
%0 Journal Article
%A Macnish, A. J. 
%A Joyce, D. C. 
%A Shorter, A. J. 
%T A simple non-destructive method for laboratory evaluation of fruit firmness
%J Australian Journal of Experimental Agriculture
%D 1997/10/13
%V 37
%N 6
%P 709-713
%K 
%R https://doi.org/10.1071/EA97033
%U https://www.publish.csiro.au/paper/EA97033 
%X Summary. Devices which offer simple, inexpensive, reliable and non-destructive objective measurement of fruit firmness assist in the monitoring of quality. For the present study, the Analogue CSIRO Tomato Firmness Meter (AFM), which measures fruit deformation under a 500 g load applied for 30 s was modified by replacing the analogue displacement gauge with a digital gauge and by using a laboratory jack for positioning the fruit in the vertical dimension. Non-destructive measurements of tomato fruit softening during ripening and determined with the Digital Firmness Meter (DFM) were strongly correlated with both firmness measured with the AFM (r2 = 0.96, n = 19) and with firmness determined subjectively by hand pressure (r2 = 0.93, n = 19). Similarly, mango fruit softening during ripening was monitored and DFM and hand firmness measurements were well correlated (r2 = 0.95, n = 10). The firmness of individual fruit could be measured around 20% faster with the DFM than with the AFM, and displacement was easier to read from the digital than from the analogue display. The DFM proved to be a suitable device for measuring fruit firmness in postharvest laboratory studies and warrants evaluation under commercial packing and handling conditions. 
