β-葡聚糖对戚风蛋糕的品质特性及抗老化的影响

以β-葡聚糖为添加剂,探究β-葡聚糖对戚风蛋糕的比容、持水性、硬度等抗老化能力的影响。在储藏期,戚风蛋糕会随存储时间推移而产生老化改变,表现为产品的水分散失,硬度增加,微观结构松散等。通过测试蛋清液性能及成品戚风蛋糕的比容、含水量与烘焙损失、质构特性与老化速率、水分迁移、热力学性质、微观结构等水平以直接反映添加β-葡聚糖对戚风蛋糕品质及抗老化能力的影响。结果显示：添加量为0.06%和0.08%的β-葡聚糖使蛋清液泡沫体系兼备良好的起泡能力与稳定性,均能够提高戚风蛋糕的比容。当β-葡聚糖添加量为0.06%时,戚风蛋糕的硬度降低了7.05%;当β-葡聚糖添加量为0.04%时,戚风蛋糕的硬度降低约为7.59%。添加量为0.06%的β-葡聚糖蛋糕硬度增幅最低且老化速率最低。     

大豆分离蛋白对蛋糕品质及质构的影响

用大豆分离蛋白部分替代蛋清制作蛋糕,研究了不同替代比例(10%、20%、30%、40%)下蛋糊比重、粘度、蛋糕比容、烘焙损失率变化情况,并对蛋糕进行了感官评定与质构分析。结果表明:大豆分离蛋白的加入会增大蛋糊比重,降低蛋糊粘度,增大蛋糕的硬度与咀嚼性。当大豆分离蛋白溶液对蛋清替代率为10%时,所得蛋糊的粘度与对照组(纯蛋清蛋糕)无显著性差异,且所得蛋糕烘焙损失率最低(对照组烘焙损失率为0.099,10%替代组为0.093),比容最大(对照组比容为4.64 cm3/g,10%替代组为4.12 cm3/g);在质构分析中,蛋糕硬度、咀嚼性与弹性都与对照组无显著性差异,此外,大豆分离蛋白的加入增加了蛋糕的回复性,使蛋糕吃起来柔软、爽口;在感官评价中,蛋糕在组织状态、外观上与对照组无显著性差异,色泽、口感、滋味和可接受度的评分均高于对照组。由此可见,大豆分离蛋白部分替代蛋清来制作蛋糕是可行的,其中10%替代率的产品质量最佳。     

添加蛋白质对外裹糊鱼块深度油炸过程油脂渗透的影响

在模式外裹糊(高纯度的小麦淀粉和小麦面筋蛋白)中分别添加6%的大豆蛋白、蛋清蛋白、乳清蛋白和大米蛋白,于170 ℃初炸40 s后190 ℃复炸30 s制作油炸外裹糊鱼块。分析外壳中蛋白质的表面疏水性(H0)、巯基和二硫键含量、荧光强度和二级结构,小麦淀粉的晶体结构,油炸外裹糊鱼块的表面油脂、表面渗透油脂含量及油脂的渗透与分布规律,探讨添加蛋白质对外裹糊鱼块深度油炸过程油脂渗透的影响,为低脂油炸外裹糊鱼块的规模化生产提供科学指导。结果显示,大豆蛋白组、蛋清蛋白组和乳清蛋白组的H0大于对照(未添加蛋白质),而大米蛋白组的H0小于对照;大豆蛋白组和蛋清蛋白组的荧光发射峰的最大吸收波长(λmax)从349 nm增至351 nm,而乳清蛋白组和大米蛋白组的λmax从349 nm减至341 nm;乳清蛋白组的二硫键含量高于大豆蛋白组、蛋清蛋白组和大米蛋白组,且均高于对照。大豆蛋白组的β-折叠向β-转角转化较多,且荧光强度、相对结晶度以及表面油脂(除大米蛋白组外)和表面渗透油脂含量均最低,其次是蛋清蛋白组、乳清蛋白组、大米蛋白组和对照。结果表明:在外裹糊中添加的蛋白质影响了蛋白质疏水基团的暴露和小麦淀粉的糊化,最终改变了外裹糊鱼块深度油炸过程的油脂渗透。     

