羟丙基甲基纤维素对混合脂搅打奶油品质的影响

<正>混合脂搅打奶油是由植物油脂和动物油脂（黄油、奶粉等）混合加工而成的搅打充气类乳制品，属于乳浊液体系，具有不稳定性，在实际生产中常添加乳化剂以提高奶油产品品质。羟丙基甲基纤维素（Hydroxypropyl Methyl Cellulose,HPMC）是由D-葡萄糖通过β-(1-4)糖苷键连接的线性高分子化合物，具有大量羟基，可与水分子形成氢键，使其具有良好的水溶性、持水性和乳化性。本文在实验室原有配方的基础上，通过与市售奶油对比，测定不同添加量的HPMC对混合脂搅打奶油乳浊液粒径、脂肪部分聚结率、     

植脂鲜奶油稳定性的研究

以氢化棕榈油为主要原料,经过配料、混合、乳化、均质、急冷制成植脂鲜奶油,然后进行打发做成裱花。通过对乳化剂、增稠剂、油添加量、水添加量和HPMC等原辅料的选择,以及对打发温度、打发速度、打发时间等因素的控制,植脂鲜奶油稳定性提高。     

零反式脂肪酸搅打奶油制备研究

该研究在调研搅打奶油配方及制备工艺参数基础上,以极度氢化棕榈仁油为基料油,采用正交实验设计,以打发率及保形性综合评分为指标,对影响搅打奶油产品性能主要工艺参数进行优化。结果表明,保温温度为70℃、老化时间为5 h、均质压力为30 Mpa下制备得到零反式脂肪酸搅打奶油产品打发率达到2.61%,保形性达到0.92,达到市售高反式脂肪酸搅打奶油产品性能要求。     

速冻食品专用油脂制备及其在汤圆中的应用评价

速冻专用油脂一般要求具备良好的保型抗融和乳化性能。熔点、乳化性能以及固体脂肪含量是影响速冻专用油脂品质的重要因素。以酯交换后的棕榈硬脂与棕榈油(质量比50∶50)混合做为基料油脂制备速冻食品专用油脂,含水率16.6%,复合乳化剂(单甘酯∶丙二醇酯=1∶1)为油质量的1%。专用油脂的乳化稳定性93.0%,熔点45℃,塑性范围在25~40℃时为8.4~28.2,具有较宽的可塑性范围。应用于速冻汤圆中,能有效降低汤圆的开裂率,使产品表面更光滑,降低产品煮后浑汤现象的发生,口感更佳,制作的速冻汤圆感官评价得分为87。     

油脂熔点对植脂鲜奶油质量性能的影响及其机理的研究

利用质构分析仪分析泡沫硬度和内部质构,油溶性色素法(油红-O)测定脂肪球部分聚结率,研究油脂种类对植脂鲜奶油质量性能的影响.结果表明,不同种类油脂制备的植脂鲜奶油的质量性能有较大差异,油脂种类对质量性能的影响与其熔点有关.随油脂熔点不同,在搅打过程中发生脂肪球部分聚结的程度也不同,从而影响最终的泡沫结构.搅打5 min后,熔点为47～53℃的部分氢化植物油HP-51的部分聚结率大于70%,天然奶油的部分聚结率小于10%,大豆油和极度氢化油不发生部分聚结,均不能形成稳定的泡沫结构.熔点为36～41℃的部分氢化植物油制备的植脂鲜奶油,部分聚结率为65%,膨胀率为4.0,获得稳定的泡沫结构.     

神奇欧洲奶油 陷入你的甜蜜漩涡

正奶奶油是从牛奶中分离出来的。1980年4月,法国颁布的法令中明确定义了奶油的成分与主要类别:每100克鲜奶油中至少含30克全脂牛奶经过脱脂后取得的脂肪。每100克"低脂奶油"中必须含有12克脂肪,低于此含量就不得称为"奶油"。在甜点中,奶油可谓是一个神奇的存在,它膨胀后就不油腻,而且同一个产品的制作过程会经历奶油的多种不同状态。一些著名的甜品店会指定专人负责"奶油"这个非常特殊的工作。     

