Detection of Enocyanin in Cranberry Juice Cocktail by HPLC Anthocyanin Profile

Adulteration of cranberry juice products by enocyanin, a colorant from grapes, was detected by comparing HPLC chromatographic profiles of cranberry anthocyanins with those from enocyanin. Two peaks present in all enocyanin samples but not in cranberries were identified as delphinidin-3-glucoside and petunidin-3-glucoside. A group of unidentified pigments which eluted after the cranberry pigments was also present in enocyanin. It was possible by considering differences in the chromatograms to detect replacement of 5% or more of the expected amount of cranberry juice in cranberry juice cocktail by a solution of enocyanin. A CG-50 column was used to concentrate the pigments followed by chromatography on a polymer styrene column at pH 1.6. The method gives reliable results even on samples 18 months of age.     

Pressure Degradation Kinetics of Anthocyanin Pigment and Visual Color of Chinese Bayberry Juice

Pressure degradation kinetics of the anthocyanin pigment content and visual color (L, a, and b values) of Chinese bayberry juice were evaluated at selected pressures (400, 500, and 600 MPa) and holding times (5–10 min). Results indicated that the degradation of anthocyanin content after high pressure processing and during storage followed the first-order models, as well as the change of a and L × a × b values after high pressure processing. The activation energies (V_a) for anthocyanin content, a and L × a × b changes after high pressure processing were –19.845, –14.915, and –12.908 cm³ mol^–1, respectively. V_a analysis indicated that anthocyanin was more pressure sensitive than visual color parameters.     

Color and Pigment Stability of Red Radish and Red-Fleshed Potato Anthocyanins in Juice Model Systems

Color and pigment stability of model juices (pH 3.5) were evaluated during 65 wk of storage at 2°C and 25°C in the dark. Two acylated pelargonidin-based anthocyanins, red-fleshed potatoes (Solanum tuberosum) and red radishes (Raphanus sativus), and 2 extraction methods, C-18 resin and juice processing, were used and compared to FD&C Red #40. Color (CIELch) and pigment degradation depended on storage temperature, anthocyanin structure and extraction method, with chemically extracted radish anthocyanins showing the best overall stability. At room temperature (25°C), higher stability was obtained with C-18 purified radish anthocyanins (22 wk half-life) and lowest with potatojuice concentrate (10 wk half-life). Refrigeration increased the half-life of pigments to over a year.     

Major Volatile Components of the Juice of American Cranberry

SUMMARY– Volatiles from the juice of the American cranberry ( Vaccinium macrocarpon Ait.) were investigated using gas chromatography, mass spectrometry and infrared spectrophotometry. Forty-two compounds comprising over 95% of the aroma complex were identified. These consist of 14 aromatic compounds, 7 terpenes, 9 aliphatic alcohols, 6 aliphatic aldehydes and 6 other compounds including the 2 acids, benzoic and 2-methylbutyric. The aromatic compounds (benzaldehyde, benzyl and benzoate esters) and the terpenes appear to be the major contributors to the aroma of cranberry juice. The remaining 5% of the aroma complex contains over 200 components. Although these compounds occur in very small concentrations, they appear to be important in the overall aroma.     

提汁过程蔗汁铁和酚类色素含量对色值影响的研究

测定研究甘蔗提汁过程各座次压榨机出汁以及典型蔗汁中铁、酚类色素含量和色值,分析蔗汁增色因素的变化规律及致因。结果表明,提汁过程榨出汁色值与蔗汁中铁和酚类色素含量显著相关。不同厂同列榨机出汁含铁量随榨机座次增加,前三座榨机蔗汁酚类色素含量递增;两家糖厂初压汁含铁量分别为54.0和220.1μg/mL·○Bx,初压汁酚类色素含量分别为3021和1791mg/kg·○Bx;前五座榨机蔗汁色值随榨机座次明显升高。预灰对铁的去除效果不明显,对酚类色素的去除较明显,预灰后蔗汁色值有所降低。     