挤压预糊化淀粉的性能及其添加对糙米发糕品质的影响

通过挤压不同水分含量（45%、25%和18%）的大米淀粉制备预糊化大米淀粉,测定其分子量、结晶度、糊化度、水吸收指数、水溶解指数、冷糊黏度等指标,并考察了预糊化淀粉添加对糙米粉糊化特性及糙米发糕品质的影响。结果表明,与原大米淀粉相比,45%、25%和18%水分含量挤压制备的预糊化大米淀粉结晶度分别降低了51.93%、58.93%和59.04%;水吸收指数分别提高了1.56、4.69和6.11倍;水溶解指数分别提高了7.04、16.30和27.64倍;冷糊黏度分别提高了2.00、21.44和14.67倍。挤压还使大米淀粉分子发生降解,产生了更多的小链分子。预糊化大米淀粉性能变化与挤压过程中淀粉的水分含量有关。添加预糊化大米淀粉显著提高了糙米发糕的品质（P<0.05）,高的冷糊黏度和低的分子量（18%水分挤压）更有利于制备比容大（1.64 cm3/g）、孔洞细腻均匀、硬度低（338.59 g）和有弹性的糙米发糕。     

米粉种类及添加量对蛋糕品质的影响

以籼米、粳米、糯米为原料,用一定比例的米粉替代面粉制作蛋糕.采用感官、质构、比容等指标评价米粉种类及添加量对蛋糕品质的影响,建立米粉物性指标与蛋糕品质指标间的相关性.结果表明,米粉的种类及添加量对蛋糕的感官、质构、比容等均有显著性影响;米粉物性指标与蛋糕品质指标间均有一定相关性,其中蛋糕的口感、弹性分别与米粉添加量呈极显著负相关(-0.910)与极显著相关(0.811);蛋糕比容分别与米粉水分含量、脂肪含量均呈极显著正相关(0.823、0.764);回归分析得蛋糕感官总分的回归方程为:Y感官总分=1.63+0.990X蛋糕口感+1.646X米粉添加量-8.058X米粉水分含量+0.136X蛋糕外观-0.23X蛋糕比容.     

热处理蛋清粉对小麦面团及馒头品质影响研究

通过将不同比例的热处理蛋清粉添加到小麦粉中,研究热处理蛋清粉对小麦面团及馒头品质的影响。结果表明：随着热处理蛋清粉的添加,混合面团吸水率明显下降,面团形成时间和稳定时间有所增加,且稳定时间最长至13.10min;添加了热处理蛋清粉混合粉的峰值黏度逐渐上升;当添加量为4%时,混合面团的拉伸距离和拉伸强度最大,分别提高了5.6%、75%;随着热处理蛋清粉添加量的增加,α-螺旋和β-折叠先上升后下降;添加热处理蛋清粉可增强面筋蛋白包裹淀粉颗粒的能力;热处理蛋清粉的添加使馒头的硬度、胶着度及咀嚼性增大;当热处理蛋清粉添加量为4%时,馒头比容增加了2.3%,且感官评价最好。     

蛋黄与蛋清对特二粉面筋聚集特性的影响

目的:蛋黄与蛋清添加到小麦粉中以期为加工与改良特色面制食品提供数据支撑。方法:以特二粉及鸡蛋为原料,利用面筋聚集仪研究特二粉在添加蛋黄与蛋清时面筋聚集特性的变化,并分析了聚集过程中面团显微结构和淀粉颗粒度的变化。结果:蛋黄添加量为5 mL时峰值扭矩(BEM)下降了9.5 BU,下降比例为19.39%;蛋清添加量为3 mL时BEM增加了4.08%,达到最大值;蛋清更有利于峰值扭矩的维持。蛋黄添加量为2 mL时峰值时间(PMT)下降了18.56%,达到最低值;蛋清添加量为1 mL时PMT上升了29.52%,达到最大值;表明添加蛋黄与蛋清对PMT的影响作用相反。随蛋黄添加量的增加S₃值占总能量的比例从81%增加到96%;而蛋清随添加量的增加S₃值占总能量的比例从43%波动增加到52%。结论:蛋黄与蛋清对面筋聚集特性的影响作用效果不一致,蛋黄与蛋清均显著改变面筋聚集能量的分布状态,蛋黄可降低面筋网络结构的连接力,使面筋蛋白网络结构断裂而分布更加均匀;而蛋清对面筋蛋白网络连接有促进作用,且蛋清对淀粉颗粒具有一定的保护作用。     

