Effect of seasonal variation on the properties of whipping cream,soft cheese and skim milk powder in the UK

Whipping cream, skim milk powder and soft cheese were produced throughout the year. Whipping cream manufactured in spring and winter produced significantly higher overrun and better serum stability, and whipping time was related to buffering capacity of raw milk. Heat stability of reconstituted skim milk powder (RSMP) at 9% total solids (TS) was greater in summer and autumn, and >25% TS throughout the year. It was positively related to the protein content of raw milk, but negatively with fat. In contrast to other dairy products, no significant effect of season on the properties of soft cheese was found.     

Frozen Wild Blueberry-Tofu-Soymilk Desserts

Both wild (lowbush) blueberries (Vaccinium angustifolium Ait.) and soybeans (Glycine max L.) possess a variety of antioxidants, and both foods appear to have multiple health benefits. Our objectives were to identify whether wild blueberry juice concentrate was more acceptable than puree in frozen desserts with a soy milk‐tofu base; to determine whether fat‐free products were as acceptable as those with 10% added fat; and to compare several levels of blueberry juice concentrate. Four frozen dessert formulations were prepared in duplicate from soy milk, silken tofu, sucrose, stabilizer, BJC or puree, soybean oil or polydextrose, sweetened dried blueberries, salt, and lemon juice. Samples were assayed for total anthocyanins, antioxidant activity using the DPPH method, color, overrun, and solids. Fifty‐five persons evaluated the samples using a 9‐point hedonic scale for color, flavor, texture, and overall acceptability. Samples containing blueberry juice concentrate were darker and less blue. Anthocyanin levels were highest in the puree sample and the fat‐free product with 7.8% blueberry juice concentrate. However, antioxidant activity was highest (28 Trolox equivalents per gram) in the samples made with soybean oil and 7.4% blueberry juice concentrate. The puree formulation received higher hedonic scores than did the low‐fat blueberry juice concentrate formulations. The puree formulation received overall acceptability scores of like very much or like extremely by 45% of the consumers. These findings may aid processors in defining potential formulations that combine 2 healthful food ingredients.     

A modified ice cream processing routine that promotes fat destabilization in the absence of added emulsifier

The quality of ice cream made without added emulsifier using a modified processing routine was compared to ice cream made conventionally with and without added emulsifier. “Two-phase process” ice cream was created by preparing two separate phases; emulsion (fat, some protein, water) and solution (remaining protein, sugar, corn syrup solids, stabilizer, water) and combining them just before freezing. Quality indicators included percent fat destabilized, overrun and meltdown rate. Conventional process ice cream containing emulsifier exhibited a high degree of fat destabilization, high overrun and slow meltdown. Ice cream produced conventionally without emulsifier underwent little fat destabilization, had low overrun and melted rapidly. Ice cream produced by the two-phase process showed good fat destabilization and slow meltdown with moderate overrun, suggesting this method was successful in promoting desirable structure formation without added emulsifier.     

低脂冰淇淋的性质研究

用籼米为基质的脂肪替代品替代冰淇淋配方中的部分脂肪开发了低脂冰淇淋；研究了低脂冰淇淋的膨胀率、抗融化能力、硬度、贮能模量和感官指标。结果表明：随着冰淇淋配方中脂肪含量减少，冰淇淋的膨胀率逐渐增加，抗融化能力略有下降，脂肪替代品能明显增加低脂冰淇淋的膨胀率并改善其抗融化性。低脂冰淇淋的硬度和G^＋下降。用模糊数学的方法评价了低脂冰淇淋的感官指标，发现低脂冰淇淋中脂肪的最佳含量为4％。脂肪替代品能明显改善低脂冰淇淋的感官品质。脂肪含量为4％的低脂冰淇淋的感官指标与中脂冰淇淋相当。     

以乳清蛋白为基质的脂肪替代品对冰淇淋品质的影响

以乳清蛋白WPC-80为基质制备脂肪替代品,替代中脂冰淇淋中25%的脂肪。随着脂肪替代率的增加,冰淇淋浆料黏度和膨胀率增大,抗融化率和硬度下降,制得的低脂冰淇淋的各项感官指标均与中脂冰淇淋相当。当替代全部脂肪时,所制得的无脂冰淇淋也有较好的感官接受性。     

