Search Results

You are looking at 21 - 30 of 2,772 items for :

  • fruit color x
  • Refine by Access: All x
Clear All
Free access

Jane E. Lancaster, Carolyn E. Lister, Peter F. Reay, and Christopher M. Triggs

The color of fruits and vegetables results from the presence of chlorophyll, carotenoid, and anthocyanin pigments. Instrumental measurements of color are used routinely in describing processes of changing color, such as fruit ripening. The applicability of using skin color measurements to predict changes in pigment composition was investigated using a wide range of fruit and vegetables. Skin color was measured using a Hunter Colorlab and represented as the coordinates X, Y, Z, L*, a*, b*, chroma (C*), and hue angle (ho). Identical skin samples were extracted and analyzed for chlorophyll, carotenoid, and anthocyanin concentration. Sets of pairwise scatter plots were generated for each set of color variables and for the chlorophyll, anthocyanin, and carotenoid pigments. There were linear relationships between ho and anthocyanin concentration and between L* and log [chlorophyll concentration]. Multiple regressions for each pigment variable and sets of color variables also were calculated. However, there was no unique linear combination of pigments that gave rise to a unique point in the color space. Conversely, a given set of coordinates in the color space can be accounted for by many combinations of pigments. Therefore, a given color measurement cannot be described in terms of a unique combination of pigments. Caution is urged in interpreting tristimulus color coordinates in terms of a simple change in pigment composition without prior knowledge of the pigment composition within the fruits and vegetables. The surface topography of fruits and vegetables may be of considerable significance in measuring color.

Full access

Stuart G. Reeves, Jacqueline F. Nock, Pamela M. Ludford, Lydia L. Hillman, Linda Wickham, and Richard A. Durst

The use of a new, inexpensive scanning reflectometer, the Colortron, as a field and laboratory colorimeter is investigated. The results obtained from a series of color swatches and from a variety of fruit samples are compared with those obtained from other commercially available, but more expensive, colorimeters (Hunter and Minolta). The Colortron is shown to be very good for gathering and analyzing data. The results of all three instruments were extremely close when measuring color swatches, but the Colortron gave aberrant results with certain fruit having translucent skin and flesh. Despite this caveat, it still has considerable potential for the measurement of fruit color in the field and laboratory.

Free access

Georges T. Dodds, J. Wyatt Brown, and Pamela M. Ludford

Univ.; R. Robinson, New York State Agricultural Experiment Station, Geneva; and S. Valerie, U.S. Dept. of Agriculture Germplasm Resources, Geneva, N. Y., for samples of tomato fruit and seeds and K.S. Yourstone for statistical advice. The cost of

Free access

Frank Cheng, Norman Weeden, and Susan Brown

The ability to pre-screen apple populations for fruit color at an early seedling stage would be advantageous. In progeny of the cross `Rome Beauty' × `White Angel' red/yellow color variation was found to be highly correlated with the genotype at Idh-2, an isozyme locus that was heterozygous in both parents. We postulate that the red/yellow color variation was produced by a single gene linked to I&-2 and also heterozygous in both parents. This population was also screened with over 400 primers to detect randomly amplified polymorphic (RAPD) markers for fruit color. DNA extraction procedures were developed for bark, and DNA was extracted from bark samples and leaves. Red and yellow fruited individuals were examined in bulk. Several markers have been found that are linked to red color. A high density map is being constructed in this region. These markers are being examined in other crosses segregating for fruit color. The application of these markers will be discussed in relation to the inheritance and manipulation of fruit color.

Free access

Xuetong Fan and James P. Mattheis

Enclosing `Fuji' apple (Malus ×domestica Borkh.) fruit in paper bags 2 months after full bloom delayed the increase in internal ethylene concentration at the onset of fruit ripening, and increased the respiration rate early in the bagging period. Bagging delayed and reduced red color development, especially on the blush side, but did not affect fruit resistance to gas diffusion. External surface color changed significantly within the first 4 days after bags were removed. Exclusion of UV-B from sunlight by Mylar film after paper bag removal impaired red color development. Bagging during fruit development increased superficial scald but eliminated stain during cold storage. Exposure to sunlight for 19 or 20 days before harvest reduced scald incidence in comparison with leaving bags on until harvest.

