酶制剂对面包品质的影响

目的 研究3种酶制剂及其复合酶对面包品质的影响。方法 采用单因素实验分析木聚糖酶、葡萄糖氧化酶、转谷氨酰胺酶这3种酶制剂对高筋面粉的粉质特性和面团微观结构的影响,并探讨这3种酶制剂对面包比容、质构、感官和老化特性的影响。以面包感官作为评价指标,通过正交实验优化复合酶对面包品质的改良效果。结果 在单因素实验中,添加适量的3种酶制剂均可以显著改善高筋面粉的粉质特性、面团内部的网络结构以及面包的品质。正交实验确定了复合酶制剂最佳组合为：4 mg/kg木聚糖酶、2 mg/kg葡萄糖氧化酶和8 mg/kg转谷氨酰胺酶,按此配方制作的面包质构更好、比容更大、感官评分更高,且具有显著的抗老化效果。结论 酶制剂可以有效改善面包的品质,为酶制剂在面包中的应用提供理论参考依据。     

麦芽糖淀粉酶对面包品质及面团特性的影响

研究枯草芽孢杆菌来源的麦芽糖淀粉酶对面包品质及面团特性的影响,为深入了解酶制剂在烘焙产品中的作用提供理论依据。本实验主要研究了麦芽糖淀粉酶(添加量0%、0.02%、0.04%和0.06%)对面包比容、质构、贮藏期间面包保水性、质构、感官品质及面团流变学特性的影响。结果表明:面包保水性随麦芽糖淀粉酶添加量的增加而显著提高(P<0.05),而且麦芽糖淀粉酶能显著延缓面团黏度和回生值的增加(P<0.05),改善面团品质。当面包贮藏天数的增加,麦芽糖淀粉酶还能延缓面包硬度和咀嚼性的增加,减缓贮藏期面包品质下降(P<0.05)。其中,添加0.04%的麦芽糖淀粉酶能够明显延缓面包老化,对面团淀粉糊化特性影响较小。面包贮藏第7 d时,能减少水分损失36.92%,保持面包弹性。因此,麦芽糖淀粉酶能够延缓面包老化和面包品质下降。     

影响面包老化因素及抗老化途径

该文综述近年来国内外有关面包老化研究成果,介绍影响面包老化主要因素,并从改变原辅料、添加酶制剂、乳化剂和亲水性胶体等方面论述抑制面包老化方法。     

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.     

复配型面包品质改良剂在板栗面包中的应用

首次利用面包品质改良剂对板栗面包的焙烤品质及延缓老化的作用效果进行了研究。依据各种改良剂对面包防老化效果的不同,确定出试验用改良剂为黄原胶、α-淀粉酶、单甘酯。分别以三种面包品质改良剂做单因素实验,实验结果表明:当黄原胶以板栗粉与面包粉总重量的0.5%、1%、1.5%、2%的比例添加到板栗面包中时,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1%时,不但板栗面包具有良好的焙烤品质而且延缓了面包的老化;当α-淀粉酶按不同的比例添加时,在添加量为0.01%或0.005%时,板栗面包的抗老化效果及焙烤性能均较对照组好,但当添加量为0.03%、0.06%时,致使板栗面包芯发粘,面包醒发性能受阻;在单甘酯的单因素实验中,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。选择几种改良剂的较优添加量做正交实验,实验结果表明:在板栗面包制作过程中按板栗粉及面包粉总重用量添加1.5%黄原胶、0%α-淀粉酶、0.3%单甘酯时,板栗面包具有良好的焙烤品质,且在贮存7d后,面包芯硬度比对照组下降44%,延缓了面包老化,延长了其货架期。     

蛋氨酸在面包中应用研究

通过添加不同量蛋氨酸研究其对面粉粉质拉伸特性及对面包焙烤品质和贮存过程中老化程度影响。结果表明:蛋氨酸可改善面团流变特性,适量添加可增加面包体积和比容,改善面包芯硬度和组织结构,对增加面包蛋白质含量和持水能力、提高面包营养和感观品质有促进作用,同时能有效延缓面包老化,延长其货架期;蛋氨酸最适添加量为0．15％。     

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

用发酵小麦粉制成酸面团,用发酵小麦麸皮基质制成酸面团,通过采用不同发酵基质酸面团来分析对酵母面团体系面包烘焙及老化特性产生的影响。结果表明:与小麦粉制作面包相比,引入小麦酸面团以及小麦麸皮酸面团对面包比容与感官品质有很大提升,能够改变面包的老化特性,并且,酸面团添加量的不同,其比容、感官、老化特性也有所不同。     

酶制剂对于麸皮面包的改良研究

研究了纤维素酶、真菌木聚糖酶、葡萄糖氧化酶、真菌α-淀粉酶对麸皮面包品质的影响。结果显示,四种酶单独使用都能很大程度上增大麸皮面包的体积,改善其质构,降低其老化速率。在此基础上,利用正交实验得出复配型酶制剂的最佳配方。     

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。     

酶制剂在面包加工中的应用

本文综述了各类酶制剂在面粉品质改良中的作用原理及作用效果,同时探讨了各类酶制剂对面包品质的改良作用。     

Method to Measure Microwave-Induced Toughness of Bread

Bread slices were placed in a custom holding device and cut with a wire cutter attached to a TA.XT2 Texture Analyzer. The peak force required to cut the bread was taken as a measure of toughness. Microwave reheated, conventionally reheated, and unheated bread were compared as were the effects of bread age (firming). Certain emulsifiers were added and microwave toughness of bread compared. Use of certain emulsifiers and increasing the water content of the bread (through use of fiber) decreased toughness of microwave-reheated bread. The developed method was effective in measuring microwave heating induced toughness.     