朝鲜蓟花苞汁总酚、总黄酮、抗氧化性比较及体外模拟胃肠消化特性

比较不同部位花苞汁及体外模拟胃肠消化前后总酚、总黄酮质量浓度,并通过总还原力和1,1-二苯基-2-三硝基苯肼自由基、2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸阳离子自由基、超氧阴离子自由基清除率4 种方法评价其抗氧化能力。结果表明：花托汁总酚质量浓度为2.46 mg/mL,分别为内苞叶汁、外苞叶汁的1.13、1.94 倍;总黄酮质量浓度为6.53 mg/mL,分别为内苞叶汁、外苞叶汁的1.15、2.06 倍。在4 种抗氧化评价体系中,自由基清除能力强弱顺序均为花托汁＞内苞叶汁＞外苞叶汁,且自由基清除率均随着样品总酚质量浓度增加而增大。在体外模拟胃肠消化实验中,以花托汁为样品,经过模拟胃液处理后,模拟胃液组和胃酸对照组抗氧化性均显著增强（P＜0.05）,但经过模拟肠液处理后抗氧化能力下降,表明胃蛋白酶、胃酸、胰蛋白酶均能促使抗氧化活性因子释放,提高抗氧化能力。     

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。     

油脂用量对搅打稀奶油的搅打性能和品质的影响

研究了油脂用量对搅打稀奶油的粒度分布、脂肪部分聚结、液相蛋白质浓度、搅打起泡率、质构特性、感官品质和稳定时间的影响。研究表明:随着油脂用量增加,冷却后乳浊液脂肪球粒径增大;搅打过程中脂肪部分聚结速度和脂肪球粒径d4,3均随油脂用量增加而增大,且脂肪部分聚结率与脂肪球粒径d4,3有很好的相关性;液相蛋白质浓度和搅打起泡率降低;搅打稀奶油的质构特性值增加;稳定时间呈先增后减趋势,当油脂用量为23%时,搅打稀奶油的稳定时间最长达到2.7h;搅打稀奶油的感官品质以油脂用量为20%最好,综合考虑,油脂最佳用量范围是20%-23%。     

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.     

Comparing the Effects of High Hydrostatic Pressure and Ultrahigh Temperature on Quality and Shelf Life of Cloudy Ginger Juice

The effects of high hydrostatic pressure (HHP) at 500 MPa for 10 min and ultrahigh temperature (UHT) at 110 °C for 8.6 s on the quality of cloudy ginger juice (CGJ) were investigated during storage for 91 days at 4 and 25 °C. The quality aspects studied were microbial stability and selected properties, including pH, total soluble solids (TSS), titratable acidity (TA), total phenols, gingerols, antioxidant capacity, color, and aroma composition. The results showed that HHP treatment led to a 3.0 log cycle reduction of microbial load but did not influence pH, TSS, TA, antioxidant capacity, and color (day 0). Total phenol content increased by 5.31 % after HHP treatment but decreased significantly by 14.74 % after UHT treatment (day 0). Gingerols increased by 14.43 and 14.18 % after HHP and UHT treatments (day 0), respectively. Monoterpenoids, which are the main volatile aroma compounds, did not change significantly after HHP treatment but decreased significantly by 2.27 % after UHT treatment (day 0). During storage, the decreases in total phenols, gingerols, and antioxidant capacity in the UHT-treated GCJ were more noticeable than those in the HHP-treated GCJ. Kinetic data of changes in total phenols, gingerols, and antioxidant capacity fitted into the combined model well. The changes in antioxidant capacity were positively and significantly correlated to total phenols and gingerols. Color darkened and aroma faded in both HHP-treated and UHT-treated CGJs during storage. The quality changes in samples stored at 25 °C were also more noticeable than those stored at 4 °C.     

Degradation Kinetics and Storage Stability of Vacuum Spray-Dried Micro Wet-Milled Orange Juice (<Emphasis Type="Italic">Citrus unshiu</Emphasis>) Powder

The aim of this work was to evaluate the degradation kinetics and stability of micro wet milled orange juice powders obtained by vacuum spray drying, using maltodextrin as a carrier agent. Powders were produced with four combinations of orange juice solids/maltodextrin solids 60:40, 50:50, 40:60, and 30:70 by weight. Ascorbic acid degradation, color, and antioxidant activity of powders were evaluated throughout 90 days. Powders were stored at 10, 25, and 35 °C and relative humidity of 33%. Temperature and storage time negatively influenced the stability of ascorbic acid and color, whereas antioxidant activity increased at the beginning of storage at a higher temperature then decreased slightly after 60 days. For stability study, powders were stored at different water activities (0.11 to 0.84) in order to determine the plasticizing effects of water on glass transition temperature. Both water activity and glass transition temperature were used to predict the critical conditions for storage. Vacuum spray dried powder produced with a ratio of 30:70 (orange juice solids/maltodextrin solids) was considered as the most stable, since it showed highest critical water activity (a_w?=?0.61) and lowest moisture content (0.11 g water/g of dry solid) among the four powders. Vacuum spray drying using superheated steam as the heating medium was proven to be an effective way of producing orange juice powders with minimum loss of nutrients.     

