Cured colour development during sausage processing

A study of colour evolution in dry cured sausage manufactured using industrial technology was made. Parameters which define changes related to nitrosation during curing were determined. The main changes in the colour characteristics of Spanish sausage took place during the fermentation stage. pH, nitrate and nitrite concentration, pigment nitrosation index, pigment discoloration index, a(?), b(?), C(?) and H(?) values decreased during this stage. However, the nitrosation of the myoglobin pigment continued during the whole curing process. The percent conversion of total pigments to the cured nitric oxide heme pigment form was about 70% in the minced mix, and it increased gradually to about 90% in the final product. During fermentation nitrites reacted with myoglobin (Mb) to form nitrosomyoglobin (NOMb) and metmyoglobin (MetMb), which reduced to NOMb during the drying process.     

Hierarchy in Food Colorants Absorbtion on Selected Crystalline Powders

Three food colorants, namely FD&C Blue No. 1, Red No. 40, and Yellow No. 5, were absorbed on glass beads and reabsorbed on powdered citric acid, malic acid, sucrose, and sodium chloride. At water activities below 0.58, the migration pattern of the pigment from the original host to a fresh carrier, of the same or different chemical species, served as a measure of the relative surface affinity between the pigment and the host powder. The pigments showed maximum affinity to citric acid and to a somewhat lesser extent to malic acid and sucrose. Their affinity to sodium chloride was the least intensive. Small particle size increased the interparticle affinity of dry powders. At water activities higher than a critical water-activity region (between 0.33–0.58), all pigment migration practically came to a halt, probably as a result of stabilization of the pigment-carrier agglomerates by liquid bridges.     

辣椒色素的分离纯化与光学性质的研究

探索了吸附树脂柱色谱法脱除辣椒色素中辣椒素的新方法。该方法可将辣椒色素与辣椒素分离并对红、黄色素组分实现初步分离，辣椒色素产品色价高达105。用硅胶柱色谱法可分离辣椒色素精细组分。对所得色素精细组分进行了紫外-可见光谱分析表明：红色素组分的最大吸收波长为470nm，黄色素组分的最大吸收波长为450nm；各辣椒色素组分的光稳定性也存在较大的差异，为辣椒色素各精细组分充分而有效的利用提供了理论依据。     

The effect of Saccharomyces cerevisiae and Saccharomyces bayanus yeast on colour properties and pigment profiles of a Cabernet Sauvignon red wine

Red wine was made from the same batch of Cabernet Sauvignon grapes but with two different yeasts, Saccharomyces cerevisiae (SC) or Saccharomyces bayanus (SB). The colour properties and pigment profiles of SC and SB wines were compared at 8 days and 387 days after yeast inoculation. Grape anthocyanin concentration was found to be lower in SB wines than in SC wines at day 8 and 387, but SB wine exhibited greater wine colour density, a* and b*. The anthocyanin concentration did not correlate with wine colour density. The levels of pigmented polymers and SO₂ non-bleachable pigments were found to be higher in SB wine at day 387, demonstrating that the formation of stable pyranoanthocyanins and pigmented polymers was enhanced by SB yeast. Electrospray mass spectrometry was used for the compositional analysis of pyranoanthocyanins, and direct and ethyl-bridged linked condensation dimers of malvidin 3- O -glucoside (MvG) with flavanols (catechin or epicatechin). The data demonstrated that the formation of acetaldehyde-mediated pigments was enhanced by the use of the SB yeast. The compositional analysis suggested that the differences in colour properties and pigment profiles of SC and SB wines were largely due to the greater production of acetaldehyde-mediated pigments by the use of SB yeast.     

Colour evaluation of freeze-dried roselle extract as a natural food colorant in a model system of a drink

The roselle extract, using acidified water-95% ethanol (1:1) as a solvent, was subjected to freeze-drying. Maltodextrin and trehalose, 2 and 3 g/100 ml extract, were used as stabilisers. Addition of the stabiliser retarded anthocyanin degradation. Colour changes of the freeze-dried roselle powder during storage were monitored using the CIELAB system. It was found that pigment concentration markedly changed with a minor change in lightness and hue. However, the changes in chroma mainly came from anthocyanin degradation. The freeze-dried roselle powder with maltodextrin (3 g/100 ml) proved to have superior colour stability. A model system of a drink adding this powder was carried out and the colour evaluation was compared to drinks containing commercial colorants: SAN RED RC^® and carmoesin. During a 12-week storage period at 30 °C, the change in hue of all three groups was within the same shade suggesting any change in pigment concentration had insignificant effect on hue shift. By contrast, the degradation of pigments highly correlated to changes in lightness and chroma. Even though a drink with roselle anthocyanin powder was the least stable in colour, the overall appearance of the drink was rated close to ‘like slightly’ throughout 56 days.     

