Red Pigment Formation Research Articles

Formation of yellow, orange, and red pigments in the reaction of alk-2-enals with 2-thiobarbituric acid

The reaction of four to eight carbon straight-chain alk-2-enals with 2-thiobarbituric acid (TBA) produced yellow 455-nm-, orange 495-nm-, and red 532-nm-absorbing pigments depending upon the reaction conditions. The 1:1 reaction of the aldehydes with TBA in 15% acetic acid at 100°C produced the yellow pigment at 0.25 h and the red at 6 h. The reaction of the aldehydes with TBA in excess at 100°C produced the yellow at 0.25 h, the orange at 2–6 h, and the red at 25–26 h. The formation of these pigments required molecular oxygen. These pigments could be separated from each other on HPLC. The red pigment formed from the aldehydes could not be distinguished from the red 1:2 malonaldehyde-TBA adduct by absorption spectrum and HPLC. The red color yield was the highest in the 1:1 reaction and retarded in the reaction with TBA in excess. The red color due to these aldehydes may contribute in part to the color formed in the general TBA test of lipid oxidation. The 1:1 reaction initially produced colorless 1:1 adducts X, which were subsequently converted into the yellow and red pigments under aerobic conditions. The reaction of the aldehydes with TBA in excess might initially produce X and then another colorless 1:2 adducts Y; the latter being converted into yellow, orange, and red pigments under aerobic conditions.

Red Pigment Formation by the Reaction of Oxidized Ascorbic Acid and Protein in a Food Model System of Low Moisture Content

Red Pigment Formation by the Reaction of Oxidized Ascorbic Acid and Protein in a Food Model System of Low Moisture Content

Red pigment formation by the reaction of oxidized ascorbic acid and protein in a food model system of low moisture content.

Ascorbic acid-protein mixtures of low moisture content stored for 2-3 days in aerobic conditions at 60°C produced a red coloration, which was shown to have resulted from an amino-carbonyl reaction of oxidized ascorbic acid (dehydroascorbic acid, DHA) by the facts that DHA-casein or ovalbumin systems yielded a rapid red coloration in low moisture conditions as well as in an ethanol suspension. Zein showed only a weak red coloration with DHA. An apparent decrease in the free amino group, as determined by the TNBS method, was observed to be associated in parallel with the red pigment formation. The electrophoretic pattern of ovalbumin changed significantly upon incubation with DHA, together with the formation of the red pigment. The red pigment extracted from a DHA-casein system showed an absorption spectrum, TLC Rf value, and hydrolyzed products (DHA and scorbamic acid) identical to those of 2, 2'-nitrilo di-2(2)-deoxy-L-ascorbic acid mono ammonium salt, produced from DHA and amino acid. Formation of the red pigment was also observed in the reaction of DHA with Nα-acetyl lysine. These results indicate that the ε-amino group of lysine in protein can be attributed to the formation of a red pigment identical with NDA.

Occurrence of red pigment-forming substances during autoxidation of lipids.

Occurrence and discoloration property of red pigment-forming substances (RPSs) produced during autoxidation of polyenoic acids were investigated. Autoxidezed lipids (methy1 linolenate, methyl arachidonate, linseed oil and tuna liver oil) were separated on Sephadex LH-20 with CHCl3/MeOH (1/1, v/v), and the pooled RPS-fractions were further separated by TLC. Two to four or more than four spors on the TLC plate turned into reddish-color by spraying with α-amino acids, but not by spraying with aliphatic amines, ammonium chloride, and purine and pyrimidine bases in neutral solutions. Proline and hydroxyproline developed a golden yellow color immediately. The purified RPS derived from linolenate had an absorption maximum at 226-227 nm in EtOH and in MeOH/water (2/1, v/v), and 241 nm inchloroform. By the reaction with amino acids, the absorption at λmax 226-227 nm decreased with the increase taking place at λmax 510-520 nm which was attributed to the formation of red pigment.