打发奶油型脂肪模拟物制备的关键技术

该文在单因素试验的基础上,运用响应面试验优化打发奶油型脂肪模拟物的制备工艺。市售打发奶油为对照,以打发奶油型脂肪模拟物质构与市售产品硬度、稠度、内聚性、黏度的绝对差异值为响应值,研究微粒化乳清蛋白（micronized whey protein,MWP）的pH 值、添加量、黄原胶在多糖凝胶中所占百分比对产品质构参数的影响。建立中心旋转数学模型,最终确定打发奶油型脂肪模拟物的制备工艺。结果表明,打发奶油型脂肪模拟物的最佳工艺条件：pH4.3 的MWP 分散液与多糖凝胶（黄原胶占多糖凝胶80%）按微粒化蛋白分散液添加67%进行复配,采用手持打蛋器1 100 r/min 打发4 min 即得。质构仪测定结果显示,该复合型脂肪模拟物的内聚性、黏度与市售打发奶油均无显著性差异,但是硬度不足,稠度过大。     

不同植物油脂在再制奶油干酪中的应用

为研究不同种类的植物油脂替代黄油在再制奶油干酪中的应用以及对品质的影响,测定了不同种类植物油脂制作的再制奶油干酪的质构特性、乳清析出率、油脂析出率以及感官评定,并进行比较分析。结果表明,添加玉米油和葵花籽油的奶油干酪硬度与对照组干酪相接近,分别减小了13.29%和增加了3.13%,但总体差异不显著(P0.05)。添加葵花籽油的奶油干酪涂抹性与对照组相比,增加了1.27%,数值上最为接近。在黏聚力和黏着性方面,添加稻米油和椰子油的奶油干酪与对照组相比,差异较为明显(P0.05)。添加玉米油的奶油干酪乳清析出率要优于对照组干酪,而添加其他植物油脂的奶油干酪乳清析出较为严重(P0.05)。添加葵花籽油的干酪的油脂析出率最大,为6.19%,显著高于对照组干酪(1.82%);添加玉米油的奶油干酪的油脂析出率稍大于对照组,但差异不显著(P0.05)。感官分析上,添加植物油脂制作的奶油干酪总得分都低于对照组干酪,由玉米油植物清香风味和黄油的乳香味结合带来的干酪的风味接受度要高于其他植物油脂制作的干酪。综合各项指标,玉米油是替代黄油作为再制奶油干酪原料油脂较好的植物油脂选择。     

添加植物脂肪和蛋白的羊奶粉

植脂蛋白羊奶粉以新鲜羊乳和优质花生为主要原料,鲜奶经脱脂、花生经乳化后,按产品要求合理混合,后经消毒、浓缩、强化,喷雾干燥而制成的新型粉状食品。该产品既保留羊奶制品的各种优点,又有植物脂肪和蛋白质的独特风味。它不但合理地利用了动物性脂肪和蛋白质的含量,而且增添了植物蛋白质中人体所必须的各种氨基酸和脂肪酸。因而产品有味美纯香,口适感强的特点。由于工艺的特定条件,以减少产品中的动物性脂肪的含量,因而产品中胆固醇含量大大减少。该产品是老年人和不适宜用动物性脂肪的消费者的良好食品,同时也将对于花生资源有新的利用。     

再制干酪乳化过程中理化、功能特性及微观结构的变化

以再制干酪为研究对象,探究再制干酪在不同乳化温度下（80℃和85℃）,从乳化开始到结束（5～30 min）,再制干酪功能特性（融化性、油脂析出性）、质构特性、流变学特性和微观结构的变化情况。结果表明,随着乳化时间延长,产品的融化性及油脂析出性呈下降趋势,乳化过程中85℃再制干酪的油脂析出性显著高于80℃再制干酪（P<0.05）。干酪的质构特性随着乳化时间的延长整体呈增大趋势,其中85℃干酪胶着性和咀嚼性显著增大（P<0.05）,85℃再制干酪的硬度、胶着性和咀嚼性均大于80℃。两种加工温度的干酪在相同乳化程度下干酪的储能模量（G’）均大于损耗模量（G”）,0.1～10 Hz内G’和G”都随频率的升高呈上升趋势。干酪的微观结构显示,乳化5～15 min时脂肪球数量大大减少且直径减小,分布更加均匀,蛋白质基质更加光滑,干酪结构更加致密;但乳化20～30 min时干酪的微观结构呈蜂窝状,即奶油化反应过度。因此,再制干酪加工过程中乳化时间短,奶油化反应不充分;再制干酪乳化时间过长会使质地发生不良变化。再制干酪乳化反应过程中,蛋白质-蛋白质和蛋白质-脂肪的相互作用增强,产品的功能特性...     