Effects of particle size in wasted bread flour properties

Bread is wasted at different stages in the food value chain, mainly in industry and retail markets. Wasted bread can be milled into flour to be used in the elaboration of other food products. Milling can generate flours with different particle sizes that influence their properties. This study analysed the effect of particle size (200, 500 and 1000 μm) on the hydration, pasting and gel properties of flours elaborated with four different stale breads. Bread flours show a higher cold water absorption capacity and a lower oil absorption capacity than wheat flour. No differences in water absorption properties after heating were observed. The viscosity curves of bread flours presented lower values than wheat flour curves, and the gels obtained were weaker. Bread flour properties were not influenced by different particle sizes. Therefore, a less aggressive milling, with a lower energy cost, can generates flours with properties similar to finer flours.     

Effect of amino acids on Maillard reaction product formation and total antioxidant capacity in white pan bread

Maillard reaction products (MRPs) can be an important dietary antioxidant source. Bread is the most popular bakery product; however, limited information is available on the antioxidant activities of MRPs generated during bread-baking. This paper reports the effect of different amino acids on bread properties, melanoidin formation and antioxidant activities. Totally six amino acids at four different levels were evaluated. Increasing the amount of amino acid led to darker bread crust, higher melanoidin content and stronger antioxidant activity. Among the six amino acids, bread with glycine had the highest melanoidin content and ABTS radical scavenging activity up to 1079.77 ± 8.43 μmol TE mg⁻¹. Bread with lysine had the highest DPPH radical scavenging activity up to 281.97 ± 10.52 μmol TE mg⁻¹. Bread with alanine had the highest crust metal chelating activity compared with others. Adding certain dietary amino acids is a potential approach to enhance the antioxidant capacity of bread products.     

谷氨酰胺转氨酶对藜麦-小麦面团及面包品质的影响

为开发烘焙品质较好的藜麦-小麦粉面包,利用谷氨酰胺转氨酶对其进行改良。从藜麦-小麦粉的粉质参数、糊化特性、面团质构、面包烘焙品质及老化特性等方面研究谷氨酰胺转氨酶(transglutaminase,TGase)对藜麦-小麦粉品质的影响,综合评价TGase对藜麦-小麦粉面团、面包品质的影响。结果表明,TGase增大混粉体系的吸水率、延长稳定时间。增大混合粉体系的糊化黏度、抑制体系的老化及回生。随着TGase的添加量的增大,面团硬度、弹性、黏聚性增大,当超过1.0%时,变化不显著(p>0.05)。面包品质结果表明,TGase的加入改善面包的持气能力,增大比容、感官评分、弹性及黏聚性,降低了面包的硬度,但是高剂量的TGase(>1.0%)会导致交联过度,面包品质降低。老化特性结果表明,TGase的加入使得面包老化程度降低,抑制面包老化。     

Performance of wild Saccharomyces and Non-Saccharomyces yeasts as starter cultures in dough fermentation and bread making

The use of wild Saccharomyces and non-Saccharomyces yeasts might result in bread with different and attractive sensory characteristics. This study aimed to evaluate the performance of Saccharomyces and non-Saccharomyces yeasts as starter culture in dough fermentation to bread making and the physicochemical parameters and aromatic profile of bread. All 26 wild yeasts strains isolated from Brazilian Cerrado fruit and tree bark were osmotolerant, and 19.4% were able to ferment maltose. Candida tropicalis ART101.3 and Saccharomyces cerevisiae SC5952 had the best growth capacity under high concentrations of glucose and maltose. Also, they were resistant to lyophilisation. Kinetic parameters of bioreactor cultivations showed high cell growth and lower generation time with 10 g L⁻¹ maltose. Bread produced with C. tropicalis ART101.3 and the control bread had similar physicochemical properties and acceptance of consumers. Bread with S. cerevisiae SC5951 had a lower specific volume and a different colour than control bread; however, the consumers found no significant difference. More than 70% of the consumers demonstrated purchase intention of bread produced with both wild yeasts. The present study shows the potential of native Cerrado yeasts to be used and exploited in industrial processes and contributes to the diversification of bread starter cultures.     

