Functionality of strawberry powder on frozen dairy desserts

This study investigated the potential use of freeze‐dried strawberry powder as a stabilizer in frozen dairy desserts. Five different dessert mixes were developed that contained 0%, 2.5%, 3%, 3.5%, and 4% strawberry powder. An additional dessert using strawberry extract was prepared to differentiate the effects of dietary fiber from the effect of polyphenols on sample properties. The rheological and physical characteristics of dessert mixes, fresh dessert, and stored dessert were studied. The addition of strawberry powder to dairy desserts caused an increase in the mix viscosity and a decrease in hardness and meltdown values. Complete avoidance of meltdown was achieved with the addition of 3% or greater amount of strawberry powder. The viscosity of mixes was enhanced due to the increase of total solids in the serum phase and the formation of hydrated and gel‐like networks in the presence of cellulosic material, pectin, and calcium. The increase in viscosity and unfrozen water with the addition of strawberry powder also caused a reduction in ice crystallization, which resulted in softer and more stable desserts over time.     

乳清产品在冰淇淋和冷冻乳制品甜食中的应用

<正> 乳清和乳清蛋白产品在过去的60多年中已经被成功应用于冰淇淋和其他冷冻乳制品甜食中。甜乳清、乳清浓缩蛋白(蛋白质含量34～89%)和乳清分离蛋白(蛋白质含量≥90%)是最常用的乳清产品。其他的乳清配料,如脱乳糖乳清和脱盐乳清也是常用的配料。成本优势和提升产品质量是使用乳清产品的主要出发点,     

Bulking agents in low calorie frozen dairy desserts

The use of intense sweeteners in the manufacture of low calorie frozen desserts has brought about the need to add bulking agents to replace the sugar omitted in such products. A bulking agent acts as a filler and reproduces the physical properties of sugar, but not its sweetness and caloric content. Careful attention must be paid to combining sweeteners (polyols) with bulking agents in order to regulate the freezing point of the mix, and to restrict the levels to those which do not impart off­flavours or create gastrointestinal distress. Some modifications in the freezing and serving conditions are needed with the addition of bulking agents. The newlmodified bulking agents need to be approved by the regulatory bodies to ensure their safety. There is a need to identify a low or non-caloric bulking agent with little or no laxative effect.     

Properties of frozen dairy desserts processed by microfluidization of their mixes

Sensory properties and rate of meltdown of nonfat (0% fat) and low-fat (2% fat) vanilla ice creams processed either by conventional valve homogenization or microfluidization of their mixes were compared with each other and to ice cream (10% fat) processed by conventional valve homogenization. Mixes for frozen dairy desserts containing 0, 2, and 10% fat were manufactured. Some of the nonfat and low-fat ice cream mixes were processed by microfluidization at 50, 100, 150, and 200 MPa, and the remaining nonfat and low-fat ice cream mixes and all of the ice cream mix were processed by conventional valve homogenization at 13.8 MPa, first stage, and 3.4 MPa, second stage. The finished frozen and hardened products were evaluated at d 1 and 45 for meltdown rate and for flavor and body and texture by preference testing. Nonfat and low-fat ice creams that usually had a slower meltdown were produced when processing their mixes by microfluidization instead of by conventional valve homogenization. Sensory scores for the ice cream were significantly higher than sensory scores for the nonfat and low-fat ice creams, but the sensory scores for the conventional valve homogenized controls for the nonfat ice cream and low-fat ice cream were not significantly different from the sensory scores for the nonfat ice cream and low-fat ice cream processed by microfluidization of the mixes, respectively. Microfluidization produced nonfat and low-fat ice creams that usually had a slower meltdown without affecting sensory properties.     

Uses for dairy ingredients in ice cream and other frozen desserts

The use of milk products in ice cream in the UK is governed by legal requirements and the way in which these are interpreted. Sources of fat, and of milk-solids-not-fat in concentrated form, are considered. After basic legal requirements have been met. whey powders or concentrates can provide additional protein. Lactose and whey syrups can also be used as sweeteners. Other milk-based desserts such as sherbets and mousse have no legal compositional requirements, so milk products can be used in their formulation in different ways.     

Natural exopolysaccharides enhance survival of lactic acid bacteria in frozen dairy desserts.

