部分水解瓜尔胶的酶法制备及其对面包烘焙特性的影响〖

为研究部分水解瓜尔胶(partially hydrolyzed guar gum,PHGG)对面包烘焙特性的影响,以瓜尔胶(guar gum,GG)为原料,采用酶解法制备PHGG。在比较PHGG和GG基本组成差异的基础上,采用质构仪、低场核磁共振仪、差示扫描量热仪和九分嗜好评分法研究PHGG添加量对面包烘焙品质及储藏特性的影响。基本组成分析结果表明,与GG相比,PHGG的黏度和分子质量显著下降,分别为(118.80±0.62)mPa·s、8.1kDa。烘焙品质分析结果表明,添加PHGG对面包比容无显著影响,但可显著降低面包的烘焙损失率,从(14.08±0.77)%降低至(11.73±1.29)%;并赋予了面包更好的色泽。面包储藏特性研究结果表明:在7d储藏期内,PHGG显著提高了面包的保水率,从(77.48±0.43)%增加至(85.58±4.15)%;改善了面包的内聚性和回复性;促进了面包内部水分的迁移,进而增加了面包内部结构的稳定性,具有延缓面包老化的效果。此外,感官评价结果表明,PHGG添加组面包的感官评分高于对照组面包。PHGG添加量(质量分数)为2.5%~4.5%时可显著改善面包的烘焙品质、储藏特性和感官品质,研究旨在为PHGG在食品加工中的应用提供一定理论参考。     

木聚糖酶对面粉糊化特性和面包品质的影响

探讨不同添加量的木聚糖酶对面粉的糊化特性、面包焙烤品质以及面包贮存品质的影响.结果表明:添加木聚糖酶对面粉的糊化温度、衰减值、回生值影响不大,但可降低面粉的峰值黏度、最低黏度和最终黏度,木聚糖酶能有效地改善面包焙烤品质,显著增加面包比容,有效改善面包的硬度和弹性,明显的降低了面包的老化程度.当木聚糖酶添加量为10 mL/kg面粉时,面包焙烤品质及贮存效果最佳.     

中性木聚糖酶在面包制作中的应用

通过探讨不同浓度的中性木聚糖酶对面粉粉质、面包焙烤品质以及面包贮存过程中老化程度的影响 ,研究中性木聚糖酶作为焙烤添加剂的可行性。结果表明 ,中性木聚糖酶能显著地改善面粉的粉质 ,当添加量为 0 3mL/kg(面粉 )时 ,面团的形成时间可减少 5 0 %左右 ;能有效地改善面包焙烤品质 ,明显地增加面包的体积和比容 ,同时可以改善面包心的弹性和硬度 ,减小面包皮的硬度 ;酶添加范围为 0 0 5～ 0 48mL/kg(面粉 ) ,能增加面包的抗老化作用 ,贮藏 7d后 ,面包的硬度和弹性没有明显变化 ,延长了货架期     

谷朊粉对面包基础粉品质特性的影响

探讨不同添加量的谷朊粉对面包基础粉蛋白质的品质、流变特性及面包烘焙品质的影响。结果表明:谷朊粉可以明显增加面包基础粉的湿面筋含量、沉淀值和蛋白质含量,强化其流变学特性,有效改善面包烘焙品质,增大面包比容和高径比并改善其弹性和硬度。当谷朊粉添加量为10%时,面包烘焙品质最好。     

Effect of prebaking and frozen storage on the sensory quality and instrumental texture of bread

The effect of part‐baking, freezing, frozen storage, thawing and rebaking on the quality of bread has been investigated. Quality evaluation of the stored bread was done using sensory analysis, instrumental texture profile analysis (TPA) and cutting tests of the crumb and crust. It was found that frozen bread with 71% fraction of baking time showed high stability of sensory features and rheological parameters during the entire storage period (11 weeks) and, after thawing and rebaking, had superior quality in comparison with its frozen and thawed full‐baked (100%) counterpart. Second‐order regression showed that the optimal time for the initial prebaking lies within the wide range from 74 to 86% of the time needed for the full‐baking of unfrozen bread. It is therefore a good method for preventing the staling process and obtaining a product of a quality close to that of fresh, not frozen bread. It has also been shown that a fraction of baking time equal to 43% was too small to ensure desirable sensory and textural features of bread after its frozen storage and rebaking. © 2002 Society of Chemical Industry     