谷氨酰胺转氨酶添加量对蛋黄粉乳化性和凝胶性的影响

谷氨酰胺转氨酶(transglutaminase,TGase)通过交联作用能有效提高蛋白质的性质,进而提高食品的特性。通过在蛋黄液中添加不同量的TGase,经喷雾干燥得到蛋黄粉,研究经TGase处理后所得蛋黄粉乳化性和凝胶性的变化,运用傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FTIR)、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)和测定表面巯基数分析TGase对蛋黄粉乳化性影响和凝胶性影响的机理。结果显示:随着TGase的添加,蛋黄粉的凝胶性呈现先升高后降低的趋势,其在TGase添加量为1.5 U/g蛋黄时达到最大;经SDS-PAGE电泳和测定表面巯基数分析,TGase的交联作用能改变其表面巯基数含量,改变其凝胶网络状态,使其对水的束缚能力发生变化,进而改善蛋黄粉凝胶性;蛋黄粉的乳化活性指数(emulsification activity index,EAI)随TGase的增加呈现先升高后降低的趋势,其...     

1,2-二羰基化合物及晚期糖基化终产物在蒸蛋糕中的形成及调控

鉴于烘焙食品中美拉德反应有害产物的形成,选择不同蒸蛋糕配方(糖种类、油脂种类、糕点酸度调节剂、蛋黄蛋清比例),分析蛋糕中乙二醛(glyoxal,GO)、甲基乙二醛(methylglyoxal,MGO)及晚期糖基化终产物(advanced glycation end products,AGEs)含量的变化,并通过添加天然黄酮(染料木素、木犀草素)对蛋糕中GO、MGO及AGEs进行抑制试验。研究结果表明:用果糖(六碳糖)加工的蛋糕产生的MGO最高,木糖(五碳糖)产生的GO最高,木糖醇产生的GO及MGO含量均为最低;油脂对GO、MGO和AGEs生成量的影响由高到低依次为玉米油、大豆油、棕榈油、植物黄油;GO、MGO和AGEs的含量随着酸度调节剂的增加而呈下降趋势;添加蛋黄低于40%时,随着蛋黄添加量的减少有害指标均能显著降低。黄酮能显著抑制有害产物GO、MGO和AEGs的形成,且木犀草素的抑制效果高于染料木素。     

谷氨酰胺转氨酶及辅料对南海鸢乌贼鱼糜凝胶特性的影响

研究了谷氨酰胺转氨酶(TGase)以及辅料(蛋清粉、大豆分离蛋白、马铃薯淀粉)对南海鸢乌贼鱼糜凝胶硬度和弹性的影响。结果表明,TGase和辅料对鸢乌贼鱼糜凝胶硬度和弹性的提高起重要作用。一定范围内,随着添加物量的增加,鸢乌贼鱼糜凝胶硬度显著增强,然而由于鸢乌贼肌肉本身低凝胶性的特点,添加物对鸢乌贼鱼糜凝胶弹性的影响不如对凝胶硬度的影响显著,凝胶弹性增大到7.5 mm左右后就不再发生明显变化。TGase(100 U/g)的最适添加量为2%,选择二段加热法,凝胶条件为35℃水浴1 h;蛋清粉、大豆分离蛋白、马铃薯淀粉的适宜添加量分别为鱼糜质量的6%、9%、15%。     

Using modified soy protein to enhance foaming of egg white protein

BACKGROUND: It is well known that the foaming properties of egg white protein are significantly reduced when a small amount of yolk is mixed in the white. To improve foaming properties of yolk‐contaminated egg white protein, soy protein isolate (SPI) and egg proteins were modified to make basic proteins, and effects of these modified proteins on egg white foaming were evaluated in a model and an angel cake system. RESULTS: SPI and egg yolk proteins were modified to have an isoelectric point of 10, and sonication was used to increase protein dispersibility after the ethyl esterification reaction. However, only the addition of sonicated and modified SPI (SMSPI) showed improvement of foaming in the 5% egg protein model system with 0.4% yolk addition. SMSPI was then used in making angel food cake to examine whether the cake performance reduction due to yolk contamination of the white would be restored by such alkaline protein. Cake performance was improved when cream of tartar was used together with SMSPI. CONCLUSION: Basic soy protein can be made and used to improve egg white foaming properties and cake performance. Copyright © 2012 Society of Chemical Industry     

