NE-183 Fruit Quality Evaluation Protocol
Revised, July 1998

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:

1.Fruit weight. Record the composite weight of fruit to the nearest gram.

2.Fruit 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.

3.Soluble solids concentration (SSC). Determine the SSC and report in % to one decimal from a composite juice sample collected from all 10 fruit.

4.Starch 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:

1.Fruit weight. Report the weight of each of the 10 fruits to the nearest gram

2. 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 decimal.

3.Titratable 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).

4.Color 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.

5.Fruit overcolor (red). Estimate to the nearest 5% the percent surface showing typical red overcolor for the cultivar. Report the mean for the 10 apple sample.

6.Fruit 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.