两种大豆分离蛋白对肉糜品质的影响

研究不同添加量的两种大豆分离蛋白SPI-A和SPI-B对猪肉糜蒸煮损失、质构特性的影响.结果表明,随着大豆分离蛋白添加量的增加,肉糜蒸煮损失逐渐降低,SPI-B降低蒸煮损失效果优于SPI-A;添加两种大豆分离蛋白后,肉糜硬度、弹性、黏聚性、咀嚼性、回复性均显著升高,在试验范围内,相同添加水平下SPI-B的效果均优于SPI-A的添加效果.     

预乳化大豆分离蛋白对乳化香肠品质的影响

为改善大豆分离蛋白(SPI)在肉制品的应用效果,将经过超高温瞬时热处理和预乳化的SPI应用于乳化香肠的制作,并研究其对产品蒸煮损失、质构特性和颜色的影响。结果显示:预乳化技术能够显著增强SPI在乳化香肠中的作用,添加量为10%²0%时,预乳化SPI制作的香肠产品质构和色泽与纯肉体系产品无显著性差异(P<0.05),且好于商业SPI的产品,而蒸煮损失明显降低;在30%20%时,预乳化SPI制作的香肠产品质构和色泽与纯肉体系产品无显著性差异(P<0.05),且好于商业SPI的产品,而蒸煮损失明显降低;在30%⁶0%的高添加量下,预乳化SPI的香肠制品质构品质要略逊于纯肉体系,但明显好于商业SPI的产品,产品亮度和红度有所下降,黄度明显增加,其蒸煮损失低于纯肉体系产品,接近于商业SPI的产品,表明添加预乳化SPI可明显降低乳化香肠的蒸煮损失,改善产品质构品质。     

乳清分离蛋白水解物对猪肉糜抗氧化作用的研究

研究乳清分离蛋白(WPI)的碱性蛋白酶(alcalase)水解物的抗氧化能力,并将其应用于生肉糜中研究其抗氧化效果。实验分为6组,第1组为对照组,第2组加入2.0%的WPI未水解物,第3～5组中分别加入1.0%、1.5%、2.0%的水解物冻干粉(5h),第6组中加入0.02%的BHA,在冷藏过程中测定肉糜的红度值(a*)、硫代巴比妥酸值(TBARS)值、pH值、高铁肌红蛋白(MetMb)含量,并对产品的感官指标进行评定。结果表明,在贮藏7d内,与对照组相比,添加WPI水解物处理组能够显著抑制生肉糜脂肪的氧化(P<0.05),其中2%WPI水解物处理组效果最明显,能显著降低TBARS值、增加肉糜的红度值(a*)(P<0.05),且其高铁肌红蛋白(MetMb)含量仅为对照组的79%,与添加BHA处理组的水平相当。同时,WPI水解物处理组抑制脂肪的氧化效果比WPI未水解组好。因此,WPI水解物可以有效的抑制食物中脂肪氧化,且其抗氧化效果与水解物的使用量相关。     

大豆分离蛋白的酶改性与水解处理对猪肉火腿肠品质的影响

研究了大豆分离蛋白的谷氨酰胺转移酶(MTG)改性与水解处理及其添加量对猪肉火腿肠品质的影响。分别对火腿肠保水性、质构指标、色泽及感官品质进行测定。结果表明:添加不同处理蛋白,产品的保水性均有显著的提高(P0.05),且随着蛋白添加量的增大而增大。在相同添加量下,添加大豆水解蛋白的火腿肠的保水性最高;添加MTG改性蛋白的产品的质构特性最好,大豆水解蛋白可以改善火腿肠的硬度,蛋白的添加使产品的L值增大,a值、b值降低;感官评定结果显示,3种蛋白均能改善火腿肠品质,其中MTG改性蛋白最明显。因此,MTG改性蛋白及大豆水解蛋白在改善火腿肠品质方面均有各自的优势,考虑成本问题,可以与大豆分离蛋白复配应用到实际生产中,利用大豆水解蛋白良好的生理生化特性开发营养型的火腿肠是可行的。     

