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。     

豌豆膳食纤维粒径对面包面团及面包品质的影响

研究豌豆膳食纤维的添加及其粒径对混合粉（膳食纤维-小麦粉）的粉质特性、面团发酵持气特性、面包质构及面包老化的影响。结果表明：随着添加的豌豆膳食纤维的粒径减小,膳食纤维与小麦粉的混合粉的吸水率增加,面团形成时间增加,而面团稳定时间显著降低;添加豌豆膳食纤维后,面团发酵的最大高度、最终高度显著降低,面团的稳定性和面团的持气性也明显下降;膳食纤维粒径在150 μm～180 μm时,面团的持气性最大;面包的硬度随着添加豌豆膳食纤维粒径的减小而增加;随着豌豆膳食纤维粒径的减小,贮藏期内面包硬度呈增加趋势;添加6%豌豆膳食纤维可显著延缓面包的老化。     

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％。     

水不溶酵母多糖对小麦粉粉质、面团流变特性及其面包品质的影响

水不溶酵母多糖(Insoluble yeast polysaccharide,ISYP)富含β-葡聚糖，是优良的膳食纤维来源。文章探讨ISYP对小麦粉粉质特性、面团流变特性、面包品质和抗老化性能的影响。根据粉质和拉伸研究结果表明，少量添加ISYP对面筋网络的影响不大。面团发酵流变与动态流变结果显示，添加ISYP的面团，其发酵高度增加、产气减弱、持气能力增强、网络结构增强。面包C-cell图像分析结果表明，ISYP的加入能够增加面包比容和切片细胞面积，适量添加ISYP的面包粗细胞的体积及分布变化不明显。面包储藏实验结果表明，ISYP能够降低面包在储藏过程中硬度增加速度，延缓老化。因此，适量ISYP可用于改善小麦面包的品质并延缓面包的老化，对营养面包的开发具有重要的指导意义。     

面包新鲜度量化指标的测定及研究

利用先进的物性测试仪对面包储存期间的物性参数进行了测定,得出了面包老化的物性参数变化规律,探讨了面包老化的机理,分析了面包老化过程中硬度与弹性的相关性,确定了面包老化的定量物性参数范围,为面包老化定性分析向定量参数分析转变作了有益的探索。     

橄榄绿链霉菌木聚糖酶组对面包品质的改善

本文研究了橄榄绿链霉菌(Streptomyces olivaceovirdis)E-86产生的分子量约1200kDa木聚糖酶组对面包品质的影响。焙烤试验结果表明，添加20ppm木聚糖酶组的面包比容增加了38．8％，新鲜面包芯硬度降低了1／3，面包老化速率也明显减小。该木聚糖酶组具有内切酶和切枝酶的活性，在面粉中水溶性和水不溶性阿拉伯木聚糖组成比例范围内，对水不溶性阿拉伯木聚糖的降解作用比水溶性阿拉伯木聚糖快。因此，该酶组能够改善面包的品质。     

四种无磷持水物质对低温熏煮香肠持水性的影响

开发无磷持水剂是生产健康肉制品的要求之一。将无磷持水剂山梨糖醇、海藻酸钠、柠檬酸三钠、碳酸氢钠,分别加入低温熏煮香肠中,研究其对熏煮香肠的持水作用,并与复合磷酸盐的持水作用进行了对比。结果表明:四种持水剂都能够改善产品的持水性,其中海藻酸钠(添加量为0.3%)和碳酸氢钠(添加量1.0%)的加入能使产品的水分含量提高3%～4%。综合考虑各因素,合适的添加浓度为:山梨糖醇8%、海藻酸钠0.3%、柠檬酸三钠0.5%、碳酸氢钠1%。     

菊糖对面团流变学特性及面包品质的影响

添加不同比例的菊糖于面包粉中,对面包面团特性及面包品质变化进行研究。结果表明,添加菊糖能够明显影响面包粉的粉质和拉伸等流变特性。随着菊糖添加量的增加,面团吸水率显著下降,面团形成时间和面团稳定时间延长,弱化度减小;添加菊糖可增加面团的延伸度、拉伸面积和拉伸阻力;面粉的峰值黏度、最终黏度、衰减值和回生值也显著降低,其淀粉老化速度得到延缓;弹性模量和黏性模量显著增加,面团的网络结构得到改善;但面团发酵体积显著减小,使得面包的比容减少,面包初始硬度显著性增加,在面包贮藏过程中,添加2.5%、5%、7.5%的菊糖面包硬度明显低于未添加菊糖的面包硬度,说明适宜添加量的菊糖能够改善面包内部结构,降低其贮藏过程中的硬度和老化速率,延长面包货架期。     