Optimization of Gluten-Free Formulations for French-Style Breads

ABSTRACT:  The formulation of gluten-free bread, which will be suitable for patients with coeliac disease, was optimized to provide bread similar to French bread. The effects of the presence of hydrocolloids and the substitution of the flour basis by flour or proteins from different sources were studied. The added ingredients were (1) hydrocolloids (carboxymethylcellulose [CMC], guar gum, hydroxypropylmethylcellulose [HPMC], and xanthan gum), and (2) substitutes (buckwheat flour, whole egg powder, and whey proteins). The bread quality parameters measured were specific volume, dry matter of bread, crust color, crumb hardness, and gas cell size distribution. Specific volume was increased by guar gum and HPMC. Breads with guar gum had color characteristics similar to French bread. Hardness decreased with the addition of hydrocolloids, especially HPMC and guar. Breads with guar gum had the most heterogeneous cell size distribution, and guar gum was therefore selected for further formulations. Bread prepared with buckwheat flour had improved quality: an increased specific volume, a softer texture, color characteristics, and gas-cell size distribution similar to French bread. Bread with 1.9% guar gum (w/w, total flour basis) and 5% buckwheat flour (of all flours and substitutes) mimicked French bread quality attributes.     

Effects of Waxy Wheat Flour and Water on Frozen Dough and Bread Properties

ABSTRACT:  The quality of bread made from frozen dough is diminished by changes that occur during freezing. New cultivars of waxy wheat flour (WWF), containing less than 2% amylose, offer unique properties for the production of baked products. In this study, dough properties and bread quality were investigated at various levels of WWF (0% to 45% flour weight) and water (55% to 65%). Dough stickiness increased with higher levels of WWF and water. During frozen storage, dough with greater WWF and lower water had less change in stickiness. Maximum resistance to extension (MRE) decreased with higher WWF and water. Dough with greater WWF and less water had less change in extensibility after frozen storage. Dough with greater WWF and water was more extensible. Nuclear magnetic resonance (NMR) studies showed that frozen dough with higher WWF content had lower transverse relaxation ( T ₂) time of 9 to 11ms. After frozen storage, dough with higher WWF still showed lower T ₂. Dough with 15% WWF had higher yeast activity. Bread made from 15% and 30% WWF had higher volume in bread made from unfrozen and frozen dough. Bread firmness decreased with higher amounts of WWF and water. This research demonstrated that specific combinations of WWF and water produced a better quality of frozen dough and bread.     

Quality of bread made from ozonated wheat (Triticum aestivum L.) flour

BACKGROUND: Ozone gas could be used as a fumigant during grain and flour storage. Experiments were conducted to determine the effects of exposure to ozone and the effects of blending ozone‐treated flour with control flour on flour functionality and bread‐making quality. RESULTS: Ozone treatment oxidized lipids, increased brightness and reduced the yellow hue of flour, and increased peak viscosity and setback viscosity of flour. Bread made from flour treated with ozone at 1500 mg kg^?1 for 4.5 min and bread made from flour blended with 100 g kg^?1 ozonated flour had good crust color and a whiter crumb and had more crumb cells, which resulted in a greater specific volume of the bread when compared with control flour. Flour functionality declined as ozone exposure increased beyond 9 min and as the concentration of ozonated flour increased beyond 200 g kg^?1. CONCLUSION: Bread made from flour exposed to ozone for 4.5 min or flour that contained 100 g kg^?1 fully ozonated flour had greater specific loaf volume and whiter crumb compared to bread made with control flour. Exposure of flour to ozone for longer times (9–45 min) and higher blends (200–1000 g kg^?1) deteriorated quality of bread. Copyright © 2011 Society of Chemical Industry     

质构仪在面团和面包品质评定中的应用研究(英文)

以八种品牌面粉为试验材料,采用英国 CNS-FARNELL 公司制造的质构仪测试了面团的硬度、弹性、粘力、粘着性、断裂力、断裂能量、断裂回复形变程度、回复能量、回复形变程度等九种指标,并通过相关分析研究了这些指标与面包品质(面包体积和弹性变化率)以及与小麦面粉的品质性状的相互关系。研究结果表明:面团的硬度、粘力与面包的体积呈正相关,相关系数分别为 0.546、0.568,弹性与面包的体积呈负相关,相关系数为-0.606;粘力与24h后室温下弹性变化率呈显著的正相关,相关系数为0.707。面团的质构特性与面粉的品质指标的相关性也非常明显。     

预糊化变性淀粉在麻糬面包中的应用

本文研究了预糊化木薯变性淀粉、预糊化马铃薯变性淀粉、预糊化玉米变性淀粉和预糊化大米粉对麻糬面包的感官评价、比容、弹性的影响,分析了预糊化变性淀粉的布拉班德粘度曲线,结果表明,预糊化木薯变性淀粉与预糊化马铃薯变性淀粉制作的麻糬面包口感及外观较好,而预糊化玉米变性淀粉与预糊化大米粉制作的产品口感不佳、比容小,预糊化木薯变性淀粉与预糊化马铃薯变性淀粉质量比为1:1时,麻糬面包加工性能好、口感清爽、弹性强、比容较大、保型性佳。