几种改良剂对板栗面包焙烤品质及老化指标的影响

采用单因素实验,研究了黄原胶、α-淀粉酶、单甘酯三种面包改良剂对板栗面包焙烤品质及老化指标的影响。实验结果表明：黄原胶的添加对板栗面包的感官品质及老化指标均产生了显著影响,当添加量为板栗粉及面包粉总重的1%时,板栗面包具有良好的焙烤品质,贮存7天后,其硬度比对照组下降了9%;不同添加量的单甘酯对板栗面包的老化均有延缓作用,但对面包的焙烤品质均产生负面影响;当α-淀粉酶添加量为0.01%或0.005%时,板栗面包的抗老化效果及焙烤性能均好于对照组,但当添加量较高时,面包焙烤品质骤然下降。     

面包老化抑制因素研究

随着经济水平提高,面包已悄悄走进我们的生活;但是,老化面包口感差,易掉屑且香味丧失,不为广大消费者所接受。为此,需要究面包老化机理,并从理论上寻找抑制面包老化方法,提高面包质量。该文综述近年来国内外对面包老化研究成果,从水分、淀粉结晶、添加剂、淀粉酶、贮存和温度几方面论述抑制面包老化方法;并对抑制面包老化,全面提高面包质量研究趋势进行展望。     

面包老化抑制因素的研究

在西方国家,面包是餐桌上的主食,面包的质量与人们的健康和幸福息息相关.随着经济水平的提高,面包已经悄悄走进了我们的生活.但是,老化的面包口感差,易掉屑且香味丧失,不为广大消费者所接受.我们需要研究面包老化的机理,并从理论上寻找抑制面包老化的方法,提高面包的质量.本文综述了近年来国内外对面包老化的研究结果,从水分、淀粉结晶、添加剂、淀粉酶、贮存和温度几方面论述了抑制面包老化的方法.并对抑制面包老化,全面提高面包质量的研究趋势进行了展望.     

添加剂对面包老化的影响

综述了添加淀粉酶、乳化剂、起酥油、可溶性蛋白、戊聚糖和水解胶体等品质改良剂对面包老化的影响,根据不同面粉的要求正确、合理选用一种或几种添加剂,能达到延缓面包老化的目的。     

不同发酵基质的酸面团对酵母面团体系面包烘焙及老化特性的影响

应用分离自我国传统酸面团的区域特色乳酸菌--旧金山乳杆菌分别发酵小麦粉和小麦麸皮基质制成（小麦/麦麸）酸面团,研究了两种不同发酵基质的酸面团及其添加量对酵母面团体系面包烘焙及老化特性的影响。结果表明：与小麦粉制作的空白组面包相比,小麦酸面团可以明显改善面包的比容和感官品质;添加未发酵麦麸制作的非酸面团麦麸面包品质低于空白组,但引入麦麸酸面团（10%、20%、30%）后面包比容和感官评定得分均高于相对应的非酸面团麦麸面包。小麦酸面团和麦麸酸面团以及小麦麸皮均可以改善面包的老化特性,在相同贮藏期内,酸面团面包和麦麸面包的硬度增加量、水分迁移量和老化焓值都低于空白组,并且添加麦麸酸面团的面包其硬度和老化焓值都低于相对应的非酸面团麦麸面包。     

Bread Staling: Updating the View

Staling of bread is cause of significant product waste in the world. We reviewed the literature of the last 10 y with the aim to give an up‐to‐date overview on processing/storage parameters, antistaling ingredients, sourdough technology, and measurement methods of the staling phenomenon. Many researchers have been focusing their interest on the selection of ingredients able to retard staling, mainly hydrocolloids, waxy wheat flours (WWF), and enzymes, but different efforts have been made to understand the molecular basis of bread staling with the help of various measurement methods. Results obtained confirm the central role of amylopectin retrogradation and water redistribution within the different polymers in determining bread staling, but highlighted also the importance of other flour constituents, such as proteins and nonstarch polysaccharides. Data obtained with thermal, spectroscopy, nuclear magnetic resonance, X‐ray crystallography, and colorimetry analysis have pointed out the need to encourage the use of one or more of these techniques in order to better understand the mechanisms of staling. Results so far obtained have provided new insight on bread staling, but the phenomenon has not been fully elucidated so far.     

