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erable variation occurred in weather conditions and fruit quality.

Evaluating Palatability

As pointed out in a recent s}Tmposium (1) flavor is highly complex and usually involves more than the major flavor constituent. The complexity of flavor is shown by the fact that analysis of volatile odorous substances in the strawberry has led to the isolation of about 35 substances; however, it is still not possible to reconstitute a really fresh strawberry flavor. The characteristic aroma of citrus is ascribed to high-boiling, sparingly water-soluble oils. Unlike the plant lipids, which are esters of long-chain fatty acids, these oils are mainly mixtures of terpenes, such as G?-limonene.

Special attention was given to the eating quality of the fruit, since the taste ratings were to be com

stituents. Taste appeal is determined by the texture of the flesh, juiciness, contents of total solids and total acid, the ratio of total solids to total acid, frequently referred to as the solids-to-acid ratio, and a host of trace components which go to make up "flavor."

In each taste test about 100 tangelos were used. The fruits were halved crosswise, and from each half two wedge-shaped pieces were cut for testing. Each judge was instructed to taste several pieces before rating the lot. Judges did not discuss their ratings with each other. Each judge individually appraised each lot of fruit and gave it a numerical rating, and the ratings of all judges were averaged. Tasters were not restricted to any numerical range in rating insipid or aged fruit. Scoring of all samples of tangelos was done according to the following scorecard.

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1 This scorecard was used by the panel of taste testers. A rating of 70 was selected as the arbitrary standard below which the judges would consider the fruit not acceptable, or not meeting consumer approval.

Chemical Analyses

Juice of 25 fruits from the samples rated for palatability was composited for chemical analysis. The juice was extracted by a pressure extractor {12) and strained to re

move seeds and pulp. Chemical analyses continued through the 4 seasons for 21 plots, through 3 seasons for 13 plots, through 2 seasons for 3 plots, and through 1 season for 5 plots. The analyses included determinasugars), total acid (as citric), ascorbic acid (vitamin C), and active acidity (pH). Standard methods were followed (2, 4, 7).

Evaluating Physical Characters

The appearance or "eye appeal" cannot be overlooked in general marketability, even though it may not always be correlated with taste. In this, as in other studies on citrus fruits (8, 9, 10, 12) considerable attention was given to the measuring of physical characteristics each time the fruit was rated for palatability. The measurements of these characteristics were averaged to determine the correlation between the appearance and physical qualities and the results of chemical analyses and palatability tests.

Certain characters, such as weight , volume of juice, and weight of juice are readily measured and averaged. Other characteristics, such as color and texture were determined as described herein.

Color Op Rind.—The color of the rind was determined for each sample by matching the fruit with the colors A to L of plate II. The "average" color for each sample was ascertained by assigning a numerical value to each color, averaging these values, and then converting each numerical average to the nearest color designation.

Color Of Flesh.—Color of the flesh of tangelos was determined by matching the halves of 25 transversely cut fruit with the color charts of the Maerz and Paul Dictionary of Color (13). Because the color graduations were many, these colors were grouped in five classes: PY, pale yellow; TY, tannish yellow; OY, orange yellow; YO, yellow orange; O, orange. Typical color for a sample lot was determined by the procedure given in the previous paragraph.

Condition Of Flesh.—The texture of the flesh was determined

were halved transversely. Classification was based on the percentage of tangelos in each sample that were of coarse texture, good texture, and overmature. Fruit in which the vesicle cell walls were thick and conspicuous and the juice vesicles not distended with juice was designated as coarse; that fruit in which the vesicle cell walls were thin and inconspicuous and the juice vesicles fully expanded was designated as good-textured; and that fruit in which the flesh had separated from a part or most of the rind, or where there was a separation of the segments, or granulation or drying-out of the flesh, was designated as overmature.

Results

Values obtained for Orlando, Thornton, Minneola, and Seminole tangelos by averaging original data for the plots studied are presented in tables 2, 5 to 16 and in figures 1 to 3. Values representing the 4-year averages were arithmetic averages of the total plots for the four crop years and were weighted according to the number of plots observed per year. Data for individual plots are presented in appendix, table 18. Comparisons among certain varieties and rootstocks are also presented but data are somewhat limited.

Relationship of Physical and
Chemical Factors to Palatability

Quality of citrus fruits affects prices, sales, and the consumer's decision to buy or not to buy a particular product. With this in mind, considerable study was given to the correlation of results of taste tests with chemical analyses and physical characteristics (tables 2, 5 to 16, figs. 1 to 3).

Palatability as measured by taste test panels generally increased rapidly as fruit matured, and was correlated with increases in total solids

SOLIDS, ACID, AND PALATABILITY OF
TANGELOS AT TIME OF PICKING

Averages, J952-56

%

12

10

8 %

2.C 1.0 0

RATIO"

12

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Figure 1.—Palatability (see scorecard p. 6), percentages of solids and acid by weight and solids-to-acid weight ratio of Orlando, Thornton, Minneola, and Seminole tangelos on Cleopatra rootstock at different picking periods. (Averages, 1952-56)

and total solids to total acid ratio (fig. 1), color of rind, weight of fruit, volume of juice (fig. 2), and pH values (fig.3). The Orlando reached maturity first and Seminole

last; Thornton and Minneola were intermediate. At prime condition, the Orlando and Minneola tangelos rated higher in palatability than the Thorntons and Seminoles.

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Figure 2.—Weight of juice as a percentage of weight of fruit, volume of juice per fruit, weight per fruit, and color of rind (as rated according to the standards shown in plate II) of Orlando, Thornton, Minneola, and Seminole tangelos on Cleopatra rootstock at different picking periods. (Averages, 1952-56)

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ACTIVE ACIDITY AND ASCORBIC ACID
CONTENT OF JUICE OF TANGELOS

Averages, 1952-56

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Figure 3.—Weight of ascorbic acid per milliliter and active acidity of juice of Orlando, Thornton, Minneola, and Seminole tangelos on Cleopatra rootstock at different picking periods. (Averages, 1952-56)

Table 2.—Palatability ratings: Seasonal changes in tangelos, by variety and by kind of rootstock, 1952-56

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1 Average of ratings given by about 35 tasters using the scorecard shown on p. 6.

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