面粉中二硫键含量对面片水分分布状态的影响

为明确面粉中二硫键对面片水分状态的影响,先用亚硫酸钠处理小麦面筋蛋白以改变其二硫键含量,然后将其加入面粉中,得到不同二硫键含量的混合粉,通过低场核磁共振和差式扫描量热仪技术研究面片样品中水分的形态及分布,并对二者的测定结果做相关性分析。结果表明,混合粉样品的游离巯基、二硫键及二者比值有显著变化,总巯基含量基本平稳;弱结合水是水分主要存在形式,添加面筋蛋白能减弱面片中水分的流动性,而二硫键的减少可直接导致面片水分子的流动性变大;添加面筋蛋白可显著降低面片的水分融化焓变和可冻结水百分比,不可冻结水百分比则显著提高(P0.05),随着二硫键含量的减少,不可冻结水百分比呈显著下降趋势,而热焓、可冻结水百分比呈显著升高趋势(P0.05)。相关性分析结果为:游离SH与SS比值与水分分布参数呈不显著相关,而SS键与Wfro,T21,T22,A22呈极显著负相关,与Wnf,T23,A21呈极显著正相关,这说明两种方法具有一致性,混合粉中二硫键含量与面片水分分布的相关性较强,而游离巯基与二硫键比值不能表征面片水分的迁移。     

鲜面片色泽稳定性及与小麦品质性状的相关性分析

以来源于不同地区的71份小麦品种(系)为材料,分析研究了鲜面片在放置、干燥和煮后的色泽变化,并初步探讨了面片色泽与小麦品质的相关性。结果表明,鲜面片色泽在参试材料间存在极显著差异(P 0.01),a~*值的变异系数最大,L~*值的变异系数最小;鲜面片放置、干燥和煮后,L~*值会下降,b~*值升高;鲜面片L~*值随放置时间延长逐渐降低,a~*值和b~*值则呈升高趋势。相关分析表明,小麦粉白度、粗蛋白和总淀粉含量与鲜面片色泽及其稳定性的相关性达显著或极显著水平。筛选出3个面片色泽亮白且稳定的优异材料,可作为培育优质面条小麦的亲本加以利用。     

巯基、二硫键对面团流变学特性的影响

为了探讨巯基（SH）、二硫键（SS）对面团流变学特性的影响,将不同浓度亚硫酸钠（Na2SO3）处理的小麦面筋蛋白加入面粉中,得到不同SH、SS键含量的粉样,然后测定面团的揉混参数和延展参数,做相关性分析。结果表明,随着混合粉的SS含量显著下降,粉样的吸水率变差,粉质质量指数变小,形成时间、稳定时间变短,各粉样间上述指标差异显著（P＜0.05）。粉样B的拉伸性能最好,最大拉伸阻力和延伸度最大,其余粉样的拉伸性依次变差,其中粉样H的拉伸性能最差,然而仍好于空白样品。SS键含量与面粉吸水率、形成时间、粉质质量指数、稳定时间、最大拉伸阻力呈极显著正相关,与延伸度和拉伸曲线面积呈显著正相关关系,与弱化度呈显著负相关。游离SH/SS比值与面粉流变学特性的相关性较差,而SS键含量对面粉的流变学特性有积极影响。本研究可为揭示面筋蛋白对面粉、面条等加工性质的影响以及特定小麦品种培育提供理论依据。     

