脂肪替代物对微乳体系流变性质与晚期糖基化终末产物的影响

为探究亲水胶体类脂肪替代物对含脂微乳体系流变学特性与晚期糖基化产物生成的影响,试验以葡萄糖、赖氨酸和亚油酸构建的微乳体系为基础,分别添加0.1%魔芋胶或黄原胶,测定各组的静、动态流变特性和乙二醛、甲基乙二醛、戊糖素及荧光AGEs的含量。结果表明,黄原胶可改变体系的静态流体特性,黄原胶和魔芋胶均可显著影响体系的黏性及弹性。糖基化反应随温度的升高而加剧,魔芋胶和黄原胶均可在4℃和25℃下抑制(P<0.05)乙二醛、戊糖素和荧光AGEs的生成,在60℃下抑制乙二醛的生成;黄原胶可在60℃下短期抑制荧光AGEs的生成。综上,亲水胶体的加入不但能调整脂肪的流变特性,还能在不同程度上抑制AGEs及中间产物的生成,该结果为脂肪替代物在功能食品中的应用提供新的视角与理论依据。     

芦丁抑制牛血清白蛋白糖基化

目的：考察芦丁对糖及活性二羰基化合物诱导的牛血清白蛋白（bovine serum albumin,BSA）糖基化的抑制效果。方法：建立牛血清白蛋白-丙酮醛（bovine serum albumin-methylglyoxal,BSA-MGO）、牛血清白蛋白-乙二醛（bovine serum albumin-glyoxal,BSA-GO）、牛血清白蛋白-还原糖反应体系,利用荧光光谱的方法考察MGO、GO和还原糖对于BSA糖基化的影响,并考察芦丁对于3 个反应体系中晚期糖基化终末产物（advancedglycation end products,AGEs）的抑制作用。结果：MGO、GO、还原糖浓度分别为0.5、0.5、10 mmol/L时引发BSA蛋白糖基化反应较为显著。对于上述3 个体系,芦丁的添加浓度分别为0.25、0.25、1 mmol/L时,能有效地抑制AGEs的形成。结论：芦丁能有效地抑制BSA-MGO、BSA-GO、BSA-还原糖体系的牛血清白蛋白糖基化。     

不饱和脂肪酸对卵清蛋白糖基化反应的影响

糖基化反应是高营养食品常见的一类反应,食品中的脂类成分对糖基化反应有很大影响。本研究以葡萄糖和卵清蛋白（OVA）建立糖基化对照体系,与含有不饱和脂肪酸（UFA）的模型组进行对比,探究脂肪酸氧化对于糖基化反应产物二羰基化合物、晚期糖基化终产物（AGEs）及糖基化蛋白结构的影响。结果表明UFA通过不同方式促进二羰基化合物的形成,并通过改变OVA蛋白的高级结构显著促进糖基化反应。脂肪酸的不饱和度与二羰基化合物含量、TBA值、POV值均成正比,与羧甲基赖氨酸和吡咯素含量成反比。通过SEM结构模型的路径分析可知,脂质氧化次级产物对二羰基化合物的影响力较强（路径系数0.814）,对两种AGEs的影响力相对较弱（0.246）;脂质氧化初级产物对两种AGEs的影响力强于二羰基化合物。     