基于品质指标的苹果浊汁品种与产地差异性分析

以来自7?个不同主产区的21?个主栽品种,共41?份苹果鲜果为研究对象,对每个品种鲜榨浊汁的出汁率、浊度、果汁颜色、褐变度、透光率、可溶性固形物、可滴定酸、总酚、糖、有机酸、VC、矿物质、抗氧化性等品质指标进行测定。运用描述性分析、逐步线性判别分析进行数据处理。结果表明：不同品种或不同产地的苹果浊汁,品质差异较大。总体来看,a*值、原始浊度、褐变度、可滴定酸、葡萄糖、蔗糖、苹果酸等指标的变幅均较大,分别为94.07%、70.41%、42.86%、35.26%、42.02%、42.40%、37.69%。对于不同品种的苹果浊汁,由于褐变度、总酚、抗氧化性等色泽品质指标以及糖、酸等营养品质指标间具有较大差异,其分布呈现分散状态。其中新红星品种的褐变度、总酚含量、DPPH自由基清除率等品质指标普遍居高,色泽品质差异最显著。富士品种大部分样品的果糖、葡萄糖、蔗糖、苹果酸等指标含量较高,具有较好的营养品质。然而对于不同产地间的样品,其浊度、可滴定酸、可溶性固形物等加工品质指标具有较大差异,样品分布较为分散。河北省样品的出汁率、原始浊度、可滴定酸等指标普遍较低,加工品质较差。来自山东省不同品种苹果浊汁的样品以及来自不同产地富士苹果浊汁的样品间均具有较大差异,并且分别获得了77.8%和72.7%的判别准确率。以上结果表明,不同产地、不同品种苹果原料制得的苹果浊汁存在较大差异,通过对其品质指标进行差异性分析,可为上游育种与种植产业结构调整提供数据基础;通过判别模型的建立实现品种与产地的识别与预测,可以指导企业对苹果原料进行制汁专用化筛选。     

黄油-代可可脂基奶油生产工艺优化及其晶型形成分析

在分析油脂用量对黄油-代可可脂基奶油品质影响的基础上,通过正交试验研究油脂用量、黄油-代可可脂质量比和均质压力对奶油搅打性能、质构特性、脂肪球部分聚结率、结晶特性等的影响。结果表明,在油脂用量30%、黄油-代可可脂质量比2∶3、均质压力60?MPa的条件下,能保证脂肪部分聚结的发生,并保持搅打稀奶油较好的感官特性、起泡性和结晶特性。60?MPa的均质压力保证了体系的稳定性,使大量游离脂肪球产生从而促进脂肪部分聚结。晶型形成分析结果表明,在优化条件下,原料乳浊液X-射线衍射峰峰形由较宽、较尖锐变为峰形适中均匀,适宜搅打稀奶油的β’晶型晶体明显增多,搅打稀奶油乳浊液在低温条件下发生脂肪结晶,表现为脂肪晶体尺寸增大。     

Grape wine lees improves the rheological and adds antioxidant properties to ice cream

The effect of adding grape wine lees (GWL) (50, 100 and 150 g kg⁻¹, wet weight basis) on the rheological and antioxidant properties of ice cream was evaluated to determine the potential of using GWL as a value-added ingredient in ice cream. Black queen grape was selected because it was the only species for red winemaking in Taiwan. The addition of GWL decreased the specific gravity, pH, melting rate, firmness, lightness and the amount of freezable water in ice cream, but increased the viscosity, yellowness and fat destabilization in a dose dependent circumstance. However, the ice cream with high GWL contents (100 and 150 g kg⁻¹) also showed unpleasant effects, such as the decrease of overrun and the increase of particle size of fat globule. The level of 50 g kg⁻¹ was applicable because it improved the functionality without the disadvantages in the overrun and particle size. Furthermore, GWL significantly increased the DPPH radical scavenging activity and reducing power of ice cream, and also its inhibitory effect toward the oxidation of human erythrocyte membrane. It appeared that the antioxidants in GWL were quite stable to the process of ice cream making.     

