酸奶冰淇淋的配方及工艺条件

对酸奶冰淇淋的配方和具体工艺条件进行了研究，着重探讨了酸奶的生产工艺、酸奶的加入量、添加顺序、稳定剂等对冰淇淋质量的影响。即酸奶加入20％，于均质前加入，在40℃均质，稳定剂选用黄原胶0．025％、刺槐豆胶0．025％、耐酸CMC 0．035％、瓜尔豆胶0．12％、蔗糖酯0．15％、单甘酯0．1％。     

核桃仁冰淇淋的研制

以全脂奶粉为原料，添加一定量的核桃制成核桃仁冰淇淋，所制得的核桃仁冰淇淋不但营养丰富，风味独特，而且具有保健功能，实验中还对最佳生产配方作了研究，结果表明，以添加6％核桃仁的比例制得的核桃仁冰淇淋最好。     

Effect of vacuum application on the physical,rheological and sensory characteristics of an artisanal ice cream

Four milk-based ice cream samples were produced by heating (65°C) the ingredients at different pressures (0.5, 1.0 bar) and times (5, 30 min). Overrun, melting behaviour, particle size, viscosity and sensory analysis were conducted for each time/temperature combination. The 5-min vacuum application resulted in a reduction of overrun and air bubbles size, whereas ice cream viscosity increased. Opposite outcomes were found for the sample treated with vacuum for 30 min, which also showed a significant fat globule size reduction (<3.0 μm). Sensory analysis revealed that the use of vacuum improved sweetness, milky and creamy sensations regardless the treatment times.     

Physicochemical properties and organoleptic aspects of ice cream enriched with microencapsulated pistachio peel extract

The purpose of this study was to produce a functional ice cream by the addition of microcapsules of pistachio peel extract (MPPE). Various properties of the resulting ice cream were investigated. By increasing the amount of MPPE the total phenolic content and antioxidant activity increased about 2.0‐ and 3.7‐fold, respectively, compared with the control sample. The rheological properties of the mixes were fitted by the Power Law model. All mixes showed non‐Newtonian pseudoplastic behaviour. By increasing the concentration of MPPE, the consistency coefficient (m), viscosity, and shear sensitivity were increased, but the flow behaviour index (n) decreased. The addition of MPPE to ice cream mixes improved the melting resistance, first dripping times and functional properties of ice cream such as antioxidant activity and total phenolic content. The results of the sensory analysis showed that the addition of MPPE had no significant effect on the overall acceptability of the product. Based on our findings, MPPE has the potential to be used as an added‐value ingredient in the ice cream industry to enhance the functional properties of their products.     

Comparison of the effects of adding microbial transglutaminase to milk and ice cream mixture on the properties of ice cream

In this study, the effect of recombinant microbial transglutaminase enzyme on the physicochemical properties of ice cream produced by two different methods was investigated. For this purpose, different enzyme units (2, 4 and 6 U/g milk protein) were applied to both ice cream mixture and milk. While with the first method, a 10% increase in the overrun value of ice cream samples was observed, a 7% increase was obtained by the second method. All ice cream samples exhibited pseudoplastic behaviour. This study indicated that  transglutaminase concentration is an important factor in terms of improving the physicochemical properties of ice cream.     

改性大豆分离蛋白-磷脂复合物对冰淇淋品质的影响

针对大豆分离蛋白(SPI)取代部分乳粉生产冰淇淋,产品膨胀率低、易融化、口感较硬和有豆腥味等问题,本实验采用超高压改性大豆分离蛋白(USPI)、大豆分离蛋白-磷脂复合物(SPI-PLW)和超高压均质改性大豆分离蛋白-磷脂复合物(USPI-PLW)分别替代乳粉生产冰淇淋,研究了不同改性条件的大豆蛋白对冰淇淋浆料的静态流变学、膨胀率、融化率、硬度和微观结构的影响。通过对比研究得出,以USPI-PLW为原料制作成的冰淇淋的各项标准都优于其它类型的大豆分离蛋白冰淇淋。USPI-PLW冰淇淋融化率为33.17%,膨胀率可达86.86%,较传统低脂冰淇淋融化率降低26.86%,膨胀率提高了94.84%,且储藏硬化后无较大冰晶,相对于传统冰淇淋口感更绵软。     

Enrichment of ice cream with dietary fibre: Effects on rheological properties,ice crystallisation and glass transition phenomena

