The Impact of Iron on the Bleaching Efficacy of Hydrogen Peroxide in Liquid Whey Systems

Whey is a value‐added product that is utilized in many food and beverage applications for its nutritional and functional properties. Whey and whey products are generally utilized in dried ingredient applications. One of the primary sources of whey is from colored Cheddar cheese manufacture that contains the pigment annatto resulting in a characteristic yellow colored Cheddar cheese. The colorant is also present in the liquid cheese whey and must be bleached so that it can be used in ingredient applications without imparting a color. Hydrogen peroxide and benzoyl peroxide are 2 commercially approved chemical bleaching agents for liquid whey. Concerns regarding bleaching efficacy, off‐flavor development, and functionality changes have been previously reported for whey bleached with hydrogen peroxide and benzoyl peroxide. It is very important for the dairy industry to understand how bleaching can impact flavor and functionality of dried ingredients. Currently, the precise mechanisms of off‐flavor development and functionality changes are not entirely understood. Iron reactions in a bleached liquid whey system may play a key role. Reactions between iron and hydrogen peroxide have been widely studied since the reaction between these 2 relatively stable species can cause great destruction in biological and chemical systems. The actual mechanism of the reaction of iron with hydrogen peroxide has been a controversy in the chemistry and biological community. The precise mechanism for a given reaction can vary greatly based upon the concentration of reactants, temperature, pH, and addition of biological material. In this review, some hypotheses for the mechanisms of iron reactions that may occur in fluid whey that may impact bleaching efficacy, off‐flavor development, and changes in functionality are presented. Practical Application: Cheese whey is bleached to remove residual carotenoid cheese colorant. Concerns regarding bleaching efficacy, off‐flavor development, and functionality changes have been reported for whey proteins bleached with hydrogen peroxide and benzoyl peroxide. It is very important for the dairy industry to understand how whey bleaching can impact flavor and functionality of dried ingredients. Proposed mechanisms of off‐flavor development and functionality changes are discussed in this hypothesis paper.     

一种新型漂白剂在箱纸板微漂中的应用

介绍了一种新型漂白剂在废纸浆生产箱纸板轻微漂白中的应用。通过实验室进行工艺优化,并进行中试生产。结果表明,使用该漂白剂在中性条件下处理废纸浆料,成纸亮度和L*值均得到提高,在漂白剂用量2.5 kg/t浆时,成纸L*值提高2.53个单位,且水处理负荷及生产成本增加不多。     

Aroma-active Components of Liquid Cheddar Whey

ABSTRACT: Fresh Cheddar cheese whey batches from 2 processing plants and 4 starter culture rotations were extracted with diethyl ether followed by isolation of volatiles by high-vacuum distillation. Odorants were evaluated by gas chromatography-olfactometry (GCO) and aroma extract dilution analysis (AEDA). 2,3-butanedione (buttery), hexanal (green), 2-acetyl-1-pyrroline (popcorn), methional (potato), ( E,E )-2,4-decadienal (frying oil) and ( E,E )-2,4-nonadienal (frying oil) were potent neutral/basic aroma-active compounds identified in all whey samples. Odor intensities of hexanal, ( E,E )-2,4-nonadienal, 2,3-butanedione, and ( E,E )-2,4-decadienal were variable. Short-chain volatile acids were predominant in acidic fractions and their intensities differed among the whey samples. GCO findings agreed with quantitation results. Liquid whey aroma components are influenced by starter culture rotation.     

以臭氧漂白为基础的TCF漂白工艺

以硫酸盐竹浆为原料,研究了以臭氧漂白为基础的TCF漂白,并研究了TCF漂白各工段物理性能的变化,其漂白后得到纸张抗张指数为61.43N·m/g,撕裂指数为10.47mN·m2/g,耐破指数为5.01kPa·m2/g,耐折度为53次。最后TCF漂白与传统的CEH漂白对比,结果表明TCF漂白后纸浆具有较好的白度稳定性和较高的强度性能,充分显示了TCF漂白的优越性。     