Biochemical Studies on Some Chemical Characteristics of Sliced Egyptian Onions

ABSTRACTBiochemical studies were carried out on two widely distributed Egyptian onion varieties (Behairy and Selected Giza 6). Several treatments (soaking in tap water, boiling water, cold water, warm ethanol, or sodium chloride solution) were proposed to overcome onion reddening during industrial processing. Some chemical characteristics (L‐ascorbic acid, free amino acids, volatile sulfur compounds, carbonyl compounds, pungency and color) were determined in fresh, treated and stored sliced onions. Unsaturated fatty acids can be considered as a secondary source for carbonyl compounds and are involved in the formation of red pigments. Pronounced changes among hydrocarbons and little changes in sterols were due to application of various treatments and storage. In general, the most efficient treatments towards keeping onion quality were soaking the sliced onions in cold water or 5% (w/v) sodium chloride for 24 hr before onion dehydration.

Biochemical Studies on Some Chemical Characteristics of Sliced Egyptian Onions

AbstractBiochemical studies were carried out on two widely distributed Egyptian onion varieties (Behairy and selected Giza 6). Several treatments (soaking in tap water, boiling water, cold water, warm ethanol and sodium chloride solution) were proposed to overcome onion reddening during industrial processing. Some chemical characteristics (L‐ascorbic acid, free amino acids, volatile sulfur compounds, carbonyl compounds, pungency and colour) were determined in fresh, treated and stored sliced onions. The fatty acid composition of onion samples revealed that unsaturated fatty acids can be considered as a secondary source for carbonyl compounds and take place in the formation of red pigments. Pronounced changes among hydrocarbons and little changes in sterols were found due to application of various treatments and storage. In general, the most efficient treatments towards keeping onion quality were soaking the sliced onions in cold water and 5 % (w/v) sodium chloride for 24 hr before onion dehydration.

Factors affecting perithecial production in Gibberella (Fusarium) tricincta

Three pigmentation types (brown, red, and white) of Fusarium tricinctum (Corda) Sacc. were observed when an isolated mass culture from leaf spots on English ivy (Hedera helix L.) was single spored. Perithecia of the heterothallic fungus Gibberella tricincta El-Gholl were produced at 20 and 27 °C on stem pieces of Cynodon dactylan Pers. resting on water agar, under 12-h alternating light and dark when certain pigmentation types were paired. Pairing of red and brown pigmentation types yielded significantly (P < 0.05) more perithecia than red and white pairings at 20 and 27 °C. Perithecia were formed only in combinations of red with brown or white pigmentation types. In both sets of pairings, significantly (P < 0.05) more perithecia were produced at 27 than at 20 °C. No perithecia were formed in constant darkness. Occasionally, the red pigmentation type became white after subsequent transfers and never reverted to the red pigmentation on various media and failed to produce perithecia with any pigmentation type. Continuous darkness slightly favored red pigment formation over continuous light as detected by the Munsell color codes. Increasing temperatures from 20 to 32 °C decreased the colony growth diameter of the red-pigmented cultural type. At 32 °C a change in hue was noted with corresponding changes in color codes. Red mycelial pigmentation was intensified by the addition of copper, iron, manganese, and zinc to a basal medium. The addition of 0.1% yeast extract favored mycelial development and caused a more pronounced red mycelial pigmentation in the presence of heavy metals.

Pleiotropic consequences of mutations towards antibiotic-hypersensitivity in Serratia marcescens

Various mutants (oxas) were isolated from Serratia marcescens SM-6 by selecting for hypersensitivity towards oxacillin. All mutants found are highly pleiotropic and able to yield spontaneous revertants which behave like the wild-type. Mutant W 1421 mostly studied shows the following phenotypic properties not found in the wild-type: (1) The growth is hypersensitive to various antibiotics, detergents and dyes which differ remarkably in their chemical structure and antibacterial action-mechanism, (2) the cells can be easily solubilized by 0;05% Sodium-dodecyl-sulfate, (3) the cells allow the adsorption of the rough-mutant specific Salmonella phage 6SR; (4) strong cellular binding of crystal violet, (5) agglutination of the cells in 0.3% auramin solution and (6) reduced formation of red pigment. Strain W 1421 is assumed to be a lipopolysaccharide-defective mutant. The outer membrane of mutant W 1421 analyzed by Sodium-dodecylsulfate-polyacrylamide gel electrophoresis possesses a single protein less than that of the wild-type. Mutant W 1421 is further characterized by its low exolipase activity; exoprotease and exonuclease activities are as in the wild-type. This specific exoenzyme deficiency can be overcome either by backmutation to oxacillin-resistance or by growing mutant W 1421 in a medium supplemented with certain non-metabolizable polysaccharides, e.g. glycogen or pectin B. Both polysaccharides increase the exolipase activity of the wild-type too.

