共查询到20条相似文献,搜索用时 468 毫秒
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以优质小麦郑麦366为原料,通过低场核磁共振技术(NMR)研究调质过程中在不同加水量梯度下的水分弛豫特性。结果表明:T_(21)、A_(21)与加水量梯度呈正相关性,且调质过程呈一直上升趋势;T_(22)、T_(23)与A_(22)、A_(23)均呈先上升后下降的趋势,各参数变化和T_(22)、A_(22)终值与水分梯度呈正相关性,而T_(23)、A_(23)与水分梯度无明显相关性。小麦调质过程加水量高低对各状态水分活度和含量变化具有显著影响,且不同加水量梯度对各状态水分自由度变化的影响小于各组分水总含量变化的影响。 相似文献
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馒头在冻藏过程中出现硬度增大、比容变小等品质劣变现象,通过研究其在冻藏过程中的水分变化,可以为改善速冻馒头品质提供理论基础。通过差示扫描量热仪(differential scanning calorimeter,DSC)、低场核磁共振(low field-nuclear magnetic resonance,LF-NMR)及质构仪等研究冻藏以及复蒸过程中馒头可冻结水含量、水分状态、质构和比容等品质特性的变化,并对馒头水分变化与质构特性之间的关系进行了相关性分析。结果表明,冻藏以及复蒸过程中馒头的水分含量均显著降低;冻藏60 d时,馒头的失水率达1.19%,可冻结水的融化焓△H增加了6.32 J/g;冻藏过程中半结合水变得更易流动且含量有所降低。并且,冻藏馒头以及复蒸馒头的比容显著降低(P0.05),硬度与咀嚼性显著增大(P0.05)。失水率与冻藏馒头的硬度和咀嚼性呈显著正相关,可冻结水含量与复蒸馒头的硬度和咀嚼性呈显著正相关。 相似文献
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采用激光共聚焦显微拉曼光谱仪及低场核磁共振成像分析仪对冻结过程中面团面筋蛋白分子结构变化规律和水分迁移进行原位表征和分析。结果表明:45%加水量面筋蛋白二硫键构型最为稳定,二硫键gauche-gauchegauche(g-g-g)构型的相对含量在冻结后下降了4.33%,冻结过程中,相对稳定的g-g-g构型向不稳定的gauchegauche-trans(g-g-t)和trans-gauche-trans(t-g-t)构型转化;代表氨基酸侧链微环境的拉曼图谱中740 cm-1与1 004 cm-1处吸收峰的比值(I740/1 004)在面团加水量45%时达到最大值,并在冻结过程中持续下降;不同加水量面筋蛋白在冻结终点时,二级结构中α-螺旋相对含量并无明显差异,随着温度下降α-螺旋相对含量下降3.63%;水分分布及水分迁移的结果表明,面团冻结过程中,由冰晶生长引起的品质劣变随着加水量的增加更早出现。本研究从微观尺度和分子水平揭示了面团冻结过程中面筋蛋白结构和水分的变化规律,阐明了面团冻结过程中品质劣变的机理。 相似文献
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通过测试不同大豆品种的抗压力,分析大豆籽粒挤压过程中的抗压力与大豆水分、脂肪之间的关系,结果表明:不同品种大豆的抗压力差异显著,大豆抗压力值与大豆的水分含量呈极显著负相关性,大豆抗压力值与大豆的脂肪含量呈极显著正相关性。 相似文献
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和制馒头面团时,添加20% 由酵母菌(Saccharomyces cerevisiae CGMCC 2.0562)和/ 或乳酸菌(Lactobacillus brevis CGMCC 1.0579)发酵的老面团进行混合发酵,通过检测pH 值、总酸度及可溶性糖含量的变化,研究老面团馒头发酵过程中微生物生长及代谢特性。采用高效液相色谱 (HPLC)- 蒸发光散射检测器(ELSD)检测可溶性糖(麦芽糖、蔗糖、果糖、葡萄糖)含量,其流动相为乙腈- 水体积比70:30,流速1.0mL/min,柱温25℃,ELSD 漂移管温度83.5℃,载气空气流速2.2L/min。结果显示:与对照组相比,添加老面团的样品pH 值较低,TTA 值较高,尤其是添加单一乳酸菌发酵老面团的样品酸度最低;不同样品发酵过程中各种可溶性糖的含量及变化趋势存在差异。由此看出,不同菌种对原料的利用不同,所以馒头面团发酵过程中代谢产酸及可溶性糖含量变化存在差异,这很可能会影响到馒头的品质。 相似文献
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不同酵母对面团发酵特性及馒头品质的影响 总被引:2,自引:1,他引:1
就不同酵母对面团发酵特性和馒头品质的影响进行了试验.通过比较不同酵母发酵面团的产气量和面团膨发状态,进而确定相同条件38℃,88%RH,酵母添加量0.8%,不同酵母的最适发酵时间,然后对其发酵的馒头进行感官评价和质构测定,结果显示:不同酵母发酵面团时的产气量和面团膨发状态不同,Y-1、Y-2、Y-3和Y-4的最适发酵时间依次为40、30、25和30 min.由感官评价和质构测定结果还得出结论:不同酵母显著影响馒头产品的感官评价总分,且感官评价和质构测定参数与其面团发酵性能相一致. 相似文献
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Wenjuan Feng Sen Ma Fengcheng Wang Xiaoxi Wang 《International Journal of Food Science & Technology》2022,57(3):1748-1762
This article presents a novel idea for the preparation of frozen dough and steamed bread by which black rice flour (BRF) with different particle sizes (0.18–0.25 mm, 0.15–0.18 mm and 0.125–0.15 mm) was added into wheat flour (WF), considering the nutritional values of BRF. The characteristic of the composite flour (CF), frozen dough and steamed bread was studied. CF had higher contents of dietary fibres (2.01–2.16%) but lower content of protein (11.57–11.92%) compared with WF (1.6% and 12.60%, respectively). Correlation analysis showed that the addition of BRF could alleviate the damage to dough caused by freezing, which may be due to that water in CF dough was more stable. The content of freezable water in WF dough increased by 23.48%, while that in CF dough increased by 6.09–12.11% after frozen storage. With decreasing particle size, the hardness of CF dough decreased and the resistance to extension and gas retention coefficient increased, whereas the specific volume and the soft crumb texture of CF steamed bread increased. In short, small-sized BRF is more suitable for use in the preparation of steamed bread. 相似文献