Stability of Color in'Concord'Grape Juice and Expression of Color

The experiment was designed to determine the influence of chemical additives, ascorbic acid and storage time on‘Concord’grape juice color. Adding low concentrations of CaSO₄ and SnCl₂ increased retention of color as measured by Color Difference Meter (CDM) L, a and b values and by color expression a/L, aL and ab/L. Rapid color changes occurred during storage after 3 months except in juice with added CaSO₄ and SnCl₂. Ascorbic acid fortification accelerated color loss in some of the treatments. The highest correlations between sensory quality and instrumental color were those between sensory ratings for browning, flavor and hue and CDM L values, anthocyanins and absorbancíes at 535/430 nm.     

Red Raspberry Juice and Wine: Effect of Processing and Storage on Anthocyanin Pigment Composition, Color and Appearance

Red raspberry wine was made from thawed fruit by fermentation of pulp, depectínized juice, and pasteurized depectinized juice. The influences of fining and storage were also investigated. The anthocyanin pigment profiles of the samples were determined by high performance liquid chromatography (HPLC), and additional color indices by spectrophotometry and Hunter colorimetry. Anthocyanin pigments degraded mainly during fermentation, with total losses after storage of at least 50%. Cyanidin-3-glucoside was the most unstable anthocyanin, disappearing completely during fermentation; cyanidin-3-sopho-roside (the major anthocyanin) was the most stable pigment. Pasteurized, depectinized wine that had undergone fining, had the most stable color and best appearance after storage.     

Favorable Glycemic Response of Type 2 Diabetics to Low‐Calorie Cranberry Juice

ABSTRACT: Fruit and vegetable intake is typically low for type 2 diabetics, possibly due to a perceived adverse effect on glycemic control. Cranberry juice (CBJ) may represent an attractive means for increasing fruit intake and simultaneously affording positive health benefits. This single cross‐over design compared metabolic responses of type 2 diabetics (n= 12) to unsweetened low‐calorie CBJ (LCCBJ; 19 Cal/240 mL), carbohydrate sweetened normal calorie CBJ (NCCBJ; 120 Cal/240 mL), isocaloric low‐calorie sugar water control (LCC), and isocaloric normal calorie sugar water control (NCC) interventions. CBJ flavonols and anthocyanins, and proanthocyanidins were quantified with HPLC, LC‐MS, and MALDI‐TOF that includes an original characterization of several large oligomeric proanthocyanidins. Blood glucose peaked 30 min postingestion after NCCBJ and NCC at 13.3 ± 0.5 and 12.8 ± 0.9 (mmol/L), and these responses were significantly greater than the LCCBJ and LCC peaks of 8.1 ± 0.5 and 8.7 ± 0.5, respectively. Differences in glycemic response remained significant 60 min, but not 120 min postingestion. Plasma insulin values 60 min postingestion for NCCBJ and NCC interventions were 140 ± 19 and 151 ± 18 (pmol/L), respectively, and significantly greater than the LCCBJ and LCC values of 56 ± 10 and 54 ± 10; differences were not significant 120 min postingestion. Metabolic responses within the 2 high and 2 low‐calorie beverages were virtually identical; however, exposure to potentially beneficial nutrients was greater with CBJ. Relative to conventionally sweetened preparation, LCCBJ provides a favorable metabolic response and should be useful for promoting increased fruit consumption among type 2 diabetics or others wishing to limit carbohydrate intake.     

Color Characteristics and Stability of Nonbleeding Cocktail Cherries Dyed with Carotenoid Pigments

Experimental cocktail cherries dyed with carotenoids and commercial cherries were compared by spectrocolorimetry to determine color characteristics and stability. Cherries dyed with canthaxanthin, apo-carotenal and oleoresin paprika were more tomato- or orange-red than cherries dved with Red No. 40. Red No. 3. or carmine. No color bleeding was observed with carbtenoid-dyed cherries. The color of cherries dyed with canthaxanthin was stable for 1 year at 4°C. Color stability was not as good in cherries dyed with apo-carotenal but could be improved greatly by addition of ethylenediaminetetraacetic acid (EDTA) and ascorbic acid to preservative solutions in which cherries were stored.     