CHROMOPLAST ULTRASTRUCTURE AS AFFECTED BY GENES CONTROLLING GRANA RETENTION AND CAROTENOIDS IN FRUITS OF CAPSICUM ANNUUM

Plastids in the fruits of isogenic lines of pepper (Capsicum annuum) were examined by electron microscopy with reference to four genotypes determining the carotenoid composition and the colors red, yellow, brown, and green of the ripe fruit. One gene pair (y+/y) influences carotenoid content and the other pair (cl+/cl) controls the chlorophyll. The retention of the grana and chlorophyll in the ripe fruits of the brown and green phenotypes is correlated with the cl cl genotype. The y+ gene increases the total carotenoids and promotes the formation of red pigments. Giant grana were found in the yellow and green phenotypes, but during ripening these disappeared in the yellow. Unusual dichotomous and concentric grana were observed in the green. Globule‐associated carotenoids forming fibrillar crystalloids were present in all color types, although to a lesser degree in the yellow fruit. Membrane‐associated carotenoids occurred only in the yellow and green phenotypes.

LOW DOSE GAMMA IRRADIATION OF BOVINE METMYOGLOBIN

SUMMARY Bovine metmyoglobin (MetMb) in a pure state, in several differing states of purity and in meat was irradiated with ionizing gamma rays. Irradiation caused the brown MetMb to convert to a red myoglobin pigment which is similar but not identical to oxymyoglobin (MbO2). The formation of red pigment was accelerated at slightly basic pHs and under nitrogen atmospheres. Rate of red pigment formation is not dependent upon MetMb purity. Rate of red pigment formation in meat is identical to the rate of formation in buffered MetMb solutions. This study also demonstrated that gamma irradiation does alter MetMb structure. This alteration may be the loss of amide nitrogen from the protein.

The Effects of Auxins, Amino Acids, and Catechols on the Formation of Red Pigment in Helianthus tuber slices

AbstractThe mechanism of red pigment formation in tuber slices of Helianthus tuberosus during incubation with auxins has been studied and the following results were obtained. 1. The degree of expansion of the tissue slices in the presence of indole‐acetic acid (IAA), 2,4‐dichloropbenoxyacetic acid (2,4‐D), or α‐naphthaleneacetic acid (NAA) was not parallel to the colour intensity which developed during incubation. 2. The pigment solutions which were extracted by pyridine. ethanol, or dioxane commonly showed a peak at around 515 nm in the absorption spectrum. 3. The o‐diphenol oxidase activity in the tissue slices was increased by incubation with 2.4‐D. 4. I.‐Proline or hydroxy‐L‐proline as reactants in the formation of red pigment by the o‐diphenol oxidase system could not be replaced by L‐arginine, L‐histidine and L‐tryptophan. 5. The red pigment may resemble 4‐(4′‐hydroxy‐2′‐carbethoxy ‐1′‐pyrrolidyl)‐5‐methyl‐o‐benzoquinone, formed by the o‐diphenol oxidase system in the presence of homocatechol and hydroxy‐L‐proline.

Chemical Color Enhancement of Cranberry Fruit12

Abstract Color enhancement in Howes and Early Black cranberry, as measured by pigment analysis and influenced by malathion, indole-3-acetic acid (IAA) and succinic acid 2,2-dimethyl hydrazide (Alar) sprays prior to harvest, was investigated under New Jersey conditions. Malathion at the rate of 2.5 lbs. of active material/A. applied at 200 gal./A. significantly enhanced the extractable pigment content in both Howes and Early Black cranberry. The color enhancement was noted within four days of application, and the differential in pigment content between the malathion treated and control berries was maintained throughout the sampling period. Neither IAA at 50 ppm nor Alar at 2000 and 4000 ppm active material increased color in Early Black. There was an indication that Alar delayed red pigment formation in Early Black. Soluble solids and titratable acidity measurements of Howes and Early Black fruit did not indicate any significant difference between treated and control fruit at a given sampling date.

