ARS | Publication request: A BIOYIELD TESTER FOR MEASURING APPLE FRUIT FIRMNESS

Submitted to: ASAE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: May 16, 2005
Publication Date: July 17, 2005
Citation: Lu, R., Srivastiva, A., Beaudry, R. 2005. A bioyield tester for measuring apple fruit firmness. ASAE Annual International Meeting. Paper No. 056171.

Technical Abstract: The objective of this research was to evaluate a newly developed bioyield tester for measuring apple fruit firmness and its measurement variability within individual fruit. The specially designed soft tip bioyield probe was coupled to a handheld digital force gauge that was mounted on a tabletop motor driven stand. Bioyield force and Magness-Taylor (MT) firmness were measured on Delicious apples under different storage conditions and/or treatments. The correlation between MT firmness and bioyield force ranged from 0.62 to 0.81 with a standard error between 5.2 N and 6.7 N. Bioyield force decreased at about the same rate as that for MT firmness when apples were stored in refrigerated air at 5 deg C. When fruit were kept at room temperature (24 deg C), the percent decline in bioyield force over the test time period was less than that in MT firmness. Bioyield force measurements within individual apples were 42.6% to 46.8% more variable than MT firmness, as measured by the coefficient of variation. Since the bioyield tester does not degrade apple fruit, it will be useful for measuring and monitoring fruit firmness during growth and harvest and postharvest operations.