乳化棕榈油对猪肉贡丸品质的影响

文中研究了使用大豆分离蛋白乳化的棕榈油部分或全部(50%和100%)替代猪背膘对猪肉贡丸品质及肉糜流变性的影响。添加乳化棕榈油,提高贡丸的L*值、b*值和硬度值。增加乳化棕榈油添加量,显著提高(P0.05)贡丸的水分和蛋白质含量,能量值从1 006.42 k J/100 g降到811.07 k J/100 g。与100%猪背膘和100%乳化棕榈油肉糜相比,50%乳化棕榈油肉糜的蒸煮得率最高。在80℃时,50%乳化棕榈油肉糜的G'值最高(17.5 k Pa),对照组最低(15.8 k Pa)。因此,使用50%乳化棕榈油替代猪背膘的贡丸品质最好。     

猪肉乳化香肠中大豆分离蛋白的检测

通过聚丙烯酰胺凝胶电泳法(sodium dodecyl sulfate polyacrylamide gel electrophoresis,SDS-PAGE)电泳检测猪肉乳化香肠中的大豆分离蛋白(soybean protein isolate,SPI)。结果显示,大豆蛋白主要有5条蛋白条带(β-大豆伴球蛋白中的d1、α'、β、d2亚基和大豆球蛋白的d3亚基) 能和猪肉的蛋白条带区分开;其中,获得了由α'亚基蛋白条带的光强度值与SPI质量分数计算得到的一个线性回归方程,该方程作为检测猪肉乳化香肠中SPI添加量(0.5%～10%)的标准曲线。应用得到的标准曲线预测已知SPI质量分数(7%、3%、1.5%、0.8%、0.5%)的猪肉乳化香肠,结果证明该方法具有很好的重复性(变异系数1.90%～7.01%)。同时将SPI质量分数的预测值和真实值进行线性回归分析,得到相关系数为0.98,证明了这种检测方法能应用于猪肉乳化香肠中大豆分离蛋白的定量检测。     

不同食盐添加量和蒸煮温度对猪肉糜品质的影响

食盐添加量和蒸煮温度影响猪肉糜的加工特性和肉制品品质。该文主要分析不同食盐添加量(质量分数为1%、2%和3%)和蒸煮温度(70、80和90℃)猪肉糜的色差、蒸煮得率、质构和流变性,研究食盐和蒸煮温度对猪肉糜凝胶性能的影响。猪肉糜的L*值、蒸煮得率和硬度、弹性、内聚性均随食盐添加量的增加显著(p0.05)升高,而b*值显著(p0.05)下降;从25℃加热到95℃,食盐添加量(质量分数)为3%的猪肉糜的储能模量(G')最高。在相同食盐添加量的猪肉糜中,蒸煮得率和弹性在70℃时最高,随着温度的升高而降低,而b*值和内聚性随着温度的升高而显著增加(p0.05);G'在89℃时达到最大值,之后显著下降。综上所述,采用合适的食盐添加量和蒸煮温度有利于提高猪肉糜制品的品质。     

猪血浆蛋白乳化棕榈油对猪肉糜凝胶特性的影响

以质量分数25%和50%猪血浆蛋白乳化棕榈油替代猪背膘,研究其对猪肉糜凝胶特性、流变性、水分分布 状态和水分迁移特性的影响。结果表明：添加乳化棕榈油可显著提高猪肉糜凝胶的L*值、b*值、蒸煮得率、硬度 和弹性（P＜0.05）,在替代量为50%时猪肉糜凝胶有最高的L*值、b*值、蒸煮得率、硬度和弹性。在80 ℃,猪背 膘替代量为50%时猪肉糜的G’最高。低场核磁共振结果表明：添加乳化棕榈油猪肉糜凝胶的T22起始弛豫时间较短, T21的峰面积比例增加,而T22的峰面积比例降低,说明水分可移动性降低,不易流动的水分含量增加,猪肉糜凝胶 的保水性增强。     