Chemical Color Enhancement of Cranberry Fruit12

Abstract Color enhancement in Howes and Early Black cranberry, as measured by pigment analysis and influenced by malathion, indole-3-acetic acid (IAA) and succinic acid 2,2-dimethyl hydrazide (Alar) sprays prior to harvest, was investigated under New Jersey conditions. Malathion at the rate of 2.5 lbs. of active material/A. applied at 200 gal./A. significantly enhanced the extractable pigment content in both Howes and Early Black cranberry. The color enhancement was noted within four days of application, and the differential in pigment content between the malathion treated and control berries was maintained throughout the sampling period. Neither IAA at 50 ppm nor Alar at 2000 and 4000 ppm active material increased color in Early Black. There was an indication that Alar delayed red pigment formation in Early Black. Soluble solids and titratable acidity measurements of Howes and Early Black fruit did not indicate any significant difference between treated and control fruit at a given sampling date.

緑膿菌の赤色色素の産生に関する研究

The formation of red pigments by Ps. aeruginosa. strain NO.145, was studied.1. DL-glutamic acid was found to be a good substrate for the synthesis of the red pigments in culture media by Ps. aeruginosa.and it could be replaced by several related amino acids (DL-alanine and L-leucine).2. The red pigments formation on the medium containing one of these amino acids varied according to its concentration and the incubation time of the bacteria.The maximum yield of the red pigments was obtained at 1% concentration of DL-glutamic acid or DL-alanine in 80 hrs. after incubation, although the production of the red pigments was rather lower by leucine medium.3. The yellow pigments produced by Ps. aeruginosa. strain No 145, in the up-right medium converted its color gradually into red by age, but on the slant medium they changed the color rapidly in red.4. The fleshly isolated strains of Ps. aeruginosa.obtained from human speciemens have commonly the ability of the red pigments formation on the glutamic acid medium, although the ability was decreased gradually successive subcultures.5. The synthetic medium containing DL-glutamic acid at 1.0% (for 80 hrs. incubation)has been found to be the most suitable for production of the red pigments by Ps. aeruginosa.

A REACTION PYRIDOXAL WITH C-3 UNSUBSTITUTED INDOLES.

THE formation of a red pigment from indole and pyridoxal interferes in the enzymatic determination of L-tryptophan1. On the basis of the following evidence, it is proposed that the pigment has the structure IIa shown in Fig. 1 and is therefore analogous to the rosein-doles of Fischer2.

