both mixing and proofing behaviour is presented. Bread evaluation revealed that carob and pea fibre supplementation, although decreasing specific loaf volume (very slightly in the case of carob fibre), conferred softness to the bread crumbs. In addition, sensory evaluation showed that consumer panellists judged these fibre-enriched breads as acceptable. Therefore, their use, especially carob, allows an increase of the daily intake of fibre without promoting negative effects on the rheological properties of doughs or quality and overall acceptability of the resulting breads. The whole study indicates that these three fibres can be used as additives in breadmaking in order to fortify the diet.     

Impact of the addition of RS-III prepared from sweet potato starch on the quality of bread

In the present study, control bread (CB-0% resistant starch) and experimental breads (EB1-10% and EB2-15% resistant starch) were formulated and their quality was evaluated. Resistant starch (RS) content was greater in EB2 (12.99%) than EB1 and CB. Loaf weight of experimental breads was positively correlated with the moisture content of bread loaves. Sensory analysis revealed that an addition of 15% RS in the bread caused a darker color and a harder texture as evident from the instrumental data. A decreased L* value was noted in both control and experimental breads during storage. The hardness of all bread crumbs was increased over the storage time while this increment was more prominent in EB2. Results showed that the EB1 was accepted with a highest overall sensory acceptance of 3.33 than EB2 (3.00) and CB (2.83) during storage. Microbial analysis indicated that the bacterial colonies increased in the control bread and EB1 during the storage while the EB2 was free of microbial contamination. The study revealed that EB1 (10% RS) was found most acceptable in terms of sensory and textural characteristics.     

Production and physicochemical properties of resistant starch from hydrolysed wrinkled pea starch

The content and physicochemical properties of resistant starches (RS) from wrinkled pea starch obtained by different molecular mass reduction processes were evaluated. Native and gelatinised starches were submitted to acid hydrolysis (2 m HCl for 2.5 h) or enzymic hydrolysis (pullulanase, 40 U g^?1 for 10 h), followed by hydrothermal treatment (autoclaving at 121 °C for 30 min), refrigeration (4 °C for 24 h) and lyophilisation. Native starch showed RS and total dietary fibre contents of 39.8% and 14.3%, respectively, while processed ones showed values from 38.5% to 54.6% and from 22.9% to 37.1%, respectively. From these, the highest contents were among acid‐modified starches. Processed starches showed endotherms between 144 and 166 °C, owing to the amylose retrogradation. Native and processed starches showed low viscosity, which is inversely proportional to the RS concentration in samples. The heat treatment promoted an increase in the water absorption index. The pea starch is a good source for obtaining resistant starch by acid hydrolysis.     

Effect of green plantain flour addition to gluten‐free bread on functional bread properties and resistant starch content

Green plantain flour (GPF) was used as a functional ingredient to produce gluten‐free (GF) bread based on a flour blend of rice flour and GF wheat starch (50:50) to improve their functional properties and to increase their resistant starch (RS) content. In pretrials, an addition of up to 30% GPF provided acceptable bread quality with maximum RS content. Based on these trials, two 2³ factorial screening experimental designs were applied, where water content, baking temperature and baking time of GF bread containing 30% GPF addition were optimised. The best baking conditions to achieve satisfying GF bread quality – higher loaf volume, softer crumb firmness and regular porosity structure at the highest RS content could be defined to a maximum addition of water at 160%, baking temperature of 180 °C and baking time of 90 min. The incorporation of GPF showed good potential to improve the quality of GF bread.     

Effect of heat-moisture treated maize starch on the properties of dough and bread

Twenty percent of wheat flour was substituted with heat-moisture treated maize starch (HMT-M) or native maize starch (N-M), and the dough properties and the bread qualities were studied. Bread was baked with optimum (farinogram water absorption (63.0–66.4%)), 70% and 75% of water at the presence or absence of shortening. Elasticity of the dough with HMT-M decreased as compared with that of N-M and the control (without any maize starches) as measured by farinograph. Differential scanning calorimetry (DSC) and viscograph results showed that HMT-M hardly swelled and gelatinized in the dough. Specific volume of bread and softness of crumb baked with optimum water absorption decreased by the substitution of HMT-M. Bread quality containing HMT-M was improved at 70% water absorption as compared with optimum water absorption. By the addition of shortening, the specific volume of bread baked with HMT-M increased and the grain structure became finer. However, the firmness of crumb baked with HMT-M at the presence or absence of shortening was the same. As a result, HMT-M is still needed to study further for its application in breadmaking.     

