不同凝固剂对豆腐品质特性及风味成分的影响

为探究不同凝固剂对豆腐品质特性和风味成分的影响,利用质构分析、扫描电镜分析和固相微萃取-气相色谱-质谱联用（SPME-GC-MS）等技术以及聚类分析和主成分分析等分析方法研究了MgCl₂、CaSO₄、乳酸、醋酸、葡萄糖酸内酯（GDL）和酸浆对豆腐得率、质构、色差、微观结构以及挥发性物质组成的影响。结果表明:酸浆豆腐和GDL豆腐含水量和得率显著高于其他凝固剂豆腐（P<0.05）;醋酸豆腐的硬度（244.04 mN）和咀嚼性（176.34 mJ）最大,而L*值（82.77）最低;CaSO₄豆腐和GDL豆腐具有致密的网状结构,醋酸豆腐表面粗糙,具有孔隙。从豆乳和不同种凝固剂豆腐中共检测出醇类、醛类、酮类、酯类、酸类、酚类等100种挥发性风味物质,且豆乳中挥发性物质总量显著高于不同凝固剂豆腐的挥发性物质总量（P<0.05）。酸浆豆腐挥发性物质种类最多,但致“豆腥味”挥发性物质含量最低。聚类分析表明乳酸豆腐、醋酸豆腐和MgCl₂豆腐的挥发性风味特征相似度高,CaSO₄豆腐和GDL豆腐的挥发性风味特征相似度高。主成分分析表明对豆腐风味贡献较大的挥发性物质有2, 4-壬二烯醛、(E)-2-辛烯醛、1-己醇、(E)-2-癸烯醛和(E, E)-2, 4-癸二烯醛。感官评价表明CaSO₄豆腐和酸浆豆腐优于其他凝固剂豆腐。综上,不同凝固剂对豆腐得率、质构、色差、微观结构、风味物质和感官评价影响显著,其中CaSO₄豆腐和酸浆豆腐与其他凝固剂豆腐相比,拥有更佳的质地、风味和更高的消费吸引力。     

复合凝固剂对豆腐品质的影响

我国传统的豆腐生产工艺中广泛使用的是单一凝固剂。单一凝固剂作用于大豆蛋白制成的豆腐各不相同。本文对凝固剂的种类与豆腐品质的关系进行了研究,试验先以出品率、含水率、保水性、蛋白含量和感官评价确定了3种单一凝固剂（石膏、氯化镁和葡萄糖酸-δ-内酯）的最佳用量,然后将葡萄糖酸-δ-内酯（GDL）、石膏（CaSO4）与氯化镁按一定比例混合制成复合型凝固剂,然后按照优选法的原则,确定了3种凝固剂用量比例为5∶3∶2时,其豆腐出品率、保水性、蛋白质含量、豆腐外观、内部结构及风味等各个方面均好于单一凝固剂制品豆腐。     

复合凝固剂组分对豆腐品质影响的研究

在我国豆腐生产中广泛使用的是单一凝固剂。每种单一凝固剂对豆腐品质的影响不同。本文对凝固剂与豆腐品质的关系进行了研究 ,将石膏与δ 葡萄糖酸内酯按一定比例混合制成复合型凝固剂 ,并通过试验优选法获得了最佳配比。当δ 葡萄糖酸内酯与石膏质量比为 2∶1时 ,其出品率、含水率、离水率、蛋白质含量、豆腐外观、内部结构及风味等各个方面均好于单一凝固剂豆腐。     

锌豆腐凝固剂的研究

锌强化豆腐是以含锌盐的复合凝固剂,用传统的豆腐生产工艺过程研制出的豆腐新品种,保持了豆腐的风味,锌含量是普通豆腐的2倍多,并通过动物实验检验证明,锌强化豆腐中的锌易被人体吸收,是一种国内外首创的补锌食品。     

豆腐复合凝固剂的研究

实验先以凝胶强度、保水性和感官评价确定了3种单一凝固剂（葡萄糖酸-δ-内酯、乙酸钙和氯化镁）的最佳用量，然后按照优选法的原则。确定了3种凝固剂用量比例为2：1：1时，制作出的豆腐在各项品质均优于单一凝固剂。     