不同片型复烤片烟色差及质体色素的变化

为分析不同片型复烤片烟色差、质体色素的差异性及变化,选择红大C3F、K326 B3F烟叶作为对象,利用叶片振动分选机分别对2种烟叶原料的复烤片烟进行筛分,并对不同片型复烤片烟色差参数L~*(明度值)、a~*(红度值)、b~*(黄度值)、△E(总色差值)及质体色素(叶黄素、β-胡萝卜素)质量分数的差异、变化趋势以及色差参数与质体色素间的Pearson相关性、函数关系进行分析。结果表明:(1)对于红大C3F、K326B3F复烤后片烟,不同片型间的色差参数L~*、a~*、b~*、△E值及叶黄素和β-胡萝卜素质量分数总体均存在显著性差异。(2)随着片烟尺寸的减小,L~*值呈先降低后升高的变化趋势,a~*、b~*、△E值及2种质体色素质量分数均呈先升高后降低的变化趋势,且4个色差参数及2种质体色素变化的拐点均为小片。其中,小片的L~*值最低,a~*、b~*、△E值以及2种质体色素质量分数均为最高;碎末的L~*值最高,但a~*、b~*、△E值以及2种质体色素质量分数均为最低。(3)叶黄素、β-胡萝卜素及其总量与L~*值呈显著或极显著负相关,与a~*、b~*、△E值呈显著或极显著正相关;分别对2种烟叶原料不同片型复烤片烟的色差参数与质体色素总量进行回归分析,L~*、a~*、b~*、△E值与质体色素总量之间均存在高度拟合的线性关系。对于同一等级烟叶,不同片型复烤片烟的色差和质体色素质量分数存在较大差异和规律性变化趋势。     

预烘干对即食梅香黄鱼热杀菌前后色泽和质构特性的影响

为研究预烘干程度对即食梅香黄鱼热杀菌前后色泽和质构特性的影响,将腌制脱盐后的梅香黄鱼烘干至不同含水率后进行高温杀菌,以烘干前样品作为对照,测定了杀菌前后色差指标、质构指标和汁液流失率的变化。结果表明,烘干前不同部位的色差、质构指标均有显著差异(P<0.05);烘干过程中,总体来说,L~*值下降、a~*值和b~*值升高,硬度、咀嚼性先增后减,弹性、内聚性和回复性均减小,剪切力、韧性均增大;杀菌后,总体来说,L~*值下降、a~*值和b~*值均上升,硬度、弹性、内聚性、咀嚼性和回复性减小,剪切力、韧性增大;含水率为57%～54%时样品杀菌前后各色泽指标变化幅度相对较小,含水率为48%～45%时各质构指标变化幅度相对较小,含水率小于51%时汁液流失率相对较小。综上所述,预烘干对即食梅香黄鱼热杀菌前后色泽和质构特性有较大影响,适当的预烘干程度有利于减少产品杀菌后品质破坏的程度。综合色差、质构指标和汁液流失率来考虑,可选含水率51%作为适宜烘干程度。     

不同茶树品种夏季鲜叶工夫红茶适制性比较

目的比较不同茶树品种夏季鲜叶工夫红茶适制性,为工夫红茶加工提供理论参考。方法通过比较10个茶树品种所制工夫红茶主要内含成分、汤色L~*a~*b~*值及感官品质,分析各因素与感官品质间的相关性。结果 10个品种工夫红茶感官品质依次表现为:蜀永2号巴渝特早蜀永1号早白尖5号四川中小叶种名山白毫131福鼎大白茶渝茶一号崇枇71-1南江1号。鲜叶中多酚氧化酶(polyphenylene oxide,PPO)活性与感官审评得分相关性不显著,过氧化物酶(peroxidase,POD)活性与审评得分呈显著负相关性,相关系数-0.660;鲜叶水浸出物、成茶酚氨比、茶汤b~*值、茶褐素、茶色素生成量(gross of tea pigment, GP)与审评得分呈极显著正相关性,相关系数分别为0.820、0.785、0.855、0.771、0.795;鲜叶茶多酚、鲜叶酚氨比、成茶茶多酚、茶汤a~*值、茶黄素、茶红素与审评得分呈显著正相关性,相关系数分别为0.649、0.637、0.668、0.731、0.760、0.698;成茶氨基酸、茶汤L~*值与审评得分分别呈显著和极显著负相关性,相关系数为-0.768、-0.782。结论在本研究中,蜀永2号、巴渝特早、蜀永1号、早白尖5号、四川中小叶种、名山白毫131夏季鲜叶表现出较好的工夫红茶适制性。茶叶中茶多酚及其氧化物含量、氨基酸和水浸出物含量、茶汤L~*a~*b~*值可作为判断夏季工夫红茶适制性的参考指标。     