高压处理大豆分离蛋白水解物对羊肉糜凝胶特性及贮藏期氧化稳定性的影响

为研究添加不同高压处理(0.1、100、200、300 MPa)的大豆分离蛋白水解物(soy protein isolate hydrolysate, SPIH)对羊肉糜凝胶特性及贮藏期间氧化稳定性的影响,以未添加水解物的羊肉糜为对照组,测定了羊肉糜的质构、流变特性和微观结构,同时检测了在4℃贮藏8 d的过程中,羊肉糜的色差、酸价、硫代巴比妥酸值、羰基及总巯基含量。结果表明：与对照组相比,添加不同高压处理的SPIH的羊肉糜硬度、弹性及回复性显著提高(P<0.05);升温过程中,添加不同高压处理的SPIH的羊肉糜弹性模量G′均先下降后上升,且在整个升温过程中,SPIH处理压力为200 MPa时,羊肉糜的G′值始终最高;同一频率振荡下,添加200 MPa处理的SPIH的羊肉糜G′值也最高;扫描电镜结果显示,与对照组相比,添加水解物的羊肉糜结构更加致密均匀;随着贮藏时间的延长,添加不同压力下原料肉质量2.0%的SPIH能够抑制羊肉糜的b~*值(黄度)、酸价、硫代巴比妥酸值和羰基含量的上升以及L~*值(亮度)、a~*值(红度)和总巯基含量的下降,且200 MPa处理的SPIH抑制脂肪、蛋...     

大豆油对大豆分离蛋白凝胶特性的影响

通过添加不同比例的大豆油于大豆分离蛋白中,在不同凝胶条件下制备大豆油-大豆分离蛋白复合凝胶。以凝胶强度、弹性、胶凝性、内聚性这4个主要的质构参数,以及二硫键含量、色度和保水性为指标,对不同组分的复合凝胶的凝胶性进行相关研究,用以阐明不同含量的大豆油对大豆分离蛋白凝胶生成机制的影响。结果表明:随着大豆油的添加,原有的蛋白质-蛋白质三维凝胶网络结构被破坏,形成蛋白质-脂肪复合凝胶体系,导致凝胶硬度、内聚性、胶凝性降低,弹性先增加后降低;二硫键含量呈下降趋势;色度的变化较大;保水性逐渐降低。     

Technological and functional properties of reduced-salt pork batter incorporated with soy protein isolate after pressure treatment

To investigate the effects of different pressures (0.1–400 MPa), the techno-functional properties, water distribution and mobility of reduced-salt pork batters (1% NaCl) supplemented with soy protein isolate (SPI, 2%) were examined. Compared with the batters treated at 0.1 MPa, those treated at 100–300 MPa showed significantly increased the cooking yield, hardness, springiness, cohesiveness, chewiness, and G′ values of gel and reduced the initial relaxation times of T_2b, T₂₁ and T₂₂, as observed from the results of low-field NMR. Among all samples, those treated at 200 and 300 MPa had the highest L^* value, cooking yield, hardness, springiness, cohesiveness, chewiness and G′ value of gel, with the largest peak ratio of P₂₁ and the smallest peak ratio of P₂₂. Overall, treatments at 200 and 300 MPa improved the gel properties and lowered the water mobility of reduced-salt pork batters supplemented with SPI.     

