The Global Leader In Viscosity For Over 75 Years
Brookfield AMETEK



Simple penetration test of pears.

Test Objective

To quantify the difference between ripe and unripe pears through implementation of simple penetration principles.


Pressure tests have traditionally been applied in the quantification of textural properties of pears. Correlation of instrumental mechanical measures with perceived sensory characteristics provides an objective method of quantifying subjective parameters. Quantification of textural properties is beneficial in:

  1. Determining optimum point of harvest
  2. Controlled ripening and storage
  3. Optimization of process operations (e.g., freezing, blanching, cooking, etc.)
  4. Indicator of potential mechanical injury (bruising)
  5. Control of raw materials through application of objective quality measures
  6. Conformance to customer requirements and supply of correctly ripened products
  7. Quantification of product shelf-life in relation to ripening


Samples were taken from modified atmosphere packaging on day of purchase at ambient conditions. A small section of each fruit was removed (as in illustration) to give stable test surface through which to penetrate.


Click to enlarge


Click to enlarge



The unripe pear is much harder than the ripe pear; it exhibits greater resistance to penetration by the 2mm probe. The inner flesh of the ripe pear is much softer than the unripe pear, as shown by the mean of selected peaks, after rupture or yield of the skin.


This simple test clearly shows differences in pear ripeness.