大豆11S球蛋白糖基化有害交联产物的形成及抑制机理

目的：针对食品工业大豆蛋白糖基化改性工艺,建立大豆11S球蛋白-糖模拟体系,探究该体系中晚期糖基 化终产物（advanced glycation end products,AGEs）形成的影响因素,探究黄酮类化合物抑制AGEs形成的机理, 以便进行有效调控。方法：荧光光谱法（λex/λem＝340 nm/465 nm）测定糖的种类和浓度、温度、pH值以及黄酮抑制 剂等对AGEs形成的影响,十二烷基硫酸钠-聚丙烯酰胺凝胶电泳表征糖基化过程及黄酮对AGEs的抑制效果,通过 液相色谱-串联质谱（liquid chromatograph-tandem mass spectrometry,LC-MS/MS）测定反应过程中槲皮素及其产物 的变化。结果：糖种类为果糖;11S球蛋白与果糖质量浓度分别为2、8 mg/mL,pH值为9.2,温度为121 ℃条件下产 生的荧光性AGEs量最多;槲皮素、木犀草素、染料木素、芦丁4 种黄酮对荧光性AGEs的形成均有一定抑制效果; LC-MS/MS结果表明槲皮素通过捕获糖基化中间产物甲基乙二醛（methylglyoxal,MGO）,抑制了大分子交联性的 荧光性AGEs形成;十二烷基硫酸钠-聚丙烯酰胺凝胶电泳验证了1 mmol/L槲皮素有效降低了大分子交联的产物,但 不影响糖的修饰改性,乳化性能得到较好的改善。结论：采用分子质量较大的糖,降低糖质量浓度、pH值和反应 温度,添加黄酮类化合物可有效抑制大豆蛋白糖基化过程中有害产物AGEs的形成。     

8种别样茶对AGEs抑制能力的筛选及其抑制机制探究

目的:本研究通过检测非酶糖基化终末产物（advanced glycation end-products,AGEs）生成量评价8种别样茶的糖基化抑制能力,并探究抑制效果较好的别样茶对AGEs生成各阶段的抑制作用机制。方法:本研究首先对8种别样茶水提液中总黄酮含量进行检测,接着通过构建体外蛋白质非酶糖基化模型实验检测了8种别样茶抑制AGEs生成的能力,最后择优测定其对糖基化早期产物果糖胺、中期产物活性羰基化合物以及蛋白质交联的抑制能力,从而探究其对非酶糖基化反应的抑制机制。结果:大叶苦丁茶（Ilex latifolia Thunb）和甜茶（Rubus suavissimus S. Lee）对AGEs的抑制效果在8种别样茶中较为突出,50 μg/mL时AGEs抑制率分别达到了76.31%±0.87%和81.75%±0.41%;大叶苦丁茶和甜茶主要通过抑制糖基化早期、中期产物的生成量来减少AGEs的产生。其中,500 μg/mL甜茶对果糖胺抑制率最高（59.12%）,蛋白质交联抑制率最高（81.41%）,5000 μg/mL大叶苦丁茶对活性羰基化合物抑制率最高（94.24%）。结论:大叶苦丁茶及甜茶可以作为抑制糖基化反应的功能食品,本研究可为具有抑制AGEs产生功效原料的综合开发利用提供一定的理论依据。     

亲水胶体对低脂肉糜加热稳定性的影响

研究了四种亲水胶体对低脂肉糜加热稳定性的影响.结果表明:四种亲水胶体的最佳配比为大豆分离蛋白2.0%,魔芋精粉2.0%,黄原胶0.5%,卡拉胶0.4%,按此最佳配比添加于肉糜中,在80℃下,加热1.5 h,加热稳定性好.感官品质佳.     

不同藜麦粉添加量对海绵蛋糕面糊特性及烘焙特性的影响

为提高无麸质蛋糕的品质,通过测定不同藜麦粉添加量的面糊的流变特性和密度;蛋糕的比容、烘焙损失率、色差、感官评分以及贮藏7 d后蛋糕的质构特性、水分分布和老化焓值等指标,探究藜麦粉对无麸质面糊特性及蛋糕品质的影响。结果表明,面糊的弹性模量（G′）、黏性模量（G″）和密度与藜麦粉添加量呈正相关,进而增大了蛋糕比容并降低烘焙损失率,蛋糕气孔分布更加均匀。高比例的藜麦粉（30%～50%）能有效延缓蛋糕的老化。在贮藏7 d后,对照组和50%藜麦粉老化焓值分别增加至1.42 J/g和0.92 J/g。综上,添加藜麦粉能够显著提高面糊的流变特性和蛋糕的烘焙特性,延缓蛋糕老化。综合蛋糕感官评分和老化特性,藜麦粉添加量为30%时较为适宜,可以赋予无麸质海绵蛋糕更好的品质。     

