Carrot Color Research Articles

Major QTL for carrot color are positionally associated with carotenoid biosynthetic genes and interact epistatically in a domesticated × wild carrot cross

We performed QTL analyses for pigment content on a carotenoid biosynthesis function map based on progeny of a wild white carrot (QAL) which accumulates no pigments x domesticated orange carrot (B493), one of the richest sources of carotenoid pigments-mainly provitamin A alpha- and beta- carotenes. Two major interacting loci, Y and Y(2) on linkage groups 2 and 5, respectively, control much variation for carotenoid accumulation in carrot roots. They are associated with carotenoid biosynthetic genes zeaxanthin epoxidase and carotene hydroxylase and carotenoid dioxygenase gene family members as positional candidate genes. Dominant Y allele inhibits carotenoid accumulation. When Y is homozygous recessive, carotenoids that accumulate are either only xanthophylls in Y(2)__ plants, or both carotenes and xanthophylls, in y(2) y(2) plants. These two genes played a major role in carrot domestication and account for the significant role that modern carrot plays in vitamin A nutrition.

Effects of Ozone Treatment on Botrytis cinerea and Sclerotinia sclerotiorum in Relation to Horticultural Product Quality

Botrytis cinerea and Sclerotinia sclerotiorum are fungal pathogens that cause the decay of many fruits and vegetables. Ozone may be used as an antimicrobial agent to control the decay. The effect of gaseous ozone on spore viability of B. cinerea and mycelial growth of B. cinerea and S. sclerotiorum were investigated. Spore viability of B. cinerea was reduced by over 99.5% (P < 0.01) and height of the aerial mycelium was reduced from 4.7 mm in the control to less than 1 mm after exposure to 450 or 600 ppb ozone for 48 h at 20 degrees C. Sporulation of B. cinerea was also substantially inhibited by ozone treatments. However, ozone had no significant effect on mycelial growth of S. sclerotiorum in vitro. Decay and quality parameters including color, chlorophyll fluorescence (CF), and ozone injury were further assessed for various horticultural commodities (apple, grape, highbush blueberry, and carrot) treated with 450 ppb of ozone for 48 h at 20 degrees C over a period of 12 d. Lesion size and height of the aerial mycelium were significantly reduced by the ozone treatment on carrots inoculated with mycelial agar plugs of B. cinerea or S. sclerotiorum. Lesion size was also reduced on treated apples inoculated with 5 x 10(6) spores/mL of B. cinerea, and decay incidence of treated grapes was reduced. The 450 ppb ozone for 48 h treatment had no significant effect on color of carrots and apples or on CF of apples and grapes. Ozone, an environmentally sound antimicrobial agent, inactivates microorganisms through oxidization and residual ozone spontaneously decomposes to nontoxic products. It may be applied to fruits and vegetables to reduce decay and extend shelf life.

Training of a sensory panel and profiling of winter hardy and coloured carrot genotypes

The aim of the study was to determine the performance of a sensory panel in evaluation of carrots by investigating the effect of training sessions on the reliability of the sensory attributes. A sensory panel ( n = 10) was trained in profiling five carrot genotypes during a training session with seven sensory replications and 13 attributes. A significant effect of training on the sensory profile was determined for bitterness, green flavour and burning aftertaste, indicating that a learning process in judging these attributes was taking place. Terpene flavour, terpene aroma and burning aftertaste were the most reliable determined attributes and carrot flavour, soapiness flavour and nutty flavour were the least reliable attributes. The developed sensory profile was applied on 16 carrot types with a large variation in quality. Winter hardiness, carrot genotype and carrot colour formed distinct groups within the sensory profile, which indicates that the present sensory profile is relevant for assessing sensory quality of carrots. The winter hardy genotypes were characterised by having relatively high intensities in green aroma, carrot aroma, nutty flavour, carrot flavour and sweetness, while the reverse was true for the Nantes types and the coloured carrots with the red and white genotype as being the most extreme.