In the present study, the effects of four dietary fibre sources (oat, wheat, apple and inulin) on the rheological and thermal properties of model sucrose–polysaccharides solutions and ice cream mixes were investigated. The content of fibre in insoluble compounds increased significantly the viscosity and the shear thinning behaviour of the model solutions and ice creams, due to the increase of total solids and the formation of networks comprised of hydrated cellulose and hemicellulose. The increase of soluble material did not alter significantly the rheology of the samples but limited the freezing point depression and elevated the glass transition temperatures, indicating a potential cryoprotective action. The use of oat and wheat fibre favoured viscosity development due to water-binding, whereas inulin caused a remarkable increase of glass transition temperature (T_g) in model solutions and ice cream mixes, indicating the reduction of water molecule mobility from the bulk aqueous phase to the ice crystals’ surface. Apple fibre addition greatly increased viscosity and elevated the T_g values, particularly in the presence of proteins. Thus, our results suggest the potential use of dietary fibres as crystallisation and recrystallisation phenomena controllers in frozen dairy products.     

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.     

Effects of homogenisation conditions on the physical properties of high-fat ice cream

The effect of homogenisation pressure on the physical properties of high-fat ice cream was investigated. Nonhomogenised ice cream was hard, with low resistance to meltdown, and ice crystals grew rapidly therein. Fat globule networks were not formed in the nonhomogenised ice cream. The ice cream homogenised at 5 MPa or more was harder and showed a higher resistance to meltdown. Ice crystals in the ice cream homogenised at 5 MPa or more grew slowly. The physical properties of each ice cream varied with homogenisations from 5 to 25 MPa and could be controlled by homogenisation pressure.     

The effect of inulin as a fat replacer on the quality of low‐fat ice cream

The influence of different levels of inulin as fat replacer on the quality of ice cream was investigated. Inulin was added at 2, 4 and 6% to replace milk fat and the experimental ice creams were compared to a control with 10% milk fat. The chemical composition, overrun, water activity, viscosity, melting rate, hardness and colour value were determined. Sensory properties of the ice cream samples were evaluated during storage. The overall acceptability of ice creams prepared with 2 and 4% substitution were similar to the control.     

Effects of Lactobacillus rhamnosus GG addition in ice cream

A 2⁴ full factorial experimental design was applied to verify the effects of Lactobacillus rhamnosus GG (LGG) addition in retail-manufactured ice cream stored at two different freezing temperatures (−16°C and −28°C) and containing two different levels of sugar (15–22%) and fat (5–10%). In addition to microbial counts, the pH, acidity, viscosity of the mixes and functional properties of the ice creams were evaluated. Both fresh and frozen-thawed LGG cells underwent preliminary resistance tests to bile, antibiotics and acidity. The LGG strain proved to be highly resistant to most of the stress factors. When the micro-organism was added to ice cream mixes in a quantity of 10⁸ cfu/g, it did not change the overrun, firmness or melting behaviour of the finished product. Regardless of formulation, no count decay of LGG cells was observed in ice cream stored for up to 1 year.     

冰淇淋成分抑制冰晶重结晶机制及研究技术

冰淇淋的品质受到冷冻过程中产生冰晶的大小和数量的影响,冰晶重结晶形成的大冰晶使冰淇淋质地粗糙,冰晶感强,失去了冰淇淋应有的光滑细腻感。为了提高冰淇淋的品质和储存稳定性,本文深入阐述了冰晶重结晶的机制,首先总结了冰晶的3个过程,介绍了用于冰淇淋低温保护的成分,包括酶类物质、冰结构蛋白、膳食纤维等多糖类稳定剂等,提出多糖类稳定剂是目前抑制冰晶重结晶较为有效的方法,且成本低廉。同时总结了国内外研究冰淇淋重结晶的常用技术,分析了抑制冰晶重结晶的措施及机制,包括低温光学显微技术、聚焦光束反射技术和低场核磁共振技术,其中,低温光学显微技术是最有效的技术手段,该技术和其他技术的结合为优化冰淇淋品质提供了理论依据,以期为冰淇淋研发人员和生产厂家制作良好冻融稳定性冰淇淋提供科学依据和技术参考。     

Time-intensity analysis and acceptance test for traditional and light vanilla ice cream