牛蒡多酚对荧光性晚期糖基化终产物形成的抑制作用

目的:晚期糖基化终产物(Advanced glycation end products,AGEs)是由还原糖的羰基和多肽、蛋白质等分子的自由氨基通过非酶反应形成的一系列复杂的化合物。多项研究发现,AGEs具有多种不可忽视的生理毒性。文章通过检测模拟食品热加工和人体环境模型中荧光性AGEs的生成情况,评价牛蒡多酚的抗糖化作用。方法:分别建立体外模拟食品热加工和人体环境形成AGEs的模型,采用荧光分析法测定2种模型中总荧光AGEs、特征荧光AGEs(戊糖素)以及蛋白质氧化产物双酪氨酸、犬尿氨酸生成量,对牛蒡多酚的抗糖化作用进行评价。结果:在食品热加工模型中,牛蒡多酚对总荧光AGEs生成的抑制率最高可达60.62%,对戊糖素生成的抑制率最高可达81.47%;同时,对蛋白质氧化产物双酪氨酸和犬尿氨酸的抑制率分别为57.36%和44.25%。在模拟人体环境形成AGEs模型中,牛蒡多酚对总荧光AGEs抑制率最高可达48.37%,对戊糖素生成的抑制率最高可达52.81%;对蛋白质氧化产物抑制率分别为双酪氨酸42.63%和犬尿氨酸30.72%。结论:在食品热加工和人体环境形成AGEs的模型中,牛蒡多酚均具有较好的抗糖化作用,可作为糖化反应抑制剂用于功能性食品添加剂或膳食补充剂。     

响应面法优化石榴瓤多酚的提取工艺及抗糖基化活性分析

探讨应用响应面法优化石榴瓤多酚提取的最佳工艺条件,并测定其体外抗糖基化活性。以石榴瓤多酚得率为考察指标,料液比、乙醇体积分数和超声时间为影响因素,在单因素试验基础上,采用Box-Behnken Design(BBD)试验设计优化石榴瓤多酚的最佳提取工艺条件,并通过建立牛血清白蛋白(BSA)-果糖模拟反应体系和BSA-丙酮醛模拟反应体系,评价石榴瓤多酚对非酶糖基化终末产物(AGEs)的抑制作用。结果表明,当料液比1:17(g/mL)、乙醇体积分数63.5%、超声时间37 min时,石榴瓤多酚得率达15.81%,与模型预测结果接近。在浓度0.375～36μg/mL内,石榴瓤多酚与对AGEs的抑制作用之间呈一定的正相关关系,在浓度为36μg/mL时,对BSA-果糖模型中AGEs的生成抑制率达到56.1%,抑制作用的IC_(50)=27.807μg/mL,对BSA-丙酮醛模型中AGEs的生成抑制率达到52.2%,抑制作用的IC_(50)=30.363μg/mL。该方法提取石榴瓤多酚可行、可靠,产物具有较好的抗糖基化活性。     

槲皮素与葛根素对食品体系中非酶糖基化的抑制作用

通过对果糖胺、二羰基化合物、5-羟甲基糠醛（5-hydroxymethylfurfural,5-HMF）和荧光性末端产物的检测,考察槲皮素和葛根素对食品体系非酶糖基化反应的抑制作用。结果表明：槲皮素能促进非酶糖基化早期产物果糖胺和5-HMF的生成,对反应中期的二羰基化合物和非酶糖基化末端产物（advanced glycation end products,AGEs）具有较强的抑制作用;葛根素能促进果糖胺的生成,抑制二羰基化合物的生成,对5-HMF和AGEs无影响。这可能与槲皮素与葛根素的结构差异有关。     