壳低聚糖作为豆腐凝固剂研究进展

豆腐凝固剂主要有传统盐卤和熟石膏,及近年发展应用葡萄糖酸内酯,但现有凝固剂制成豆腐货架期均较短;壳低聚糖能使大豆蛋白发生胶凝,具有较强抑菌作用,能有效延长豆腐货架期。该文综述壳低聚糖作为豆腐凝固剂研究进展,分析壳低聚糖替代现有豆腐凝固剂优势及存在难点。     

豆腐凝固剂的研究现状及发展前景

豆腐凝固剂是我国传统豆制品生产中不可缺少的原料,是决定豆腐质量好坏的关键因素之一。本文对豆腐凝固剂的种类、作用机理及应用和研究现状进行了综述,并对今后的研究进行了展望,旨在为豆腐凝固剂的应用及进一步的研究提供参考。     

豆腐用复合凝固剂的研究

中国传统豆腐广泛应用的是单一凝固剂(石膏或卤水),凝固剂的浓度与用量直接影响豆腐的品质,研究确定了单一凝固剂的浓度,并在此基础上,将石膏与卤水按一定比例混合制成复合型凝固剂,并通过实验优选法获得了最佳配比,当石膏与卤水质量比为4∶6时,豆腐质量和口感都较好。      

豆腐用复合凝固剂的研究

中国传统豆腐广泛应用的是单一凝固剂(石膏或卤水),凝固剂的浓度与用量直接影响豆腐的品质,研究确定了单一凝固剂的浓度,并在此基础上,将石膏与卤水按一定比例混合制成复合型凝固剂,并通过实验优选法获得了最佳配比,当石膏与卤水质量比为4∶6时,豆腐质量和口感都较好。     

凝固剂混合方式对盐卤豆腐品质特性的影响

为明确凝固剂混合方式对盐卤豆腐的品质特性的影响,本研究分别比较了在60、120、180、240 r/min条件下加入凝固剂,搅拌10、20、30 s后,制备盐卤豆腐的品质差异,并在最佳搅拌条件下进一步比较不同批次（分1～4 次）加入凝固剂,制备盐卤豆腐的品质差异。结果表明：凝固剂一次性加入时,在120 r/min搅拌30 s条件下豆腐的得率最高为282.0 g/100 g,在240 r/min搅拌30 s时豆腐的得率最低为183.9 g/100 g。在凝固剂的加入方式上,研究发现分批次加入凝固剂后,豆腐的保水性增强,品质特性有所改善,分3 次加入凝固剂制备的豆腐差异最明显,豆腐的硬度、内聚性和胶着性分别增大了19.9%、6.9%和30.0%。     

Effect of different coagulants on yield and quality of tofu from soymilk

Soymilk tofu coagulated with four indigenous coagulants was compared in terms of chemical, textural, colour, and sensory attributes with calcium sulphate (CS) coagulated tofu. Coagulants used are Epsom salt (ES), lemon juice (LJ), alum and top water of fermented maize (TWFM). Protein and magnesium content significantly (P < 0.05) increased from 44.5 to 51.7 g/100 g and 252 to 324.6 mg/100 g, respectively, in soybean grain to soymilk. Calcium and magnesium contents increased and decreased significantly (P < 0.05) in tofu coagulated with CS and ES, respectively. Lightness (L) values were 86.3, 86.2, 77.8, 72.4 and 84.6, redness (a) values are 0.34, 0.21, 0.87, 1.05 and 0.32, and yellowness (b) values were 24.0, 23.9, 27.3, 20.3 and 23.4 for CS, ES, LJ, alum and TWFM. The hardness, chewiness and brittleness of textural properties of tofu were significantly (P < 0.05) affected by different sources of coagulation. Sensory evaluation data shows that LJ impacts a significantly acceptable sensory attribute to tofu. This study has demonstrated that tofu quality is affected by the type of coagulant used in curding the soymilk.     