Viable lactic acid-producing bacteria in frozen dairy desserts can be a source of beta-galactosidase for persons who absorb lactose insufficiently. However, freezing kills many of the cells, causing loss of enzymatic activity. Cultures selected for high beta-galactosidase activities and high survival rates in the presence of bile were examined for survivability during freezing in reduced-fat ice cream. Encapsulated S. thermophilus strains survived better than their nonencapsulated mutants in reduced-fat ice cream after freezing and frozen storage at -29 degrees C for 16 d (28 vs. 19%). However, a small nonencapsulated strain of Lactobacillus delbrueckii sp. bulgaricus survived better than the large encapsulated strain in reduced-fat ice cream. Factors that improved survival of encapsulated S. thermophilus 1068 in ice cream were 1) harvest of cells in the late-log phase of growth at 37 degrees C rather than at 40, 42.5, or 45 degrees C; 2) overrun at 50% rather than 100%; and 3) storage at -17 degrees C rather than -23 or -29 degrees C. Survival of strain ST1068 was unaffected by 1) neutralization of acid during growth or 2) substitution of nitrogen for air in building overrun.     

牛奶甜点-奶油布丁的研制

介绍了一种以鲜牛奶、酪蛋白酸钠和白砂糖为主要原料，采用L9（3^4）正交试验的方法，研究了不同胶体和灌装温度对牛奶甜点产品一奶油布丁的组织状态和口感的影响，最终确定了该产品生产的最佳配方和灌装工艺为：卡拉胶最佳型号为H型．卡拉胶质量分数为0．2％．改性蜡质玉米质量分数为2．5％，最佳灌装温度30℃。     

Sensory properties of thickened and protein-enriched plant-based frozen desserts

The number of consumers following plant-based diets has increased and in turn, the variety of plant-based foods available on the market has also increased. Many plant-based foods aim to mimic the functionality and sensory properties of conventional dairy products; however, they may not be suitable for specific populations. Dysphagia, for example, is a swallowing condition requiring texture-modified foods that meet specific criteria. While many conventional thickened products exist that are safe for individuals with dysphagia, the growing interest in plant-based eating alongside the increasing prevalence of dysphagia prompts a need for research on the use and safety of thickened plant-based alternatives. This study investigated the sensory properties of a thickened protein-enhanced ice cream (dairy and whey) compared to thickened protein-enhanced plant-based frozen desserts (cashew and pea, and coconut and pea). The formulations were evaluated using the International Dysphagia Diet Standardization (IDDSI) Spoon Tilt Test and a sensory trial (n = 104 participants, 47 flexitarians and 57 typical consumers) using static (hedonic scales and check-all-that-apply [CATA]), and dynamic (temporal check-all-that-apply (TCATA)) methods. The dairy and whey sample consistently passed the IDDSI test, while the plant-based samples did not. TCATA identified that the plant-based samples had an increased cohesiveness and adhesiveness, and decreased slipperiness when compared to the dairy and whey sample. The differences in textural properties may explain why the plant-based samples did not pass the IDDSI test. The study identified that although plant-based foods strive to mimic conventional dairy products, they have different textural and flavor properties.     

工艺条件对奶冻品质影响的研究

为阐明工艺条件对奶冻品质的影响,选取水化、均质和杀菌方式3个关键工艺点为研究对象,以产品的硬度、弹性和d_4,3值为指标,采用L₉（3⁴）正交实验对水化温度、水化时间及均质压力进行优化,同时研究了杀菌温度和杀菌时间对奶冻质构特性、粒径分布和感官品质的影响。结果表明,在75℃水化15min,采用30MPa均质使奶冻获得较优的硬度、弹性和d_4,3值;100℃/30min杀菌处理得到的产品粒径较小,呈现乳白色有光泽且硬度、弹性、胶着性和咀嚼性能等质构指标都优于137℃/5s和121℃/15min的感官品质。此工艺操作简单、稳定性好、可行性高。      

生产无脂充气冷冻甜食的重点

<正> 在冷冻甜食产品中,冰淇淋是最为人们接受和喜爱的产品。冰淇淋是将空气混入乳基配料再经过冷冻而制成的冷冻乳制品,是一种口感滑润、富奶油感的甜食。其他充气冷冻甜食还包括雪芭_(sorbet)和冰糕(sherbet)。 雪芭是不含乳类成分的产品,是一种由水、酸、果泥(或果汁)和糖组成的冷冻制品,食用时具有良好冷     

Inulin-enriched dairy desserts: Physicochemical and sensory aspects

The aim of this work was to study how adding inulin of different average chain lengths (long-chain, native, and short-chain inulin) at a concentration of 7.5% (wt/wt) would affect the physicochemical and sensory characteristics of starch-based dairy desserts formulated with either skim or whole milk. The results have shown that the effect of adding 7.5% inulin of different average chain length can give rise to products with different rheological behavior and different sensory characteristics. The skim milk sample with long-chain inulin and the whole milk sample without inulin showed similar flow behavior. Both samples were perceived to have the same creaminess and consistency intensity, but addition of long-chain inulin increased roughness intensity and, consequently, the sensory quality could be negatively affected. The information obtained may be of great interest in designing new products with nutritional and sensory characteristics that meet consumer demands.     