Partial Replacement of Egg White Proteins with Whey Proteins in Angel Food Cakes

This study was conducted to investigate the effects of partial replacement of egg white proteins (EWP) with whey protein isolate (WPI) on the appearance, structure, texture, and sensory properties of angel food cakes baked in conventional and microwave/conventional ovens. Factors studied were: 1) replacement of 25% or 50% of EWP with WPI; 2) added xanthan gum (XG), methyl cellulose (MC), cupric sulfate (Cu⁺²) or sodium phosphate (PHOS); and 3) conventional vs microwave/conventional oven baking. EWP replacement cakes without additives were generally inferior to 100% EWP control cakes, whereas EWP replacement cakes with added XG were most similar to 100% EWP control cakes with respect to appearance, texture, and sensory properties and those with added MC exhibited air cell size distributions that most closely resembled control cakes. The other additives and microwave/ conventional vs conventional baking had minor effects on the quality of EWP replacement cakes.     

炸制过程中油脂氧化对鱼饼中晚期糖基化终末产物生成的影响

旨在为炸制鱼饼中晚期糖基化终末产物(AGEs)含量的控制提供理论依据和参考,以冷冻鲢鱼糜为原料制作鱼饼,通过分析连续炸制过程中(每3 h炸制1次)鱼饼中AGEs的生成与其理化指标和油脂氧化程度之间的相关性,探讨炸制过程中油脂氧化对鱼饼中AGEs生成的影响。结果表明：鱼饼外层AGEs含量显著高于内层,炸制9～18 h,鱼饼AGEs含量显著高于其他阶段(p<0.05);鱼饼中AGEs含量与水分含量呈极显著负相关,与脂肪含量和丙二醛含量呈极显著正相关,说明水分散失、油脂吸收以及油脂氧化促进了AGEs的生成。综上,在连续炸制过程的中期,鱼饼中水分含量较低,油脂氧化较为严重,AGEs含量较高。     

Rheology and breadmaking performance of rice-buckwheat batters supplemented with hydrocolloids

The aim of this work was to investigate the effects of hydrocolloid addition on rheological properties and breadmaking performance of rice-buckwheat batter at different water levels. Xanthan gum (XG) and propylene glycol alginate (PGA) were added to rice-buckwheat blend (60:40) at levels of 0.5–1.5%. Batter rheological properties were investigated using dynamic measurements in the linear viscoelastic range (frequency sweep and time cure tests). The addition of both hydrocolloids significantly enhanced the storage modulus (G′) of batter. XG exerted greater effect on G′ than PGA. Different effects on starch gelatinisation were observed for the two hydrocolloids. PGA breads showed higher improvement in terms of increased specific volume (V_s), decreased crumb firmness and crumb structure than XG breads. Different technological behaviours were explained on the basis of batter rheological properties.     

The use of selected hydrocolloids to enhance cooking quality and hardness of zero‐salt noodles

The effects of table salt (TS) and hydrocolloids on water‐holding capacity, optimum cooking time, cooking qualities, pH and textural properties of noodles were investigated. TS, xanthan gum (XG), carrageenan (CRG), Arabic gum (AG) and locust bean gum (LBG) were added at 0.5%, 1.0%, 1.5% and 2.0% of flour weight. XG, CRG and LBG contributed to significantly (P < 0.05) higher water‐holding capacity of dough and firmer texture, but significantly (P < 0.05) lower cooking loss than zero‐salt noodles (ZSNs) and white‐salted noodles (WSNs). Hydrocolloids contributed in shorter optimum cooking time than ZSNs. Springiness of noodles was not significantly (P > 0.05) affected by increment of TS and hydrocolloids. TS1.5, ZSN‐XG1.5, ZSN‐XG2.0 and ZSN‐CRG1.5 had significantly (P < 0.05) higher cooking yield than ZSNs. The increment of TS and hydrocolloids had significantly (P < 0.05) increased the pH values of noodles. ZSN‐XG2.0, ZSN‐CRG1.5 and ZSN‐LBG1.5 may be useful to enhance ZSNs due to the better noodles qualities than ZSNs.     