Leaching of metribuzin metabolites and the associated contamination of a sandy Danish aquifer

As degradation products of metribuzin have received little attention as potential groundwater contaminants, we evaluated leaching of metribuzin and its primary metabolites desaminometribuzin (DA), desaminodiketometribuzin (DADK), and diketometribuzin (DK) at a sandy test site in Denmark. Soil water and groundwater were sampled monthly over a four-year period. Leaching of metribuzin and DA was negligible. DK and DADK leached from the root zone (1 meter below ground surface (mbgs)) in average concentrations considerably exceeding the EU limit value for drinking water (0.1 microg/L). Both metabolites appear to be relatively stable and persisted in soil water and groundwater several years after application. Past application of metribuzin at the site had contaminated the groundwater with both DK and DADK, which were detected in 99% and 48%, respectively, of the groundwater samples analyzed. Except for three of the groundwater samples, the DADK concentration never exceeded the EU limit value. In contrast, the annual concentration of DK exceeded 0.1 microg/L at 90% of the screens analyzed. The present findings suggest that as the degradation products of metribuzin can leach through sandy soil in high concentrations, they could potentially contaminate the groundwater. In view of this risk DK and DADK should both be included in monitoring programs and their ecotoxicological effects should be further investigated.     

A permease exhibiting a dual role for lysine and biotin uptake in Saccharomyces cerevisiae

Among Saccharomyces cerevisiae strains each defective in one of 11 amino acid permeases, a lysine permease disruptant (DK) exhibited about 2-fold reductions in maximum cell density and fermentation ability compared to the parent in a synthetic medium. These unusual properties of DK were found to result from the requirement of biotin for growth, in contrast to the parent whose growth was not dependent on external biotin. The rate of 14C-labeled biotin uptake and the intracellular free biotin content of DK were 2-2.5 fold lower than in the parent. We suggest that lysine permease in S. cerevisiae has the ability to transport both lysine and biotin.     

油酸单甘酯的合成及其在毛纺中的应用研究

采用油酸为原料,通过甲酯化和酯交换反应合成油酸单甘酯,并从各项影响因素综合考虑,确定了一条在低温下合成单甘酯的新路线,然后,以油酸单甘酯为润滑剂,复配烷基酚氧乙烷醚磷酸酯钠盐和ＯＰ－１０,得到一种新型的和毛油,并测试其在毛纺应用所需的各项性能指标,为进一步研究开发和应用提供了可靠的依据。     

Develop a Novel Method for Removing Fusel Alcohols from Rice Spirits Using Nanofiltration

ABSTRACT: The removal effect on excessive fusel alcohols from rice spirits were investigated using nanofiltration (NF) and ultrafiltration (UF). Compared to UF (GE and GH membranes), NF (DK and DL membranes) showed 10 times greater effect for fusel alcohols rejection due to molecular weight cut-off. On operating pressures, 488.95 kPa was suitable with a rejection rate attaining 44.2% for DK membrane. Only slight changes in physicochemical indices including ethanol concentration, flavor, total acidity, pH value, and soluble solid content were observed for rice-spirits after NF treatment. Moreover, rice spirits treated with the DK membrane achieved a higher score in sensory evaluation. We anticipated a practical application of the nonheat processes in rice spirits production.     

