毛霉发酵对豆制品的质构和微观结构的影响

利用质构仪和扫描电子显微镜研究毛霉发酵豆腐的质构和微观结构,通过电泳分析豆腐的蛋白质水解情况,并与未发酵豆腐进行对比。结果表明,与未发酵豆腐相比,发酵豆腐的硬度和黏性增大,内聚性和弹性减小。其微观结构较均匀致密。电泳分析和微结构分析均显示出大分子量的蛋白质在豆腐发酵过程中的降解。     

小麦胚芽对馒头水分迁移以及微观结构的影响

采用低场核磁共振(LF-NMR)和扫描电镜(SEM)研究小麦胚芽对馒头水分迁移和面团微观结构的影响。LF-NMR结果表明,添加胚芽的面粉制成的新鲜馒头中,弱结合水含量上升,紧密结合水含量下降,老化作用后,紧密结合水和弱结合水含量均下降;且当添加比例为6%时,T_2值均较低,水分相对更稳定;RVA表明添加胚芽的混合粉峰值黏度与崩解值均降低;SEM结果证实添加胚芽后,面筋结构的交互作用被弱化。说明添加胚芽可改善馒头的保水性,但不利于面筋结构的形成。当添加比例为6%时,保水能力最强,适宜储存,为最佳添加比例。     

大米脂肪模拟物对低脂酸奶质构特性及微观结构的影响

本研究用α-淀粉酶将大米粉水解制备了大米脂肪模拟物,将此模拟物应用于酸奶中制备了几种添加不同量的大米脂肪模拟物的低脂酸奶,并与不添加脂肪模拟物的全脂对照和低脂对照酸奶比较,进行了成分分析、质构分析、微观结构分析及感官评价.结果表明添加大米脂肪模拟物的低脂酸乳显示出了与全脂对照酸乳相似的感官特性、质构特性和消费者可接受性(p＞0.05),并表现出了较全脂对照酸奶较低的脂肪含量和较空旷、松散的蛋白网状微观结构.     

Wheat Germ Lipoxygenase: Its Effect on Dough Rheology,Microstructure, and Bread Making Quality

Extracted lipoxygenase from defatted wheat germ of commercial bread wheat along with raw and defatted germ were used to study their effect on rheological characteristics of wheat flour dough and bread making quality. The addition of 500 U and 1000 U of lipoxygenase increased the water absorption from 59.5 to 62.3 and 66.7%, respectively. The dough stability increased to 10.5 min, whereas mixing tolerance index values marginally decreased, and the addition of raw or defatted germ did not affect the mixing profile of the wheat flour dough. Breads with lipoxygenase were softer with a lower firmness value of 546 g when compared to the control (594 g) and had brighter crumb as seen in the reduction in ΔE values from 22.34 (control) to 19.04. The addition of gluten along with the lipoxygenase showed a synergistic effect. The specific volume of breads increased to 3.95 cc/g and the firmness values decreased to 538 g. Scanning electron micrographs at different stages of bread processing have shown improvement in the gluten network.     

不同水分含量对南极磷虾烤虾质构和色泽的影响

以质构和色泽为指标,并结合感官评定,对水分含量分别为22％、25％、28％和31％的四种南极磷虾烤虾品质进行研究。实验结果表明,水分含量对南极磷虾烤虾质构有一定影响,水分含量22％的南极磷虾烤虾的硬度、胶粘性、咀嚼性和剪切力与其他水分含量的南极磷虾烤虾呈显著性差异（P〈0．05）,水分含量25％和28％的南极磷虾烤虾的内聚性和弹性相对较高,品质较好;通过测定四种烤虾的RG雅,发现四种样品的色泽均属于粉色系,对外观的影响不是很大,随着烤虾水分含量下降,制品的色泽越容易接受。水分含量28％的南极磷虾烤虾的感官评分最高,为8．99±0．05,通过对不同水分含量的南极磷虾烤虾的质构和色泽分析,结合感官评定,认为南极磷虾烤虾的水分含量为28％时品质最佳。     

