薄膜蒸发浓缩对乳蛋白浓缩物加工性质的影响

乳蛋白浓缩物(Milk protein concentrate,MPC)是近年来新兴的牛乳蛋白制品,在食品加工中有着广泛的应用。本试验采用薄膜蒸发浓缩牛乳超滤截留液至固形物含量为15.55%,18.17%和26.12%,研究了不同浓缩程度对MPC粉末的粒径,溶解性,流动性和喷流性指数等性质的影响。结果表明,浓缩至超滤截留液固形物含量为26.12%时,MPC具有较好的加工特性。     

牛乳蛋白与淀粉相互作用的研究进展

淀粉基食品的感官品质和营养价值主要取决于淀粉在加工过程中其结构（颗粒态、分子态结构）和理化性质（糊化、流变学和回生性质）的变化。牛乳蛋白可通过疏水相互作用吸附于淀粉颗粒的表面,抑制淀粉吸水膨胀和淀粉酶对其的降解作用;牛乳蛋白亦可在静电相互作用、氢键、疏水相互作用等的共同作用下与淀粉分子间形成稳定或不稳定（相分离）的凝胶,改变淀粉基食品的流变学特性。本文综述了淀粉和牛乳蛋白之间相互作用方式以及牛乳蛋白对淀粉热特性、流变学特性和消化性质影响的最新研究进展,旨在明晰淀粉和牛乳蛋白相互作用机理,为利用牛乳蛋白改善淀粉基食品的加工性能、感官和营养品质提供指导。     

乳蛋白对豆乳凝胶物性学特征的影响机理

为改善豆乳酸奶制品,分别从体系层面、颗粒层面和分子层面研究不同类型的乳蛋白——乳清分离蛋白（whey protein isolate,WPI）、乳浓缩蛋白（milk protein concentrate,MPC）和酪蛋白酸钠（sodium caseinate,NaCas）对豆乳凝胶特性的影响及机理。结果表明：WPI（≥20%）、40% NaCas的加入可以有效增强豆乳凝胶强度,其中WPI（≥20%）的作用最为显著。低替代比例的乳蛋白可以显著减小凝胶颗粒的粒径,而高比例的WPI会大幅度增大体系的凝胶颗粒。在微观结构方面,MPC的添加使得凝胶结构更为致密规则,NaCas的添加形成了细丝网状结构,而WPI的添加使得凝胶结构趋于不规则、致密。聚丙烯酰胺凝胶电泳及其光密度扫描结果显示,添加WPI（≤20%）可能会促进大豆7S蛋白的β亚基参与凝胶,而NaCas则会阻碍大豆11S蛋白碱性亚基的凝胶化。     

低脂冰淇淋质构与感官评价的相关性研究

分别利用南瓜、大豆、菊粉以及变性淀粉作为脂肪的替代品,制作脂肪替代度为60%的低脂冰淇淋。采用感官评价和质构仪器分析法分别对所制得的低脂冰淇淋品质进行分析,然后使用SPSS19.0对感官评价与仪器分析结果进行主成分分析和相关性分析。通过因子和主成分分析,感官评定得出2个主成分。通过相关性分析发现,感官评价与质构特性参数二者之间在程度不同的相关性(r=-0.187~-0.991,P0.05或P0.01)。由感官评价和质构特性参数二者之间的相关性可知,黏稠度和坚实度与TPA模式中的硬度、内聚性、胶黏性和弹性4个指标之间存在显著或极显著的相关性(r=-0.756~-0.991,P0.05或P0.01)。故选取主要感官指标为因变量,仪器分析指标为自变量,得到具有统计意义的感官指标平滑性和坚实度的回归模型,为低脂冰淇淋的研究提供可行的评价方法。     

蛋清基脂肪替代品对冰淇淋的理化性质及微观结构的影响

利用蛋清基脂肪替代品降低高脂冰淇淋中的脂肪,开发低脂冰淇淋。通过理化性质测量、感官评价和微观结构的观察,综合分析脂肪替代品在冰淇淋中的代脂肪效果。结果表明：脂肪替代率15%时,冰淇淋的气泡和脂肪总聚集数量多,膨胀率提高,从54.9%增大到72.6%,而融化率降低,从48.32%降低到24.3%。在脂肪替代率25%～30%时,冰淇淋的口感和接受度降低。因此,脂肪替代率15%时,冰淇淋的可接受度最佳。     