鹰嘴豆分离蛋白对减盐猪肉糜凝胶品质的影响

为探究鹰嘴豆分离蛋白(chickpea protein isolate, CPI)不同添加量对2种盐含量(质量分数1.4%和2%)猪肉糜凝胶品质的影响,将猪瘦肉与猪背膘斩拌成肉糜,分别设置不同盐含量和鹰嘴豆分离蛋白的处理组并加热制成凝胶。测定猪肉糜凝胶的色泽、乳化稳定性、质构、水分分布和流变特性。结果表明,在不添加鹰嘴豆分离蛋白的条件下,1.4%食盐质量分数的猪肉糜凝胶的汁液流失和硬度值显著高于2%食盐浓度的猪肉糜凝胶;相同食盐浓度条件下,随着CPI添加量的增加,猪肉糜凝胶的a^*值、b^*值、硬度、弹性、咀嚼性以及不易流动水比例均显著增加(P<0.05),动态流变储能模量G′值升高,汁液流失率显著降低(P<0.05),并在CPI添加量为1.2%时达到最大值或最小值;在相同CPI添加量条件下,1.4%食盐1.2%CPI的猪肉糜凝胶的储能模量G′值高于2%食盐1.2%CPI的猪肉糜凝胶,且2组凝胶的不易流动水比例、乳化稳定性、质构特性无显著差异(P>0.05)。综上,鹰嘴豆分离蛋白的添加能够在降低食盐用量的同时提升猪肉糜的凝胶品质...     

不同产地原料大豆粕分离蛋白提取率研究

以不同产地大豆粕为原料制取大豆分离蛋白(SPI),对比研究在工厂实际生产中相同工艺条件下大豆粕质量对SPI提取率影响;结果表明,高蛋白大豆粕提取SPI相对困难,有待提取新工艺开发。     

不同工艺条件对大豆分离蛋白提取率的影响

结合工厂大豆分离蛋白(SPI)生产实际情况,研究了二次碱提过程中影响蛋白质提取率的主要因素。通过单因素实验和正交实验优化确定的最佳二次碱提工艺参数为:温度45℃,时间25min,料液比1:10,pH 8.40。将优化后的生产工艺与实验室新开发的工艺(三次碱提工艺)对高蛋白大豆粕蛋白质提取率的影响进行对比,结果表明新开发的工艺可有效降低高蛋白大豆粕残渣中蛋白质含量至20%以下。     

Trained sensory perception of pork eating quality as affected by fresh and cooked pork quality attributes and end-point cooked temperature

The present study evaluated individual and interactive influences of pork loin (n = 679) ultimate ph (pH), intramuscular fat (IMF), Minolta L∗ color (L∗), Warner-Bratzler shear force (WBSF), and internal cooked temperatures (62.8 °C, 68.3 °C, 73.9 °C, and 79.4 °C) on trained sensory perception of palatability. Logistical regression analyses were used, fitting sensory responses as dependent variables and quality and cooked temperature as independent variables, testing quadratic and interactive effects. Incremental increases in cooked temperature reduced sensory juiciness and tenderness scores by 3.8% and 0.9%, respectively, but did not influence sensory flavor or saltiness scores. An increase of 4.9 N in WBSF, from a base of 14.7 N (lowest) to 58.8 N (greatest) was associated with a 3.7% and 1.8% reduction in sensory tenderness and juiciness scores, respectively, with predicted sensory tenderness scores reduced by 3.55 units when comparing ends of the WBSF range. Modeled sensory responses for loins with pH of 5.40 and 5.60 had reduced tenderness, chewiness, and fat flavor ratings when compared with responses for loins with pH of 5.80 to 6.40, the range indicative of optimal sensory response. Loin IMF and L∗ were significant model effects; however, their influence on sensory attributes was small, with predicted mean sensory responses measurably improved only when comparing 6% and 1% IMF and L∗ values of 46.9 (dark) when compared with 65.0 (pale). Tenderness and juiciness scores, were related to a greater extent to loin WBSF and pH, and to a lesser extent to cooked temperature, IMF and L∗.     

Meat quality and cooking attributes of thawed pork with different low field NMR T(21)

A relationship of low field NMR T(2) components to meat quality and cooking attributes of pork was investigated. Longissimus muscle was removed from 23 pig carcasses at 24h postmortem for meat quality measurements and cooking test. Frozen samples were classified into three groups by LF-NMR T(21) of thawed samples: A (<40ms), B (40-44ms) and C (>44ms). There were significant differences (P<0.05) in pH, lightness (L* value) and pressing loss among the three groups. Cooking time to attain 70°C was slightly lower in group C than the other groups. Shear force value of cooked samples was not affected by T(21). The component T(21) correlated (P<0.05) with L* value, muscle pH and pressing loss, while L* value correlated (P<0.05) with thawing loss and muscle pH. Therefore, combined LF-NMR and color measurements could be a good way to differentiate water holding capacity of pork.     