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The performance of barley fibre-rich fractions (FRF), as high dietary fibre ingredients, in two-layer flat bread was investigated. In addition, the effects of particle size reduction by pin milling on functional properties of FRF were studied. FRF enriched in non-starch polysaccharides (β-glucans and arabinoxylans) were obtained by roller milling of hull-less barley. Pin milling (PM) of FRF significantly reduced their particle size, slightly increased the solubility of β-glucans and arabinoxylans, and increased the viscosity of water slurries containing FRF. The addition of 20% of barley FRF to wheat flour significantly increased dough water absorption and weakened the dough properties, as indicated by farinograph mixing curves, but the FRF-enriched doughs exhibited good handling characteristics at the dividing and sheeting stages. The appearance, diameter, layer separation, crumb, and aroma of the FRF-enriched flat breads were comparable to that of the control. The PM of FRF did not significantly affect the dough handling or the quality characteristics of flat breads. The addition of 20% of barley FRF to wheat flour flat bread provided substantial health benefits by significantly increasing the total and soluble dietary fibre contents and by decreasing starch digestibility. 相似文献
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Wang Yuan-Yuan Norajit Krittika Kim Mi-Hwan Kim Young-Ho Ryu Gi-Hyung 《Food science and biotechnology》2013,22(1):89-97
This study was to evaluate the influence of hemp addition and extrusion conditions on properties of dough and bread. The extruded and non-extruded hemp/ rice flours with different hemp/rice ratio were mixed with wheat flour at 15% ratio. In those flour assays, extrusion greatly decreased the paste viscosities, while the addition of hemp inhibited the decrease of peak viscosity on the extrusion condition. The onset gelatinization temperature was extended due to the hemp addition. The test on dough properties showed that extrusion increased water absorption, arrival time, weakness, extensibility, and the volume after 105 min fermentation, and decreased the stability time and elasticity of dough, while hemp addition mainly increased the weakness and extensibility. For bread properties, extrusion decreased the specific volume, crust and crumb L value, and uniformed air cells, when the hemp addition increased the bread specific volume and decreased the hardness during storage time. 相似文献
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Alice V. Moroni Emanuele Zannini Gloria Sensidoni Elke K. Arendt 《European Food Research and Technology》2012,235(4):659-668
This study investigates the exploitation of buckwheat sourdough for the production of wheat bread. The fermentation induced extensive hydrolysis of buckwheat main storage proteins, but did not influence the total protein, starch and polyphenols content of buckwheat. Buckwheat sourdough was incorporated at 10 and 20?