溶血磷脂在面包中应用的探讨

磷脂酶A1催化酶解大豆磷脂获得溶血磷脂。采用单因素试验研究溶血磷脂在面包中的应用,发现溶血磷脂在面包中添加量在0.65%～0.9%范围内能有效增大面包的体积。利用质构仪对添加溶血磷脂面包和浓缩大豆磷脂面包储存期间的物性参数进行了测定,硬度值变化表明,溶血磷脂能有效延缓面包的老化。     

不同贮藏时间和方式对马铃薯面包老化的影响

通过测定马铃薯面包比容、老化热焓、色泽、质构、水分活度并结合电子鼻进行分析,探究不同贮藏时间和方式对马铃薯面包老化特性的影响。试验结果表明:不论常温还是冷藏保存马铃薯面包,都会显著降低马铃薯面包的弹性、水分活度、比容,大大提升马铃薯面包硬度、咀嚼性、老化速率,使面包的品质风味下降。在贮藏过程中,风味差异较大,电子鼻可以有效区分贮藏期间不同天数马铃薯面包,同时两种保存方式下样品的比容、质构、色泽的测量值与电子鼻数据之间相关性较好,电子鼻可有效预测马铃薯面包的品质。综合分析可知,常温贮藏法贮藏效果明显优于冷藏贮藏法。     

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     

脱毒亚麻籽粕在面包中的应用研究

由于亚麻籽富含各种营养成分,目前正作为一种功能食品来源。本文将亚麻籽粕脱除毒性物质生氰糖苷后,将其添加到面粉中,以研究其对面团特性、面包烘焙品质以及面包贮存过程中老化程度的影响。结果表明,水煮法处理对除去生氰糖苷有较好的效果,通过正交实验确定以2%的比例添加可改善面团特性及面包烘焙品质,并增加面包的抗老化作用,延长了货架期。     

Effect of freezing and frozen storage on the staling of part-baked bread

The effect of part-baking, freezing, frozen storage, thawing, rebaking on the aging behaviour of bread was evaluated. The amylopectin modification during the process was assessed by differential scanning calorimetry (DSC), while changes in bread quality were followed by crumb hardness measurements. During frozen storage no retrogradation of amylopectin was detected in the part-baked dough. When analysing the aging of the rebaked samples, it was observed that the time of frozen storage produced a progressive increase of the retrogradation temperature range of the amylopectin, and also great energy was required for amylopectin melting at longer storage period, indicating that structural changes of amylopectin were produced during frozen storage. Regarding the quality of the fresh bread resulted after rebaking, crumb hardness increase with the time of frozen storage, and also the hardening rate during aging was dependent on that time. Crumb hardness results of the fresh bread and also DSC studies indicate that some changes are produced during the frozen storage.     

Effect of damaged starch levels on flour-thermal behaviour and bread staling

The effect of the amount of damaged starch in two different flours (wheat and triticale) on the bread quality and its behaviour during storage has been analysed. Two wheat and one triticale flour cultivars were milled in a disc mill to obtain different levels of damaged starch. Differential Scanning Calorimetry (DSC) and Rapid Visco Analyser (RVA) were used to characterize the flour properties and TA-XT2 textural analyses were made on breadcrumb. The effect of the damaged starch content on the bread firming, the amylopectin retrogradation and starch-pasting properties were studied in order to establish any relationship between damaged starch and bread staling. DSC analysis showed that the damaged starch content changed the thermal behaviour of flour–water mixtures: the higher the levels of damaged starch the lower the starch-gelatinization enthalpy and the higher the melting enthalpy of amylose–lipid complexes. The amount of amylopectin retrogradation and breadcrumb firming increased with the damaged starch content at the beginning of storage time; however, differences were decreasing at final storage time. The flour viscosity during pasting decreased as their damaged starch content increased.     