Effect of temperature and light on the coloration of rose flowers

Pigmentation of flowers in red is a very complex phenomenon. Various flower colors in many species have been shown to be due to genetic factors. Even if the necessary genes are present, however, synthesis of anthocyanin will not occur in a plant unless environmental conditions are favorable. Of environmental factors regulating anthocyanin formation, sunlight and temperature influence it directly in some plant tissues. To obtain flowers of good color under glasshouse conditions, temperature and light must be regulated by means of heating or cooling and supplementary lighting or shading, especially during the winter or summer season.The authors attempted in the study to obtain an information on the effects of temperature and sunlight on the coloration of rose flowers. The influence of temperature on the form of epidermal cells in the petal is also presented in this paper. As the materials, two varieties of garden roses were used. Using a variety of Hybrid Tea, Crimson Glory, the authors have followed the formation of red pigments quantitatively at various temperatures in the phytotron. After the differentiation of flower buds about 3 weeks after pruning, the potted plants were treated at various temperatures. At 20° and 10°C petals became dark red and showed a velvet-like appearance. According to anatomical observations, anthocyanin distributed only in the epidermis on the adaxial and abaxial surface of the petal. In the vertical section, the thickness of the upper epidermis of the petal treated at 20° and 10°C is much greater than that treated at 30°C. On the other hand, the upper epidermis showed a flat structure and red color did not appear at noon-and/or night-temperature of 30°C.In the experiment of the measurement of color, and the analysis of pigments in petals, the roses were treated at 13° and 23°C after the bud formation. At 23°C the petals have a purplish hue and become bluish purple red later. On the other hand, at 13°C they have a red hue and a lower luminosity, and become brown later. Paper chromatographic analysis showed that the anthocyanins in Crimson Glory variety are cyanin and chrysanthemin. Of these pigments, cyanin is the highest in content. The anthocyanin content of petals at 13°C is much higher than that treated at 23°C.Using a variety of Floribunda, Masquerade, an attempt was made in this paper to elucidate the effect of sunlight on the development of flower color. The flowers of the variety change their color ranging from yellow to red as the age of petals advances. Flower buds were covered with colored cellophane prior to their opening, which was removed after two weeks. Although the flowers bloomed, red color did not develop in their petals. Regardless of light quality, the anthocyanins were not formed at lower light intensity. It therefore appears that the flowers of Masquerade require high intensity of sunlight for development of their red color. There was a rise in anthocyanin content in the petals as the time advanced after flowering. In the petals of Masquerade, the anthocyanins are cyanin and chrysanthemin. Of the two anthocyanins, chrysanthemin has highly increased in content with advancing age of flowers.

Studies on the Mechanism of the Oxidation of Tea Leaf Catechins

A study is made on the oxidation of a mixture containing epigallocatechin and epicatechin with tea oxidase as well as a oxidizing reagent, in order to understand the formation of red pigments in tea manufacture. As the reaction proceeds a remarkable colored substance is formed, which can be obtained in reddish orange needles (from water) and is supposed to be a troponoid compound having a 3′,4′-dihydroxybenzotropolone nucleus as suggested by a tentative structural formula III from a consideration of its spectral characteristics.

Occurrence of a porphyrin pigment in streptomycetes.

The formation of an intramycelial red pigment of coproporphyrin type in submerged cultures of Streptomyces griseus and S. fradiae was detected. Its production is more intensive in the variants of S. griseus Z38 that give a low yield of streptomycin, and in the absence of Fe(++) in fermentation media.

Occurrence of a Porphyrin Pigment in Streptomycetes

The formation of an intramycelial red pigment of coproporphyrin type in submerged cultures of Streptomyces griseus and S. fradiae was detected. Its production is more intensive in the variants of S. griseus Z38 that give a low yield of streptomycin, and in the absence of Fe ++ in fermentation media.

RED PIGMENT FORMATION BY INTERACTION OF MOLDS PART 5 FACTORS AFFECTING FORMATION OF THE PIGMENTS

Various conditions affecting the cobiontic formation of red pigments caused by Penicillium verruculosum L 9 and Trichoderma viride L 6, were investigated and the following results were obtained.When grown together on an agar plate the pigment formation was not affected by the initial pH in the range from 4.0 to 8.0. When grown in a liquid medium on a shaker, the optimum pH for the pigment formation was found to be at 6.0-7.0. On inoculating the spores of T. viride into precultures of P. verruculosum of varying length, it was found that the red pigment formation decreased remarkably when the preculture of the latter lasted more than 6 hours. Conversely, on inoculating the spores of P. verruculosum into precultures of T. viride of varying lengths, the amounts of the red pigments formed were almost the same as that in the control culture, except in the cases of 7 and 8hours precultures, in which the red pigment formation was considerably less. The red pigments were scarcely produced when the ratio of inoculum sizes (spores) of P. verruculosum to T. viride, was 5: 1-15:1, while a distinct pigment formation occurred when the ratio in question was 1:5-1:15.Vigorous aeration of the culture medium was necessary for the red pigment formation and it was inferred that a close relation may exist between the sporulation of P. verruculosum and the cobiontic red pigments formation. The red pigments were produced over the temperature range of 20° to 30° where both test molds could grow well, the optimal temperature being found in the range of 25° to 30°.