The Effect of Enzymatic Treatment on Dried Vegetable Color

The usefulness of enzymatic treatment for improving dried vegetable color was checked using carrot and pumpkin as experimental material. The color differences were expressed using the L*, a*, b* chroma and hue values. For selected samples, color attractiveness was also assessed by ranking method. The results show positive influence of enzymatic treatment on dried carrot and pumpkin color retention. The best effects of improving color of dried material were obtained for Panzym SMASH XXL (for both species) and Rohament CL (for pumpkin). The positive influence of enzymatic treatment on attractiveness of dried carrot color enlarged during storage.

Effect of Variety on Drying Characteristics and Selected Quality Attributes of Dried Carrots

The effects of variety on drying characteristics, color, and water absorption of carrots were investigated. Six different varieties of carrots, viz. Kazan, Maxima, Nandor, Nektarina, Simba, and Tito were evaluated. The hot air drying characteristics of carrot cubes dried under forced convection conditions were determined and drying data were analyzed to obtain parameters of Page and first-order kinetic models as well as moisture diffusivity. Color characteristics were determined for fresh, dried, and dehydrated samples by measuring lightness (L*), redness (a*), and yellowness (b*). Water absorption data were analyzed for ground samples. It was observed that drying characteristics, such as color and water absorption were significantly influenced by variety. The varieties of Kazan and Nektarina were found to be characterized by highest and lowest moisture diffusivity of 7.52 × 10−9 and 3.31 × 10−9m2/s respectively. Kazan variety was also characterized by shortest drying time. The lowest changes in color caused by drying were observed for Tito variety. The variety of Kazan was characterized by the highest resistances to color changes affected by drying followed by rehydration. Nandor and Tito varieties displayed the highest water absorption near to 560 g/100 g. The best drying characteristics and good water absorption accompanied by the high color attributes of dried and rehydrated samples implies that Kazan variety is expected to be the most useful to drying industry.

Mapping of Major Carrot Color Genes an Expression of Carotenoid Biosynthetic Genes

While the carotenoid biosynthetic pathway has been studied several horticultural and agronomic crops, very little information exists for this conserved pathway in carrot, a primary source of dietary carotenoids. Though orange carrots are the most familiar color to Western consumers, yellow, red, and white carrots also exist and have been historically important. Modern carrot breeders are showing renewed interest in these unusual color phenotypes. Beta- and alpha-carotene are the primary pigments in orange carrot roots. Yellow carrots accumulate xanthophylls (oxygenated carotenes), red carrots accumulate lycopene (the precursor to alpha- and beta-carotene), and white carrots accumulate no detectable pigments. Differences between these phenotypes are usually monogenic or oligogenic. Our research has focused on identifying putative genes for carotenoid biosynthetic enzymes in the carrot genome, mapping them, and examining expression patterns in various tissues and carrot root pigment phenotypes. We are using this information to create a carrot pigment biosynthesis function map incorporating biosynthetic enzymes, major carrot color genes, and gene expression information.

Using Edible Coating to Enhance Nutritional and Sensory Qualities of Baby Carrots

ABSTRACT: Xanthan gum coating was used to carry 5% Gluconal Cal, a mixture of calcium lactate and gluconate, and 0.2%α‐tocopheral acetate (vitamin E) by weight, respectively. Peeled baby carrots were dipped in the coating solutions, dried, and then stored at 2 °C and 85% relative humidity for up to 3 wk. Calcium and vitamin E contents of the coated samples, per serving (85g), increased from 2.6% to 6.6%, and from 0 to about 67% of the Dietary Reference Intakes (DRI) values respectively. Edible coatings (p &lt; 0.05) improved the desirable surface color of carrots without effects (p &lt; 0.05) on the taste, texture, and fresh aroma and flavor except for a slightly slippery surface. The β‐carotene level in the baby carrots (p &lt; 0.05) was not affected by edible coating.