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。     

专用油脂对冷冻面团焙烤品质的影响

将以棕榈油和大豆油为原料制备的专用油脂应用于冷冻面团中,研究专用油脂对冷冻面团流变学特性影响及对冷冻面团焙烤面包品质的影响。结果表明：添加专用油脂制备的冷冻面团面包比容大、纹理细腻、口感柔和、品质良好;专用油脂可以有效地提高冷冻面团的筋力和延伸性,并能延缓冷冻面团因冻藏导致的焙烤品质下降,对延缓面包老化效果良好;确定专用油脂在冷冻面团中的添加量为配方中面粉质量的6%。     

An investigation of bread-baking process in a pilot-scale electrical heating oven using computational fluid dynamics

A computational fluid dynamics (CFD) model was developed for bread-baking process in a pilot-scale baking oven to find out the effect of hot air distribution and placement of bread on temperature and starch gelatinization index of bread. In this study, product (bread) simulation was carried out with different placements of bread. Simulation results were validated with experimental measurements of bread temperature. This study showed that nonuniform air flow pattern inside the oven cavity leads to uneven temperature distribution. The study with respect to placement of bread showed that baking of bread in upper trays required shorter baking time and gelatinization index compared to those in the bottom tray. The upper tray bread center reached 100 °C at 1200 s, whereas starch gelatinization completed within 900 s, which was the minimum baking index. Moreover, the heat penetration and starch gelatinization were higher along the sides of the bread as compared to the top and bottom portions of the bread.     

Comparative study of different bread baking methods: Combined ohmic – infrared,ohmic – conventional,infrared – conventional,infrared, and conventional heating

Developing bakery techniques is essential to improve the qualitative and quantitative parameters of the bread baking process. In this study, the influence of different baking methods was evaluated on baking kinetics, energy consumption, mechanical properties, volume expansion, and sensory parameters of the bread. The results showed that ohmic-conventional method increased the baking time compared with conventional baking. The baking time of the combined infrared–conventional was 63.0–73.7% lower than the conventional method. The maximum values of specific energy consumption and volume expansion were found in the combined ohmic-conventional method. The specific volume expansion, firmness, and shearing force of the baked samples under infrared-conventional conditions were higher than the infrared and infrared-ohmic conditions. The maximum energy efficiency was obtained using the oven-infrared method. The sensory evaluation indicated that the baked samples in the infrared-conventional method had higher scores of taste and flavor than the other baking methods (p < 0.05). Future studies to optimize the baking parameters on bread quality are recommended for improved results.     

螯合剂对L-抗坏血酸氧化作用影响的研究

研究了食品中常用螯合剂对L-抗坏血酸氧化作用的影响，研究结果表明：螯合剂螯合作用受pH值影响较大，受温度影响较小。面团的拉伸试验表明螯舍剂有效地延缓了L-抗坏血酸的氧化作用。面包烘焙试验进一步证实螯合剂可以使L-抗坏血酸氧化作用变慢，螯合剂与L-抗坏血酸的协同作用可以提高面包烘焙品质，其中柠檬酸作用最为明显。     

液体大麦精在面包烘焙中的应用

研究了液体大麦精的不同添加量对面团流变学特性和面包烘焙品质的影响,并进行了面包的贮藏试验,得出了大麦精面包中大麦精的最适添加量.研究发现,液体大麦精的添加会改变面团的流变学性质,对面包的理化指标有所改善.经过感官品质分析可得出:液体大麦精的添加在一定程度上提高了面包的口感,改善了面包的风味和内部结构.同时,面包添加液体大麦精,延缓了面包的陈化速率,延长了面包的保质期.试验结果显示,大麦精面包中大麦精的最适添加量为蔗糖替代量的60%.     

Effect of baking and amino acid supplementation on the protein quality of arabic bread

The effect of supplementation of flour with lysine, lysine-threonine, lysine-methionine, and lysine-threonine-methionine on the protein quality of Arabic bread was studied. In addition the effect of baking on the protein quality of non-supplemented and supplemented flour and bread was investigated. For the preparation of bread samples the dough was made in the laboratory and baked in a local bakery. Rats were used for evaluation of protein by protein efficiency ratio, weight gain and feed consumption. The results showed that the addition of 0.3 % L-lysine to flour improved the protein quality of flour and bread to a significant degree. Supplementation of lysine-fortified flour with 0.62% DL-threonine caused further improvement in protein quality, whereas methionine had no effect. Baking did not change the protein quality of lysine or lysine-threonine supplemented bread.     