Comparative study of the effect of the maturation process of the olive fruit on the chlorophyll and carotenoid fractions of drupes and virgin oils from Arbequina and Farga cultivars

Two varieties of olive fruit (Arbequina and Farga) have been characterized by their contents and types of chlorophyll and carotenoid pigments during the olive ripening. Independently of the initial content, the pigment concentrations decreased with fruit maturity. Chlorophyllides a and b, esterified xanthophylls and α-carotene were only detected in Arbequina fruits. Moreover, the synthesis of esterified xanthophylls, when the skin fruit colour changed from green to turning-colour only, was observed in this variety. The pigments transferred from fruit to the oil were also studied. All the pigments that were found in the fruit were transferred to the oils, in addition to derivative pigments associated with acidic medium in the oil extraction process. The destruction of the chlorophyll fraction was greater than of the yellow pigments during the olive oil extraction process.     

Chlorophyll, colour and pH changes in H.T.S.T. processed green pea puree

Summary. Pea puree of pH 6.95 and pH 8.45 was heat processed in thermal death-time tubes at temperatures between 115.6°C and 148.9°C to a process value of F₀= 6.0. Chlorophyll pigments, Hunterlab colour indices and pH were determined before and after high temperature-short time (H.T.S.T.) processing and during storage for 18 months at 20°C, 2.8°C, and −23.3°C.
Highly significant correlations were found between per cent conversion of chlorophylls to pheophytins and objective colour indices derived from tristimulus measurements on stored pea puree. the degree of chlorophyll conversion, and hence puree colour, were both markedly affected by process temperature, product pH, storage time and storage temperature, but long-term storage stability was achieved only by combinations of two or more variables.
Changes in pH of processed and stored puree were directly related to changes in pigments and colour, and it appears that pH control during processing and storage offers the most likely means of colour and pigment retention in heat processed chlorophyll-containing foods.     

Effect of dietary iron on the colour and pigment concentration of veal

The colour and pigment concentration of muscles from veal calves whose dietary iron intake was 10, 40 and 100 μg/g milk powder were measured. The colour was related to pigment content which was related to the dietary iron concentration and anatomical location of the muscle. The myoglobin content of veal from calves receiving 100 μg Fe/g was twice that of veal from calves receiving 40 μg Fe/g but there was no difference in myoglobin content between 10 and 40 μg Fe/g. Calves receiving 10 μg Fe/g contained less haemoglobin in their blood. The lightness of cooked veal was found to be linear with the lightness of the raw, with little change in saturation but a large change in hue.     

Stability Modeling of Red Pigments Produced by Monascus purpureus in Submerged Cultivations with Sugarcane Bagasse

Monascus purpureus red pigments were produced in submerged cultivations employing sugarcane bagasse (SB) as carbon source in combination with various nitrogen sources. Peptone and soy protein isolate (SPI) as nitrogen sources generated the best pigment yields. NH₄Cl has not supported high pigment production. Red pigments produced using SB and SPI as growth substrates were submitted to temperature and pH stability analysis. Data from thermal pigment degradation were fitted to five mathematical models, and a first-order equation was accepted as the best one to describe color decay. Red pigments showed high stability at low temperatures (30–60 °C) and at near-neutrality pH values (6.0–8.0) when compared to that at high temperatures (above 60 °C) and at acidic pH values (4.0–5.0). Monascus pigments produced using a low-cost agroindustrial waste (SB) as carbon source could be utilized as colorants in foods and foodstuffs manufactured under mild process conditions.     

