Ice cream structural elements that affect melting rate and hardness

Statistical models were developed to reveal which structural elements of ice cream affect melting rate and hardness. Ice creams were frozen in a batch freezer with three types of sweetener, three levels of the emulsifier polysorbate 80, and two different draw temperatures to produce ice creams with a range of microstructures. Ice cream mixes were analyzed for viscosity, and finished ice creams were analyzed for air cell and ice crystal size, overrun, and fat destabilization. The ice phase volume of each ice cream were calculated based on the freezing point of the mix. Melting rate and hardness of each hardened ice cream was measured and correlated with the structural attributes by using analysis of variance and multiple linear regression. Fat destabilization, ice crystal size, and the consistency coefficient of the mix were found to affect the melting rate of ice cream, whereas hardness was influenced by ice phase volume, ice crystal size, overrun, fat destabilization, and the rheological properties of the mix.     

Effect of Sweeteners and Stabilizers on selected Sensory Attributes and Shelf Life of Ice Cream

Guar and locust bean gums were combined with sucrose, 36 DE corn syrup and/or 42 high fructose corn syrup (HFCS) in a minimum fat (10%) ice cream formulation. A total of 27 combinations were evaluated for sweetness, iciness, chewiness and vanilla intensity. Replacing 50% of the sucrose with 42 HFCS did not significantly affect sweetness or vanilla intensity. Chewiness was enhanced when high corn syrup levels were combined with a high guar to locust bean gum ratio. Storage study data showed that ice creams containing high levels of HFCS became objectionably icy earlier than ice creams containing low levels or no HFCS. With a high guar to locust bean gum ratio ice creams became both detectably and objectionably icy sooner than if a low ratio of these gums was used.     

Effect of Okra Cell Wall and Polysaccharide on Physical Properties and Stability of Ice Cream

Stabilizers are used in ice cream to increase mix viscosity, promote smooth texture, and improve frozen stability. In this study, the effects of varying concentrations (0.00%, 0.15%, 0.30%, and 0.45%) of okra cell wall (OKW) and its corresponding water‐soluble polysaccharide (OKP) on the physical characteristics of ice cream were determined. Ice cream mix viscosity was measured as well as overrun, meltdown, and consumer acceptability. Ice recrystallization was determined after ice cream was subjected to temperature cycling in the range of ?10 to ?20 °C for 10 cycles. Mix viscosity increased significantly as the concentrations of OKW and OKP increased. The addition of either OKW or OKP at 0.15% to 0.45% significantly improved the melting resistance of ice cream. OKW and OKP at 0.15% did not affect sensory perception score for flavor, texture, and overall liking of the ice cream. OKW and OKP (0.15%) reduced ice crystal growth to 107% and 87%, respectively, as compared to 132% for the control (0.00%). Thus, our results suggested the potential use of OKW and OKP at 0.15% as a stabilizer to control ice cream quality and retard ice recrystallization. OKP, however, at 0.15% exhibited greater effect on viscosity increase and on ice recrystallization inhibition than OKW.     

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.     

Sensory Textural Properties of Stabilized Ice Cream

Vanilla ice cream samples containing five different levels of sodium carboxymethylcellulose (CMC) were evaluated for textural differences using time-intensity and graphic rating (line-marking) methods. The time-intensity method showed significant correlations between CMC concentration and the sensory textural properties of iciness, viscosity, and melting time. The graphic rating tests showed significant correlations between CMC concentration and the sensory textural properties of coldness, iciness, viscosity, and firmness. Comparison of time-intensity and graphic rating tests for the same textural properties showed significant correlations for iciness and viscosity. This investigation showed time intensity and graphic rating to be complementary methods for the sensory evaluation of the textural properties of a stabilized vanilla ice cream.     

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.     

Ice recrystallization inhibition in ice cream as affected by ice structuring proteins from winter wheat grass

Ice recrystallization in quiescently frozen sucrose solutions that contained some of the ingredients commonly found in ice cream and in ice cream manufactured under commercial conditions, with or without ice structuring proteins (ISP) from cold-acclimated winter wheat grass extract (AWWE), was assessed by bright field microscopy. In sucrose solutions, critical differences in moisture content, viscosity, ionic strength, and other properties derived from the presence of other ingredients (skim milk powder, corn syrup solids, locust bean gum) caused a reduction in ice crystal growth. Significant ISP activity in retarding ice crystal growth was observed in all solutions (44% for the most complex mix) containing 0.13% total protein from AWWE. In heat-shocked ice cream, ice recrystallization rates were significantly reduced 40 and 46% with the addition of 0.0025 and 0.0037% total protein from AWWE. The ISP activity in ice cream was not hindered by its inclusion in mix prior to pasteurization. A synergistic effect between ISP and stabilizer was observed, as ISP activity was reduced in the absence of stabilizer in ice cream formulations. A remarkably smoother texture for ice creams containing ISP after heat-shock storage was evident by sensory evaluation. The efficiency of ISP from AWWE in controlling ice crystal growth in ice cream has been demonstrated.     