Role of fat on the quality and shelf-life of gluten-free bread baked by Ohmic heating and conventional deck oven

The addition of fat to gluten-free (GF) bread can influence several quality attributes, such as texture and starch retrogradation. Therefore, the aim of this study was to investigate the influence of different fats on GF bread properties using two different baking methods (conventional and ohmic heating), in order to understand how these affect the physical bread quality, the formation of amylose-lipid complexes and its effect on crumb firming behavior. Fats (coconut, rapeseed, butter, and palm) with different physico-chemical properties, and physical state (solid, liquid) were tested in standard GF bread formulations. Results showed that fat significantly improved crumb pore uniformity. Crumb texture and pasting properties were mostly influenced by the type of fat, storage time and baking method. Staling was delayed in all breads added with fat due to the formation of amylose-lipid complexes, which were highest with palm fat and were usually higher when baked by ohmic heating.     

Increment Kinetics of Acidity in French Bread and Critical Control Point Analysis During Baking and Storage

This study analyzed the increment kinetics of acidity in French bread during baking and storage and discussed some critical control points based on the acidity of French bread. The reactions of acidity increments in baking and storage were first order reactions and the relationship between reaction rate and temperature fitted the Arrhenius equation. The activation energy of acidity increment during baking was 16.80 kJ/mol. Furthermore, by adding antioxidants, the activation energy of acidity increment in the storage increased from 14.50 to 19.25 kJ/mol. Antioxidants, such as 3-tert-butyl-4-hydroxyanisole, could be used to control the acidity increment in French bread. Finally, some critical control points in the production of French bread, which are important to the property of bread, include adjusting fermentation temperature, checking oil quality, adding appropriate amount of salt, and checking the cleanness of baking molds.     

马铃薯粉对面包烘焙特性与风味化合物的影响

以小麦面包为对照,研究马铃薯粉添加量为15%对面包烘焙特性的影响,并应用电子鼻以及顶空固相微萃取-气相色谱-质谱联用技术,分析马铃薯面包挥发性风味化合物的特征。结果表明,马铃薯粉的添加对面包的品质影响显著,马铃薯粉使面包的比容提高到4.12 mL/g,水分含量增加了7%,硬度减小了6 N,水分活度降低,面包的色泽和总体可接受程度明显提高,保质期和烘焙品质得到有效改善;对于风味,电子鼻主成分贡献率为97.3%,说明电子鼻能够很好地区分小麦面包和马铃薯面包的风味;顶空固相微萃取-气相色谱-质谱分析结果表明小麦面包和马铃薯面包的主要挥发性成分为酯类物质,添加马铃薯粉使各类风味化合物的相对含量发生变化,其中马铃薯面包中含有异薄荷酮、对薄荷-3-烯、1-甲基-4-(1-甲基亚乙基)-环己烯、丙二酸二乙酯等风味化合物,烯烃类物质相对含量和种类明显增多。     

添加HPMC对无麸质大米面包品质的影响

水稻是全球主导的粮食作物之一,作为无麸质食品的主要原料倍受青睐。但水稻中缺乏面筋蛋白,在发酵过程中难以形成持气性较好的网孔结构,所以很难获得理想的面包类发酵产品。本论文探讨了采用HPMC为面筋替代物制作无麸质大米面包的可行性,并研究了HPMC对大米面包品质的影响,从而为无麸质大米面包的制作奠定基础,为大米资源的广泛应用开辟新的途径。结果表明,当添水量提高到100%110%时,4%的HPMC可以作为面筋替代物,用以改善大米面团的品质,烘焙出优质、理想的无麸质大米面包,但其淀粉体外消化率和整体感官评价却受到影响。最后认为,应该把无麸质大米面包看作为一类新型的焙烤食品,不一定要完全适用小麦面包的评价体系。     

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.     

Two-dimensional CFD modeling and simulation of crustless bread baking process

A special type of baking oven was developed where crustless bread was made by gently baking the dough at controlled temperature by spraying water at prefixed intervals on the surface of the dough. In this study, a two-dimensional (2D) CFD model for crustless bread during baking has been developed to facilitate a better understanding of the baking process. Simultaneous heat and mass transfer from the bread during baking was successfully simulated. It was found that core temperature of the bread reached at 95 °C at the end of baking where as moisture of the bread satisfies the normal bread quality. The model can be successively applied to study the unsteady heat and mass transfer from the crustless bread during baking.     

膨化黑米粉对面包品质影响研究

以膨化黑米粉为主要原料,通过探讨添加膨化黑米粉对面粉粉质、面包焙烤品质及面包贮存过程中老化程度影响,以期制作高质量黑米面包。试验结果表明,添加膨化黑米粉对面团流变性有一定副作用,在不超过8%添加量时影响很小,若超过8%添加量,则性质急剧下降,不适于生产,通过焙烤实验,添加膨化黑米粉可大大改善面包风味,结合储藏实验,在添加量不超过8%情况下面包各理化指标变化不大。     

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。