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。     

大豆磷脂冰激凌的研制

介绍了大豆磷脂的生理功能和功能作用,以大豆磷脂再加复合稳定剂,制备的冰激凌,性能良好,营养丰富。     

草莓果泥冰淇淋的研制

本文通过对比试验确定了最佳的护色剂;通过对杀菌后浆料中Vc的损失情况分析,确定了最佳的杀菌工艺;并通过正交试验研究了CMC-Na、明胶、单甘酯和草莓果肉的最佳配比。研制出了较为理想的草莓果泥冰淇淋。     

乳化剂和稳定剂在冰淇淋加工中的应用

介绍了乳化剂和稳定剂在冰淇淋加工中的作用机理。冰淇淋的基本加工工艺包括：①原料及混合；②巴氏杀菌；③均质；④老化；⑤搅打及凝冻；⑥硬化。乳化剂在冰淇淋加工中起到两种基本作用：①乳化，使脂肪以稳定的乳化状态分散于冰淇淋混料中；②在物料凝冻过程中促进脂肪球一定程度上的附了聚与联聚。同时介绍了稳定剂在冰淇淋加工过程中的作用以及常用稳定剂的特性。     

Effect of calcium chloride addition on ice cream structure and quality

The influence of calcium fortification by the addition of calcium chloride on quality parameters of ice cream based on physical properties was investigated, as was the effect of κ-carrageenan at modifying the effects of this calcium fortification. Four ice cream mixes of conventional composition, with added κ-carrageenan (0 or 0.025%) and added calcium chloride (0 or 4.4 g L⁻¹ = 40 mM of added Ca²⁺), were prepared. Modulated temperature-differential scanning calorimetry was used to investigate the effect of calcium chloride on the nucleation temperature, enthalpy of melting, and freezing point depression. The protein composition of 15.4% (wt/wt) reconstituted skim milk powder solutions with or without 4.4 g L⁻¹ added CaCl₂ and in the supernatant after ultracentrifugation was determined. Fat particle size distributions in ice cream were characterized by light scattering. Ice crystal sizes before and after temperature cycling were determined by cold-stage light microscopy. The results demonstrated that the addition of calcium chloride led to a substantial increase in ice crystal sizes and in fat partial coalescence, which were exacerbated by the addition of κ-carrageenan. These results can be explained by the interaction between Ca²⁺ ions and casein micelles, rather than any effects on freezing point depression. The calcium ions led to a more compact micelle, less serum β-casein, and high fat destabilization, all of which would be expected to reduce macromolecular structure and volume occupancy in the unfrozen phase, which led to increased rates of ice recrystallization.     

The use of spinning disc reactor for processing ice cream base – effect of ageing in making model ice cream

Spinning disc reactor (SDR) technology was tested to produce an ice cream base, which was subsequently used to make model ice cream. The ice cream base containing butterfat, lecithin, xanthan gum, sugar, skimmed milk and double cream was passed over the SDR disc spinning at 2900 rpm, heated at 80 °C and at a flow rate 6 mL s⁻¹. The physical properties of the SDR-processed ice cream base such as particle size and viscosity measurments, and of model ice cream including overrun, meltdown rate and sensory perception were investigated. The SDR-processed ice cream base exhibits narrow particle-size distribution (average particle d ₃₂ = 1.65 μm, d ₄₃ = 2.98 μm) and the viscosity was found to be similar at zero and 18 h ageing, whilst the model ice cream requires zero-hour ageing and has a high overrun value (∼85%) and slow meltdown rate as compared with a commercial sample. The results reveal that the SDR is capable of producing a highly stable ice cream base that requires significantly less ageing than the 18 h typically associated with the traditional process of making ice cream. The SDR process provides intense mixing of ingredients which facilitates the hydration of milk proteins and stabilisers.     