海藻酸丙二醇酯对全麦冷冻面团冻藏稳定性和烘焙特性的影响

本文研究了海藻酸丙二醇酯（Propylene glycol alginate,PGA）对全麦冷冻面团冻藏期间稳定性的影响,并探究了冷冻面团烘焙面包品质的变化。将0.3%的PGA加入全麦面团,通过测定冷冻面团冻藏1、2、3、4和5周后发酵特性、流变特性、蛋白质二级结构、微观结构以及面包的比容、质构特性、内部纹理结构和老化程度等,研究冷冻面团冻藏期间的稳定性。结果表明,随着冻藏时间的延长,添加PGA的冷冻面团在冻藏5周后具有较好的保水性,其发酵特性及流变特性相对于对照组均有所改善。冻藏5周后,对照组与PGA组其面包比容分别下降了19.872%和14.153%;面包硬度分别升高了64.186%和36.386%;气孔表面积分率分别下降了3.497%和2.300%;老化焓值分别上升了65.142%和42.416%。添加PGA能延缓冷冻面团冻藏期间β-折叠含量的上升和β-转角相对含量的下降。电镜扫描图（SEM）显示,随着冻藏时间的延长,PGA组的冷冻面团孔洞数目相比对照组明显减少且大小均匀,面筋网络结构完整性和连续性提高。研究结果表明PGA可以有效地延缓冷冻面团在冻藏期间的品质劣变,维持冷冻面团的稳定性并提高面包的烘焙特性。     

Effect of frozen storage time on the bread crumb and aging of par-baked bread

The effect of frozen storage time of par-baked bread on the bread crumb and staling of bread obtained after thawing and full baking is described. The moisture content, hardness and retrogradation enthalpy of the amylopectin were determined in the par-baked bread and in the full baked bread after 7, 14, 28 and 42 days of frozen storage at −25 °C. In addition, the effect of frozen storage on the crumb microstructure was analyzed by cryo scanning electron microscopy (Cryo-SEM). The moisture content of both partially and full baked bread decreased with the time of frozen storage. The crumb hardness of the par-baked bread after different periods of frozen storage was kept constant, while that of their full baked counterpart increased with the time of frozen storage. In both types of breads, the enthalpy of amylopectin retrogradation did not vary with the period of frozen storage. The staling, measured as hardness increase and amylopectin retrogradation, increased along the frozen storage. The changes observed on the frozen par-baked bread after thawing were attributed to the damage of bread structures produced by the ice crystallization, and the microstructure study support that conclusion.     

Investigation of physicochemical properties of breads baked in microwave and infrared-microwave combination ovens during storage

Staling of breads baked in different ovens (microwave, infrared-microwave combination and conventional) was investigated with the help of mechanical (compression measurements), physicochemical (DSC, X-ray, FTIR) and rheological (RVA) methods. The effect of xanthan-guar gum blend addition on bread staling was also studied. Xanthan-guar gum blend at 0.5% concentration was used in bread formulation. The gums were mixed at equal concentrations to obtain the blend. After baking, the staling parameters of breads were monitored over 5 days storage. During storage, it was seen that hardness, retrogradation enthalpies, setback viscosity, crystallinity values, and FTIR outputs related to starch retrogradation of bread samples increased, whereas FTIR outputs related to moisture content of samples decreased significantly with time. The hardness, retrogradation enthalpy, setback viscosity, and crystallinity values of microwave-baked samples were found to be highest among other heating modes. Using IR-microwave combination heating made it possible to produce breads with similar staling degrees as conventionally baked ones in terms of retrogradation enthalpy and FTIR outputs related to starch retrogradation. Addition of xanthan-guar gum blend decreased hardness, retrogradation enthalpy and total mass crystallinity values of bread samples showing that staling was delayed.     

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.     

不同酶制剂对面包品质影响

研究葡萄糖氧化酶(GOD)、转谷氨酰胺酶(TG)、脂肪酶和真菌淀粉酶对面包比容、出品率、硬度及水分迁移影响。结果表明,葡萄糖氧化酶能增大面包体积、降低出品率、提高面包芯硬度和有效延缓贮藏期水分散失;转谷氨酰胺酶能增大面包体积、降低出品率、降低面包芯硬度,对水分保持作用不明显;脂肪酶会减小面包体积、增加出品率、明显降低面包芯硬度和保持面包芯水分;真菌淀粉酶能有效增加面包体积、降低出品率、降低面包芯硬度,对水分保持无明显作用。     

卡拉胶对面包品质影响

研究卡拉胶对面包质构参数如硬度、弹性、咀嚼性及水分含量、水分活度影响。结果表明,增加卡拉胶添加量,面包比容减小、出品率增加;随贮藏时间延长,面包硬度增加、弹性下降、咀嚼性值不断增大,添加卡拉胶可有效降低面包硬度、咀嚼性值,且添加量越大,硬度、咀嚼性值降低越大;卡拉胶添加量增大有利于降低弹性下降,但整体上对面包弹性影响不大;且卡拉胶添加量增加可减缓面包水分含量、水分活度减小趋势。可见,添加卡拉胶有利于延缓面包老化,可改善保质期内面包品质。