不同品种羊肉熏制加工适宜性评价模型研究

中国肉羊品种资源丰富,不同品种羊肉营养理化品质特性存在差异,原料肉基本品质决定了熏制羊肉的品质。为研究不同品种羊肉营养理化品质特性的差异及其熏制加工适宜性,本实验以10?个品种肉羊的通脊为原料,分别测定了原料肉的7个指标(水分含量、蛋白质含量、脂肪含量、pH24 h值、L~*值、a~*值、b~*值)、熏制羊肉的9个品质指标(熏制损失率、剪切力、硬度、弹性、黏聚性、咀嚼性、表皮L~*、表皮a~*、表皮b~*)。通过多元统计分析研究了熏制前原料肉品质与熏制后羊肉品质之间的关系,结果发现水分含量与熏制损失率呈极显著正相关,蛋白质含量与黏聚性呈极显著正相关关系(P0.01),脂肪含量与弹性呈极显著负相关关系(P0.01)。筛选出关键理化指标分别为蛋白质含量、脂肪含量、pH24 h值、b~*值,建立了熏制羊肉品质的综合评价模型Y=0.190 9A+0.355 5B+0.234 3C+0.219 3D,其中,A为蛋白质含量、B为脂肪含量、C为pH24 h值、D为b~*值。     

面粉中二硫键变化对面条品质的影响研究

为明确面粉中二硫键(S—S)变化对面条品质的影响,小麦面筋蛋白经不同质量浓度亚硫酸钠处理后,加入面粉中可得到不同S—S键含量的混合粉并制备面条,通过质构分析技术研究面条特性变化,并做相关性分析.结果表明:随面粉中S—S键含量的减小,熟面条的拉断力和拉伸距离下降,且大部分样品间差异显著;除鲜湿面条5之外,其余面条的最大剪...     

基于计算机视觉的午餐肉颜色测定系统研究

目的建立一种对午餐肉样品物理特性要求较少,能对物料表面整体颜色进行准确测量的无损检测方法。方法采用计算机视觉系统对24色色彩测试板测定得L,a,b值,使用色彩色差计对24色色彩测试板测得L~*,a~*,b~*值,对两组数据进行线性回归;计算机视觉系统测定午餐肉的L,a,b值,带入回归方程得到标准的L,a,b值,色彩色差计对午餐肉测定得L~*,a~*,b~*值,用SPSS软件对得到的标准L,a,b值和L~*,a~*,b~*值进行成对样本检验。结果 L,a,b值回归方程的相关系数r~2分别为0.9900、0.9707和0.9801,有高度相关性;午餐肉标准L,a,b值和L~*,a~*,b~*值成对样本检验得到的P值分别为0.146、0.087、0.109,大于显著性水平0.05,回归方程转换值与色差计测定结果无显著差异。结论本文建立的基于计算机视觉的午餐肉颜色测定方法可以准确测定午餐肉颜色,其效果可以代替色差计。     

超微绿茶粉对绿茶面包加工过程中色泽的影响

以超微绿茶粉为原料,研究绿茶面包加工过程中和面、发酵、烘烤3个加工工序关键节点处色泽和茶多酚含量的变化。结果表明,在加工过程中,烘烤工序对色泽变化影响较大;当超微绿茶粉的添加量增加时,L~*、a~*值都显著下降,而b~*值却先显著上升而后缓慢下降,在超微绿茶粉添加量(质量分数)为4%时,b~*值最大。茶多酚含量随超微绿茶粉含量的增加而增加,各个加工工序的进行均造成茶多酚含量的减少,其中烘烤工序对茶多酚含量减少影响最显著。绿茶面包颜色感官评分随着超微绿茶粉添加量的增加呈先上升后下降的趋势,当超微绿茶粉添加量(质量分数)为4%时,评分最高。通过不同方法间的相关性分析,发现色差仪测定与化学方法测定茶多酚含量、感官评定法间相关性较好。     

面条加工过程中蛋白质中巯基和二硫键的变化规律

为探究面条加工过程中蛋白质的巯基(SH)和二硫(SS)键的变化规律及其对面条质量的影响,先制备不同SH、SS键含量的面粉样品,后分别制作面条.选取制面过程中的和面、面絮熟化、面片熟化、压延切条、鲜湿面水煮、恒温恒湿干燥、室温干燥等7个主要工序取面样,从中提取醇溶蛋白、麦谷蛋白大聚体(GMP),探讨醇溶蛋白、GMP中的S...     