Eliciting the Sensory Modalities of Fat Reformulated Yoghurt Ice Cream Using Oligosaccharides

In the present work, fat reduction of Greek strained yoghurt ice cream (YIC) was carried out in three proportional milkfat levels i.e. 30, 50 and 70% using three types of oligosaccharides namely long-chain inulin, oligofructose and maltodextrin 12 DE. Greek strained yoghurt was blended with ice cream mixes in ratios of 1:3 and 1:1. The physico-chemical, textural and thermal characteristics of the YIC mixes and their obtained frozen end products were determined. The sensory modalities (olfactory, gustatory, tactile and oro-tactile) of the YIC were monitored following 2 and 16 weeks of quiescent frozen storage at ?25 °C. Milkfat reduction impaired significantly (p?<?0.05) the perceived creaminess and mouthcoating sensation stimuli, whist it intensified the oral tissue friction associated sense stimuli such as astringency, wateriness and coarseness. Long-chain inulin- and maltodextrin-based samples received the highest scores for creaminess, mouthcoating, gumminess, hardness and iciness. The increase of the yoghurt to ice cream mix ratio escalated the friction/recrystallization-associated sensations e.g. astringency, sourness, coarseness and wateriness. Notwithstanding yoghurt supplementation reinforced the pseudoplasticity and macroviscosity of the ice cream mixes, it suppressed their aeration capacity leading to heavy-bodied ice creams. However, no significant effects of yoghurt supplementation level on the colligative and meltdown rate of the YIC formulations were identified. Partial least squares coupled discriminant analysis (PLS-DA) revealed that fat reformulation of YICs using oligosaccharides results in a substantially diversified sensory profile. Generally, a 50% fat reduction of YICs using long-chain oligosaccharides appears to be a technologically tangible solution.     

不同类型稳定剂和乳化剂对冰淇淋品质特性的影响

本文研究了不同类型的稳定剂和乳化剂在冰淇淋中的作用,以三种代表性的不同类型的稳定剂:卡拉胶（离子型多糖）、瓜尔豆胶（非离子型多糖）和明胶（蛋白质）,以及具有不同亲水亲油性的乳化剂:单硬脂肪酸甘油酯（Glyceryl Monostearate, MG,HLB=3.8）和吐温80（HLB=15）作为研究对象,以冰淇淋的物理特性（粘度、膨胀率与融化率）和感官（粘稠度、顺滑性、口融性与颗粒感）为指标,讨论了稳定剂和乳化剂对冰淇淋品质的影响。结果表明,与吐温80相比,加入MG的冰淇淋膨胀率更高,抗融性更好,二者对浆料粘度的作用无显著性差异（P<0.05）;三种稳定剂均可增大冰淇淋浆料的粘度,其中,卡拉胶较瓜尔豆胶和明胶对浆料粘度的影响差异显著（P<0.05）,抗融性最强,瓜尔豆胶对膨胀率影响最大。其中MG与卡拉胶复配所得浆料粘度和抗融性最佳,分别为898.35 cp,融化率4.74%;与瓜尔豆胶复配所得冰淇淋膨胀率最高为66.95%。在此基础上,以MG作为乳化剂,复配瓜尔豆胶和卡拉胶,研究不同复配比例的稳定剂在冰淇淋中的作用。结果表明,稳定剂总添加量为0.25%时,卡拉胶与瓜尔豆胶的质量比为1:1.5,冰淇淋的浆料粘度可达1036.5 cp,融化率为17.4%,感官评分最高。     

Development of Formulations and Processes to Incorporate Wax Oleogels in Ice Cream