YDM—S煮练剂及YDM—B型氧漂助剂在大麻粗纱煮漂工艺中的应用

采用YDM-S煮练剂及YDM-B型氧漂助剂对大麻粗纱进行煮漂试验,通过正交优化设计,得出最优工艺。并测定了YDM-S煮练溶液的COD,结果表明其对环境污染较小。     

脱盐乳清粉营养素的波动

为研究脱盐乳清粉营养素成分含量,试验分析了蛋白质、脂肪、乳糖、维生素、矿物质及其他营养素的含量及波动情况。结果显示:不同批次脱盐乳清粉营养素含量相对稳定,蛋白质、脂肪、乳糖营养素含量很稳定,相对标准偏差大于5%,维生素E相对标准偏差大于40%。维生素B2、维生素B6、维生素B12的含量相对标准偏差大于15%;矿物质元素中镁、钙元素的相对标准偏差大于40%;钾、碘、硒元素相对标准偏差大于15%;功能性营养成分中1, 3-二油酸-2-棕榈酸甘油三酯(OPO)含量波动很大,相对标准偏差为76.81%。α-亚麻酸、胆碱、肌醇、牛磺酸酸低聚果糖含量波动较大,相对标准偏差大于15%。     

漂白温度及时间对烧碱-AQ法麦草浆H2O2漂白的影响

探讨了漂白温度及时间对麦草化学浆 Ｈ２ Ｏ２ 漂白的影响。结果表明： 在５０ ～９０ ℃之间, 漂后浆白度随漂白温度的提高而提高, 且出现漂白停滞现象的时间逐渐提前, 适当提高漂白温度或延长漂白时间不会对漂后浆的物理性质带来不利影响。     

离子强度和温度对乳清蛋白凝胶的影响

本实验主要研究凝胶温度和CaCl2 浓度对乳清蛋白冷凝胶的影响。结果表明：较低的凝胶温度和增加CaCl2浓度能够致使乳清蛋白形成清亮的凝胶;在0、10、20℃凝胶温度条件下,增加CaCl2 浓度使得凝胶硬度有所增加;乳清蛋白凝胶的持水性在凝胶温度为0、10℃,CaCl2 浓度为20、40mmol/L 时受到影响;除了0℃ 和20mmol/LCaCl2 条件下,低温能够使乳清蛋白形成较高的凝胶硬度和持水性。凝胶温度和CaCl2 浓度是影响乳清蛋白冷凝胶的关键因素。     

棉织物氧漂稳定剂和螯合剂的应用

分析绵织物氧漂体系中稳定剂和螯合剂的作用，测试不同配伍对双氧水分解率的影响，定性地说明各种助剂的使用性能，以优化选择合理，安全的漂白工艺，防止破洞和纤维脆损的发生。     

无氯漂白剂的种类与工艺流程及选择准则

综述了无氯漂白剂的种类 ,全无氯漂白的工艺流程及其选择的准则     

尿素在杨木APMP漂白过程中的影响

该实验探讨了在杨木碱性过氧化氢机械浆（APMP）漂白中加入尿素对纸浆ISO白度和打浆性能的影响以及在尿素存在的情况下过氧化氢（H2O2）漂白的最佳工艺。结果表明,加入尿素能提高纸浆白度,并且对纸浆的物理强度没有明显的影响,同时能降低生产成本和减轻后续处理的负担。     

含氯漂白的危害与全无氯高白度漂白新技术的发展

本文介绍了含氯漂白的危害及其预防措施，并对无氯漂白（ＥＣＦ，ＴＣＦ）新技术的发展作了介绍和预测。     

乳清多肽的制备及乳清多肽酒的研制

采用蛋白酶水解乳清粉,并对乳清多肽进行酵母菌发酵,并对发酵所得乳清酒进行风味调配。乳清粉最佳的水解条件为:[E/S]=1%、T=60℃、pH=9.0、时间=120min,水解度为DH=21.22%。乳清多肽酒的最优发酵条件:接种量为5%、起始pH为7.5、温度为22℃、发酵60h,酒度可达到3.9。多肽乳清酒的最佳基本调配是:酸量(苹果酸:柠檬酸=1:1)为0.1%、蔗糖为7%、环状糊精为0.6%。     

The effect of starter culture and annatto on the flavor and functionality of whey protein concentrate

The flavor of whey protein can carry over into ingredient applications and negatively influence consumer acceptance. Understanding sources of flavors in whey protein is crucial to minimize flavor. The objective of this study was to evaluate the effect of annatto color and starter culture on the flavor and functionality of whey protein concentrate (WPC). Cheddar cheese whey with and without annatto (15 mL of annatto/454 kg of milk, annatto with 3% wt/vol norbixin content) was manufactured using a mesophilic lactic starter culture or by addition of lactic acid and rennet (rennet set). Pasteurized fat-separated whey was then ultrafiltered and spray dried into WPC. The experiment was replicated 4 times. Flavor of liquid wheys and WPC were evaluated by sensory and instrumental volatile analyses. In addition to flavor evaluations on WPC, color analysis (Hunter Lab and norbixin extraction) and functionality tests (solubility and heat stability) also were performed. Both main effects (annatto, starter) and interactions were investigated. No differences in sensory properties or functionality were observed among WPC. Lipid oxidation compounds were higher in WPC manufactured from whey with starter culture compared with WPC from rennet-set whey. The WPC with annatto had higher concentrations of p-xylene, diacetyl, pentanal, and decanal compared with WPC without annatto. Interactions were observed between starter and annatto for hexanal, suggesting that annatto may have an antioxidant effect when present in whey made with starter culture. Results suggest that annatto has a no effect on whey protein flavor, but that the starter culture has a large influence on the oxidative stability of whey.     

