TEXTURE DETERMINATION OF AVOCADO (PERSEA- AMERICANA MILL) BY PENETRATION TESTS

Penetration tests of avocados at two stages of maturity were performed with an universal testing machine fitted with different diameter Magn ess-Taylor plungers. The shape of each force-distance curve was analys ed and the maximum force, yield force and yield point distance were de termined. There were no significant differences between the maximum an d yield forces; the yield point distances increased with the plunger d iameter. The compression and shear components of the penetration force were determined. With unripe avocados, the dominant effect was of a c ompression nature. Both components contributed, approximately, equally in soft avocados. Results showed the compression component increased with the plunger diameter. Finally, the readings obtained with the Eff egi hand pressure tester and the universal testing machine were compar ed: the Effegi can be used for unripe avocados with the 3/16'' plunger . With ripe avocados, the Effegi fitted with a 9/16'' plunger may be u sed if a significant level of 1% is accepted.