Evaluation of the processing quality of noodle dough containing a high Tartary buckwheat flour content through texture analysis

A texture analysis method for evaluating the processing quality of noodle dough with a high Tartary buckwheat flour (BF) content was established. And then the improvement of wheat flour (WF), wheat gluten (WG), and pre-gelatinized Tartary buckwheat flour (PBF) for the processing quality of buckwheat noodle dough was compared quantitatively, and the mechanism was explored through the observation of gluten network in dough sheets. Texture results showed that the coefficients of variation of tensile strength and adhesiveness of dough sheets among 16 groups were 17.76% and 40.72%, respectively, and the intragroup variation coefficients were only 4.17% and 7.07%, respectively. The tensile strength of dough sheets was significantly positively correlated with gluten index of WF and WG. In addition, with the increase of WG and PBF addition, the tensile strength and adhesiveness of dough sheets showed a linearly increase trend. Furthermore, the gluten network in the dough sheets containing WF or WG with high gluten index distributed more evenly and compactly than that with low gluten index. The dough sheet with 9% PBF showed more uniform gluten network, compared with that without added PBF. Overall, texture analysis of dough sheet can be used to evaluate the processing quality of noodle dough containing 70% BF, and the WF and WG with high gluten index had better improvement than PBF.     

受热对小麦粉品质及其面团特性的影响

小麦粉在加工过程中会受到热的影响,导致小麦粉品质发生变化。该文研究不同受热条件下小麦粉品质及其面团特性的变化,以稳定或提高小麦粉品质。采用干热处理方式,在60~90℃分别对小麦粉加热10~50 s,测定小麦粉的水分含量、干面筋含量、面筋指数、蛋白质组分含量等理化特性,以及游离巯基含量、二硫键含量、面筋蛋白二级结构等结构组成和面团质构特性。研究结果表明,受热后小麦粉水分含量显著降低,在较长时间和较高温度时,随着温度升高和时间的延长,干面筋含量总体呈先升高后降低的趋势,当温度较高时,面筋指数均低于原粉,且随时间的延长先升高后降低;随着温度升高和时间延长,清蛋白和球蛋白含量降低,醇溶蛋白和麦谷蛋白含量先升高后降低;游离巯基和二硫键含量有显著变化,蛋白质的二级结构受温度影响显著,时间仅对β-转角含量有影响;面团质构特性在起始醒发时差异不大,但在醒发45 min后差异极显著,在温度高时,面团坚实度和黏弹性的值较大。     

黑小麦面片加工过程中色泽变化研究

研究不同品种黑小麦在加工和储藏过程中色泽变化及PPO活性,并对黑小麦面粉色泽及其面片色泽进行相关分析。结果表明,黑小麦面粉白度较低,色泽偏绿、偏黄,但达到原粮食部对小麦粉白度等级标准一级要求;黑小麦面粉加工成不同种类面片后,L*值明显降低,a*值、b*值均升高,符合中国黄碱面条要求,其中鲜面片色素含量和PPO活性最高,是影响鲜面片色泽关键。相关分析表明,黑小麦面粉L*值与鲜面片及蒸煮后冷冻面片和干面片L*值呈显著或极显著正相关关系;黑小麦面粉PPO活性与面粉、鲜面片、干面片、冷冻面片及其蒸煮后L*值均呈极显著负相关关系,且面片中PPO活性与其色素含量呈显著正相关;而黑小麦色素与面片色泽没表现出很强相关关系。     

A Study on the Relationship Between Rheological Properties of Wheat Flour,Gluten Structure,and Dumpling Wrapper Quality