LINEAR AND NONLINEAR VISCOELASTIC BEHAVIOR OF OIL-IN-WATER EMULSIONS STABILIZED WITH POLYSACCHARIDES

The rheological behavior and stability of oil-in-water emulsions stabilized by different thickening agents were analyzed. Food emulsions were prepared with commercial sunflower oil (40% w/w oil-in-water) and stabilized with 1% emulsifier. The tested thickeners were: (1) 1% w/w xanthan gum (XG), (2) 5% w/w potato starch (PS), (3) 5% PS + 0.5% XG, (4) 1% w/w guar gum (GG), and (5) 0.5% XG + 0.5% GG. Mean droplet size and droplet size distribution (DSD) of emulsions were determined by static light scattering. Steady flow (viscosity versus shear rate), transient flow (viscosity versus time) and oscillatory shear tests (linear viscoelasticity) were performed. The addition of thickening agents improved the stability of the emulsions, the effect was less marked in systems containing only GG. DSD was not significantly modified in emulsions containing starch or hydrocolloids. Microscopic observations showed that all the tested emulsions were flocculated due to the presence of hydrocolloids. The observed shear thinning behavior was attributed to the molecular structure of the polysaccharides and to the flocculation/deflocculation process; viscosity data were satisfactorily fitted to the Cross model. Frequency sweeps showed that emulsions with PS or XG have a weak gel structural network (G' > G); those with GG correspond to a polymeric solution where G' and G" curves intersect within the range of tested frequencies. The viscoelastic linear behavior was described according to the Maxwell generalized model. The discrete relaxation spectrum and relaxation times were estimated from the experimental values of G' and G" for emulsions with PS, PS + XG, and XG. Nonlinear viscoelasticity was also studied from stress relaxation curves at different shear strains. The damping function was calculated and the Soskey-Winter parameters were determined. Transient flow viscosities at different shear rates were comparable to the values estimated from stress relaxation measurements.     

Effects of some hydrocolloids and water activity on nonenzymic browning of concentrated orange juice

5-hydroxymethyl furfural (HMF) accumulation and brown pigment formation (BPF) were studied in the presence and absence of some hydrocolloids in concentrated orange juice. The influence of addition of 1.5% xanthan gum (XG) and 1.5% XG and 0.5% microcrystalline cellulose (MCC) were observed on the nonenzymic browning reactions in concentrated orange juice at 45, 60, and 75 degrees C. The effect of water activity was also observed by replacing the samples into different water activity media (0.11 +/- 0.01, 0.30 +/- 0.01, 0.50 +/- 0.01, 0.75 +/- 0.01, and 0.80 +/- 0.01). It was observed that the samples containing 1.5% XG and 0.5% MCC showed the lowest BPF and HMF accumulation, whereas the browning rate and HMF accumulation in pure orange juice were the highest at all temperatures. Maximum BPF and HMF accumulation were observed in the range of water activity between 0.30 and 0.75. The lowest values were observed at aw 0.80.     

Effect of common and new gums on the quality,physical, and textural properties of bakery products: A review

Hydrocolloids (gums) have a good functional characteristic such as emulsifying, gelling, solubility, and textural improvement. In the bakery products, hydrocolloids were used to improving dough performance, bread and cake characteristics, sensorial quality, and extension the products shelf life. Several studies reported the potential use of hydrocolloids in breads, biscuits, cakes, and pasta formulation. The present review summarized the effect of the most common and new hydrocolloids (xanthan, guar, Arabic, carrageenan, karaya, alginate, acacia, methylcellulose, carboxy methyl cellulose, hydroxyl propyl methyl cellulose, locust bean, balangu seed, wild sage seed, basil seed, and cress seed gums) on the rheological, physicochemical, textural, and quality characteristics of bakery products. Gums addition improved volume and porosity of the breads and cakes. Gums influence on the gelatinization and retrogradation of starch and decreased the retrogradation of starch. In the bakery products, hydrocolloids were used to improving mixing and increasing the shelf life of the products through moisture preservation and avoidance of syneresis in some frozen foods. This study summarized the influence of the most common and new hydrocolloids on the rheological, physicochemical, textural, and quality characteristics of bakery products. Addition of seeds gum to the breads, biscuits, cakes, and pasta formula led to an increase in the viscosity of the batter. Also, the firmness of bakery products showed that they became softer with increasing gum levels.     