凝固剂对白玉饺品质特性的影响

为丰富豆腐深加工产品的形式,以豆腐为饺皮、猪肉为馅料制备一种特色传统豆腐菜肴——白玉饺,并比较凝固剂种类对白玉饺质构(Texture Profile Analysis,TPA)、色泽、感官特性、持水性以及基本营养成分(水分、粗蛋白、粗脂肪、灰分)的影响。结果表明:盐卤、石膏和内酯(GDL)制备白玉饺皮的最适添加量分别为2.5,2.5,2.0g/100g干豆;石膏白玉饺与内酯白玉饺持水性无显著差异(P0.05),但显著(P0.05)高于盐卤白玉饺(62.89%),且硬度(石膏白玉饺和内酯白玉饺分别为760.88,745.08g)显著小于盐卤白玉饺(861.86g),而咀嚼性、回复性、凝聚性、黏附性方面无显著差异(P0.05);石膏白玉饺的a*值显著(P0.05)低于盐卤和内酯白玉饺,但亮度值L*值无显著(P0.05)差异;石膏白玉饺在折叠破碎情况、口感细腻和外形等感官特性方面优于盐卤和内酯白玉饺。因此,可选择2.5g/100g干豆的石膏作为特色菜肴白玉饺加工的凝固剂。     

热处理方式对豆腐品质特性的影响

为了确定豆腐的最佳预处理条件和参数,对其在电磁炉煮制、蒸制、过热蒸汽、油炸、微波短时加热处理过程中的品质变化进行了研究。探索在不同加热方式处理下豆腐中心温度的变化规律。结果表明:在微波加热处理时豆腐的中心温度升高速度最快,加热过程中大量的水分快速蒸发,4 min处理后质量损失达76. 97%;油炸处理对豆腐的色泽变化影响较大;微波加热对豆腐的质构品质影响较大;经热处理豆腐切面观察表明,蒸煮对豆腐结构影响最小,豆腐切面孔隙最小。综合上述指标分析得出:微波处理时间90 s、蒸制8 min、水煮4 min、160℃过热蒸汽处理8 min、150℃油炸5 min时豆腐的综合品质较好。     

Effect of different coagulants on the isoflavone levels and physical properties of prepared firm tofu

The objective of this study was to understand the effect of different coagulants in their ability to retain isoflavones in prepared firm tofu. Harovinton beans were processed to obtain soymilk and a specific amount of this soymilk was coagulated using different types of coagulants for the preparation of tofu. A reversed phase high performance liquid chromatographic method was used for determining the concentration of isoflavones in tofu and whey. Quality parameters such as the texture, color and moisture of tofu, prepared from different coagulants were also determined in this study. Tofus coagulated with different coagulants were found to contain different amounts of isoflavones. Calcium sulfate was found to be the most suitable coagulant for tofu making in terms of its high yield, retention of maximum amount of isoflavones and in obtaining a firm, but not hard texture of tofu.     

Influence of four different coagulants on the physicochemical properties,textural characteristics and flavour of tofu

The coagulation mechanism and quality characteristics of tofu depend on the choice of coagulant. The effects of using magnesium chloride (MgCl₂), calcium sulphate (CaSO₄), glucono-δ-lactone (GDL) and fermented soybean whey (FSW) as coagulants for tofu were investigated using solid-phase microextraction (SPME), two-dimensional gas chromatography coupled with mass spectrometry (GC×GC-MS), scanning electron microscopy (SEM) and analysis of textural characteristics and physicochemical properties. Results showed that GDL tofu exhibited the highest yield (202 g 100 g⁻¹) and moisture content (76.3%). FSW tofu had the highest protein content (18.5%), amino acid content (15.85%) and textural properties. GC×GC-MS analysis revealed the number of 49, 44, 55 and 63 flavour substances, respectively. In sensory evaluation tests, GDL tofu was reported to possess a smooth surface and white colour. The microstructure of FSW tofu was dense and uniform. Through the above technical researches, the study suggested FSW gave tofu the best quality, more unique flavour and more potential popular among consumers.     

谷氨酰胺转氨酶处理对鸭血豆腐品质的影响

采用物性分析仪、高精度分光测色仪、低场核磁共振分析仪及扫描电子显微镜等技术手段,研究谷氨酰胺转氨酶添加量和保温时间对鸭血豆腐持水能力、质构特性、颜色的影响。在单因素试验基础上,以酶添加量和保温时间为正交试验设计因素水平,以蒸煮损失率为指标,确定最佳酶处理方式:谷氨酰胺转氨酶添加量为0.25%,40℃下保温30min。通过弛豫时间与水分分布、全质构、微观结构的测定证实,该水平下谷氨酰胺转氨酶的添加可以显著提高鸭血豆腐的持水性、改善鸭血豆腐的胶着性和内聚性。     