单甘酯延缓面包陈化的研究

研究了添加不同比例单甘酯的面包专用粉的流变学性质,确定了单甘酯添加范围。进行面包实验,借助感官评定和质构仪相结合的评价方法评定试验面包。结果证明,单甘酯增加了面团的稳定时间,增大了面团的拉伸曲线面积。单甘酯的亲油基进入直链淀粉螺旋结构形成不溶性复合物,可防止直链淀粉颗粒之间的再结晶发生回生,从而延缓面包陈化。     

天然酵母发酵对面包老化的影响

以梨和脐橙两种水果为培养基质,得到两种水果天然酵母,研究了两种水果天然酵母对储藏期间面包的硬度、水分含量、水分活度和老化焓值的影响,并通过分析不同分离菌株对面包老化特性的影响,探究优势微生物对面包老化的影响机理。结果表明,天然酵母发酵能够减缓面包在储藏期间水分的损失,降低淀粉的回生焓值,其中梨组天然酵母面包(PSB)的淀粉回生焓值为对照组面包(CB)的76.01%,脐橙组天然酵母面包(OSB)的淀粉回生焓值为CB的80.66%。此外,乳酸菌发酵对减缓水分损失和抑制淀粉回生焓值的增长有积极影响。     

Effect of Baking Procedure and Storage on the Pasting Properties and Staling of Part-Baked and Rebaked White Pan Bread Crumb

In this investigation, the white pan breads were part-baked for 10, 15, 20 minutes at 230°C with and without calcium propionate (0.2%), were stored at room temperature (20°C) for 3, 5, 7 days wrapped with two polyethylene bags. After storage, baking time of part-baked breads was completed to the baking time of control breads (25 minutes). Breads were subjected to softness analysis and pasting properties of bread crumb were determined using the Brabender Amylograph. Addition of Ca-propionate decreased softness value of crumb of bread rebaked after part-baked, while the peak, holding end and cooling end viscosities increased. The increase in initial baking time resulted in a decrease in the pasting temperature and softness value and an increase in the bump area and viscosity of the rebaked bread crumb. Bump area, water activity, softness value and peak, holding end and cooling end viscosities of crumb of the rebaked bread after part-baking decreased with longer (intermediate storage) time. Peak viscosity and water activity significantly correlated with softness of bread crumb rebaked following part-baking and storage at room temperature. Rebaking bread for 10 and 15 minutes after storage of 3 and 7 days at room temperature resulted in softer crumb than the control group.     

影响面包老化的因素

证据表明许多因素影响面包的老化，其中包括面包的水分，不同来源的α－淀粉酶，起酥油，表面活性剂，面包的贮藏温度，蛋白质含量等。     

馒头老化指标的初步研究

研究了馒头在储存过程中物理化学特性的变化并进行了相关性分析，初步确定馒头芯的硬度与弹性、馒头瓤上清液中干物质和蛋白质含量以及上清液与碘试剂络合吸光度为馒头老化的代表指标。     

Bread Staling: Molecular Basis and Control

The molecular basis of staling is examined by reviewing what is known about the components of wheat flour, factors that affect staling rate, and the various mechanisms that have been proposed. The conclusion reached is that bread staling is a complex phenomenon in which multiple mechanisms operate. Polymer crystallizations with the formation of supermolecular structures are certainly involved. The most plausible hypothesis is that retrogradation of amylopectin occurs, and because water molecules are incorporated into the crystallites, the distribution of water is shifted from gluten to starch/amylopectin, thereby changing the nature of the gluten network. The role of additives may be to change the nature of starch protein molecules, to function as plasticizers, and/or to retard the redistribution of water between components. Nothing more definite can be concluded at this time.     