Production and physicochemical characterization of resistant starch type III derived from pea starch

Smooth pea starch was used for the production of physiological important resistant starch type III. For reduction of the molecular weight of the starch, different strategies including enzymatic debranching and acid hydrolysis (lintnerization), were tested to obtain an optimal starting material for retrogradation. The resulting polymer chain lengths were analyzed by high-performance anion-exchange chromatography. Temperature regimes and starch concentrations in gel were optimized during the retrogradation with the aim to obtain a high yield of resistant starch. Optimal conditions led to resistant starch contents up to 74%. The products were thermostable and showed no loss of resistant structures after autoclaving. The peak temperatures of the thermal transition were at approximately 147 degrees C. The resulting resistant starch products are suitable for the generation of functional foods.     

Impact of quinoa bran on gluten-free dough and bread characteristics

Besides an appealing texture and taste, gluten-free products should feature a well-balanced nutrient profile, since celiac disease or chronic inflammations are likely to induce malnutrition for involved patients. Due to their composition, pseudocereals represent a promising ingredient to improve nutrient profile of gluten-free bread. The objective of this study was to investigate the impact of quinoa bran on gluten-free bread quality, focusing on volume, pore size and sensory acceptance. The impact of quinoa bran was studied in a gluten-free bread formulation. Five different quinoa bran and two whole grain flour concentrations were evaluated and compared to a control formulation based on rice and corn flour. The rheological properties of quinoa bran as well as the effect on dough development up to a replacement level of 80 % were investigated. Baking tests were carried out, and loaf volume, crumb firmness and sensory characteristics were determined. Quinoa fractions significantly increased carbon dioxide formation (p < 0.05) due to a higher substrate availability. Gas retention was reduced by increasing bran levels (p < 0.05). Oscillation measurements indicated a firming impact of quinoa bran which might have caused a more permeable dough structure, promoting the release of carbon dioxide. With regard to the specific loaf volume significant differences were found across the quinoa milling fractions and the applied levels (p < 0.05). Overall this study demonstrated that 10 % bran improved the bread volume by 7.4 % and enhanced the appearance without compromising the taste.     

变性淀粉对面包品质的影响

采用改良一次发酵法制作面包,将交联淀粉、醋酸酯淀粉、交联酯化淀粉分别添加到面包中,详细探讨了变性淀粉用量对面包比容、水分含量、保水性及硬度等品质指标的影响,旨在为提高面包的品质,延缓其老化作用提供有益的帮助.结果表明:不同变性淀粉的添加量不同对面包品质有不同程度的影响.适量添加(1%～3%)变性淀粉可使面包的比容增大、含水量提高、保水性增强、硬度降低,对延缓面包老化起到一定作用.其中交联酯化淀粉可弥补单一改性淀粉的不足,更适合添加到面包中,对改善面包品质、延缓面包老化比交联淀粉和醋酸酯淀粉更明显.     

酯化淀粉对面团性质的影响及其在馒头中的应用

柠檬酸和醋酸酯化淀粉对面团的流变学特性均有一定影响:添加了酯化淀粉的面团,吸水率有所下降,面团稳定时间增加,稳定性提高;弱化度减少,粉质评价值升高.添加于馒头中对其硬度、弹性、黏性等有不同程度影响,最后确定酯化淀粉在馒头中的最适添加量均为5%～10%.     