Removal of Higher Fatty Acid Esters from Taiwanese Rice-Spirits by Nanofiltration

The amounts of the three higher fatty acid esters (ethyl palmitate, ethyl oletate, and ethyl linolenate) in rice spirit were significantly decreased, over 65 % through nanofiltration (NF) with DK or DL membranes, compared to the 26–42 % reduction observed for an ultrafiltration membrane. The molecular weight cut-off was the main factor for the removal of the higher fatty acid esters. In addition, the rejection rates were increased with operating pressures; 60 psi was the most suitable pressure for the NF system. Not less than 80 % of higher fatty acid esters could be removed by the DK membrane under 60 psi pressure at 4 °C; only slight changes in physicochemical indices, including the ethanol concentration, flavor, and total acidity were observed for rice spirits following the NF treatment. On the other hand, the fusel alcohols in the treated-rice spirits were simultaneously decreased from 4.5 to 2.5 g/L (reaching the Chinese National Standard, below 3.3 g/L) and the product achieved a higher score in color via sensory evaluation. We anticipate a practical application of non-heat processes, such as NF, in Taiwanese rice spirits production due to the quality improvement achieved thereby.     

蔗糖脂肪酸酯的制备及应用研究进展

蔗糖脂肪酸酯简称蔗糖酯,是一种良好的表面活性剂,被普遍应用于食品工业。蔗糖酯的合成方法主要包括化学法和酶法,对蔗糖酯的化学合成法进行了详细介绍,概述了酰氯酯化法及酯交换法的操作步骤、优选工艺及优缺点,并与酶法进行了对比。概述了蔗糖酯的结构、理化性质、应用及工业发展现状,以期为蔗糖酯的工业化生产提供参考。     

紫胶色酸酯的制备工艺优化

对紫胶色酸分子中的羧基先进行甲酯化,然后再用醋酸酐进行乙酰化,最后制备得到了紫胶色酸酯。通过单因素及正交试验确定了紫胶色酸酯的制备工艺条件为：紫胶色酸1.0 g、对甲苯磺酸用量为紫胶色酸质量的5.0%、甲酯化时间36 h、醋酸酐用量1.0 mL、三乙胺用量2.5 mL。在此条件紫胶色酸的酯化率为81.3%,标准偏差为0.67%。通过傅里叶变换红外光谱、紫外-可见吸收光谱表征表明紫胶色酸酯中酯基及烷基的吸收峰变强;通过差示扫描量热仪及热重分析测定,表明紫胶色酸酯的熔融温度为68 ℃,温度高于198 ℃时出现热分解。紫胶色酸酯的色价为121,可溶于大多数有机溶剂,脂溶性增强,其在1 L菜籽油可溶解0.340 g,保存28 d后,油样呈红色,且澄清无沉淀,保存率达96.2%,说明其稳定性良好,对油脂类物质染色效果好,具有潜在的应用价值和前景。     

多元醇脂肪酸酯的防腐保鲜效果

本文综述了多元醇脂肪酸酯的防腐保鲜作用。重点介绍了单甘酯和蔗糖酯在防腐保鲜方面的性质、原理、有效范围和应用领域，并对其在食品中的应用前景作了展望。     

乳化剂为中小规模糖果企业带来新思维

<正>和过去相比,糖果的质量、口感、风味、营养价值、健康等指标有了质的飞跃,尤其是新概念的糖果的异军突起更引发了糖果市场的一场变革,它们以乳脂肪含量较高的硬糖、具有沙质口感的水     

Computational and experimental validation of antioxidant properties of synthesized bioactive ferulic acid derivatives

Ferulic acid, a well-known natural phenolic compound, is considerably reported for its hydroxyl and peroxyl radical scavenging activities. However, the antioxidant capacity of ferulic acid is limited by its relatively low solubility in hydrophobic media thereby preventing its application for autoxidation of fats and oils. To this end, several research efforts are being made to maximize the therapeutic benefits of ferulic acid and these efforts included but not limited to structural modification of ferulic acid to produce its derivatives. In this study, we synthesized ester and amide derivatives of ferulic acid and evaluated them for in vitro antioxidant potential as well as molecular docking properties. Data revealed that ferulic ester and amide derivatives had excellent antioxidant capacity and demonstrated strong inhibitory potential. Analysis of molecular docking indicated ferulic ester as potent inhibitor of target proteins in breast cancer as well as in oxidative stress. Taken together, the findings support potent antioxidant properties by these ferulic derivatives. Findings may become relevant where structural modification to enhance physico-chemical properties without compromising the antioxidant and/or medicinal potential are desirable.