魔芋葡甘聚糖改善馒头品质的研究

为改善馒头老化,在馒头制作过程中,研究改良剂魔芋葡甘聚糖(konjac glucomannan,KGM)对馒头制品抗老化的影响。采用响应面方法(Plackett-Burman 试验)筛选并确定馒头的制作因素,并用正交试验对工艺进行优化。结果表明：面粉200g、加水量100.0mL、KGM 添加量12.5g、酵母粉2g、白砂糖1g、搅拌1h、醒发时间3h。根据优化条件下制得的馒头表皮光滑、高挺、比容大、内部结构细腻,并可改善馒头老化速度。     

Effect of Retrograded Waxy Corn Starch on Bread Staling

Waxy corn starch pastes (10%) were stored at 5 °C for up to 35 days, and the powder specimens of retrograded starches thus obtained were added to wheat flour for bread baking at a level of 5%. The effect of retrograded starch on the staling of bread was determined. The loaf which contained retrograded waxy corn starch, which was prepared by storing the 10% paste at 5 °C for 7 days, showed an increase in specific volume and the results of the sensory evaluation showed that it was very acceptable. During the storage of bread, the increase in firmness and decrease in degree of gelatinization were suppressed by adding retrograded waxy corn starch. The moisture content of bread crumbs did not relate to firmness. Added retrograded waxy corn starch decreased the final viscosity of flour. The crystalline region of retrograded waxy corn starch used for bread baking included longer chains from amylopectin which in raw starch occurred in the amorphous region.     

低温脱脂豆粉与大豆豆皮膳食纤维改善馒头品质及老化的比较

实验证明适量添加低温脱脂豆粉、大豆豆皮膳食纤维均可制作品质优良的馒头；适量低温脱脂豆粉、大豆豆皮膳食纤维均可作为改良剂提高馒头和面粉的品质、有效地延缓馒头老化；且大豆豆皮膳食纤维较低温脱脂豆粉改良效果好。     

小麦理化性质对馒头老化影响的研究

通过比较8种不同小麦的理化性质及其实验室制作的馒头,研究了小麦粉理化性质对客观评价法检测的馒头品质及老化现象的影响.研究表明:8种不同小麦品种理化性质间存在较大的差异,而馒头品质的质构参数间也存在较大的差异;利用SPSS软件进行相关性分析表明:直链淀粉含量与馒头芯第1天硬度呈显著的正相关;蛋白质含量和质量(由Brabender粉质参数反映)与硬度以及回复性的相关系数均较小;灰分含量与馒头芯第1天和第5天的硬度呈较显著负相关性,与第1天和第5天的回复值呈显著负相关;出粉率与第5天的回复值呈一定的负相关.     

黄原胶延缓面包陈化的研究

研究添加不同比例黄原胶的面包专用粉的流变学性质,并确定了黄原胶添加范围,然后进行面包实验,借助感官评定和质构仪相结合的评价方法评定试验面包。结果证明,添加黄原胶,面团吸水率、稳定时间和拉伸阻力均增加,黄原胶可与淀粉形成复合物阻止淀粉回生从而延缓面包陈化。     

主配料对面包老化的影响研究

通过实验系统研究了乳化剂SSL、水、油脂对面包老化及烘焙体积的影响。水、油做为面包主配料,对面包老化起着显著的延缓作用,乳化剂SSL是一种理想的面包抗老化剂。它们对增加面包烘焙体积有着显著的正面效果,体积与老化速率间的线性相关表明,这三种配料均通过增加面包体积而延缓了面包老化。     

Measurement of Starch Properties During Staling of Arabic Bread

The DSC and X-ray diffraction data showed that the starch crystallinity increased in Arabic bread (khaboos) samples during the storage period. The appearance of crystalline regions during ageing as shown by X-ray diffraction data could serve as an indication of the extent of staling that was observed in these khaboos samples. The information obtained from scanning electron microscopy could not be used for assessing the extent of staling of Arabic bread, but showed interesting differences in the gelatinization behaviour of starch granules in the crumb and crust areas. The crust areas, when viewed under the scanning electron microscope, show intact small as well as large starch granules. The limited amount of water available in the crust area of khaboos may be responsible for the incomplete gelatinization of starch granules.     

The Effect of Non‐Gluten Proteins on the Staling of Bread

As part of our studies on the mechanisms of bread staling, starch bread was used as a research tool that enables us to gain insights into the individual contributions that starch and gluten have on staling. Reconstitution experiments have demonstrated that bread of equivalent specific loaf volume stales at the same rate irrespective of protein concentration, or type of protein. However, other properties of bread, such as specific loaf volume, may be altered by specifically changing the protein component in the flour.