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Title: MEASURING BLACKBERRY FIRMNESS RAPIDLY: A COMPARISON OF SUBJECTIVE RATINGS AND INSTRUMENTED COMPRESSION MEASUREMENTS

Author
item Perkins Veazie, Penelope
item ARMSTRONG, P. - OKLAHOMA STATE UNIVERSITY
item CLARK, J.R. - UNIVERSITY OF ARKANSAS

Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: 2/22/2000
Publication Date: 7/1/2000
Citation: N/A

Interpretive Summary:

Technical Abstract: Firmness of blackberries greatly determines shelf life for fresh market. Firmness in blackberries appears to be due to a combination of skin toughness and internal receptacle to permit large sample size measurements. Subjective rating of fruit require consistent evaluation by raters over harvest dates and years, and is subject to fatigue error. The FirmTech2 firmness tester was developed to provide rapid compression measurements and has been successfully used in determining the firmness of cherries and blueberries. Blackberries from a large number of clones ranging in firmness from rock-hard to squishy were measured with the FirmTech2 using a deformation range of 25 to 100 grams. Additionally, blackberries were placed in storage at 2, 5, and 2/20 C to monitor effects of storage temperature on blackberry firmness. Berries were subjectively rated and then placed on the Firmtech for measurements. A comparison of firmness readings for fruit only in the '1' (firm) category was made. Differences found among fruit readings agreed with observed differences in field subjective ratings. Stored fruit that had become soft and mushy could not be statistically differentiated from firmer fruit in quantitative readings. In conclusion, the Firmtech2 allowed rapid evaluation of breeding lines before storage.