Factors contributing to taste and quality of commercially processed strained carrots

Commercially processed strained carrots were obtained from three different processing locations over a 1-year span. Selected carrot lots exhibited both desirable and undesirable sensory attributes based on informal evaluations, while additional carrots were chosen based on postharvest storage factors that may have influenced overall quality. Physicochemical analysis was conducted to determine factors influencing carrot taste and color attributes that could be utilized for retail quality assessment. Quantitative sensory analysis was performed on a subset of the production lots representing a diverse range in chemical composition. Basic taste attributes indicated that concentrations of 6-methoxymellein (6-MM), soluble phenolics and organic acids in relation to high moisture content were critical factors for strained carrot taste. Strained carrot color could not be attributed to processing location or chemical composition and was likely due to raw product variation between cultivars. Variation between each processing location was greater than variation within each location, and overall differences between lots was attributed to 6-MM and soluble phenolic acid concentrations. By screening raw carrots for indications of stress induced chemical constituents, an understanding of those factors contributing to commercially processed strained carrot taste can be obtained.

Antioxidant changes and sensory properties of carrot puree processed with and without periderm tissue.

Carrot purees were thermally processed with and without the periderm tissue after a long and short blanch time, with and without vacuum deaeration treatments. Samples were stored at an elevated temperature (40 degrees C for 4 weeks) to determine physicochemical changes affecting antioxidant activity (AOX), as measured by the coupled oxidation of beta-carotene and linoleic acid assay, and overall quality characteristics. Differences in AOX between treatments before thermal processing and during storage were associated with increased levels of phenolic acids and the subsequent development of numerous compounds thought to be oxidation products of phenolic acids. Samples processed with periderm tissue contained higher levels of phenolic acids, total carotenoids, and sugars than samples processed without periderm tissue. Strained carrot color was adversely affected by a long blanch time compared to a short blanch in treatments with and without periderm tissue, indicating improved color with reduced preprocessing heating. Sensory analyses by a quantitative descriptive analysis panel indicated increased musty/moldy and terpene flavors in samples processed with periderm tissue that were seemingly related to elevated levels of phenolic acids and volatile terpenoids. Terpenoid levels were reduced with deaeration steps prior to thermal processing. Processing carrots without removal of periderm tissue has proven to be a viable option when short blanch times and deaeration steps are employed.

Ethephon Increases Carotene Content and Intensifies Root Color of Carrots

Poor root color is a recurring problem in carrot (Daucus carota L.) production. Consumers prefer dark orange carrots that are high in carotene. However, unfavorable environmental conditions and certain production practices can lead to light orange roots with low carotene content. Growers sometimes refer to this as “white root.” No one has clearly established the causes or cures for this disorder. Several environmental factors are known to affect the color of carrots, but to date there is no practical treatment. High-density planting often reduces carotene content. Field studies were conducted in the 1995-96 and 1996-97 winter growing seasons to determine if foliar applications of ethephon would improve carrot color, carotene content, and yield. Carotene content and root color increased as the number of applications or the amount of ethephon applied with each application increased. Root weight was not significantly affected.

Sensory Profiles of Carrot (Daucus carota L.) Cultivars Grown in Georgia

Descriptive analysis was used to compare sensory color, flavor, and textural attributes of Georgia-grown carrots. The relation between °Brix, total sugar, and intensity perception of sweetness was also studied. Significant differences existed in the perception of sweet taste and of color, and in levels of °Brix and percentage of sugar among all cultivars, but perceived intensity of sweetness was not related to the levels of °Brix or percentage of sugar. No significant differences were found among cultivars in harsh carroty, green, astringent, and earthy flavors, and in the perception of sour taste. Intensity ratings for perceived hardness were nonsignificant in either study. Differences in sensory profiles existed among all cultivars, but no trend was evident in the relation of sweetness to harsh flavor.

High‐Pressure and Freezing Pretreatment Effects on Drying, Rehydration, Texture and Color of Green Beans, Carrots and Potatoes

ABSTRACTHigh‐pressure pretreated and frozen green beans, carrot dice or potato cubes were fluidized bed dried and compared to untreated, pressure‐treated or water‐blanched dried samples. Drying rates varied with pre‐treatments. Freezing resulted in highest drying rates. Pressure‐treated and water‐blanched samples retained highly acceptable colors. Freezing or hot‐water blanching or high‐pressure pretreatment, followed by freezing, gave good rehydration. High‐pressure treatment resulted in incomplete rehydration but combined with freezing, water uptake was between 2.1 and 4.8 mL/g. Retention of cell wall structures of frozen samples during drying was presumed responsible for more efficient mass transfer. Texture measurements revealed significant effects of pretreatments. Pressure‐treated samples had texture nearest that of the raw material. No major differences in color were observed.

