老酵面团对碱工艺最佳pH值的研究

用老酵来发酵的面团其制品口感好，风味好。由于发酵过程产生有机酸对碱中和，如何控制对碱量，达到最佳风味效果，历来为面点工艺上的一个难点。研究证明，发酵面团对碱后立即制作，其面团的ｐＨ值在６．１５～６．２０区域内，制成品的效果很好，发酵面团对碱再醒发２５分钟后，其面团的ｐＨ值在６．１２～６．１５区域内，这时制成品的效果更好。     

浅谈调制好发酵面团的技术关键

发酵面团是我国传统面点制作中常用的四大面团之一,酵面制品也一直是深受大众喜爱的面点品种。如要制作出合格的酵面制品,自然要先调制好发酵面团。但是在实际操作中,人们却往往因为未能做到这一点而影响到酵面制品的质量。为此,笔者特根据自己多年的教学经验和烹饪实践,浅显地谈谈调制好发酵面团的技术关键。一、选料的注意事项选料是调制好发酵面团的关键之一,也是保证发酵面团质量的先决条件。所以,要调制好发酵面团,首先要把好面粉的质量关。目前,我国种植的小麦按其性质可分为硬麦和软麦两大类。硬麦具有胚乳坚硬、含蛋白质多、筋力大…     

米发糕固体老酵制作工艺研究

本试验采用单因素和正交试验对米发糕固体老酵制作工艺进行了优化。结果表明:以糯米为原料、安琪酒曲为酵种,于30℃糖化发酵60 h生产米酒;取早籼米浸泡过夜,添加米酒和煮熟并冷却的米饭(早籼米∶米酒∶米饭的质量比=1∶0.24∶0.1),磨浆;浆液于32℃发酵11 h,干燥后得到米发糕固体老酵。顶空固相微萃取/气相色谱-质谱分析结果表明,该固体老酵发酵的米发糕挥发性成分总含量为657.05μg/kg,而传统液体老酵发酵的米发糕仅为483.3μg/kg。感官分析表明本研究所得米发糕风味更加浓郁,品质更好,为米发糕的工业化生产奠定了基础。     

发酵温度和pH值对酱油产率的影响

酱油酿造过程中制曲的目的是培养米曲霉在原料上生长繁殖,以便在发酵时利用它所分泌的多种酶进行分解。发酵就是利用多种酶在一定的条件下,最后形成酱油的色、香、味、体。所以制曲所获酶活的高低是酱油发酵过程中分解好坏的关键,而发酵起始温度和 pH 值往往容易被忽视,本文对此做一论述:1 发酵温度的影响发酵起始温度的高低决定着发酵是否成     

面团pH对馒头膨松效果的影响

研究不同的酸味剂与小苏打作用对面团pH的影响,从而反映出馒头制品膨松效果的变化。结果表明,当面团的pH在6.40～6.60时制出的馒头色泽自然、口感好、膨松度好。对应得出几种较好的酸味剂进行复配制成膨松剂,并与酵母对比做馒头可达到酵母效果。该膨松剂配方为NaHCO3∶KAl(SO4)2∶C6H10O6∶淀粉=35∶18∶33∶14。     

面团pH对馒头膨松效果的影响

研究不同的酸味剂与小苏打作用对面团pH的影响,从而反映出馒头制品膨松效果的变化。结果表明,当面团的pH在6.40～6.60时制出的馒头色泽自然、口感好、膨松度好。对应得出几种较好的酸味剂进行复配制成膨松剂,并与酵母对比做馒头可达到酵母效果。该膨松剂配方为NaHCO3∶KAl(SO4)2∶C6H10O6∶淀粉=35∶18∶33∶14。      

pH值对碱溶法罗非鱼鱼糜制备及凝胶性质的影响

在pH0.5~12.5的范围内,采用碱溶法制备了罗非鱼鱼糜(TS)。研究表明,随着pH值的升高,TS蛋白回收率得到显著提高,但在pH值由11.5升至12.5时,得率仅提高11.56%,而碱液耗费却增加了77.65%;pH值的升高使溶解蛋白的ATP酶活性急剧降低(51.80%→0%),而表观疏水性则表现出增强趋势,表明pH值的升高促进了肌球蛋白的构象展开。电泳结果显示,pH值升高并未使等电点处可溶性蛋白及TS中蛋白组分发生明显变化。pH值的升高使TS白度先升高(75.40→80.50),之后下降(→76.20);TS凝胶破断力也表现出先升高后下降的趋势(290.00→335.20→278.80g),表明极端的碱性条件(pH12.0)会对TS凝胶品质产生负面影响。TS凝胶的电泳结果表明,不同pH值条件下提取的TS所制备的凝胶蛋白组分之间没有明显差别,并且TS凝胶形成过程中没有显著的肌球蛋白交链发生,意味着TS中内源谷氨酰胺转胺酶(TG酶)活性相对于传统鱼糜变得很低,这可能是由于在等电点处离心时TG酶与TS发生了分离。     

铅测定中最佳pH值的选择

铅测定中最佳ｐＨ值的选择冯一兵，刘会（东北农业大学食品系，哈尔滨１５００３０）王辉（哈尔滨市１３４中）罐头食品的马口铁焊锡中铅含量高达４０％～６０％，因此罐头食品由于马口铁焊锡部分溶出而受污染。当人们经常食用含铅的食品时，铅能在人体内积累，引起人们慢...     