Optimization of Carrot Juice Color and Cloud Stability

Investigations were conducted on the effects of heating, acidification, and enzyme treatment on carrot juice color and cloud stability. Heating whole carrots to 93°C prior to milling and pressing improved juice color, but reduced juice yield compared to heating milled carrots to 93°C. Juice color was improved by acidification of milled carrots to pH 5 or 4 with citric acid prior to pressing. Juice from carrots heated before milling clarified quickly if not acidified before pressing. Acidification after juice extraction did not stabilize cloud. A commercial pectinase/hemicellulase preparation improved juice color, but not juice yield. Only 20% of potential β-carotene was extracted from carrots during pressing, and β-carotene was extracted to a greater extent than α-carotene.     

使用ICC特性文件分色应注意的问题

随着色彩管理技术的完善,印前工作人员可以选择在图像输入、图像处理甚至在图像输出时进行分色,其中最重要的一个手段便是使用输出设备ICC特性文件进行分色。由于ICC特性文件精确地描述了设备的色域,同时它又是采用与设备无关的色彩模式定义,更便于不同用户之间进行色彩交流,因此在未来必然会有越来越多的用户采用ICC特性文件分色!1如何从ICC特性文件中获取信息?使用ICC特性文件分色,一方面可以将固定的CMYK设置保存成ICC特性文件,以便以后调用;另一方面也可以使用分光光度计、IT8标准原稿及ICC特性文件制作软件(如:海德堡公司的…     

Pressure-Temperature Degradation of Green Color in Broccoli Juice

Broccoli juice greenness was marginally affected by pressure at low temperatures (30-40°C). At 800 MPa and slightly higher temperatures (50-60°C), first-order degradation of green color was observed. The greenness loss was suggested to be due to chlorophyll-pheophytin conversion with no further pheophytin degradation. Pheophytin degraded further when higher temperatures (≥70°C) were combined with elevated (or atmospheric) pressures (0.1–850 MPa). At these conditions greenness loss could be modeled by two consecutive first-order degradation steps. Temperature dependency of the rate constants for both degradation steps could be described by the Arrhenius equation with activation energies increasing with pressure. However, their pressure dependency could not satisfactorily be described by the Eyring equation.     

Color and Cloud Stabilization in Cloudy Apple Juice by Steam Heating During Crushing

Steam heating of crushed apples in the range 65–70°C for 15 to 20 sec controlled enzymatic browning and effectively stabilized cloudiness. Particles in fresh pressed cloudy apple juice were 3 mm but after 15 min of centrifugation at 4200 × g almost all particles had a diameter of 1 mm, and cloud could be considered stable. Median and modal diameters were virtually coincident, suggesting a symmetrical distribution. The specific surface area of the cloudy juice particles was 50 mm²/g and no agglomeration occurred.     

Detection of Phenylalanine Ammonia-Lyase in the Skin of Blueberry and Cranberry Fruits

Phenylalanine ammonia-lyase (PAL) was extracted from the skin of individual berries and assayed spectrophotometrically under conditions minimizing interference from co-extracted constituents. Analyses for total anthocyanin (TAcy), soluble solids (SS), and titratable acidity (A) were performed on the same berries. In blueberry fruits, PAL activity was present at all maturity levels examined. Cultivar differences in anthocyanin accumulation were unrelated to PAL activity. PAL activity in cranberry fruit was unrelated to harvest date, cultivar differences in anthocyanin accumulation, or values of TAcy and SS/A in individual berries. Activity was retained in cranberries during 4 wk of refrigerated storage.     