抗氧化处理对风干肉贮藏期间质构特性的影响

以风干肉为研究对象,2.0 g/L壳聚糖＋1.0 g/L乙酸＋ 0.5 g/L茶多酚混合涂膜处理作为抗氧化处理组,未处理的风干肉作为对照组,所有样品真空包装后,分别贮藏于4 ℃和－20 ℃,测定其在0～120 d贮藏期内的pH值、水分含量及质构特性等指标。结果表明：在120 d的贮藏期内,抗氧化处理能够将风干肉的水分含量保持在22%左右,对防止其硬度及咀嚼性的增加有显著效果（P＜0.05）,并保持风干肉的内聚力处于合适水平,对风干肉的弹性和黏性影响不显著,且能够显著降低风干肉的过氧化值（P＜0.05）;在4 ℃条件下贮藏时,抗氧化处理对降低风干肉的硫代巴比妥酸值有显著效果（P＜0.05）。因此,抗氧化涂膜处理可以有效保持风干肉贮藏期间的水分含量和质构特性,并明显抑制风干肉的脂肪氧化。     

油炸对鹅肉理化性质、质构与微观结构的影响

为选择鹅肉合适的油炸条件,采用常规物化特性测定方法,研究油炸对鹅肉理化性质、质构与微观结构的影响。结果表明,随油炸温度升高、时间延长,油炸损失率逐渐增加,135℃油炸5 min比120℃油炸2.5 min的损失率增加了12.87%(P0.05);p H值与剪切力的变化规律相似,呈现出了总体上升趋势,120℃与135℃油炸5 min时,剪切力值分别为40.432 N与55.783 N(P0.05);油炸后,鹅肉L*值降低,a*值与b*值逐渐增加,135℃油炸5 min的a*值与b*值分别比油炸2.5 min的增加了27.85%与32.95%;油炸后鹅肉硬度、咀嚼性总体变大,弹性、凝聚力、黏性及恢复性总体变小。120℃油炸3.5 min时,肌束膜内出现少许颗粒,125℃油炸3.5 min时,肌束膜变形严重,部分溶解,至135℃油炸5 min时,肌细胞结构已十分模糊。130℃油炸3 min是鹅肉较好的油炸条件,在此条件下,鹅肉损失率为38.24%、剪切力值为41.897 N、色泽金黄、质构特性良好。     

糙米直链淀粉含量对其面包质构和体外消化性质影响研究

将不同直链淀粉含量的5种糙米磨粉,添加20%谷朊粉制作糙米面包,以比容、质构及体外消化性质为指标,研究糙米直链淀粉含量对面包品质的影响。结果表明,5种糙米直链淀粉质量分数范围在15.96%~21.88%之间。不同的糙米面包比容在2.53以上,直链淀粉质量分数大于19%时,糙米面包硬度、黏性、耐咀性显著提高。随着糙米中直链淀粉含量的增加,糙米面包淀粉体外消化率显著降低,糙米面包中抗性淀粉含量增加。直链淀粉含量19%以上的糙米制作的糙米面包品质较好。     

苹果渣膳食纤维面包的研制及其质构特性的测定

我国浓缩苹果汁每年产生约100万t苹果湿渣,苹果渣中膳食纤维非常丰富。为开发利用苹果渣,以其作为添加剂制得苹果渣膳食纤维面包。将苹果渣粉以0%、5%、10%和15%的量混合加入面粉制得苹果渣膳食纤维面包,通过测定苹果渣膳食纤维面包感官鉴评、比容、保水性、质构等,分析影响苹果渣膳食纤维面包品质的主要因素,确定苹果渣粉的最适添加量。结果表明:随着苹果渣粉含量的增加,面包的比容和硬度降低,保水性和弹性增加。其中,当苹果渣粉添加量为5%时,面包品质最好。     

Texture and Microstructure of Steam Cooked, Vacuum Packed Potatoes

Uniaxial compression tests combined with light microscopy and scanning electron microscopy were used to study textural properties of vacuum packed, steam cooked (VPS-cooked) potato tubers. Comparisons were made with conventionally water cooked tubers for cooking intervals of 0–60 min. In the VPS-cooked potatoes the gelatinized starch formed dense clusters. In contrast, water cooked cells were filled with gelatinized starch. The textural attributes declined with increased cooking time, faster for water cooked potatoes than for VPS-cooked. After >30 min cooking, firmness of VPS-cooked potatoes increased, while cell separation and disintegration of tissue made the water cooked tubers less firm. Textural properties and cell structure were directly affected by processing conditions.     

