Application of a Compression‐relaxation Test for the Characterization of Burlat Sweet Cherry

Mechanical parameters of Burlat sweet cherries (Prunus avium) were studied as a function of ripening during three consecutive years by using a penetration test, a compression test between two plates, and a compression‐relaxation test. The latter yields the “apparent secant modulus,” i. e. the ratio of the initial maximum compression force over the applied strain. This modulus is one of the most useful mechanical parameters to discriminate between batches because its value is clearly related to the variety and degree of ripeness. Thus, the compression‐relaxation test consistently allowed the differentiation of cherries in five degrees of ripeness.