Functionality of enterococci in dairy products

Enterococci have important implications in the dairy industry. They occur as nonstarter lactic acid bacteria (NSLAB) in a variety of cheeses, especially artisan cheeses produced in southern Europe from raw or pasteurised milk, and in natural milk or whey starter cultures. They play an acknowledged role in the development of sensory characteristics during ripening of many cheeses and have been also used as components of cheese starter cultures. The positive influence of enterococci on cheese seems due to specific biochemical traits such as lipolytic activity, citrate utilisation, and production of aromatic volatile compounds. Some enterococci of dairy origin have also been reported to produce bacteriocins (enterocins) inhibitory against food spoilage or pathogenic bacteria, such as Listeria monocytogenes, Staphylococcus aureus, Vibrio cholerae, Clostridium spp., and Bacillus spp. The technological application of enterocins, shown to be produced during cheese manufacture, led to propose enterococci as adjunct starter or protective cultures in cheeses. There is evidence that enterococci, either added as adjunct starters or present as nonstarter NSLAB, could find potential application in the processing of some fermented dairy products. Literature suggest that the complex biochemical and ecological phenomena explaining the technological functionality of the enterococci in dairy products, are still to be fully understood. Clearly, the clinical research on enterococci underlines also that the safety of dairy products containing enterococci is an issue that the industry must carefully address before proceeding to their application.     

Functionality of freeze-dried L. casei cells immobilized on wheat grains

Lactobacillus casei cells were immobilized on wheat grains and the effect of nine cryoprotectants during freeze-drying was investigated. Survival and fermentative activity of the freeze-dried immobilized biocatalysts was studied by monitoring pH, lactic acid and lactose content in successive fermentations batches of both synthetic lactose medium and milk. Freeze-dried L. casei cells immobilized on wheat grains without using cryoprotectants resulted in high cell survival and metabolic activity. The same biocatalysts were stored at room temperature for 9 months and at 4 °C and −18 °C for 12 months. Reactivation of the stored biocatalysts was carried out in synthetic lactose medium. Storage at room and low temperatures (4 °C and −18 °C) resulted in about 5.11, 4.9 and 4.3 final pH respectively during fermentations, indicating the suitability of the immobilized biocatalysts for the production of mild and low pH dairy products. The immobilization of a probiotic microorganism, such as L. casei, on boiled wheat which contains prebiotic compounds might provide a potential synbiotic preparation.     

蜂蜜粉冷冻干燥工艺参数的研究

蜂蜜是一种营养丰富的天然滋补品。为了提高我国蜂蜜的深加工水平,采用正交实验的方法对冷冻干燥工艺参数进行了研究。结果表明:冷冻干燥最佳工艺参数是麦芽糊精比例为30%,可溶性固形物为10%,加热温度为100℃,真空度为50Pa。冷冻干燥前后蜂蜜中主要营养指标不变。     

卡拉胶与氯化钾用量对中性奶冻品质影响研究

研究了卡拉胶与氯化钾用量对奶冻品质的影响,以粒度分布、质构特性、微观结构与析水率等为分析检测指标。研究结果表明:当卡拉胶用量小于0.10%时,硬度低,凝胶结构差;当卡拉胶用量增至0.15%以上时,硬度适当,凝胶结构较好,但从粒度分布与显微结构判断,体系开始出现絮凝。同时,氯化钾促进凝胶,而高含量的氯化钾有诱导体系失稳絮凝的趋势,在卡拉胶用量0.20%时,影响更为显著,且此时析水率也随之增加。综合考虑,以卡拉胶0.15%用量与氯化钾0.01%用量下奶冻具有良好的质构品质。     

A 100-Year Review: Milestones in the development of frozen desserts

Ice cream has come a long way since the first snow cone was made. Innovations in a variety of areas over the past century have led to the development of highly sophisticated, automated manufacturing plants that churn out pint after pint of ice cream. Significant advances in fields such as mechanical refrigeration, chilling and freezing technologies, cleaning and sanitation, packaging, and ingredient functionality have shaped the industry. Advances in our understanding of the science of ice cream, particularly related to understanding the complex structures that need to be controlled to create a desirable product, have also enhanced product quality and shelf stability. Although significant advances have been made, there remain numerous opportunities for further advancement both scientifically and technologically.     