RETARDATION of SURFACE LIGNIFICATION ON FRESH PEELED CARROTS

The development of a white material on the surface of freshly peeled carrots can be inhibited by a 20-45 s dip in a 60C, pH 1.0 solution. This treatment insures better retention of the original carrot color and flavor, compared to untreated, and can also be easily incorporated into a production system. A level above pH 1.0 will also offer protection, but only for shorter time.

Isolation and spectrophotometric characterization of photosynthetic pigments

Introduction students in the biochemistry laboratory are introduced to the extraction and characterization of biomolecules, the tissue of choice is most often of animal origin. Plant products are seldom used; therefore, students rarely gain knowledge and appreciation of the unique biomolecules present in the plant kingdom. In order to fill in this gap, we have designed an experiment in which students isolate a mixture of pigments by solvent extraction of plant tissue, separate some of the components by chromatography and identify them by visible region spectrophotometry. Students who complete this experiment gain knowledge and technical skills in biomolecule extraction, chromatographic methods, spectrophotometric techniques and plant pigment structure. Students will follow procedures which are typical for the general extraction and characterization of lipids. However, unlike most lipids (especially those in animals), the plant pigments are highly colored and may be characterized and quantified by visible spectrophotometry. Theory Many of the colors associated with higher plants (green leaves in the spring and summer, yellow or red leaves in the fall, the orange color of carrots, some colors in flower petals) are due to the presence of pigment molecules. Review articles on plant pigments have been recently written by Goodwin 1 and Lichtenthaler. 2 General information on photosynthetic pigments can also be obtained from the standard biochemistry texts by Mathews and van Holde, 3 Stryer, 4 and Voet and Voet. 5 The major photosynthetic pigments of higher plants can be divided into two groups, the chlorophylls and the carotenoids. Both types of pigments are present in the subcellular organelles called chloroplasts, where they are bound to proteins in the thylakoids, the photochemically active photosynthetic biomembranes. Intact pigment-protein complexes, which are held together by weak, noncovalent bonds, have been isolated from chloroplasts and characterized b~( polyacrylamide gel electrophoresis and isoelectric focussing/The pigments are released in a protein-free form by grinding plant tissue in solvents such as acetone, methanol or hexane. Since the chlorophylls and the carotenoids are readily soluble in organic solvents, they are classified biochemically as lipids. The most abundant plant pigments are chlorophyll a and chlorophyll b which occur in a ratio (a:b) of approximately 3:1. As is shown in Fig 1, the chlorophylls possess a porphyrin ring with a coordinated magnesium atom at its center, a fused, 5membered ring and a C20 phytyl side chain. This nonpolar, HzC=CH H C~ 3~c#.

Flavor and Color of Peas and Carrets Cooked by microwaves

AbstractMarket samples of frozen peas and of frozen carrots were cooked in a consumer and in an institutional microwave oven with 550 W and 1150 W cooking power, respectively. Mean sensory scores for flavor and for color of peas cooked in a consumer microwave oven were significantly higher than for those cooked in the institutional microwave oven. Also, retention of chlorophyll components as determined by their specific absorptivity in 80% acetone was significantly greater after cooking in a consumer microwave oven than in the institutional microwave oven.Flavor and color of carrots cooked by all methods were acceptable. Although some significant differences occurred in the sensory scores for orange color of the cooked samples, cooking method did not significantly affect the carotene content which was analyzed by column chromatography.

Color of Cooked Carrots Related to Carotene Content . Determinations by Chromatographic and Spectrophotometric Analyses

Color of Cooked Carrots Related to Carotene Content . Determinations by Chromatographic and Spectrophotometric Analyses

A test for carrot colour in butter

The first page of this article is displayed as the abstract.