Free access

Douglas V. Shaw

The heritabilities of, and genetic correlations among, variables that describe internal and external color in fresh strawberry (Fragaria × anarrassa) fruit were estimated using factorial analyses of seedlings from 20 controlled crosses. Hunter L and a values, and a subjective score generated by comparison with color plates were obtained for seedling genotypes and their parents at two locations. Genetic effects were responsible for 33% to 61% of the phenotypic variance for color traits, after correction for location effects. Means for objective color variables differed significantly between locations, but means for subjective color scores did not. Genetic × location interaction variances were usually nonsignificant, and were < 12% of the phenotypic variance for all variables. Phenotypic and genetic correlations between objective and subjective color scores were significant and large (absolute values of r = 0.42-0.69; rg = 0.84-1.00). Multiple regression of subjective scores on L and a explained 69% and 59% of the phenotypic variation for external and internal color, respectively. Genetic correlations between measures of internal and external color were small and mostly nonsignificant, suggesting that separate sets of genes condition these traits.

Free access

Sharad C. Phatak, Jinsheng Liu, Casimir A. Jaworski, and A. Fazal Sultanbawa

The functional male sterile (fms) eggplant (Solanum melohgena L.) germplasm UGA 1-MS was crossed with two cultivars, `UGA 18 White' and `Florida Market' with normal anthers to derive F1, F2, and BC populations. Functional male sterility (fms) was governed by a single recessive allele. The gene symbol fms is proposed for this male sterile characteristic. The functional male sterility gene was linked to purple fruit color at the X/x locus. Our observations also revealed that the purple or violet color ware not only on the fruit peel, but also on the anthers and leaf buds if the eggplant fruit was purple or violet. In the transmission of parents and progenies of the cross of UGA 1-MS × `UGA 18 White', the purple line on the anther and leaf bud purple color ware tightly associated with fruit purple color. Thus, it is assumed that the allele X controls not only purple fruit, but also the expression of the purple line on the anther and purple leaf bud.

Free access

Mark A. Bennett, David M. Francis, and Elaine M. Grassbaugh

Ethephon (2-chloroethyl phosphonic acid) has been widely used under field conditions as a growth regulator to trigger the ripening of processing tomatoes prior to mechanical harvesting. Recent interest in whole-peeled and diced tomato products has raised questions about ethephon rates, and possible split applications for top quality. This 3-year field study tested two commercial cultivars of processing tomatoes (`OH8245' and `P696') and the effect of various ethephon applications on fruit firmness, color uniformity, and peeling variables. Transplants were established in mid to late May of 1996–1998 on raised beds in single rows at the OSU/OARDC Veg. Crops Branch in Fremont, Ohio. Ethrel applications for each cultivar were: 0, 0.58, 0.58 × 2 applications, 1.17, 1.17 × 2 applications, 1.75, 2.34, 4.68, and 7.02 L·ha–1. Fruit were tested for firmness, color uniformity, pH, titratable acids, and soluble solids. Samples from ethephon treatments of 0, 1.17 × 2 applications, 2.34, 4.68, and 7.02 L·ha–1 were peeled and canned for color inspection and firmness after 18 months storage. Three-year data for red fruit yield showed a typical response to increasing amounts (0 to 7.0 L·ha–1) of applied ethephon. While high rates (4.7 or 7.0 L·ha–1) gave some of the highest red fruit yields, and the greatest percent red fruit values, high rates were also linked with among the lowest fruit solids values. Split application comparisons showed little influence on quality variables examined in this study. However, chroma values were improved (more vivid color) when 2.3 L·ha–1 was applied vs. 1.17 L·ha–1 applied twice. Split applications also tended to produce softer fruit. Our results suggest that single ethephon applications of 1.17 to 2.34 L·ha–1 provide optimal fruit ripening and quality under midwestern U.S. conditions.

Free access

I. Iglesias, J. Graell, G. Echeverría, and M. Vendrell

The influence of supplemental sprinkler irrigation on fruit color of `Oregon Spur Delicious' (Trumdor) apples (Malu×domestica Borkh.) was evaluated in the area of Lleida (NE Spain) over a 3-year period. Cooling irrigation was applied for 2 hours daily for 25-30 days preceding the harvest. Three treatments were evaluated: 1) control without overtree sprinkler irrigation; 2) sprinkler irrigation applied at midday; and 3) sprinkler irrigation applied at sunset. Fruit color was significantly affected by the cooling irrigation and also by the weather of the particular year. Increased red color and higher anthocyanin content resulted from sprinkler irrigation, especially when applied at sunset. At harvest, anthocyanin content was correlated with a*/b* and hue angle, suggesting that the colorimeter measurements could provide a nondestructive estimate of anthocyanin content.

Free access

Frank J. Peryea and Rhoda L. Burrows

15 ORAL SESSION 4 (Abstr. 043–049) Nutrition/Fruit & Nuts (temperate)