Effect of lipoxygenase activity in defatted soybean flour on the gelling properties of soybean protein isolate

Soybean lipoxygenase was inactivated to different degrees by dry heating of defatted soybean flour for 0, 5, 10, 15, 20 and 25 min and soy protein isolates were prepared thereof by isoelectric precipitation of the water extract of the defatted soybean flour. The fluorescence emission intensity at 420 nm of the chloroform–methanol extract of soy protein isolates, which was indicator of the existence of peroxidized lipid, varied in parallel with the lipoxygenase residual activity in defatted soybean flours. The dispersion of soy protein isolate showed an increasing turbidity with the increase of lipoxygenase residual activity in the starting defatted soybean flour, suggesting an elevated tendency to form insoluble aggregates during the preparation of soy protein isolate. Small deformation rheological test revealed that the gelling times were shorter for those soy protein isolates derived from low lipoxygenase activity defatted soybean flours than that of high lipoxygenase activity. Frequency sweep showed that G′ of soy protein isolate derived from low lipoxygenase defatted soybean flour was independent of oscillation frequency in contrast to that of derived from non dry-heated defatted soybean flour, the latter showed a marked frequency dependence. Large deformation test revealed that the gel hardness increased about 10 times after dry heating of defatted soybean flour for 20 min. As the increase of the lipoxygenase residual activity, the gel permeability increased markedly, suggesting that soy protein isolate from high lipoxygenase defatted soybean flour produced coarser textured gel, which corresponded well with the results of scanning electron microscopy.     

改性大豆分离蛋白对微波复热鸡米花品质的影响

为解决微波复热后鸡米花表皮由于浸湿而失脆的问题,本研究向面糊层中添加了超高压均质-酶解复合改性大豆分离蛋白(UESPI),测定了鸡米花微波复热后外层的水分、油分,并分别以色差值,TPA分析中的正向峰数,面糊层孔洞结构为指标研究了面糊层中添加大豆分离蛋白对鸡米花色泽,脆度,表层微观结构的影响。结果表明,面糊中添加20%UESPI的鸡米花微波复热后,表层水分、油分显著下降(p<0.05),鸡米花呈金黄色泽,其微波复热后脆度与新鲜油炸鸡米花脆度相近(p>0.05)。SEM结果则显示面糊层结构致密、几乎无孔洞,有效的阻止了内芯水分、油分的外溢。本研究采用UESPI作为鸡米花面糊层配料,有效的提高了鸡米花微波复热后的脆性,极大的改善了鸡米花的感官特性。     

大豆分离蛋白改性对其功能性质影响

大豆分离蛋白是大豆蛋白最为精制形式,广泛应用于食品工业,并在不同产品中表现出不同功能。该文综述近年来大豆分离蛋白物理、化学、酶法及基因工程改性对其功能性质影响,经不同方式改性可产生合适功能性质,从而拓宽大豆分离蛋白在食品工业中应用。     

温度对于大豆分离蛋白起泡性的影响研究

研究了20～90℃下商业用大豆分离蛋白(SPI)的起泡性。随着溶解温度的升高,5%大豆分离蛋白的溶解性及疏水性逐渐提高,起泡能力逐渐增强,泡沫稳定性则逐渐下降;将不同温度下5%大豆分离蛋白中的可溶性蛋白采用离心方法分离后发现可溶性蛋白的起泡性表现出与5%大豆分离蛋白相反的趋势,尤其在20～40℃的溶解温度下可溶性蛋白的起泡性远远优于大豆分离蛋白的起泡性。研究结果也说明,溶液中高比例可溶性大豆蛋白的存在可能有利于蛋白质泡沫的形成,但不能对泡沫的稳定性起到良好的支撑作用,同时大豆蛋白在溶液中的构象也会影响其起泡性。