含Olestra低脂休闲蛋糕体系的流变学、微结构与烘焙特性

以Olestra为脂肪替代物替代休闲蛋糕配方中的部分脂肪(替代率分别为质量分数25%、50%、75%),研究其对面糊的密度、微观结构及流变学特性的影响,并对休闲蛋糕产品的理化参数、质构、感官评定进行研究。结果表明:当脂肪替代率为25%时,休闲蛋糕面糊流变特性和休闲蛋糕品质和对照组差别不大;脂肪替代率为50%时,会显著增大面糊密度,减少面糊中气泡数目,降低休闲蛋糕比容。TPA结果表明添加脂肪替代物会使休闲蛋糕的硬度和咀嚼度显著增加。     

搅拌时间和乳化剂对海绵蛋糕表面气泡的影响

比较研究蔗糖酯型乳化剂和单甘酯型乳化剂对海绵蛋糕起泡和消泡阶段面糊特性的影响,并重点比较了在相同面糊比重情况下,不同搅拌时间组合对海绵蛋糕表面气泡的控制及对面糊比重、黏度、微观气相结构、蛋糕烘焙特性的影响,并探讨了乳化剂与搅拌时间控制表面气泡的机理。结果表明:使用蔗糖酯型乳化剂可以控制海绵蛋糕表面气泡生成,并保持较佳的烘焙特性。在工艺方面,采用合适的搅拌组合(起泡时间3.50min,消泡时间6.33min)可以减少面糊异常气泡数量,从而减少海绵蛋糕表面气泡生成。     

海藻酸丙二醇酯对面团流变学和面包烘焙特性的影响

采用粉质仪、拉伸仪和质构分析仪研究添加不同比例(0.1%、0.2%、0.3%和0.4%)的海藻酸丙二醇酯(PGA)对面团流变学特性和面包烘焙特性的影响。结果表明,添加PGA能改善面团的粉质和拉伸特性,能显著提高面团的吸水率,延长面团的稳定时间,提高粉质评价指数,增大面团的延展性、拉伸阻力和拉伸比值。添加PGA能增大面包比容,显著提高面包的弹性,降低面包硬度,改善面包的口感,提高面包的感官评分。PGA添加量在0.2%~0.3%时,对面团和面包的改善效果最为显著,面包品质最好。     

藻酸丙二醇酯的流变学特性研究

利用MCR101流变仪研究了质量分数、pH、蔗糖、NaCl、温度对藻酸丙二醇酯（PGA）流变学特性的影响。结果表明:藻酸丙二醇酯溶液是假塑性流体,其流动特性符合Power-law模型,其粘度随PGA质量分数和蔗糖浓度的增加而升高;随剪切速率、pH、温度的增加而降低;在较低NaCl浓度下（0.01和0.1mol/L）,PGA溶液粘度降低,NaCl浓度在1mol/L时,溶液粘度增加。PGA溶液具有一定的触变性和粘弹性,在低频率区域体系以粘性为主,高频率区域体系以弹性为主,G′和G″的交点受PGA浓度、pH和温度的影响。      

乳化剂和保泡型流态起酥油对海绵蛋糕面糊及其烘焙特性的影响

比较了单甘酯型乳化剂和蔗糖酯型乳化剂与保泡型流态起酥油联用对海绵蛋糕面糊特性及其烘焙特性的影响。结果表明,采用蔗糖酯型乳化剂与保泡型流态起酥油联用组的面糊比重显著下降,面糊黏度和表面张力增加,从而提升了面糊的稳定性,此时蛋糕比容较大,达4.01mL/g,比仅含单甘酯型乳化剂的蛋糕提高了68.5%,可显著减少薄层海绵蛋糕的表面气泡。蛋糕贮藏期研究表明,贮藏28d后,含有蔗糖酯型乳化剂和保泡型流态起酥油的蛋糕硬度减小了37.8%。     