The objective of this study was to investigate the influence of emulsifiers, waxes, fat concentration, and processing conditions on the application of wax oleogel to replace solid fat content and create optimal fat structure in ice cream. Ice creams with 10% or 15% fat were formulated with rice bran wax (RBW), candelilla wax (CDW), or carnauba wax (CBW) oleogels, containing 10% wax and 90% high‐oleic sunflower oil. The ice creams were produced using batch or continuous freezing processes. Transmission electron microscopy (TEM) and cryo‐scanning electron microscopy were used to evaluate the microstructure of ice cream and the ultrastructure of oleogel droplets in ice cream mixes. Among the wax oleogels, RBW oleogel had the ability to form and sustain structure in 15% fat ice creams when glycerol monooleate (GMO) was used as the emulsifier. TEM images revealed that the high degree of fat structuring observed in GMO samples was associated with the RBW crystal morphology within the fat droplet, which was characterized by the growth of crystals at the outer edge of the droplet. Continuous freezing improved fat structuring compared to batch freezing. RBW oleogels established better structure compared to CDW or CBW oleogels. These results demonstrate that RBW oleogel has the potential to develop fat structure in ice cream in the presence of GMO and sufficiently high concentrations of oleogel.     

Effect of fat content on the physical properties and consumer acceptability of vanilla ice cream

Ice cream is a complex food matrix that contains multiple physical phases. Removal of 1 ingredient may affect not only its physical properties but also multiple sensory characteristics that may or may not be important to consumers. Fat not only contributes to texture, mouth feel, and flavor, but also serves as a structural element. We evaluated the effect of replacing fat with maltodextrin (MD) on select physical properties of ice cream and on consumer acceptability. Vanilla ice creams were formulated to contain 6, 8, 10, 12, and 14% fat, and the difference was made up with 8, 6, 4, 2, and 0% maltodextrin, respectively, to balance the mix. Physical characterization included measurements of overrun, apparent viscosity, fat particle size, fat destabilization, hardness, and melting rate. A series of sensory tests were conducted to measure liking and the intensity of various attributes. Tests were also conducted after 19 weeks of storage at −18°C to assess changes in acceptance due to prolonged storage at unfavorable temperatures. Then, discrimination tests were performed to determine which differences in fat content were detectable by consumers. Mix viscosity decreased with increasing fat content and decreasing maltodextrin content. Fat particle size and fat destabilization significantly increased with increasing fat content. However, acceptability did not differ significantly across the samples for fresh or stored ice cream. Following storage, ice creams with 6, 12, and 14% fat did not differ in acceptability compared with fresh ice cream. However, the 8% fat, 6% MD and 10% fat, 4% MD ice creams showed a significant drop in acceptance after storage relative to fresh ice cream at the same fat content. Consumers were unable to detect a difference of 2 percentage points in fat level between 6 and 12% fat. They were able to detect a difference of 4 percentage points for ice creams with 6% versus 10%, but not for those with 8% versus 12% fat. Removing fat and replacing it with maltodextrin caused minimal changes in physical properties in ice cream and mix and did not change consumer acceptability for either fresh or stored ice cream.     

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.     

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。     

Enrichment of Functional Properties of Ice Cream with Pomegranate By‐products

Pomegranate peel rich in phenolics, and pomegranate seed which contain a conjugated fatty acid namely punicic acid in lipid fraction remain as by‐products after processing the fruit into juice. Ice cream is poor in polyunsaturated fatty acids and phenolics, therefore, this study was conducted to improve the functional properties of ice cream by incorporating pomegranate peel phenolics and pomegranate seed oil. Incorporation of the peel phenolics into ice cream at the levels of 0.1% and 0.4% (w/w) resulted in significant changes in the pH, total acidity, and color of the samples. The most prominent outcomes of phenolic incorporation were sharp improvements in antioxidant and antidiabetic activities as well as the phenolic content of ice creams. Replacement of pomegranate seed oil by milk fat at the levels of 2.0% and 4.0% (w/w) increased the conjugated fatty acid content. However, perception of oxidized flavor increased with the additional seed oil. When one considers the functional and nutritional improvements in the enrichment of the ice cream together with overall acceptability results of the sensory analysis, then it follows from this study that ice creams enriched with pomegranate peel phenolics up to 0.4% (w/w) and pomegranate seed oil up to 2.0% (w/w) could be introduced to markets as functional ice cream. Enrichment of ice creams with pomegranate by‐products might provide consumers health benefits with striking functional properties of punicalagins in pomegranate peel, and punicic acid in pomegranate seed oil.     