菊粉对香肠质构及感官特性的影响

以鸡肉和猪肉为原料,在香肠的生产过程中用短链菊粉按照0,10%,30%,50%,70%,100%的比例分别取代脂肪、玉米磷酸酯双淀粉(maize distarch phosphate,MDP)及大豆分离蛋白(soy protein isolate,SPI),对各组香肠的质构特性及感官评价结果进行分析,探索菊粉部分取代香肠中以上3种原料的可行性。实验采用质构仪测定香肠的质构特性,同时进行感官评价。结果表明:菊粉取代脂肪使香肠的硬度、黏着性和回复性增加,咀嚼性和凝聚性(2项在取代比例为50%时除外)降低,当取代比例大于50%(不包含50%)时香肠的口感变差;菊粉取代MDP改善了香肠的口感,降低了香肠的硬度、咀嚼性、凝聚性(取代比例为70%的除外)和胶着性,增加了香肠的黏着性(取代比例为70%的除外)和回复性;菊粉取代SPI后香肠的质构特性和感官评分,除回复性和气味无变化外,其他均降低。综合各项分析,菊粉可用于取代香肠中的脂肪和MDP,菊粉取代脂肪和MDP的最佳比例分别为50%和70%,菊粉不适合取代SPI。     

菊粉对绿豆蛋白低脂植物酸奶品质的影响

本研究考察菊粉作为脂肪替代物对绿豆蛋白低脂植物酸奶品质的影响。以添加3%葵花籽油的绿豆蛋白酸奶作为高脂酸奶对照,通过分析不同浓度的菊粉（2%、4%、6%）对绿豆蛋白低脂酸奶（1%葵花籽油）的粘弹性、质构、持水力、微观结构及感官品质的影响,评价菊粉的代脂效果。结果表明,与对照绿豆蛋白高脂酸奶相比,添加2%菊粉的绿豆蛋白低脂植物酸奶的粘弹性、硬度、咀嚼性、持水力和感官品质与绿豆蛋白高脂酸奶相当（P>0.05）,表现出均匀致密的蛋白质网络结构。添加4%菊粉的绿豆蛋白低脂酸奶的硬度和咀嚼性分别显著提高了21.56%和32.34%（P<0.05）,持水能力达到88.55%。此时,绿豆蛋白低脂酸奶也表现出致密的网络结构,整体的感官品质最佳。添加6%菊粉的绿豆蛋白低脂酸奶的粘弹性、硬度、咀嚼性和持水力显著高于绿豆蛋白高脂酸奶（P<0.05）,但是其微观结构表现出多孔以及不均匀的蛋白质网络结构,质地和口感变差,总体感官品质最差。因此,添加2%~4%的菊粉能够显著提升绿豆蛋白低脂酸奶的品质,具有较好的脂肪替代效果。本研究结果为研发高品质的绿豆蛋白低脂酸奶提供理论依据。     

研究称菊粉具有类似乳制品中脂肪的特性

据外媒报道,西班牙两家公司在对菊粉的功能进行研究时发现,菊粉具有类似乳制品中脂肪的特性,研究人员发现,在一定的条件下,菊粉可取代乳制品中的脂肪,具有类似脂肪的口感与乳脂特性,这可能与不同状态下乳制品内部系统流变学性质变化有关。     

乳蛋白微胶囊包埋共轭亚油酸及其稳定性研究

目的比较不同乳蛋白作为微胶囊壁材包埋共轭亚油酸的效果,并考察其产品的稳定性。方法分别以牛乳浓缩蛋白MPC80(milk protein concentrate,MPC)和乳清浓缩蛋白WPC80(whey protein concentrate,WPC)为高蛋白壁材,以多不饱和脂肪酸(共轭亚油酸,conjugated linoleic acid,CLA)为芯材,制备微胶囊产品。在芯壁比(芯材和壁材质量比)分别为1:4和1:8的比例下将壁材溶液(蛋白浓度为16%)和芯材混合、均质,经由喷雾干燥制备了共轭亚油酸微胶囊产品。通过扫描电子显微镜和气相色谱等检测方法对微胶囊产品的包埋率、表面形貌以及储藏过程中芯材的氧化稳定性进行研究。结果当芯壁比相同时(1:4和1:8,m:m),MPC组微胶囊的芯材包埋率总是低于WPC组;且MPC组微胶囊产品的表面凹陷程度和内壁疏松程度也更高。当芯壁比提高后,WPC和MPC组的微胶囊效率均有所上升。但是对不同芯壁比的微胶囊产品进行氧化稳定性检测后发现,加速储藏(45℃)过程中MPC组微胶囊产品的质量都比WPC组差。结论牛乳蛋白种类对牛乳蛋白作为CLA微胶囊壁材的影响较大。WPC是CLA微胶囊的优质壁材,而MPC虽然可以作为微胶囊壁材应用,但是对敏感芯材CLA的包埋效率和保护效果都存在一定的局限性,需要进一步改善以提高其应用性能。     