Thickness suitability of prebiotic dairy desserts: Relationship with rheological properties

In food product development it is important to know to what extent changes in formulation modifies the product, affecting its sensory properties and acceptability. Addition of polysaccharides like inulin can affect product structure in particular, modifying both rheological behaviour and perceived texture. The aim of this work was to assess to what extent rheological properties can explain the acceptability of thickness perceived by consumers in starch-based desserts. Low-fat dairy desserts were prepared varying the concentration of sucrose, flavor aroma and the fat replacer with prebiotic properties (inulin) but with fixed amounts of skimmed milk and starch. The rheological behavior was characterized and the level of sample thickness suitability was evaluated by a total of 100 consumers using a 5-point JAR scale (1 = too weak, 3 = just about right; 5 = too strong). Results indicated that flow and viscoelastic parameters varied among samples depending on inulin and sucrose concentration. According to sensory results, thickness suitability varied greatly between samples. The relationships between instrumental and sensory results are studied and discussed.     

Effect of inulin addition on rheological and sensory properties of fat-free starch-based dairy desserts

The effect of inulin addition on the rheological and sensory properties of fat-free dairy desserts containing different starch concentrations (2.5%, 3.25% and 4%) was compared with the properties of full fat milk samples. All samples showed a thixotropic and shear-thinning flow behaviour. Hysteresis loops of inulin–skimmed milk samples were similar to those of whole milk samples without inulin. Skimmed milk samples showed lower consistency and lower shear thinning than either whole milk or inulin–skimmed milk samples. Inulin addition increased both storage modulus and complex viscosity values and decreased loss angle tangent value, except in the 4% starch sample. Adding inulin to fat-free dairy model desserts increased sweetness, thickness and creaminess. At low starch concentrations, inulin–skimmed milk desserts were perceived as sweeter, with more vanilla flavour and with the same thickness as whole milk desserts, but at 4% starch, the latter were thicker and creamier.     

Flow behaviour of inulin-enriched dairy desserts: influence of inulin average chain length

The effect of the addition of different types of inulin (long-chain, native and short-chain inulin) at four concentrations (0, 2.5, 5 and 7.5% w/w) on flow properties of semisolid dairy desserts formulated with either skimmed or whole milk and three modified tapioca starch concentrations (2.5, 3.25 and 4% w/w) was studied. All samples displayed shear-thinning flow behaviour. The addition of the three types of inulin to whole milk samples with low starch concentrations (2.5 and 3.25% w/w) led to combined hysteresis loops: samples showed antithixotropy at low shear rate values, but thixotropy at high shear rate values. The remaining samples showed thixotropic behaviour. The effect of the different types of inulin on the flow properties was not only highly dependent on the inulin concentration but also on milk type and starch concentration. On adding 7.5% of long-chain inulin, which significantly increased consistency index values and significantly decreased flow index values in both types of milk and for all starch concentrations.     

谷朊粉对冻干枣粉抑制吸湿作用研究

目的 研究谷朊粉对冻干枣粉吸湿特性的影响。方法 将谷朊粉与枣浆按不同比例均匀混合,真空冷冻干燥后粉粹,过60目筛制备不同配比的冻干枣粉。结果 谷朊粉显著降低了冻干枣粉的平衡含水率(equilibrium moisture content,EMC)。吸湿等温结果表明,红枣与谷朊粉质量比10:0、7:3、1:1、3:7样品的吸湿等温类型属“J”型增长,而0:10样品的属“S”型增长,表明谷朊粉的添加并未改变冻干枣粉吸湿等温类型;接触角随着谷朊粉的添加量的增大而增大,其值从31.22°增大到76.7°,说明谷朊粉可以减弱冻干枣粉的表面润湿性。从宏观和扫描电镜图中可知,冻干枣粉结块现象随着谷朊粉的添加量的增大而逐渐减轻。低场核磁结果显示,谷朊粉降低自由水的含量,减少水分向高自由度方向的迁移程度。结论 一定量的谷朊粉能够有效抑制冻干枣粉的吸湿,从而缓解结块的发生,保持流动性和分散性,进而提高冻干枣粉的品质。