发酸面团加碱量的控制研究

本文研究馒头生产中发酵面团变酸时加碱量的控制。加碱量可以滴定酸度所消耗的0.1N的NaOH的毫升数计算出，能有效地控制馒头的生产质量。     

不同pH值培养乳酸球菌对其发酵活力的影响

为了确定嗜热链球菌St-1最适生长pH值,研究了在不同pH值条件下培养嗜热链球菌St-1,对其活菌数、发酵活力及菌体形态学特征的影响.结果表明,当培养体系的pH值恒定在6.0时,其活菌数和发酵活力最高;对比发酵活力曲线和生长曲线表明,发酵活力最好时的活菌数并不是最高的;对比不同恒定pH值条件下培养活力最高时的嗜热链球菌St-1菌体形态特征发现,嗜热链球菌St-1的链越长,其发酵活力越低,链越短发酵活力越高.     

Effect of Alkali Dipping on Dough and Final Product Quality

ABSTRACT: The effects of alkali dipping on starch, protein, and color changes in hard pretzel products have never been researched. Experiments were conducted to mimic reactions occurring on the pretzel dough surface. Dough was dipped in water or 1% sodium hydroxide solution at different temperatures between 50°C and 80°C. Protein and starch profile after dipping were analyzed. Color development on pretzel surface following the extraction of pigments from flour was investigated. Whole dough and pretzel samples were also made at pilot plant and the properties were analyzed. Only starch granules on the dough surface were gelatinized following dipping. Amylose-lipid complex dissociated at a lower temperature with alkali treatment but were not dissociated, even at high-temperature dipping in water. Treating the dough at 80°C in alkali solution resulted in the hydrolysis of proteins into smaller peptides that could be not precipitated by trichloroacetic acid (TCA). Dough surface color was different following pigment extraction from flour but not significantly different following baking. The results suggest that the color that developed on pretzel surface was not due to pigments present in the flour but was contributed by the reaction within or between the starch and protein hydrolysis derivatives during baking.     

Leavened Dough pH Determination by an Improved Method

pH measured on a 10% slurry may overestimate values on canned biscuit doughs because of carbon dioxide evolution during slurry preparation. Therefore, a pH method using a surface pH electrode was developed and used to measure pH of biscuits in sealed cans and after opening. pH increased upon opening and continued to increase gradually for 5 min. The slurry method overestimated true dough pH and did not show pH change with time. pH of yeast-leavened bread dough measured by the slurry method was also higher than that by the surface method. The surface pH electrode is a reliable, accurate method of pH determination in leavened doughs.     

Effect of Temperature on the Solubility of CO2 in Bread Dough

Dough expansion during fermentation is caused by CO₂ production by yeast, and its transfer from liquid state in the dough liquor to gaseous phase in the gas cells. The liquid-gas equilibrium is controlled by the solubility of CO₂ in the dough and by the Henry coefficient. The solubility of CO₂ in bread dough was measured for different temperatures with a specific device based on the evolution of the pressure during fermentation at constant volume. The measurements range from 15 to 40°C. Data obtained was extrapolated to 0 and 50°C. Values were found between 1.6 × 10^?5 and 5 × 10^?6 g CO₂ kPa^?1 g^?1 LPD, at 0 and 50°C, respectively (LPD: Liquid Phase of Dough).     

纺织品水萃取液pH值差异指数研究

研究了纺织品水萃取液pH值差异指数测定过程的异常现象,并分析了可能的原因,指出新标准GB/T 7573-2009取消差异指数是合理的。     

浅议卤水净化过程中pH值的影响及调控

通过认识卤水pH值对制盐设备的影响及对卤水反应速度、沉降速度及精卤质量的影响，提出调节控制卤水pH值的措施及方法。     

冷冻面团中影响面团筋力因素

面团筋力影响冷冻面团稳定性,而面团筋力又受到面团加水量,面粉种类,添加剂等影响。可通过选择面粉种类,改变加水量,添加添加剂等手段提高冻冷面团稳定性。     

添加膳食纤维对面团及面制品品质的影响

越来越多的证据表明,膳食纤维的摄入量与慢性疾病之间有很密切的联系.但是膳食纤维的摄入量通常低于推荐量,因此,研究和开发高膳食纤维食品是很有必要的.本文综述了近几年国内外对高纤维面制品的研究进展,并对不同膳食纤维对面团流变学性质的影响作了总结,以期推动这方面产业的发展.     

牛乳的PH值和酸度

对牛乳酸度的来源及表示方法作了详细的介绍，并对酸度升高影响牛乳的稳定性也作了论述     

芽麦粉添加量对中筋粉面团特性的影响

本文以中筋面粉为原料,分别添加5%、10%、15%、20%和25%的芽麦粉(SWF),利用快速黏度分析仪、粉质仪和拉伸仪分析了芽麦粉添加量对中筋粉面团特性的影响。结果表明,芽麦粉的添加使面粉的糊化特性均迅速下降,但随着芽麦粉添加量的增加,下降趋势逐渐变缓;对于面粉的粉质特性,形成时间、稳定时间和粉质指数等参数均呈下降趋势,但面粉的吸水率在芽麦粉添加量超过20%时才会有明显的下降;芽麦粉添加量的增加会降低面团的拉伸特性,但是醒发时间的延长会减缓这种变化,在添加量为5%时,拉伸能量和最大阻力等参数还会略有增加。总体来说,当添加5%芽麦粉时,糊化特性会大幅度降低,面团的稳定时间在中筋粉范围内,延长面团醒发时间可以增加面团的筋力、可塑性和弹性。