苦荞粉添加量对面团性质及馒头品质的影响

通过添加不同量的苦荞粉配成苦荞-小麦混粉,研究混粉揉混特性、面团微观结构的变化以及苦荞馒头的感官品质。结果表明,当添加量在5%~15%时,揉混结果中的和面时间和峰值面积变化不大,微观结构中蛋白质面筋网络结构略微减弱,但当添加量达到20%后,和面时间和峰值面积都有大幅度降低,微观面筋网络结构也出现明显的下降。同时,苦荞粉添加量为15%时馒头感官品质较好。综合分析可知,添加量为15%时苦荞馒头仍具有较好的品质。     

Influence of extrusion condition and hemp addition on wheat dough and bread properties

This study was to evaluate the influence of hemp addition and extrusion conditions on properties of dough and bread. The extruded and non-extruded hemp/ rice flours with different hemp/rice ratio were mixed with wheat flour at 15% ratio. In those flour assays, extrusion greatly decreased the paste viscosities, while the addition of hemp inhibited the decrease of peak viscosity on the extrusion condition. The onset gelatinization temperature was extended due to the hemp addition. The test on dough properties showed that extrusion increased water absorption, arrival time, weakness, extensibility, and the volume after 105 min fermentation, and decreased the stability time and elasticity of dough, while hemp addition mainly increased the weakness and extensibility. For bread properties, extrusion decreased the specific volume, crust and crumb L value, and uniformed air cells, when the hemp addition increased the bread specific volume and decreased the hardness during storage time.     

Structural changes in the wheat dough and bread with the addition of alpha-amylases

The influence of fungal and bacterial -amylases on the texture and microstructure of dough and bread was investigated. Loaf specific volume, crumb porosity and texture properties were accepted as bread structure and texture characteristics. The microstructure analysis of dough and bread using light and scanning microscopy methods was performed.The changes in loaf specific volume, crumb porosity and texture properties showed different anti-staling activity of the enzymes used. The simultaneous action of enzyme addition and the fermentation process evoked significant changes in the microstructure of dough. The character of these changes depended on the kind of enzyme used. A substantial effect of both amylases on starch behaviour during bread baking and staling was also observed.     

变性淀粉对冷冻面团水分特性的影响

探讨了醋酸酯马铃薯淀粉对冷冻面团水分特性的影响。面团中分别添加不同量的醋酸酯马铃薯淀粉,利用脉冲核磁共振仪测定面团特水力。结果表明:醋酸酯马铃薯淀粉显著增加了冷冻面团持水力,且持水力随醋酸酯马铃薯淀粉添加量的增加而增大;添加量为15%时,持水力达到最大值;与淀粉面团相比,醋酸酯马铃薯淀粉面团中不可冻结水的相对面积增大,不可冻结水的弛豫时间显著降低,这表明添加醋酸酯马铃薯淀粉减弱了水分子的移动性,使面团中水分相对难冻结,减轻了面团冻结过程中的结构损伤。     

Lipid binding of formula bread doughs Relationships with dough and bread technological performance

 Lipid binding of straight/soured started bread doughs treated with sodium carboxymethylcellulose (CMC), hydroxypropylmethylcellulose (HPMC), fungal α-amylase and monoglycerides (MGL), diacetyl tartaric acid esters of mono-diglycerides (DATEM) and sodium stearoyl lactylate (SSL) was investigated and results correlated with dough and bread performance during breadmaking and storage. For doughs formulated with MGL or DATEM, free and bound lipids accounted, respectively, for 70% and 30% of the increase in non-starchy lipids, which preferentially bind to gluten (MGL) and to the outside part of the starch granules (DATEM). SSL mainly increased the pool of free lipids and preferentially bound to the inside part of the starch granules and loosely to the gluten. Hydrocolloids preferentially bound to the gluten (CMC) and to the outside part of the starch granules (HPMC) respectively; this was associated with a significant displacement of endogenous gluten-bounded lipids to the starchy fraction (CMC) and with a significant decrease in lipids bound to the outside part of the starch granules (HPMC). The addition of α-amylase promoted a release of endogenous, bound lipids, and the sourer starter induced the aggregation of the starch-lipid complexes, revealed by the respective decrease in the level of gluten bounded lipids (α-amylase) and increase in the level of starchy lipids. Desired trends in dough lipid parameters resulting in strengthened gluten, delayed starch gelatinization, softer bread and reduced/delayed bread staling corresponded to high values of both free and starchy lipids, achieved by the incorporation of SSL and/or CMC into doughs. Received: 22 January 1998