The time-intensity profile and acceptance of traditional and light vanilla ice creams were determined in this study. Six samples of commercial Brazilian vanilla ice cream of three different brands, in traditional and light versions, were evaluated. The analysis of variance (ANOVA) and Tukey's means test were applied using SAS software and the Internal Preference Mapping was prepared using the XLStat software. The time-intensity analysis with 10 trained judges and three repetitions revealed a bitter taste in one traditional sample (TRA3) and a residual bitter taste in two light samples (LIG1 and LIG3), which were less accepted (p ≤ 0.05) by the consumers (averages acceptance 5.2 and 5.3, respectivelly). A residual sweet taste was identified in one light sample (LIG2), however this does not affect the acceptance of LIG2 and was preferred by the consumers. In the acceptance test (9-centimeter linear hedonic scale) with 117 consumers, flavor and texture were the attributes that influenced consumer acceptance (overall liking), and only brand 2 (TRA2 and LIG2) obtained good acceptance (averages 6.0 and 6.4, respectivelly) for both samples. Sample LIG2 was the preferred sample according to the Internal Preference Mapping. Sucralose and sorbitol showed to be the most appropriate sweetener system, in relation to aspartame and sodium cyclamate to replace sucrose in ice cream. The development of the time-intensity sensory profile and data from the acceptance tests obtained in the assessment of the traditional and light ice creams on the market could help the ice cream industry to adopt procedures to improve the quality and delineate new advertising strategies.     

冰淇淋质量缺陷与质量管理

本文介绍了优良品质的冰淇淋必备的条件、冰淇淋品质的缺陷及分析产生的原因，为使品质优良必须经常检查原材料以及对制造过程进行严格的控制。     

Using spray-dried sugar beet molasses in ice cream as a novel bulking agent

In this study, it is aimed to investigate and evaluate the use of molasses which is a by-product of sugar production as a novel bulking agent in ice cream as a sugar replacer. Sugar beet molasses (75%) and 12 DE maltodextrin (25%) were converted into powder form by spray drying. Spray-dried sugar beet molasses (SDSM) was then used as a substitute of sugar in different ratios (0:100, 25:75, 50:50, 75:25 and 100:0) in the ice cream products. The increased amount of SDSM decreased the overrun, L*, whiteness index (WI) and melting behaviours and increased a*, b*, total phenolic content, consistency and viscosity. Meanwhile, thermal properties have not been affected by the use of SDSM (P < 0.05). The sensory findings have been particularly interesting especially when replacing above 50% sugar with SDSM, aroma, flavour and general acceptability decrease. According to the results of this study, substituting 25% of total sugar with SDSM as a bulking agent can decrease cost of the product and improve total phenolic content and some quality parameters without compromising sensorial properties.     

Wall slip and viscous dissipation in ice cream pipe rheometry

This paper presents a study of wall slip in ice cream pipe rheometry. Measurement of ice cream temperature at the wall enabled energy balances in the near wall region. Experiments were carried out in pressure driven shear flow along insulated pipes of different diameters at different flow rates using ice cream produced with a continuous scraped surface heat exchanger. Pipe radius dependence was evident in the flow curves, indicative of wall slip effects. This apparent slip was amenable to analysis by the Mooney method and indicated the contribution of slip to flow ranged from 70% to 100%. Results indicated a moderately thick layer of slightly heated ice cream next to the wall. Whilst these flows may be interpreted as wall slip the origin of the phenomena is different from that in most suspension flows and significantly alters interpretation.     

Optimization of microbial transglutaminase activity in ice cream using response surface methodology

In order to determine the maximum activity range of transglutaminase (TG) in ice cream, the central composite design was used and the TG concentration along with the reaction time and temperature were evaluated. The rheological behavior of the ice cream mix that provided the best response and the determination of the protein cross-linking by electrophoresis (SDS-PAGE) were evaluated. It was observed that the TG increased the consistency index and favored the pseudoplastic behavior of the ice cream samples. The maximum response (0.69 Pa sⁿ) was obtained using a TG concentration of 4 U g⁻¹ protein at 56.8 °C with a reaction time of 90 min. The protein cross-linking was confirmed by electrophoresis, which showed that κ-casein was more susceptible to attack from TG than whey proteins.     

益生菌在冰淇淋上的应用

益生菌对人体的保健作用已经大量的动物试验与临床试验所证实,如改善肠胃功能、润肠通便、调节肠道菌群、增强免疫力等功能。食品中添加益生菌已成为公众共识的发展趋势,而如何在食品中添加益生菌,最大限度地保存益生菌的活性,从而发挥其应有的功能作用,是我们技术人员所需要考虑和解决的问题。本文就冰淇淋添加用益生菌菌种筛选、菌种在冰淇淋中的稳定性及冰淇淋添加益生菌后的风味变化情况,进行了试验研究。结果表明,经过耐胃酸、耐胆汁酸盐及菌种稳定性等考察后的益生菌粉添加到冰淇淋中,其初始菌浓度为8.4×106cfu/g,经过近6个月的保,产品中活菌数仍有9.6×105 cfu/g,并且风味基本保持不变,说明冰淇淋是益生菌的良好介质,适合添加应用。