低卡型与普通型冰淇淋显微结构及其混料流变学性质比较研究

显微结构比较表明,普通型冰淇淋显微结构中存在锁链状半连续相的脂肪球三维网络结构并构成其主要框架,低卡型冰淇淋结构中仅含有由卡拉胶等多糖分子形成的凝胶网络结构并构成其主要框架,流变学研究表明,两种类型冰淇淋混料均属于屈服－假塑性流体。脂肪含量减少,蔗糖被取代会引起其混料表观粘度的降低,从而影响低卡型冰淇淋的抗融化性。     

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.     

益生菌冰淇淋的开发

近年来我国食品工业中,冰淇淋成为继饮料、方便面后发展最为迅猛的产品之一。如何将冰淇淋的嗜好性与产品的营养和功能特性进行有机结合,是冰淇淋产品未来重要的发展趋势。本文从冰淇淋发展简史与近年市场状况,益生茵的种类和作用,益生菌冰淇淋的优势、研究与开发方向等方面进行了概述。      

酸奶冰淇淋配方研究

对酸奶冰淇淋的配方组成进行了研究, 确定了酸奶冰淇淋配方的最佳组成。     

实验制作高淀粉冰淇淋

介绍了高淀粉冰淇淋的配方和工艺要点，并对实际制作过程中的操作要点进行了论述，为冰淇淋生产厂降低生产成本，寻找新的原料和食品添加剂提供了一种方法。     

辛烯基琥珀酸马铃薯淀粉酯在冰淇淋中的应用研究

将辛烯基琥珀酸马铃薯淀粉酯作为脂肪替代品代替配方中的奶油,进行了冰淇淋的制备试验。结果表明,冰淇淋配方为奶粉14%、白砂糖13%、蛋黄2%和复合稳定剂0.2%时,添加3.0%(w/w)该淀粉酯的无奶油冰淇淋制品其融化率下降、膨胀率提高,口感更加清凉、细滑;其它不同替代程度的低脂冰淇淋制品品质也较优良,整体品质明显优于添加3.0%(w/w)马铃薯原淀粉作为脂肪替代品制得的冰淇淋制品。结论为高黏度辛烯基琥珀酸马铃薯淀粉酯可以作为脂肪替代品部分或全部代替冰淇淋配方中的奶油,但相应冰淇淋的硬度略有增加。     

Effect of trehalose on the glass transition and ice crystal growth in ice cream

The effects of trehalose and sucrose on the rate of ice crystal growth in ice cream during accelerated shelf‐life were compared. Experimental and theoretical freezing curves were shown to be in good agreement. Glass transition temperatures (T_g) of maximally freeze concentrated trehalose and sucrose solutions (40% w/w) were found to be ?39.5 °C and ?47 °C respectively. For ice cream mixes, the T_g value increased from ?46.4 °C for the 100% sucrose‐based mix to ?42.0 °C for the 100% trehalose sweetened ice cream. However, no differences in viscosity, nucleation rate or inhibition of ice crystal growth were observed with increasing trehalose concentration in ice cream.     

不同改性淀粉对冷冻酸乳冰淇淋品质的影响

通过添加不同改性淀粉制备冷冻酸乳冰淇淋,分别研究不同改性淀粉及添加量在冷冻处理前对酸乳样品的硬度和黏度的影响,以及在冷冻处理后对冷冻酸乳冰淇淋样品冻融稳定性和感官品质的影响。结果显示,随着改性淀粉添加量在0～1.2 g/100 g范围增加,酸乳样品的硬度和黏度均呈现不同程度的增加,并且全部冷冻酸乳冰淇淋样品的乳析指数均呈现不同程度的下降,其中添加辛烯基琥珀酸酐（OSA）酯化淀粉微粒的样品,其硬度和黏度的增幅最大,分别为67.64%和93.43%,并且表现出最佳的冻融稳定性,其乳析指数下降幅度最大,为52.28%。当OSA酯化淀粉微粒添加量为0.8 g/100 g时,其感官品评综合得分最高,为90.54分,表明此种改性淀粉在提高冷冻酸乳冰淇淋品质上具有良好的应用效果。     

