Fruit Quality Evaluation Protocol
Treat each individual tree as a single
replication and harvest and collect quality data from each tree. If tree
has less than 10 fruits, indicate number of fruits. Report data as described
in the memo dated November 6, 1995, "NE-183 Regional Project Data Collection".
If data is collected on individual fruits for std. deviation analysis, use
columns to report data for individual fruits, e.g. fruit weight would have
10 data columns each representing a single fruit's weight.
Select at random a 10 fruit sample
for quality evaluation and collect the following data:
weight. Record the composite weight of fruit to the nearest gram.
length and diamater. Record the total length and total diameter of the 10
fruit sample to the nearest millimeter. This can be easily done using a
wooden trough with a meter stick attached in the bottom of the trough.
solids concentration (SSC). Determine the SSC and report in % to one decimal
from a composite juice sample collected from all 10 fruit.
index rating. Assign a starch index rating to each individual fruit and
compute the mean SI for the 10 apple sample. Record the mean SI index rating.
Use the procedure and the 1 to 8 rating scale described in Cornell Information
Bulletin 221. Report SI rating to one decimal.
The following data collection is optional:
weight. Report the weight of each of the 10 fruits to the nearest gram
Flesh firmness. Record the mean flesh
firmness from two readings per fruit using a McCormick (Effigi) penetrometer,
EPT-1 Electronic Pressure Tester (Lake City Tech. Products), or similar
instrument. Use the standard 11.1 mm penetrometer tip. Read to the nearest
0.25 pounds. Report mean firmness as pounds firmness to the nearest one
acidity (TA). Determine TA on the composite juice sample. Add a 10 gram
aliquot of juice to distilled water and bring to 100 grams. Titrate to an
end point of pH 8.2 using 0.1 N NaOH. Report as % acidity (as malic acid)
using formula: % acid = ml NaOH x 0.067 (mEqwt for malic acid).
space readings. Record the L*a*b* values from four quadrants of the fruit
at the equator. If fruit has less than 90% surface red color(see
option 5 below), record as many representative readings as possible (max.
of 4 readings) from areas withred color
or blush. Compute the mean L*a*b* value and report for each fruit. Report
values to one decimal. Hue angle will be computed for each fruit and the
mean for a cultivar by the statistician.
overcolor (red). Estimate to the nearest 5% the percent surface showing
typical red overcolor for the cultivar. Report the mean for the 10 apple
russet. Estimate the severity of russet on a scale of 0 = none to 5 = severe
(25% or more of fruit surface with russet). Use the following scale: 0 =
none, 1) = 0.1% to 5%, 2) = 5.1% to 10%, 3) = 10.1% to 15%, 4) = 15.1% to
20%, and 5) = 20.1% to 25%. Report the mean russet rating for the sample.