Effects of Homogenization on Sensory Characteristics of Vanilla Ice Cream

Nine different batches of ice creams that contained no emulsifier and that had been processed at various homogenization pressures were compared with a reference ice cream batch that was processed by commercial techniques (an emulsifier added and homogenized double-stage at 140.74 and 35.18 kg/cm² (2000 and 500 psi), first and second stage, respectively). The samples were compared for seven sensory attributes: chewiness, greasy mouthcoating, iciness, vanilla flavor intensity, loss of shape, wheying off, and curdling. Data showed differences in loss of shape and vanilla flavor intensity in some of the samples when compared with the reference sample. Vanilla flavor intensity was more pronounced in experimental samples, which indicated that the emulsifier in the reference mix in some way suppressed vanilla flavor intensity.     

Relationships between ice cream mix viscoelasticity and ice crystal growth in ice cream

The relationship between ice cream mix viscoelasticity and ice crystal growth in ice cream as a function of stabilizer addition was studied by a simulation of freeze-concentration using a series of ice cream mixes containing reduced quantities of water. Ice cream mixes were formulated with guar gum concentrations ranging from 0 to 0.25% and a series of concentrated mixes from each initial formulation was prepared for viscoelastic measurements by successively decreasing the water content. By plotting apparent viscosity or storage modulus against concentration factor based on water removed, a change in slope (breakpoint) could be seen. Ice crystal size analysis in ice cream before and after heat shock testing showed a minimum in recrystallization rate when the concentration of guar gum was 0.14% in the mix. At lower or higher concentrations the recrystallization rate was higher. Normalized breakpoint viscosity correlated well with recrystallization rate. Thus, it appears that stabilizer contributes to recrystallization protection in ice due to a change in polysaccharide behaviour that results from freeze-concentration.     

Ice Cream: Foam Formation and Stabilization—A Review

Ice cream has been studied from ingredients to process conditions, ice crystal formation to ice crystal growth, and ingredient selection to eating quality. One of the key aspects of ice cream is air cells, as formation and acceptance of ice cream rely on foam production and stabilization. Air cells in ice cream provide a unique structure that governs many of this product's keeping and eating qualities. The air cells are dependent upon ice cream mix composition (fat, protein, and surface active ingredients) as well as processing conditions (freezer shear force, hardening time, and storage temperatures). Optical, low-temperature scanning electron microscopy and transmission electron microscopy are applied to observe the morphology and size of air cells in ice cream. Air cells are crucial in forming the product and for eating quality and enjoyment.     

Replacement of Carbon-refined Corn Syrups with Ion-exchanged Corn Syrups in Ice Cream Formulations

Ice cream was manufactured utilizing ten corn syrups at 5% (dry basis) in the mix, 30 DE, 42 DE, 42 DE high maltose (HM), 55 DE HM and 64 DE, each of which was processed through the carbon-refined and ion-exchanged processes. An increase in DE of the syrup led to a decrease in mix viscosity, a decrease in the freezing point of the mix, a decrease in fat destabilization and a decrease in firmness of the ice cream. The ion-exchanged syrups decreased the mix viscosity and produced a drier ice cream with greater fat destabilization but had no influence on mix freezing point depression, overrun, firmness or meltdown. Sensory results from the 42DE HM and 55DE HM carbon-refined and ion-exchanged products evaluated in this study showed no differences in sweetness or texture. The flavor and acceptability of 42DE HM carbon-refined syrup in ice cream was preferred less than the 42DE HM or 55DE HM ion-exchanged syrups.     

滑菇在冰淇淋生产中的增稠稳定作用

将滑菇按料水比1∶3（m/m）加水混合并匀浆处理后用于冰淇淋的生产,研究其对冰淇淋混合料的增稠稳
定作用。以冰淇淋的抗融性、膨胀率及感官评分为考察指标,通过正交试验筛选滑菇最佳处理方法及冰淇淋最佳配
方,当滑菇在绝对压强0.15 MPa条件下煮制25 min,其他条件为滑菇浆添加量4%、羧甲基纤维素钠（CMC-Na）添
加量0.1%、单甘酯添加量0.4%时,产品综合品质最佳,无需添加明胶仍然具有良好的光洁度及保形性。比较滑菇
冰淇淋与传统牛奶冰淇淋的脂肪失稳度、硬度、黏度、显微结构等方面变化,结果表明滑菇冰淇淋优于传统牛奶冰
淇淋,其组织柔滑、口感细腻、膨胀率好、抗融性适当。