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Bernard B. Bible and Suman Singha

Differences in color development between exposed and shaded fruit during the growing season were determined for `Loring' and `Raritan Rose' peach (Prunus persica L. Batsch). The surface color of fruit exposed to sunlight in the upper canopy, and in the shade in the lower canopy, was measured with a tristimulus calorimeter, and L* a* b* values were recorded for each fruit from 17 July through harvest. Color changes (ΔE* ab) during maturation for both cultivars at either canopy position were characterized by large changes in hue (Δ H*ab) and lesser changes in lightness (Δ L*ab) and chroma (Δ C*ab). Upper canopy fruit of both cultivars were redder and darker than the lower canopy fruit initially and at harvest. Flesh firmness for `Loring' and `Raritan Rose' tended to correlate with color change from initial sampling to harvest.

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Sin-Ae Park, A-Young Lee, Kwan-Suk Lee, and Ki-Cheol Son

research experience in measuring the MET of various gardening tasks by using a portable telemetric calorimeter system for pulmonary gas exchange measurement with breath-by-breath analysis ( Park et al., 2011 , 2012 , 2013a ). In an orientation, the

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Sin-Ae Park, Ho-Sang Lee, Kwan-Suk Lee, Ki-Cheol Son, and Candice A. Shoemaker

, Guangdong, China). Evaluation of the metabolic costs of gardening tasks. To measure the metabolic costs of gardening tasks, in terms of oxygen uptake, energy expenditure, and MET, each child wore a portable telemetric calorimeter (K4b 2 ; Cosmed, Rome, Italy

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Walter Boswell, Bernard Bible, and Suman Singha

Fruit of 34 peach (Prunus persica L. Batsch). cultivars were harvested at maturity and visually evaluated by panelists on a 1 to 10 scale, where 10 = excellent color. CIELAB coordinates (L* a* b*) of fruit color were measured at the midpoint between the stem and the calyx end with a Minolta CR-200b calorimeter on the blushed and ground areas of each fruit. Simple linear regressions of color coordinates with panel ratings indicated that blush chroma, blush L*, blush hue angle and E* (total color difference between ground and blush) all influence visual color evaluation. Not only does assessing fruit color with a calorimeter permit color to be reported in internationally accepted units, but the relationships indicate that instrumental values relate well to qualitative ratings.

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Suman Singha, Tara A. Baugher, Edwin C. Townsend, and Mervyn C. D'Souza

Fruit of 10 `Delicious' apple (Malus domestica Borkh.) strains were harvested 149 days after full bloom in 1988. Fruit color was measured at four locations on each fruit at the midpoint between the stem and calyx end with a Minolta CR-200b portable tristimulus calorimeter. Anthocyanin content of corresponding skin disks was determined spectrophotometrically. Significant differences existed among strains in both the amount and distribution of anthocyanin around the fruit. High-coloring strains had a significantly higher anthocyanin concentration at both the blushed and the nonblushed surface when compared to low-coloring strains. A linear regression of anthocyanin content on the ratio of (a*/b*)2 provided an R2 = 0.59; precision was enhanced by using a separate equation for each strain (R2 = 0.80). Regressing log (anthocyanin) on L* using two linear splines yielded an R2 = 0.78. These relationships allow the use of a portable calorimeter for rapid, nondestructive estimation of fruit anthocyanin content in situ.

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Mervyn C. D'Souza, Morris Ingle, and Suman Singha

Chromaticity values (L*, a*, b*) of `Rome Beauty' apples (Malus domestics) were measured at weekly intervals during maturation periods in 1988 and 1989. Chromaticity was measured using a Minolta Chroma Meter CR-200b calorimeter on four quadrants of the fruit at locations midway between the stem and calyx ends. The apples continued to develop red color through the maturation period. After storage, the peel areas where chromaticity was measured were evaluated for scald intensity. The L* value at harvest was correlated positively with scald intensity, while the a* value was correlated negatively. An equation has been developed to describe the relationship between chromaticity values at harvest and scald intensity after storage.

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Mervyn C. D'Souza, Morris Ingle, and Suman Singha

Lycopene is the predominant carotenoid pigment in tomatoes and primarily responsible for red color. Spectrophotometric procedures for lycopene evaluation although accurate are time consuming and destructive. The objective of this study was to relate chromaticity values (L*,a*,b*) measured using a Minolta Chroma Meter CR-200b portable tristimulus calorimeter with lycopene concentrations in the pericarp of 'Celebrity', 'Mountain Delight' and 'Early Pick' tomatoes. Fruit were selected to encompass varying maturities from green to red ripe and were obtained from a commercial source. Lycopene from individual skin disks or pericarp plugs corresponding to each location of color measurement was extracted in acetone and measured spectrophotometrically at 503 nm. The L* value (a measure of lightness) or a* value (a measure of redness) was determined to be well correlated with lycopene concentration in all 3 cultivars. The linear regression of the lycopene concentration on the ratio of (a*/b*) provided the best R for all cultivars (0.75).

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S. Singha, T. A. Baugher, and E. C. Townsend

The objective of this study was to determine the relationship between temperature and color development in 3 strains of Red Delicious apple (Malus domestica Borkh). The strains `Scarlett Spur', `Ultrastripe' and `Starkrimson' were chosen based on variation in coloration. Chromaticity values (L* a* b*) were measured with a Minolta CR-200b calorimeter on 5 tagged apples on each of 4 trees of each strain. Measurements were made at approximately the same location on each fruit 23 times from July 11 through September 25, 1989. Differences in a*/b* ratio among strains were observed as early as the first sampling date; with `Scarlet Spur' having the highest ratio and `Starkrimson' the lowest. These differences were maintained for most the growing season. Temperature below 21C tended to enhance color development, whereas temperature above 21C reduced coloration. Temperature affected all 3 strains similarly.

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S. Singha, T. A. Baugher, and E. C. Townsend

The objective of this study was to determine the relationship between temperature and color development in 3 strains of Red Delicious apple (Malus domestica Borkh). The strains `Scarlett Spur', `Ultrastripe' and `Starkrimson' were chosen based on variation in coloration. Chromaticity values (L* a* b*) were measured with a Minolta CR-200b calorimeter on 5 tagged apples on each of 4 trees of each strain. Measurements were made at approximately the same location on each fruit 23 times from July 11 through September 25, 1989. Differences in a*/b* ratio among strains were observed as early as the first sampling date; with `Scarlet Spur' having the highest ratio and `Starkrimson' the lowest. These differences were maintained for most the growing season. Temperature below 21C tended to enhance color development, whereas temperature above 21C reduced coloration. Temperature affected all 3 strains similarly.

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Suman Singha, Bernard Bible, and Edward Corbett

Variations in the pattern of fall color development in the leaves of Acer rubrum, Acer saccharum, Quercus coccinea, Oxydendrum arboreum and Euonymus alatus were determined. CIELAB coordinates were measured with a Minolta CR-2000b calorimeter at a marked location on 5 tagged leaves from 2 plants of each species. The changes in hue follow similar trends in these species, but the time of onset varies. Onset of red color development increased variability in hue between leaves of the same species. Based on color changes in E. alatus anthocyanin development occurs prior to significant loss of chlorophyll and red coloration remains masked, whereas in A. rubrum anthocyanin development occurs in association with or following the loss of chlorophyll. This results in differences in the pattern of hue and chroma development between these species.