乳蛋白浓缩物特性、加工关键技术及应用

浓缩牛奶蛋白(milk protein concentrate, MPC)富含丰富的酪蛋白和乳清蛋白包括免疫球蛋白、乳铁蛋白、乳脂球膜蛋白等,具有抵抗病毒、调节免疫力、抗氧化等多种生物学功效。由于MPC具有优良的功能特性,被广泛应用到了冰淇淋、酸奶、婴幼儿食品、运动饮料、烘焙食品等产品中。MPC采用膜法过滤浓缩的绿色生产方式,除去了乳中大部分的乳糖和矿物质,浓缩乳蛋白,但在储存过程中存在溶解度下降等问题。综述了MPC的组成成分生物特性、加工关键技术和应用。旨为我国MPC的产业化生产、应用以及相关标准的制定提供理论参考。     

The functional, rheological and sensory characteristics of ice creams with various fat replacers

The effects of fat replacers (Simplesse® D-100, N-Lite D, and inulin) on the melting characteristics, overruns, hardness, rheological parameters and sensory attributes of reduced (RF, 60.0 g/kg), low (LF, 40.0 g/kg), and nonfat (NF, 1.0 g/kg) ice creams were investigated. The magnitudes of the melting rates were in the order RF>LF>NF for samples that contained Simplesse® D-100 or inulin, but the reverse order was found for samples with N-Lite D. The nonfat ice creams had lowest overrun values of around 10%. Inulin-containing ice creams possessed higher overrun values than others ( P  > 0.05). The use of fat replacer decreased the hardness of ice creams. All ice cream samples showed pseudoplastic (shear-thinning) behavior. The addition of N-Lite D and inulin decreased the flow behaviour index of ice cream samples. The reduced and low fat ice cream samples were rated as similar to the control by a sensory panel. On the other hand, no correlations ( P  > 0.05) were observed between rheological parameters and sensory texture and mouthfeel.     

冰淇淋生产中的油脂

综述了油脂在冰淇淋中的作用和冰淇淋生产中常用的油脂及其代用品。详细论述了稀奶油及奶油的组成成分、规格与理化性质；扼要介绍了食用硬化油、人造奶油、起酥油、椰子油、棕榈仁油及棕榈油．以及碳水化合物类脂肪代用品和脂肪酸酯代脂品。     

The effect of inulin on the physicochemical properties and sensory attributes of low-fat ice cream

The aim of this study was to investigate the feasibility of replacing the ice cream fat with inulin to produce a low-fat ice cream with prebiotic properties. For this purpose, inulin (2, 3 and 4%, w/w) was added to the low-fat ice cream and the physicochemical and sensory properties of the resultant ice creams were compared with those of control ice cream (containing 10% fat) and the inulin-free low-fat ice cream. The composition, pH and acidity of the ice cream mixes were measured and the melting rate, colour and texture of the frozen ice cream samples were examined. The results indicated that the low-fat ice creams had a significantly lower melting rate in comparison with the control. Inulin addition caused the adhesiveness and hardness of the low-fat ice creams to decrease significantly compared with inulin-free low-fat ice cream.     

Rheological properties of reduced-fat and low-fat ice cream containing whey protein isolate and inulin

Instrumental analyses were used to evaluate the rheological properties of regular (10%), reduced-fat (6%) and low-fat (3%) ice cream mixes and frozen ice creams stored at −18 °C. The reduced-fat and low-fat ice creams were prepared using 4% whey protein isolate (WPI) or 4% inulin as the fat replacement ingredient. The composition, colour, apparent viscosity, consistency coefficient, flow behaviour index, hardness and melting characteristics were measured. No effect of WPI or inulin was obtained on the colour values. Compared with regular ice cream, WPI changed rheological properties, resulting in significantly higher apparent viscosities, consistency indices and greater deviations from Newtonian flow. In addition, both hardness and melting resistance significantly increased by using WPI in reduced-fat and low-fat ice creams. Inulin also increased the hardness in comparison to regular ice cream, but the products made with inulin melted significantly faster than the other samples.     

Sensory Attributes and Storage Life of Reduced Fat Ice Cream as Related to Inulin Content

Effects of substitution of inulin for 42DE (dextrose equivalent) corn syrup in reduced fat ice cream were studied using sensory analysis. Three combinations of inulin and corn syrup were evaluated for iciness, chewiness, sweetness and vanilla flavor intensity. Replacing 50% or 100% of 42DE corn syrup with inulin increased chewiness. However, sweetness and vanilla flavor intensity perception of the ice cream were reduced. Storage stability data showed that partial or full replacement of 42DE corn syrupwith inulin inhibited ice crystal formation over a 6-wk thermal abuse period.     