红色猕猴桃果汁加工中色素的浸提及其理化特性研究

为研制红色猕猴桃果汁,对红肉猕猴桃果汁加工中色素的浸提及理化特性进行了研究。结果表明,红肉猕猴桃中的红色素属于花色素苷类,适度热浸提有利于色素的浸出,果胶酶、纤维素酶等处理也可在一定程度上提高色素的浸出率;但由于对出汁率的提高幅度更大,造成果汁中色素浓度的降低。红肉猕猴桃果汁色素对酸碱较为敏感,在pH4.0以下时呈鲜艳的红色,在可见光区域内其最大吸收波长在516nm左右,但吸光度随着pH值的升高而大幅下降。长时间加热处理可造成红肉猕猴桃果汁色素的降解,低温避光有利于色素的保持。     

对箱板纸中颜料染色及其参数控制的探讨

研究发现纸张生产过程中颜料可以代替染料来进行染色,颜料具有低用量、好的遮盖率、良好的稳定性和低成本等优点。该文介绍了染料染色的缺点和颜料染色目前的研究状况,并探讨了植物纤维打浆度、AKD、接触时间和pH对颜料染色的影响。通过实验,打浆度可以对染色结果造成一定的影响。其色相指标L*、a*、b*值都有一定的变化规律。加入红色、黄色和橘黄色颜料后,纸张分别朝着偏红、偏黄和偏橘黄色方向发展。最佳打浆度都为44°SR。AKD增加颜料的留着。红色和黄色颜料的最佳接触时间为6min,而橘黄色颜料的最佳接触时间为4min。红色颜料最佳pH为5.5,黄色、橘黄色颜料最佳pH都为6。因此三者都适合在酸性条件下进行染色。     

CIELAB色空间原理在血红蛋白色素呈色效果评价中的应用

目的:使用色差计测量并评价应用猪血亚硝基血红蛋白色素的肉制品颜色,以代替肉眼作出客观定量的判定。方法:对使用本实验室工作人员制备色素的肉制品,用色差计测量不同保存时间的样品表面和内部的CIE1976(L*a*b*)色空间的CIELAB值,并计算色差。结果:肉制品的表面颜色会随着保存时间的增加而变差,反映在a*值由8降到6左右,b*值由13升到15左右;而肉制品的内部颜色则保持粉红色,a*值基本保持不变,而b*值降到10左右;同时,用冷冻干燥保存的色素制作的肉制品颜色优于其它保存方法,反映在较高的a*值、b*值和较低的L*值。结论:使用色差计测定CIE1976色空间及色差值,可反映肉制品颜色的差异及变化趋势;与感官判断的结论一致,并获得定量的结果。     

天然色素高粱红开发应用

高粱红色素是从高粱壳中提取一种天然色素,无毒安全、无特殊气味,在食品、化妆品、医药等业有着广泛用途;该文综述高粱红性质、制取工艺及我国开发应用情况。     

中国甜橙果汁色泽的定量评价

色泽是甜橙及其橙汁的一项重要的感官指标,直接影响到消费者的选择。本研究采用国际公认的色差法定量测定我国主要甜橙产区目前栽培的具有代表性的94 个甜橙样品果汁的色泽参数,建立了我国橙汁色泽特征数据库。统计结果表明：我国的甜橙果汁的色泽普遍高于36,优于美国和巴西的同类品种;不同品种、不同产区甜橙果汁色泽差异显著,但不同年度采收的甜橙果汁色泽差异不显著(P ＞ 0.05)。     

影响草毒果汁红色素变化的因子研究

通过试验对草莓果汁在加工及继后贮藏过程中,影响红色素变化的因子进行了研究。结果表明,迅速加热果实温度到60℃,有利于提高果汁中红色素含量;向果汁中分别加入0.1%~0.4%的抗坏血酸、酒石酸和柠檬酸对果汁具有明显的增色作用;而加入1.0%~15.0%的葡萄糖和蔗糖对果汁颜色没有影响;调整果汁pH值到4.0以下有助于保持果汁的固有颜色;采用低温避光贮存果汁可延缓草莓果汁红色素的降解。