三种糖醇对海绵蛋糕面糊流变学、热力学及烘焙学特性影响的比较研究

以三种糖醇(麦芽糖醇(Mal)、木糖醇(Xyl)和赤藓糖醇(Ery))分别完全替代海绵蛋糕中的蔗糖,比较它们对海绵蛋糕面糊流变学、热力学和烘焙学特性的影响。主要采用旋转流变仪、显微照相仪、差示扫描量热仪(DSC)、测色仪和质构仪等分别研究了三种糖醇对面糊黏度特性、微观结构、糊化性质以及蛋糕比容、颜色、质构和感官品质等的影响。结果表明:Mal对面糊特性无显著影响(p0.05),减弱了蛋糕皮红色色调(a*),增强了其亮度(L*);Xyl主要显著降低了面糊比重(p0.05),降低了淀粉糊化起始和峰值温度,显著增大了蛋糕硬度(p0.05),但感官评定结果显示,用Mal和Xyl分别完全取代海绵蛋糕中蔗糖后,蛋糕总体质量仍可接受;Ery显著增大了面糊比重、减小了面糊黏度、降低了面糊中气泡均匀性和淀粉糊化温度(p0.05),对蛋糕比容、质构、颜色和感官特性都产生了不利影响,感官评定结果发现其总体质量不可接受。     

三种糖醇对海绵蛋糕面糊流变学、热力学及烘焙学特性影响的比较研究

以三种糖醇(麦芽糖醇(Mal)、木糖醇(Xyl)和赤藓糖醇(Ery))分别完全替代海绵蛋糕中的蔗糖,比较它们对海绵蛋糕面糊流变学、热力学和烘焙学特性的影响。主要采用旋转流变仪、显微照相仪、差示扫描量热仪(DSC)、测色仪和质构仪等分别研究了三种糖醇对面糊黏度特性、微观结构、糊化性质以及蛋糕比容、颜色、质构和感官品质等的影响。结果表明:Mal对面糊特性无显著影响(p>0.05),减弱了蛋糕皮红色色调(a*),增强了其亮度(L*);Xyl主要显著降低了面糊比重(p<0.05),降低了淀粉糊化起始和峰值温度,显著增大了蛋糕硬度(p<0.05),但感官评定结果显示,用Mal和Xyl分别完全取代海绵蛋糕中蔗糖后,蛋糕总体质量仍可接受;Ery显著增大了面糊比重、减小了面糊黏度、降低了面糊中气泡均匀性和淀粉糊化温度(p<0.05),对蛋糕比容、质构、颜色和感官特性都产生了不利影响,感官评定结果发现其总体质量不可接受。      

冷冻蛋糕的微波烘焙技术特性

文中对冻藏时间(0、2、4、6周)、冻融循环次数(0、1、2、3次,数字代表冻融循环次数)、微波烘焙功率(40%和100%)和储藏时间(0、1、3、6和24h)对冷冻面糊微波烘焙蛋糕含水量、硬度、比容、水分损失及可溶性淀粉含量等进行了研究。结果发现:随冻藏时间延长,蛋糕含水量和比容显著降低,硬度显著增大,冻融循环过程明显加剧了这些影响;微波烘焙功率越大,蛋糕含水量显著降低,比容和硬度显著增大。在储藏过程中,蛋糕硬度和水分损失都显著增加,可溶性淀粉含量显著减少;微波烘焙功率较大时,硬度和水分损失增加的明显更快,可溶性淀粉含量降低的明显更迅速;储藏过程中蛋糕硬度变化与水分损失、可溶性淀粉含量均成正相关,相关系数分别为0.93和0.86。结果说明:(1)较小的微波烘焙功率(40%)比较高的微波烘焙功率(100%)会生产出更好的冷冻面糊蛋糕,且其老化速率相对较低,(2)冷冻面糊微波蛋糕的老化主要是由于水分损失和淀粉重结晶引起的。     

丙二醇酯中游离丙二醇含量的直接测定

提出丙二醇酯中游离丙二醇含量的直接测定方法。该法和萃取法对一系列样品进行对照试验,经数理统计分析,结果表明,两种测定方法没有显著性差异。直接法更简单、快捷。回收率为95.7?.0%,相对标准偏差为0.23%0.60%。     