腌制方法对鸭蛋黄成分变化及品质影响

研究了鸭蛋在草木灰包裹法和盐水浸泡法腌制过程中,水分含量、盐分含量、R值与Q值,蛋黄总脂肪、可溶性蛋白质和巯基含量的变化以及成熟(7周)后两者蛋黄的感官品质。7周内,随腌制时间的延长,浸泡法鸭蛋黄水分含量明显低于包裹法鸭蛋黄,盐分含量却高于包裹法;蛋清R值高于蛋黄,灰蛋的R值、Q值都低于盐水蛋。第7周,灰蛋和盐水蛋的Q值上升为0.88和0.90;脂肪占湿重的含量上升至48.45%和50.67%,而腌制期总脂肪量是没有变化的;可溶性蛋白质含量增加至6.75%和6.08%;表面巯基和游离巯基下降至0.31、0.28mmol/g蛋黄和1.68、1.34mmol/g蛋黄。灰蛋蛋黄在形态、滋味和气味方面明显优于盐水蛋,感官评分分别为88.9和78.65。     

Effects of protein and transglutaminase on the preparation of gluten-free rice bread

Effects of transglutaminase (TGase) and proteins such as whey protein, caseinate, and soy protein on the preparation of gluten-free rice breads using non-waxy rice flour were investigated. Rice flour (about 12% moisture content) was prepared from dry milling of dried grain after rice got soaked. Unlike general dry milled flour, newly developed rice flour increased water binding capacity (WBC), swelling power, and peak viscosity. Soy protein increased WBC but other proteins slightly decreased with the increase of levels. Lightness decreased and yellowness increased with the addition of whey and soy protein. All pasting viscosities decreased with the addition of protein. The TGase improved the network structure of rice batter. The 2^nd proof time of rice batter with protein was shortened by 4–9 min with the addition of TGase. The specific volumes of rice breads with whey and soy protein also increased. TGase and protein additions decreased the hardness of rice bread. Sensory test showed that roasted flavor, volume, air cell homogeneity, and overall quality were significantly different (p<0.05) with protein and TGase additions.     

Development and evaluation of products from cassava flour as new alternatives to wheaten breads

Egg white with margarine, and xanthan gum, have been used to produce alternative breads from cassava flour fortified with 200 g kg^?1 soya flour. All the additives increased the amount of air entrapped in the cassava batters at the mixing stage, as indicated by their lower batter densities. The lower the batter density the higher was the maximum gas retention volume attained in the 60 min fermentation stage. However, final loaf volume also depends on the stability of the batter; egg white primarily acts as a stabiliser. Margarine, and more significantly egg white, reduced the extent of starch gelatinisation and solubilisation in the bread. Breads made with locally available egg white and margarine are sensorily acceptable to Nigerian consumers and have very good keeping qualities.     

蛋清蛋白添加对籼米-绿豆粉粉质特性及挤压米粉丝品质特性的影响

将籼米粉、绿豆粉和蛋清蛋白粉按照一定的比例复配,开发高纤维含量的杂粮米粉丝。研究了绿豆和蛋清蛋白的添加对米粉糊化特性、流变特性以及挤压米粉丝微观结构、蒸煮特性和质构等品质特性的影响。结果显示:添加一定量的绿豆粉和蛋清蛋白粉后,混合粉的峰值黏度、最低黏度、最终黏度、回生值、弹性模量、黏性模量均逐渐下降。随着绿豆粉的添加(25%,50%),米粉的蒸煮时间、断条率、蒸煮损失和吸水率均上升,硬度降低,表明米粉的品质显著降低,由扫描电镜图可以发现,加了绿豆粉之后米粉截面变得越来越粗糙,裂纹和孔洞明显增多。但当加入7.5%的蛋清蛋白后,米粉的蒸煮时间、蒸煮损失和断条率均下降,质构特性有一定程度的改善,表明蛋清蛋白良好的凝胶特性有助于提升高纤维含量挤压米粉丝的品质。     

Effect of Various Types of Egg White on Characteristics and Gelation of Fish Myofibrillar Proteins