发酵红树莓汁乳酸菌的筛选及抗氧化活性研究

从抗氧化活性、胃肠道环境耐受性、抑菌性能及菌体生长能力四个方面选出优良乳酸菌株,并对菌株发酵红树莓（Rubus idaeus L.）汁进行研究。结果表明,从12株乳酸菌中筛选出了1株优良副干酪乳杆菌（Lactobacillus paracasei）YJ1,菌株YJ1发酵红树莓汁中总黄酮和总酚含量分别增加了23.00%、18.58%,与未发酵的红树莓原汁相比,发酵后的红树莓汁体外抗氧化活性极显著提高（P＜0.01）,其DPPH和羟基自由基清除能力分别提高了22.92%、15.63%;2,2'-联氨-双-3-乙基苯并噻唑啉-6-磺酸（ABTS）和铁离子还原/抗氧化能力（FRAP）法测定的总抗氧化能力分别增加了36.31%、39.48%。     

响应面法优化超声辅助凹土-壳聚糖澄清姜汁工艺

以凹土和壳聚糖为原料负载后作为复合澄清剂,在单因素实验的基础上,以姜汁透光率为考察指标,研究超声处理对姜汁澄清效果的影响,通过响应面法对姜汁澄清工艺进行优化,并以色泽、透光率、可溶性固形物含量、总酚含量、姜辣素含量、蛋白质含量为指标,对比了超声辅助凹土-壳聚糖澄清法与其他澄清方法对姜汁澄清效果及品质的影响。结果显示,超声辅助凹土-壳聚糖复合澄清剂澄清姜汁的最佳工艺条件为:超声时间10 min、超声温度54℃、超声功率160 W。在此优化条件下,姜汁的透光率达96.78%±0.56%以上。对比不同澄清方法发现,超声辅助凹土-壳聚糖澄清法所得澄清姜汁色泽浅、透光率高、姜辣素含量最高,且差异显著(P<0.05);而影响姜汁稳定性的总酚含量及蛋白质含量最低,与其它三种方法差异显著(P<0.05);可溶性固形物含量与其它方法相比差异性甚小。     

The effect of soy protein concentrate addition on the physical, chemical, and sensory properties of strawberry flavored ice cream

The effect of soy protein concentrate (0, 1.5, 3, and 4.5%) on the physical, chemical, and sensory properties of strawberry flavored (0, 0.01 and 0.02%) ice cream samples was examined. All samples were analyzed for pH, titratable acidity, total solids, nitrogen, fat, ash, overrun, viscosity, meltdown, Hunter L-, a-, b- values, flavor, body and texture, and appearance. Substituting soy protein concentrate (SPC) in ice cream formula for non-fat dry milk (NFDM) positively influenced the nitrogen content, viscosity values, and melting and appearance properties of the ice cream samples while overrun values and flavor scores were negatively affected. SPC could be incorporated into the ice cream formula in the range of 1.5–3% devoid of significantly diminishing the physical, chemical, and sensory properties.     

Influence of hazelnut flour and skin addition on the physical, chemical and sensory properties of vanilla ice cream

The effect of hazelnut flour (1.5, 3 and 4.5%) and hazelnut kernel skin (1, 2 and 3%) on the physical, chemical and sensory properties of vanilla ice cream was examined. All samples were analysed for pH, titratable acidity, total solids, nitrogen, fat, ash, overrun, viscosity, meltdown, Hunter L‐, a‐ and b‐values, flavour, body and texture, and appearance. The samples with hazelnut flour exhibited higher pH, nitrogen, ash, viscosity, and L‐, flavour, body and texture, and appearance values than the samples with kernel skin. Samples with hazelnut flour and skin can be added to the ice cream mix to produce a non‐fat ice cream at 3% and 1% levels in combination with maltodextrin, respectively.     

A process for preparing a natural antioxidant enriched dairy product (Sandesh)

The antioxidant activities of beet (Beta vulgaris), mint (Mentha spicata L.) and ginger (Zingiber officinale L.) alone or in combination were assessed after their fortification in sandesh (a heat desiccated product of coagulated milk protein mass) using Randox's total antioxidant level determining chemicals and ultimately it was compared with the synthetic antioxidants like TBHQ, BHA and BHT. Addition of beet or mint alone in sandesh showed lower antioxidant level than the addition of ginger alone. However, combination of beet with ginger showed highest antioxidant level among the natural sources and value was almost equal to TBHQ (200 mg kg⁻¹). Besides, the suitable stage and form of addition of these herbs in sandesh were also investigated using the Randox's antioxidant level evaluating chemical. Among the four forms of herbs such as paste, tray-dried powder, freeze-dried powder and solvent extracted form, addition of solvent extracted form in sandesh showed highest antioxidant level than any other form. Similarly, addition of all these herbs at final stage of sandesh preparation showed highest antioxidant level than their addition at the initial stage of sandesh preparation. Comparative evaluations of the proximate composition of herbal sandesh with the control sandesh showed that herbal sandesh were more or less similar with control sandesh except in fat and moisture content. But according to sensory characteristics, sandesh containing beet, ginger or combination of beet with ginger or mint was more acceptable to panelist than control sandesh. Results of the study indicate that herbal sandesh is more value added health food than control sandesh.