Freezing kinetics and microstructure of ice cream from high-pressure-jet processing of ice cream mix

The effect of high-pressure-jet (HPJ) processing (0–500 MPa) on low-fat (6% fat) ice cream was studied by evaluating physiochemical properties before freezing, during dynamic freezing, and after hardening. An HPJ treatment ≥400 MPa decreased the density, increased the apparent size of colloidal particles, and altered rheological behavior (increased non-Newtonian behavior and consistency coefficients) of low-fat ice cream mix before freezing. During dynamic freezing, the particle size and consistency coefficient decreased but remained higher in 400 MPa–treated samples vs. non-HPJ-treated controls at the conclusion of freezing. The resulting ice creams (400 and 500 MPa–treated) had similar hardness values (3,372 ± 25 and 3,825 ± 14 g) and increased melting rates (2.91 ± 0.13 and 2.61 ± 0.31 g/min) compared with a control sample containing polysorbate 80 (3,887 ± 2 and 1.62 ± 0.25 g/min). Visualization of ice cream samples using transmission electron microscopy provided evidence of casein micelle and fat droplet disruption by HPJ treatment ≥400 MPa. In the 400 MPa–treated samples, a unique microstructure consisting of dispersed protein congregated around coalesced fat globules likely contributed to the altered physiochemical properties of this ice cream. High-pressure-jet processing can alter the microstructure, rheological properties, and hardness of a low-fat ice cream, and further modification of the formulation and processing parameters may allow the development of products with enhanced properties.     

稳定剂和乳化剂对低脂冰淇淋品质的影响

实验研究了一种稳定剂和两种乳化剂对低脂冰淇淋品质的影响.通过测定冰淇淋浆料的流变性质和脂肪失稳能力,以及冰淇淋的膨胀率和抗融化性,得出在低脂冰淇淋中稳定剂的添加量最佳质量分数为0.45％,由单甘酯和吐温80复配乳化剂的添加量最佳质量分数为0.1％.     

甘薯滨粉磷酸单酯在冰淇淋中的应用研究

对冰淇淋中常用稳定剂和甘薯淀粉磷酸单酯的流变特性进行了研究，同时通过对老化时间、粘度、膨胀率、融化率等方面的影响分析，探讨了甘薯淀粉磷酸单酯作为冰淇淋中的稳定剂和取代冰淇淋中部分油脂的可行性。研究结果表明，用甘薯淀粉磷酸单酯制造冰淇淋，可减少老化时间，降低融化率、抑制冰晶形成、降低产品脂肪含量，在口感、内在质地等诸方面均可为消费者接受，取得了较好的效果。     

小麦麸脂肪替代品对低脂冰淇淋品质的影响

研究了小麦麸脂肪替代品(WBFS)部分和全部替代冰淇淋中的脂肪对冰淇淋品质的影响。结果表明:WBFS可以提高冰淇淋浆料的黏度,改善冰淇淋的膨胀率;全部脂肪被替代的冰淇淋(FFS)在抗融性、感官评定和质构方面表现出与常规冰淇淋(RF)相似或者略优的品质,而部分脂肪被替代的冰淇淋(MFS)却表现出较差的抗融性和差异明显的感官和质构特性。     

Effects of Locust Bean Gum and Mono‐ and Diglyceride Concentrations on Particle Size and Melting Rates of Ice Cream

The objective of this study was to determine how varying concentrations of the stabilizer, locust bean gum (LBG), and different levels of the emulsifier, mono‐ and diglycerides (MDGs), influenced fat aggregation and melting characteristics of ice cream. Ice creams were made containing MDGs and LBG singly and in combination at concentrations ranging between 0.0% to 0.14% and 0.0% to 0.23%, respectively. Particle size analysis, conducted on both the mixes and ice cream, and melting rate testing on the ice cream were used to determine fat aggregation. No significant differences (P < 0.05) were found between particle size values for experimental ice cream mixes. However, higher concentrations of both LBG and MDG in the ice creams resulted in values that were larger than the control. This study also found an increase in the particle size values when MDG levels were held constant and LBG amounts were increased in the ice cream. Ice creams with higher concentrations of MDG and LBG together had the greatest difference in the rate of melting than the control. The melting rate decreased with increasing LBG concentrations at constant MDG levels. These results illustrated that fat aggregation may not only be affected by emulsifiers, but that stabilizers may play a role in contributing to the destabilization of fat globules.