Fifty different kinds of wheat from 10 provinces in China were chosen as samples to be milled into flour. Dumpling wrappers were made from the flour and their texture qualities and rheological properties, disulfide content, sulfhydryl content, and gluten secondary structure were determined. The web structure formed by the gluten was observed under scanning electron microscopy. These results showed that the flour’s rheological properties, apart from extensibility, were significantly correlated with several aspects of the texture of the dumpling wrapper, and the degree of softening showed negative correlations, most closely with the texture quality of the dumpling wrapper. Disulfide played an important role in forming the gluten web, its content showing significant correlations with the rheological properties of the flour and the texture quality of the dumpling wrapper. The disulfide content in gluten was positively correlated with the hardness and quality of the cooked product; the sulfhydryl content showed no significant correlations with the rheological properties of the flour and the texture of the dumpling wrapper. The gluten secondary structure showed some correlation with the rheological properties of the dough, but little with the texture quality of the dumpling wrapper. Under observation by scanning electron microscopy, the weak structure was loose with large interspaces, while the strong structure was compact with few interspaces.     

添加糯小麦粉对小麦粉及其面条品质特性的影响

糯小麦与普通小麦的主要差异是糯小麦不含直链淀粉或其含量很低,其对面制品的制作品质产生一定的影响。本研究利用"济糯1号"分别与"济麦20"和"济麦22"按20%、40%、60%和80%的添加量进行配粉,研究糯小麦粉对普通小麦粉品质特性的影响及其面条制品品质的改良作用。结果表明:"济糯1号"的淀粉糊化回升值为449 c P,显著低于"济麦20"和"济麦22";籽粒硬度达64.89,籽粒蛋白质含量(干基)达16.14%,面筋指数为66.08%,粉质仪稳定时间为2.00 min,鲜面条色泽变化小,2 h和24 h的ΔE*分别为3.83和5.29;"济糯1号"与"济麦20"的配粉中,随糯小麦粉添加量的增加,配粉的淀粉回升值降低,面筋指数降低,吸水率增加,面团稳定时间变短,鲜面条色泽2 h和24 h的ΔE*逐渐变小,配粉面条的适口性和光滑性更好;"济糯1号"与"济麦22"的配粉中,随糯小麦粉添加量的增加,面粉蛋白含量增加、面筋指数升高、吸水率增加、淀粉糊化的回升值降低,鲜面条色泽2 h和24 h的ΔE*逐渐变小,配粉的面条制作品质好,面条的适口性和光滑性均改善;糯小麦粉的添加使配粉的面粉品质特性和淀粉特性更有利于面条制作品质的改良,"济糯1号"适宜添加量为20%~40%。     

饺子实验室制作与品质评价方法研究

为建立饺子的标准化实验室制作及品质评价方法,采用中国、加拿大、澳大利亚和美国小麦等15 份样品为材料,研究饺子制作过程中和面机转速、面团加水量、和面时间、醒面时间、压片参数等因素对饺子品质的影响,并采用感官评价结合仪器分析对饺子品质进行综合评价。结果表明：饺子制作过程中和面机速度采用中等速度,本实验采用GRL-1000 型和面机,速度68r/min;加水量为40%～47%,依据样品面团强度和蛋白质含量进行调整;和面时间为12min,采用两次和面,第一次和面10min,醒面5min,第二次和面2min,再次醒面5min;采用七道压面工艺,辊间距分别为5.0、4.0、3.0、2.0、1.5、1.2mm 及1.0mm。压面机转速25r/min。饺子品质评价包括生饺子皮外观评价和熟饺子皮外观及口感品尝评价。生饺子皮光亮度L*1h 与感官评价饺子综合色泽呈极显著正相关(r=0.79,P ＜ 0.01),熟饺子皮仪器测定的弹性系数与感官评价饺子弹性呈极显著正相关(r=0.88,P ＜0.01)。采用此评价体系进行饺子品质评价,能较好反映不同小麦品种间的差异。我国小麦品种制作的饺子具有较好的弹性,硬度适中耐煮性一般;加拿大小麦制作的饺子略偏硬,弹性尚可耐煮性好;澳硬白麦制作的饺子硬,弹性偏小,澳标白麦制作的饺子弹性好,但偏软;美国小麦制作的饺子硬,弹性偏小。     