谷物色素研究进展

谷物中的色素大部分属于类胡萝卜素、花色素,例如小米、玉米黄色素中叶黄素、玉米黄素属类胡萝卜素,黑米中黑米色素、花色小麦中的色素和高粱中的高梁红色素属花青素类。介绍了玉米、小麦、黑米、高粱和小米等谷物中色素的性质、提取和应用进展。     

颜料和染料在高级文化用纸中的调色研究

在高级文化用纸的生产中,纸张的色相是成品纸的一项重要品质.本实验分别使用直接染料/荧光增白剂、颜料/荧光增白剂组合对白纸进行调色.实验证明,在白纸调色过程中两种组合均可达到效果.在高白度（CIE=155）的文化用纸生产中,直接染料/荧光增白剂组合的用量为直接紫0.12kg/t,直接蓝0.08kg/t,荧光增白剂11kg/t;颜料/荧光增白剂组合的用量为颜料紫0.2kg/t,颜料蓝0.03kg/t,荧光增白剂7.5kg/t.实验发现使用颜料/荧光增白剂组合可以使纸张达到更明亮的色相,并可以显著降低荧光增白剂用量,从而降低生产成本.     

Production of Red Water-Soluble Monascus Pigments

Water-soluble and thermal, as well as photo-stable, red Monascus pigments, were prepared by reacting the extracted pigment with aminoacetic acid and aminobenzoic acid. These modified pigments were compared to those using glutamic acid and gelatin as the modifying agents, showing that the colors and stabilities of these modified pigments were similar. Red pigments extracted from the mycelia could be dissolved in ethanol, propylene glycol, or in gelatin solution and freeze-dried. These red pigment concentrates or freeze-dried pigments could also be used as food colorants.     

Effect of ascorbic acid addition to peppers on paprika quality

The use of ascorbic acid addition to foods to protect pigments from oxidation has been widely applied. Control or ascorbic acid-added paprika peppers were processed in a similar way as for paprika manufacture. During the process, lipoxygenase activity, total colour, red/yellow pigment ratio and ascorbic acid levels were measured. In general, an increase of total colour and red pigments was observed in ascorbic acid-treated samples. The lipoxygenase activity was depressed in ascorbic acid-treated fruits on the first day of processing. However, the activity was increased again, at second day, when the ascorbic acid was oxidised, showing a close relationship between enzyme activity and the antioxidant. After the process, ascorbic acid was also added to half of the paprika from control peppers and its quality and stability of the pigments against light or heat was compared to the paprika from ascorbic acid-added peppers. At the end of the treatment a better quality was observed in paprika obtained from the ascorbic acid-added peppers. ©1997 SCI     

各国(地区)食用色素的使用现况与比对分析

食用色素分为焦油色素、天然色素和其他3类。按化学结构,食用焦油色素分为偶氮类、三芳基甲烷类、氧杂蒽类、荧光酮类、喹啉衍生物和靛系染料,天然色素分为四吡咯(卟啉类)衍生物、异戊二烯衍生物、花青苷类衍生物、酮类衍生物、醌类衍生物和其他类。食用色素的编码有INS、E-Number、CI以及部分国家(地区)对合成色素的代号。本文分类介绍了中国大陆、CAC、俄罗斯、欧盟、美国、加拿大、日本,以及中国香港、中国澳门和中国台湾10个国家(地区)的食用色素管理规定与允许使用品种。对各国(或地区)食品添加剂标准表述方式、禁止使用色素的规定、对焦油色素应用态度差异、允许使用色素(焦油色素、天然色素和其他类)品种的使用差异,以及食用色素使用范围与限量差别进行了比对分析,提出了我国出口食品生产应根据出口国(或地区)标准确定色素的使用,我国对进口食品应根据其来源确定重点关注色素品种与限量的建议,并分析了食用色素应用发展的趋势。     

Pigment changes in capsicum cultivars during maturation and ripening

The quantitative distribution of chlorophylls and carotenoids in five capsicum cultivars at four stages of maturation and ripening has been established using chromatographic, spectroscopic and chemical methods. From immature, mature, half-ripened and fully-ripened capsicum fruits, up to twelve, twelve, twenty-nine and twenty-six individual pigments respectively were isolated and most identified. The pigment composition results were consistent with a proposed pathway of synthesis of the red keto-carotenoids, capsanthin and capsorubin. Significant differences were found in pigment concentrations among the cultivars at all stages of maturation and ripening, even though the cultivars showed the same visual colour. Lycopene and chlorophyll pigments other than chlorophylls a and b were not found in any cultivar at any stage of maturation or ripening.     