Effects of different coagulants on coagulation behavior of acid-induced soymilk

Divalent calcium ions can be used into the coagulation procedure of tofu-producing. The different calcium salts also have the difference coagulation process. This paper reports an investigation on the effects of counterions of calcium salts on the coagulation process of soymilk protein by the variation of viscosity. The same amount of Lactobacillus plantarum 70810 was added because of its acid reduction effects, which plays a synergistic effect with calcium salts. Coagulation process of soymilk containing various coagulants was characterized by viscosity under a shear rate of 2 s⁻¹ at 37 °C. The textural properties and pH of tofu prepared from different coagulants were also determined. Results indicated that there are two successive first-order reactions by viscosity analysis, and the coagulation rate constant in the second stage was 4–6 times higher than that the first stage. The coagulation rate among the coagulants followed the anion series: formate > acetate > chloride > lactate. The textural properties also have correlation with the final viscosity of soybean milk mixture after 4.5 h coagulation, whereas the pH has nothing to do with the coagulants behaved. Evidence emerged that counterions of calcium source salts affect the coagulation process of soymilk protein. This fact clearly opens up many possibilities for soymilk coagulation.     

大豆分离蛋白的添加对豆腐品质和得率的影响

添加大豆分离蛋白(SPI)于豆浆浆液中,对添加SPT后豆腐的得率、品质及其微观结构进行了分析.结果表明:豆腐的得率在SPI添加量为1%时较高,随着SPI添加量的增多,其得率逐渐下降;豆腐的保水性得到了明显的改善,添加量为2%时,保水性最好;随着SPI的添加,豆腐的粘度和弹性先降低,后又逐渐增大;但豆腐的硬度和韧性随着SPI添加量的增加而降低;另外,SPI的添加使豆腐的微观结构也发生了较为明显的变化.     

不同乳酸菌发酵黄浆水对酸浆豆腐凝胶特性及其品质的影响

目的 研究不同乳酸菌发酵黄浆水对酸浆豆腐凝胶特性及其品质的影响,探究酸浆豆腐的凝固机制,提高酸浆豆腐的品质稳定性,量化生产工艺参数。方法 以大豆为原料,分别以鼠李糖乳杆菌、耐高温鼠李糖乳杆菌、混合菌(乳酸链球菌乳亚种、嗜热链球菌和耐高温鼠李糖乳杆菌)发酵黄浆水制成的酸浆作为凝固剂制作豆腐,测定豆腐的凝胶强度、持水性、出品率、色差、质构特性、感官评价、流变特性、水分分布、二级结构、三级结构、表面疏水性和微观结构等指标。结果 混合菌酸浆诱导的豆腐质构特性最好,具有较高的凝胶强度、持水性和储能模量,分别为579.63g、69.93%和8166.4Pa,感官评分最高。而耐高温鼠李糖乳杆菌酸浆诱导的豆腐凝胶强度和持水性比鼠李糖乳杆菌酸浆诱导的豆腐高。鼠李糖乳杆菌酸浆诱导的豆腐则硬度较低,为1481.38 gf,水分流动性较大。表面疏水性结果显示,混合菌酸浆诱导的豆腐表面疏水性较低,为268.75%,三级构象最为紧密,鼠李糖乳杆菌酸浆豆腐表面疏水性较大,为469.29%,三级构象较为松散。扫描电镜结果显示,混合菌酸浆豆腐呈致密均匀的三维网状结构,耐高温鼠李糖乳杆菌酸浆豆腐凝胶较为连续,孔隙较大,鼠...     

The effect of different varieties of soybean and calcium ion concentration on the quality of tofu

The Japanese food tofu (bean curd) was prepared by the traditional method using 15 varieties of soybeans. The tofu quality was evaluated on the basis of colour, taste and texture. The texture measurements were subjective and instrumental (hardness and cohesiveness).A slight variation in the texture of tofu was due to the 7S and 11S proteins in the soybean but an important factor affecting the texture of tofu was found to be the amount of calcium ions added during processing. The firmness and coarseness of the product increased with increases in the amount of calcium ions added and a linear relationship was found between the protein content of the beans and the calcium sulphate concentration required for good quality tofu.