Quality characteristics of angel food cake and muffin using lentil protein as egg/milk replacer

Replacement of animal proteins could be interesting for the food industry because it allows long‐term cost savings, among other reasons. Replacing egg/milk protein (50–100 wt%) by lentil protein (LP) was evaluated on angel cake/muffin quality. The replacement did not significantly affect final product volume, neither the muffins nor the angel food cakes. LP did not affect dough formation and contributed to hold crumb structure building an entangled network in both cake products. In addition, angel cakes and muffins containing LP had significantly lower baking loss than the control. Inferior quality for angel cakes and muffins containing LP was observed regarding hardness and chewiness that increased upon storage, compared to the control. For sensory evaluation in angel cakes, appearance of LP formulations showed lower scores than the control, likely due to the change of crumb colour. Other attributes were not significantly impacted by LP presence. For muffins, M‐100‐LPC formulation showed significant differences with the control for most of the attributes, except appearance and flavour. Indeed, consumers preferred muffins with 100% egg/milk protein replacement, which received higher acceptability scores than control. They also appreciated the ‘nutty’ flavour and moisture of angel cake with 50% egg protein replacement. This research suggests that lentil protein can totally or partially substitute egg/milk protein as foam and emulsion stabiliser in cakes, producing products with satisfactory quality.     

Effect of hydrocolloids on gluten‐free batter properties and bread quality

The objectives of this study were to assess the effect of the addition of different hydrocolloids on gluten‐free batter properties and bread quality and to obtain information about the relationship between dough consistency and bread quality. Breads were made of rice, corn and soy flours and 158% water. Following hydrocolloids were added: carrageenan (C), alginate (Al), xanthan gum (XG), carboxymethylcellulose (CMC) and gelatine (Gel). Batter consistency, bread specific volume (SV), crumb analysis, crust colour, crumb hardness and staling rate were determined. Hydrocolloids increased batter consistencies: the highest value was obtained with XG, which doubled that of control batter, followed by CMC. Breads with hydrocolloid presented higher SV than control, especially with XG whose SV was 18.3% higher than that of control bread. A positive correlation was found between SV and batter consistency (r = 0.94; P < 0.05). Crumbs with Gel, XG and CMC presented higher cell average size. XG and CMC crumbs looked spongier. Breads containing hydrocolloid evidenced lighter crusts. Crumb firmness was decreased by XG and CMC addition, and staling rate was slower. Overall, XG was the hydrocolloid that most improved gluten‐free bread quality. These results show that, in formulations with high water content, batter consistency is strongly associated with bread volume.     

Effect of radiofrequency heating on acrylamide formation in bakery products

This work was addressed to study the influence of radiofrequency (RF) heating on acrylamide (AA) formation in bakery products. To this purpose, leavened cakes and short dough biscuits were baked to a final moisture of 3.5 and 3.0%, respectively, by means of conventional convection heating or different combinations of conventional and RF heating. Results showed that, with respect to the baking process entirely carried out in an air-circulating oven, the RF-assisted baking process, i.e. the application of RF heating in the last stages of the baking process, resulted to be a promising strategy to keep low the AA levels in the bakery products. In particular, the best results were obtained for products which were moved from the hot-air baking to the RF heating when their residual moisture was still fairly high (around 10%). Results also suggested that, when very low values of residual moisture are required, this technological intervention is more suitable to thin bakery products, such as biscuits, than to thick products, such as leavened cakes, because of excessive browning in the internal portion as a consequence of the RF heating.