不同乳化剂在中日两国面粉重油蛋糕面糊体系中的比较研究

探究使用MFC和SP两种乳化剂对中国和日本两国面粉的面糊流变学特性、面糊气泡分布、烘焙学特性以及热力学特性的影响,并对蛋糕进行感官评定测试。结果表明:添加10%MFC的蛋糕面糊比重变化最大,随着MFC的添加量的增加,蛋糕的比容出现了明显的上升。MFC面糊的气泡分布更加均匀,乳化体系有很好的稳定性。当MFC产品的添加量达到了7.5%时,其产品的硬度与添加了5%SP的蛋糕产品的硬度相似。含有10%MFC的重油蛋糕的感官品质以及抗老化效果最佳。相比于日本面粉,使用中国面粉作为面糊基质的蛋糕老化速率更低。     

不同丙二醇单酯对脂肪物性影响的研究

以丙二醇硬脂酸单酯、丙二醇油酸单酯和丙二醇月桂酸单酯为原料,研究了不同丙二醇单酯对脂类的热力学性质和结晶特性的影响。示差扫描量热仪(DSC)结果得出,三种丙二醇单酯对牛油和棕榈油的热力学性质有显著影响,随着单酯加入量的增多,混合脂类熔点逐渐降低,焓值变小,特别是加入硬脂酸丙二醇单酯后,变化尤其明显;通过X-射线衍射对三种丙二醇单酯作用下的油脂晶体形态构造进行分析,可以看出饱和脂肪酸丙二醇单酯对脂类晶体转化有抑制作用,随着加入量的增加抑制作用越来越强,硬脂酸单酯效果最为显著,加入50%即可使脂肪保持稳定的α晶型,而不饱和脂肪酸丙二醇油酸单酯对晶型转化几乎没有影响。     

4种功能性低聚糖对海绵蛋糕的面糊性能和烘焙品质的影响

针对海绵蛋糕的高糖问题,选用4种功能性低聚糖完全替代海绵蛋糕中的蔗糖,分别比较了它们对海绵蛋糕的面糊性能和烘焙品质的影响。结果表明:低聚异麦芽糖、低聚果糖、低聚半乳糖的面糊性能与蔗糖组较为接近,显示出良好的替代性,使用这3种糖制作的海绵蛋糕贮藏3d后依然是可接受的。而菊粉因为吸湿性极强,其海绵蛋糕成品比容小,硬度大,咀嚼时粉质感强烈,可接受度最低。     

Optimization of a sponge cake formulation with inulin as fat replacer: structure, physicochemical, and sensory properties

The effects of several fat replacement levels (0%, 35%, 50%, 70%, and 100%) by inulin in sponge cake microstructure and physicochemical properties were studied. Oil substitution for inulin decreased significantly (P < 0.05) batter viscosity, giving heterogeneous bubbles size distributions as it was observed by light microscopy. Using confocal laser scanning microscopy the fat was observed to be located at the bubbles' interface, enabling an optimum crumb cake structure development during baking. Cryo-SEM micrographs of cake crumbs showed a continuous matrix with embedded starch granules and coated with oil; when fat replacement levels increased, starch granules appeared as detached structures. Cakes with fat replacement up to 70% had a high crumb air cell values; they were softer and rated as acceptable by an untrained sensory panel (n = 51). So, the reformulation of a standard sponge cake recipe to obtain a new product with additional health benefits and accepted by consumers is achieved. Practical Application: In this study, fat is replaced by inulin in cakes, which is a fiber mainly obtained from chicory roots. Sponge cake formulations with reductions in fat content up to 70% are achieved. These high-quality products can be labeled as "reduced in fat" according to U.S. FDA (2009) and EU regulations (European-Union 2006).     

Effects of propylene glycol or fat drench on plasma metabolites,liver composition,and production of dairy cows during the periparturient period