乳清的营养价值及乳清饮料的研究现状

乳清是工业生产干酪及干酪素的副产品,乳清的营养成分相当于除去酪蛋白的脱脂乳,约占牛乳营养成分的５５％,乳固体达６％－７％,其中粗蛋白１％,粗脂肪０．３％－０．４％,乳糖３％－５％。国外多利用乳甭生产乳清粉和乳清蛋白浓缩物等。乳清饮料有３种形式：１）乳清与果汁直接调配;２）制做无蛋白澄清饮料;３）发酵型乳清饮料。所以,乳清的合理开发利用十分重要。     

氯系新型漂白剂在纯亚麻织物上的应用初探

介绍了国内一种新型氯系漂白剂.它以次氯酸钠为原料.利用螯合技术定向改变分子结构,使产品具有对纤维损伤小,白度好,质量稳定.使用简便等特点.经佳木斯亚麻有限公司推广应用,取得明显效果,有推广价值.     

改善KP浆二氧化氯漂白效率的研究第三部分:桉木硫酸盐浆高温二氧化氯漂白

在D0段采用高温(95℃)二氧化氯漂白(总漂序为D0EPD1)比在低温下二氧化氯流程(D0EPD1D2)具有更高的漂白效率.对卡伯值10.2的经氧脱木素后的硫酸盐阔叶木纸浆来说,在相同的终漂白度要求(88%ISO)时,前者可以节约20%以上的二氧化氯用量.     

棉低温练漂的研发与应用

研究成功了低温练漂剂QR-2010、QR-2011、QR-2020。以不同比例进行棉的双氧水煮练、漂白同浴练漂,可以使练漂温度降低到80℃以下,或使冷轧堆练漂的堆置时间缩短到4-6h。阐述了该低温练漂的基本原理、大生产应用工艺及其应用效果。该工艺具有节能显著、排污减少、半制品质量优异、减少绉印和略降低加工成本的特点。     

The Effect of Feed Solids Concentration and Inlet Temperature on the Flavor of Spray Dried Whey Protein Concentrate

Previous research has demonstrated that unit operations in whey protein manufacture promote off‐flavor production in whey protein. The objective of this study was to determine the effects of feed solids concentration in liquid retentate and spray drier inlet temperature on the flavor of dried whey protein concentrate (WPC). Cheddar cheese whey was manufactured, fat‐separated, pasteurized, bleached (250 ppm hydrogen peroxide), and ultrafiltered (UF) to obtain WPC80 retentate (25% solids, wt/wt). The liquid retentate was then diluted with deionized water to the following solids concentrations: 25%, 18%, and 10%. Each of the treatments was then spray dried at the following temperatures: 180 °C, 200 °C, and 220 °C. The experiment was replicated 3 times. Flavor of the WPC80 was evaluated by sensory and instrumental analyses. Particle size and surface free fat were also analyzed. Both main effects (solids concentration and inlet temperature) and interactions were investigated. WPC80 spray dried at 10% feed solids concentration had increased surface free fat, increased intensities of overall aroma, cabbage and cardboard flavors and increased concentrations of pentanal, hexanal, heptanal, decanal, (E)2‐decenal, DMTS, DMDS, and 2,4‐decadienal (P < 0.05) compared to WPC80 spray dried at 25% feed solids. Product spray dried at lower inlet temperature also had increased surface free fat and increased intensity of cardboard flavor and increased concentrations of pentanal, (Z)4‐heptenal, nonanal, decanal, 2,4‐nonadienal, 2,4‐decadienal, and 2‐ and 3‐methyl butanal (P < 0.05) compared to product spray dried at higher inlet temperature. Particle size was higher for powders from increased feed solids concentration and increased inlet temperature (P < 0.05). An increase in feed solids concentration in the liquid retentate and inlet temperature within the parameters evaluated decreased off‐flavor intensity in the resulting WPC80.