Effect of storage temperature on quality of light and full-fat ice cream

Ice cream quality is dependent on many factors including storage temperature. Currently, the industry standard for ice cream storage is −28.9°C. Ice cream production costs may be decreased by increasing the temperature of the storage freezer, thus lowering energy costs. The first objective of this research was to evaluate the effect of 4 storage temperatures on the quality of commercial vanilla-flavored light and full-fat ice cream. Storage temperatures used were −45.6, −26.1, and −23.3°C for the 3 treatments and −28.9°C as the control or industry standard. Ice crystal sizes were analyzed by a cold-stage microscope and image analysis at 1, 19.5, and 39 wk of storage. Ice crystal size did not differ among the storage temperatures of light and full-fat ice creams at 19.5 or 39 wk. An increase in ice crystal size was observed between 19.5 and 39 wk for all storage temperatures except −45.6°C. Coldness intensity, iciness, creaminess, and storage/stale off-flavor of the light and full-fat ice creams were evaluated at 39 wk of storage. Sensory evaluation indicated no difference among the different storage temperatures for light and full-fat ice creams. In a second study, light and full-fat ice creams were heat shocked by storing at −28.9°C for 35 wk and then alternating between −23.3 and −12.2°C every 24 h for 4 wk. Heat-shocked ice creams were analyzed at 2 and 4 wk of storage for ice crystal size and were evaluated by the sensory panel. A difference in ice crystal size was observed for light and full-fat ice creams during heat-shock storage; however, sensory results indicated no differences. In summary, storage of light or full-fat vanilla-flavored ice creams at the temperatures used within this research did not affect quality of the ice creams. Therefore, ice cream manufacturers could conserve energy by increasing the temperature of freezers from −28.9 to −26.1°C. Because freezers will typically fluctuate from the set temperature, usage of −26.1°C allows for a safety factor, even though storage at −23.3°C did not affect ice cream quality.     

大豆粉取代奶粉对冰淇淋品质的影响

在冰淇淋配方中以0~80%的大豆粉取代脱脂奶粉,对冰淇淋浆料进行了流变学、稳定性、粒度检测及对冰淇淋的膨胀率与抗融性进行测定,揭示了大豆粉的取代量对冰淇淋品质的影响。研究结果表明,随着大豆粉添加量的增加,冰淇淋浆料粘度显著增加,稳定性增强,而粒径差异不显著,针对于最终冰淇淋产品而言,其膨胀率呈现先上升(20%~40%)后下降(60%~80%)的趋势,但其抗融性逐渐增强,与此同时,豆味的表现也会加强,取代量大于60%时,豆香味则占主导。      

乳化剂的协同作用在冰淇淋中的应用

本文主要研究各种乳化剂单体的乳化性能和发泡性能,并测定不同乳化剂以一定比例配合后的乳 化性能和发泡性能,在考虑市场需求的价格后,选择出较好的乳化剂的复合应用于冰淇淋的生产中。     

各种甜味料的特性及其在冰淇淋生产中的应用

阐述了各种甜味料的特性及其在冰淇淋中的应用。     

酸奶冰淇淋的研制

研制以鲜奶为主要原料,先将其中一部分加入乳酸菌进行发酵,然后再和其它配料混合,按照常规冰淇淋加工工艺进行加工,研制出风味独特、酸甜适中,集酸奶和冰淇淋优点于一身,达到冰淇淋各项指标要求的酸奶冰淇淋。实验对酸奶添加量、添加剂的使用量、均质压力等工艺参数进行研究。     

冰淇淋中奶粉替代品的研究

从考察产品的感官指标和理化性能入手,采用玉米淀粉、大豆蛋白、糊精、变性淀粉等原料替代奶粉,对冰淇淋生产的配方进行了试验,筛选出了用植物性原料替代奶粉生产冰淇淋的最佳配方。