Effect of Near-infrared Radiation and Jet Impingement Heat Transfer on Crust Formation of Bread

Rapid heat transfer methods can be used to speed up the baking process and create new product properties. This study investigates the effect of air jet impingement and infrared radiation (alone or in combination) on crust formation of par‐baked baguettes during post‐baking. The parameters investigated are crust color, crust thickness, total water loss, and heating time. The results show that infrared radiation and jet impingement, as compared with heating in a conventional household oven, increased the rate of color development of the crust and shortened the heating time. The fastest color development was obtained by combining infrared and impingement heating. The water loss rate was increased due to the high heat transfer rate, but the total water loss was reduced because of the shorter heating time. Crust thickness was most dependent on heating time and crust temperature. In general, the crust was thinner for infrared‐heated baguettes.     

超高压处理对再制奶油干酪质构、流变学特性及微观结构的影响

以低饱和脂肪酸的再制奶油干酪为研究对象,探究不同条件超高压处理(压力:150、300、450MPa;保压时间:10 min;保压温度:25℃)对再制奶油干酪质构、流变学特性及微观结构的影响.通过SPSS软件分析压力变化与干酪水分质量分数、水分活度、pH值及质构特性的相关性,通过质构分析仪测定干酪质构特性(涂抹性、硬度、...     

Impact of Almond Form and Moisture Content on Texture Attributes and Acceptability

The objectives of this study were to measure sensory texture attributes of 5 types of almonds (blanched slivered, natural sliced, whole blanched, whole dry roasted, and natural whole) conditioned at 4 different moisture levels, to measure liking of a subset of these products, and to compare the sensory texture measurements with consumer liking ratings. Thirteen panelists trained to evaluate almond texture rated the texture attributes of the 20 almond samples. A panel of 113 almond consumers rated their liking of a subset of 8 of these almonds. Compared with the whole almonds, sliced and slivered almonds had less hardness, less crunchiness, less cohesiveness, less tooth packing, and required fewer chews and swallows to consume. Compared with slivered almonds, sliced almonds were more powdery, had more surface roughness, more loose particles, and were crisper. Compared with slivered almonds, sliced almonds were less hard, broke into fewer pieces, had less moistness and cohesiveness of mass, less fatty film, and required fewer chews and fewer swallows to consume. Dry roasted almonds were generally harder, more crisp, more crunchy, and produced more loose particles than natural almonds, which were, in turn, more hard, crisp, and crunchy than blanched almonds. As moisture content increased, moistness of mass and cohesiveness of mass increased. Crispness, number of pieces, hardness, crunchiness, persistence of crunch, and particulate mass decreased with increasing moisture content. Consumer texture liking ratings were highly positively correlated with the attributes crispness, crunchiness, and persistence of crunch.     

Moisture Content Adjustment to Modify Texture of Reduced-Oil Pecans

Reducing oil content has produced pecans with extended shelf-life and less calories, but poor texture. Adjusting final moisture content may restore texture of reduced-oil pecans. Texture Profile Analysis (TPA) was performed using an Instron on cylinders taken from full-oil and reduced-oil pecans sprayed with water or with a water-based flavoring, then dried to 15 final moisture contents ranging from 2.43 to 19.85%. Wetting and partial drying increased hardness to 87%, Area 1 to 89%, and fracturability to 79% of the value for full-oil pecans. Springiness and Area 2 were practically fully restored after redrying to 5% MC.     

冷冻对脆肉鲩和草鱼肉微观结构和质构特性的影响

采用光学显微镜、扫描电子显微镜和质构仪分析比较脆肉鲩和草鱼肉在－18 ℃条件下冷冻3 d,其微观结构和质构特性的变化。结果表明：冷冻形成冰晶,破坏细胞膜,汁液流失;冷冻导致鱼块的蒸煮质量损失率增大,脆肉鲩的质量损失率高于草鱼;冷冻显著影响脆肉鲩和草鱼肉的质地。经过冷冻的脆肉鲩和草鱼肉的弹性、回复性和咀嚼性显著降低,草鱼肉的剪切力、硬度和黏附性显著降低,而脆肉鲩变化不大,但冷冻3 d的鱼肉熟制后与新鲜鱼肉质构特性差异不显著。