ABSTRACT:  Three types of egg white protein (regular dried egg white [REW], special dried egg white [SEW], and liquid egg white [LEW]) were compared for their effect in surimi (CON), containing no egg white (EW). They were characterized for enzyme inhibition and time of EW addition, either with cryoprotectants prior to freezing or during gel preparation, using Pacific whiting surimi. In addition, the setting (suwari) effect and fish protein–EW protein interactions (dynamic rheological properties, total sulfhydryl groups, and fracture gel analysis) were evaluated using Alaska pollock surimi. After 12 mo frozen storage, adding 2% and 3% SEW to Pacific whiting surimi during chopping significantly ( P  < 0.05) increased the force and deformation values compared to adding the respective EW before freezing. The highest ( P  < 0.05) force (175.2 g) and deformation (9.0 mm) values after 12 mo were obtained when 3% SEW was added during chopping. Enzyme autolysis showed that addition of 2% EW protein was effective at inhibiting enzyme activity. During setting, adding 2% SEW maintained force (1047.4 g) and deformation (17.9 mm) values similar ( P  > 0.05) to CON (1055.1 g; 19.3 mm) and significantly ( P  < 0.05) better than 2% REW (666.1 g; 15.6 mm). Texture results corresponded well to other data where 2% SEW showed the lowest total sulfhydryl groups (48.3 mole/10⁵ g), and higher elastic modulus (G'), which suggests improved protein interaction for gel formation. Overall, the addition of 2% to 3% SEW improved gel textural properties of Pacific whiting and Alaska pollock fish protein.     

Effects of protein from different sources on the characteristics of sponge cakes,rice cakes (apam), doughnuts and frying batters

Sponge cakes containing total substitution of whole egg with egg yolk had the largest volume, best texture, highest moisture, colour and flavour compared with all other cakes. Cakes made with total substitution of other proteins had smaller volumes than the control, while those made with egg white had the lowest moisture. Cakes made with whey powder had the tenderest texture. Doughnuts made with protein other than gluten had reduced oil absorption compared with the control. Doughnuts containing whey or skimmed milk had the most desirable flavour; this may be attributed to the presence of lactose. Gluten doughnuts were most disliked because of their hard texture and pale colour. Doughnuts made with total substitution of whole egg with egg white had good texture and low oil absorption. Skimmed milk powder was best for the expansion and texture of chemically leavened rice cakes (apam), while egg white produced the best expansion for yeast-leavened rice cakes, compared with the other proteins studied. The protein that produced the most desirable textures in yeast-leavened rice cakes in order of merit were skimmed milk powder, egg white and egg yolk. Whey, skimmed milk powder and gluten helped improve the crispiness of frying batters. Ovalbumin did not affect the crispiness but significantly reduced the oil absorption of the frying batters. Addition of proteins other than whey and ovalbumin, increased the oil absorption of frying batters.     

球磨处理对鸡蛋清蛋白结构、性质及起泡性的影响

蛋清因具有优良的起泡性而在焙烤等食品加工领域中被广泛应用,因此,提升蛋清蛋白的起泡性有重要意义。本实验对鸡蛋清蛋白进行球磨处理,通过测定球磨处理后蛋清蛋白的游离巯基含量、表面疏水性、水解度、Zeta-电位和粒径,并分析其热力学性质、二级结构、起泡特性和微观结构,以研究球磨处理对蛋清蛋白结构性质及其起泡性的影响。结果表明：球磨处理后的蛋清蛋白粉随处理时间的延长起泡性无明显变化,泡沫稳定性呈现先升高后降低的趋势,且在球磨处理40 min时达到最大值（33.5 s）,比对照组提高近3 倍;此外,球磨处理可显著降低蛋清蛋白表面疏水性和热变性焓（ΔH）（P＜0.05）,显著提高水解度和降低Zeta-电位绝对值（P＜0.05）,并增大粒径,但对游离巯基含量和变性温度无显著影响（P＞0.05）;随着球磨时间的延长,蛋清蛋白β-折叠结构相对含量显著升高（P＜0.05）,α-螺旋结构相对含量先降低后升高,而β-转角结构相对含量先升高后降低;扫描电子显微镜结果显示球磨处理使蛋清蛋白呈现出零散碎片化和絮状。综上,适度球磨处理可以改变蛋清蛋白分子结构,进而提升其泡沫稳定性。