自分散酞菁蓝15:3的制备及其在粘胶纤维原液着色中的应用

针对粘胶纤维原液着色色浆保存周期短、运输成本高的问题,采用喷雾干燥法制备了自分散酞菁蓝15:3,探讨了喷雾干燥时进风温度、进料速率、压力和空气流量等对自分散颜料粒径的影响,借助透射电子显微镜和扫描电子显微镜等探究了自分散颜料的表观形貌,考察了自分散颜料在粘胶纤维中的分散状态。结果表明,进风温度为165 ℃、进料速率为10 mL/min、压力为0.2 MPa、空气流量为2.95 m³/min时,自分散酞菁蓝15:3粒径为171 nm, 与水的接触角为13°,自分散性能良好,耐热、耐酸碱、耐电解质和离心稳定性均在80%以上。自分散颜料与粘胶纺丝液相容性良好,在原液着色粘胶纤维中分布均匀,纤维耐摩擦、耐水洗色牢度均达到4级。     

我国天然黑色素资源研究概况

黑色素广泛存在于自然界生物体内,具有很大应用潜力,且不同来源黑色素有一定特异 性,对黑色素开发已成为当前研究热点;该文概述黑色素资源开发状况,介绍来源于微生物、植物、 动物的各种不同黑色素性质、提取分离方法、功能特性等。     

Improved analysis of Monascus pigments based on their pH-sensitive UV-Vis absorption and reactivity properties

Monascus pigments, a mixture of azaphilones mainly composed of red, orange and yellow pigments, are usually prepared in aqueous ethanol and analysed by ultraviolet-visible (UV-Vis) spectroscopy. The pH of aqueous ethanol used during sample preparation and analysis has never been considered a key parameter to control; however, this study shows that the UV-Vis spectra and colour characteristics of the six major pigments are strongly influenced by the pH of the solvent employed. In addition, the increase of solvent pH results in a remarkable increase of the amination reaction of orange pigments with amino compounds, and at higher pH (≥ 6.0) a significant amount of orange pigment derivatives rapidly form. The consequent impact of these pH-sensitive properties on pigment analysis is further discussed. Based on the presented results, we propose that the sample preparation and analysis of Monascus pigments should be uniformly performed at low pH (≤ 2.5) to avoid variations of UV-Vis spectra and the creation of artefacts due to the occurrence of amination reactions, and ensure an accurate analysis that truly reflects pigment characteristics in the samples.     

红枣红色素的研究进展

随着食品工业的迅猛发展,食品添加剂在人们生活中发挥的作用日益显著。近年来,食品安全屡遭质疑,人们对食用色素也提出了更高的要求,相较于大多数具有致癌风险的合成色素,取自天然、无污染的植物色素更受到人们的青睐。枣红色素是一种提取自红枣果皮的天然色素资源,但开发和利用这一天然色素资源还存在许多问题。本文就色素组成、性质、药理活性、提取和精制方法及深加工技术进行了介绍,综述了近年来红枣红色素在提取、加工和应用方面的研究概况。分析表明,红枣红色素原料来源丰富,提取方便,是一种值得深度开发的性能优异的天然色素资源,但在色素结构鉴定、高效低能耗提取方法开发和产品干燥制粉等方面目前开展的工作较少,文末就此对枣红色素的研究进行了展望。     

Properties of red pigments prepared from geniposidic acid and amino acids

Red pigments formed from geniposide and amino acids were studied. Geniposide, the principal iridoid glucoside contained in the fruit of Gardenia jasminoides Ellis, was hydrolysed to geniposidic acid as a precursor for the pigment. The pigments prepared anaerobically with arginine or glutamic acid under acidic conditions with a large excess of citric acid, were reddish purple and had properties governed by the electrostatic character of the amino acid. Relative molecular masses of these pigments were determined to be several thousand by gel filtration. The pigments showed good stability to heat and pH, but were gradually bleached by light. The safety of the pigments was evaluated by studing their oral acute and the 5‐month oral toxicity of arginine‐red pigment using mice. The pigments were considered to be of low toxicity. © 1999 Society of Chemical Industry