粒度对马铃薯泥面条品质的影响

本研究通过磨浆时间和磨浆强度控制马铃薯泥的粒度,探讨粒度对马铃薯面条的外观色泽、蒸煮品质、质构品质的影响,为马铃薯泥面条的生产提供数据支持。结果表明:随着磨浆强度的增加,时间的延长,马铃薯泥的粒度逐渐变小;马铃薯泥具有明显的双峰粒度分布,大颗粒所占比例比小颗粒所占比例高;马铃薯泥在扫描电镜下,呈片状结构,片与片镶嵌在一起,随着马铃薯粒度的降低,片的厚度不断变薄,片的尺寸也不断变小;随着粒度的降低,马铃薯面条的L^*值降低,a^*值和b^*值升高,面条A的L^*、a^*、b^*值与面条B、C、D、小麦粉面条的对应L^*、a^*、b^*值具有显著性差异(p<0.05),而面条B、C、D的L^*值之间没有显著性差异(p>0.05)。随着粒度的降低,马铃薯面条的烹调损失率均呈上升趋势,从9.38%增加至10.16%;马铃薯面条的断裂距离显著高于小麦粉面条(p<0.05),不同粒度的马铃薯面条断裂距离没有显著性差异(p>0.05);马铃薯面条煮后黏度随着粒度的减小而减小;总体来说,马铃薯泥的粒度对其面条的品质显著的影响,粒度中位径d(0.5)为130 μm的马铃薯面条品质好。     

ALKALINE NOODLES AND FLOUR/GEL PROPERTIES OF HARD RED AND WHITE WINTER WHEAT

Alkaline noodle characteristics and flour gel properties made with one white and one red hard winter wheat cultivar were studied. The wheat was grown in four Oklahoma agricultural districts, with two to seven locations on each district. Both cultivars had similar flour protein content and overall raw dough sheet color stability ( ΔL * and Δb *) in three out of four agricultural districts. Cimarron and Oro Blanco showed differences in Δa *, Δb * and adhesiveness in the North Central agricultural district. Resilience values of cooked noodles from Oro Blanco were small, but significantly higher in the Central district. Higher flour peak viscosity was observed for Oro Blanco, plus a trend to lower polyphenol oxidase activity and higher elastic modulus than Cimarron.

PRACTICAL APPLICATIONS

Hard red winter wheat from the U.S.A. is used in the manufacturing of alkaline noodles in Asia. Color and texture characteristics are among the most important attributes that determine the quality of this type of noodles. Two types of winter wheat cultivars, red and white, were compared and their key properties (including gel properties) of importance in the international trade and noodle manufacturing are reported.     

Evaluation of l-ascorbic acid oxidation on SH concentration in soy-wheat composite dough during resting period

The effect of l-ascorbic acid (l-AA) on free sulfhydryl concentration (SH) was evaluated in soy-wheat composite dough from 100-500 (g/kg) soy flour substitution for wheat flour. Raw soy flour (RSF) and physically modified soy flours (PMSF1 and PMSF2) were used for the preparation of the composite dough with wheat flour. The two physically modified soy flours were prepared by steam flushing (PMSF2) and water boiling (PMSF1) of raw soy beans before flour preparation. Using a timer, dough blends were manually mixed (at approximately 60 rpm) to dough development time after which, dough was sampled for the estimation of free SH groups. l-AA (0.05% w/w) was mixed with the dough after dough development and the dough was sampled after 1 h of resting the dough. The results showed that l-AA (0.05% w/w) acted as a reducing agent by increasing SH levels in all soy-wheat dough blends (P<0.05). After 1 h of resting, soy-wheat composite dough without l-AA had lower concentrations of SH than that with l-AA. A positive correlation was shown between soy flour concentrations and SH concentration before and after dough resting. A negative correlation existed between l-AA consumption and SH concentration for RSF-wheat, PMSF1-wheat and PMSF2-wheat doughs. The results indicated that soy flour weakened wheat flour dough by increasing SH concentration and that l-AA could have a synergistic effect on the reduction of gluten proteins and thus weakening the dough.