Forty-eight Holstein cows were used to determine the effects of short-term oral drenches of propylene glycol (PG) and Ca-soaps of palm oil fatty acids (fat) on plasma concentrations of key metabolites, liver composition, and milk production during the first 3 wk of lactation. Treatments (2 x 2 factorial arrangement) given orally once daily for the first 3 d postpartum were water (control), 500 ml of PG, 454 g of fat, or 500 ml of PG plus 454 g of fat. All treatments were administered as a total volume of 1.9 L. Administration of PG decreased concentrations of nonesterified fatty acids (NEFA) in plasma during the first 7 d and the first 21 d postpartum and tended to decrease concentrations of beta-hydroxybutyrate during the first 7 d postpartum. Concentrations of insulin in plasma were not affected by treatment. Administration of either PG or fat increased plasma glucose and liver glycogen concentrations compared to the control or PG plus fat treatments. Concentrations of triglycerides in liver were not affected by treatment. Administration of PG did not affect dry matter intake or milk yield and composition during the first 3 wk postpartum; however, cows drenched with fat tended to have lower dry matter intake and milk yield during the first 3 wk of lactation. Short-term drenching of PG effectively decreased NEFA concentrations in plasma during early lactation; however, data do not support administration of fat via drench to early lactation cows and concurrent administration of dietary fat appears to blunt the metabolic response of cows to PG.     

Influence of fat content and emulsifier type on the rheological properties of cake batter

The effects of fat content and emulsifier type on the rheological properties of cake batter have been investigated by using a parallel-plate rheometer. The apparent viscosity of cake batter with five different fat concentrations (0, 12.5, 25, 37.5, and 50%) and two types of emulsifier, namely Purawave and Lecigran, was studied as a function of the shear rate. In addition, the time dependency of different cake formulations was investigated. It was found that cake batter with different fat concentrations and emulsifier types exhibited shear thinning and time-independent behavior. Experimental data provided a good fit for the power law model. The increase in fat content and addition of emulsifier caused a decrease in the apparent viscosity. The flow behavior index was not found to be dependent on the composition of cake batter.     

Randomized clinical field trial on the effects of butaphosphan-cyanocobalamin and propylene glycol on ketosis resolution and milk production

The purpose of this study was to determine the effects of a butaphosphan-cyanocobalamin combination product (B+C) and 2 durations of propylene glycol treatment (PG; 3 versus 5 d) on ketosis resolution and early lactation milk yield. Cows from 9 freestall herds (8 in Ontario and 1 in Michigan) were tested at weekly intervals between 3 and 16 d in milk. Ketosis was defined as blood β-hydroxybutyrate (BHB) ≥1.2 mmol/L. Ketotic cows were randomly assigned to treatment with 25 mL of B+C or 25 mL of saline placebo for 3 d and 3 or 5 d of 300 g of PG orally in a 2 × 2 factorial arrangement. Outcomes evaluated for all farms included ketosis cure (blood BHB <1.2 mmol/L at 1 wk after enrollment), maintenance of ketosis cure (blood BHB <1.2 mmol/L 1 and 2 wk after enrollment), and blood BHB concentrations at 1 and 2 wk after enrollment. Daily milk weights were collected in 3 herds. Poisson regression was used to evaluate cure and maintenance of cure, whereas repeated-measures ANOVA was used to evaluate blood BHB concentrations in the 2 wk after enrollment and average daily milk production in the 30 d after treatment. A total of 594 animals were enrolled in the study with 124 treated with B+C and 5 d of PG, 176 treated with B+C and 3 d of PG, 128 treated with saline and 5 d of PG, and 166 treated with saline and 3 d of PG. Animals with blood BHB >2.4 mmol/L at the time of enrollment were 1.7 times more likely [95% confidence interval (CI): 1.4 to 2.2] to cure and had a decrease of 0.25 ± 0.11 mmol/L blood BHB at 1 wk after enrollment if treated with 5 d of PG compared with 3 d, though this response was not seen in animals with BHB of 1.2 to 2.4 mmol/L at enrollment. Cows with blood glucose concentrations <2.2 mmol/L at enrollment produced 3.1 kg/d (95% CI: 1.3 to 5.0) more milk if treated with B+C and 3.4 kg/d (95% CI: 1.7 to 5.1) more milk if treated with 5 d of PG compared with their respective controls. This response was not seen in animals with blood glucose ≥2.2 mmol/L at enrollment and there was no interaction between treatments. These results indicate that extended PG treatment is beneficial in decreasing blood BHB concentrations in more severely affected animals. Additionally, both B+C treatment and extended PG treatment improved milk yield in animals with low blood glucose at the time of ketosis diagnosis.