Abstract
Firmness is a critical quality factor in kiwifruit marketing. We propose a simple dynamic force/deformation (F/D) test to evaluate kiwifruit firmness nondestructively. Various parameters from a low-frequency dynamic F/D test were compared to data from Magness-Taylor (MT) puncture F/D curves. Resonant frequencies from dynamic F/D did not adequately predict kiwifruit firmness as measured by MT maximum force (r = 0.60), while amplitudes at low frequencies predicted better (r = 0.81). The dynamic test data were more closely related to slope of the puncture curves than to maximum force, the parameter traditionally reported. Amplitudes near 60 Hz were found to be the best predictors of MT values (r = 0.88). Adding amplitudes near 98 Hz to the regression equation improved prediction only slightly (R = 0.91). A relatively simple firmness tester could be devised on the basis of 60-Hz vibrations.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