% (w/w) in wheat dough, and control doughs were produced with the addition of a chemically acidified (CA) buckwheat batter. The addition of buckwheat sourdough greatly affected the rheological properties of the dough, by inducing a strengthening of the gluten network and decrease in elasticity. The acidification of wheat dough also stimulated the baker’s yeast activity during proofing, resulting in higher release of CO2 in shorter times (volume of CO2 released (ml), control dough, 1,671.5; dough with 10?% sourdough, 2,600; dough with 10?% chemically acidified dough, 2,715.5). The properties of wheat bread were enhanced by the addition of 10?% buckwheat sourdough, which led to higher specific volume (control, 3.41?ml/g; bread with 10?% sourdough, 4.03?ml/g) and softer crumb (crumb hardness, control, 5.28?N; bread with 10?% sourdough, 3.93?N). On the other hand, the higher acidification level did not influence the bread volume, but slightly hardened the crumb (crumb hardness, bread with 20?% sourdough, 7.41?N; bread with 20?% chemically acidified dough, 6.48?N). The fermentation positively influenced the nutritional properties of buckwheat flour and wheat bread, in terms of polyphenols (control bread, 8.84?mg GAE/100?g; bread with 10 and 20?% sourdough, 17.83 and 18.20?mg GAE/100?g, respectively) and phytic acid contents. Incorporation of buckwheat sourdough also led to an extension in the shelf life of wheat bread, which became more evident for the higher addition level. Overall, the results of this study suggest that buckwheat sourdough represents a suitable tool for enhancing the overall quality and nutritional properties of wheat bread. 相似文献
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The influence of fungal and bacterial -amylases on the texture and microstructure of dough and bread was investigated. Loaf specific volume, crumb porosity and texture properties were accepted as bread structure and texture characteristics. The microstructure analysis of dough and bread using light and scanning microscopy methods was performed.The changes in loaf specific volume, crumb porosity and texture properties showed different anti-staling activity of the enzymes used. The simultaneous action of enzyme addition and the fermentation process evoked significant changes in the microstructure of dough. The character of these changes depended on the kind of enzyme used. A substantial effect of both amylases on starch behaviour during bread baking and staling was also observed. 相似文献
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分别采用水提法和酶提法从小麦淀粉加工废水中分离阿拉伯木聚糖(araboxylan,AX),并研究水提AX和酶提AX对小麦面团的粉质特性、流变发酵特性、糊化特性及水分分布的影响,运用扫描电镜、质构仪分析AX对馒头品质的影响。结果显示:酶提AX样品AX纯度为86.81%,较水提AX样品AX纯度高;适量添加水提AX和酶提AX均能改善面团的粉质特性,后者效果更为显著;AX使面粉的糊化作用降低;AX的添加降低了馒头的硬度、咀嚼性;酶提AX使馒头的蛋白质网络结构在挤压后仍能保持较好的完整性,而水提AX对馒头的面筋网络结构造成了一定影响,挤压后大量淀粉颗粒暴露出来;酶提AX的添加增加了面团的持气性,使馒头瓤气孔较为均匀,而水提AX使馒头瓤气孔大小不均匀,木聚糖内切酶可改善此破坏作用。因此,在小麦面粉制品中添加高纯度酶提AX可以实现多种优化目标。 相似文献
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Z. Y. Kyaw S. Y. Yu C. S. Cheow M. H. Dzulkifly & N. K. Howell 《International Journal of Food Science & Technology》2001,36(7):741-747
Starch granules found at the centre of fish crackers ('keropok') which contained from 0 to 10% fish did not gelatinize after 2 h steaming. This was because of water movement from the centre to the periphery during steaming. A fish protein network started to develop in dough with a 15% fish content and this entrapped water molecules. These water molecules helped to complete gelatinization. The viscoelastic properties of 'keropok' dough increased with an increasing fish to starch ratio and also because of the formation of a fish-protein network in the dough. 相似文献