Mechanical behavior of papaya fruits under axial compression

Abstract

The fruits of papaya (Carica papaya L.) are very susceptible to mechanical damage, which results in heavy losses in post-harvest. The aim of this study was to evaluate the mechanical behavior of papaya fruits in post-harvest, for which two experiments were conducted in the Experimental Field The Huasteca, INIFAP during the years 2011 and 2012. The variables evaluated were the strength and deformation required for the fruit to reach the elastic limit, biocedence and the breaking point. The compression was performed with a Instron Universal 4460. In the first experiment for ripening fruit treated with pre-harvest five combinations of fertilization, the treatment N-P-K- Cu-Zn, N-P-K-Ca-Zn, N-P-K-Fe-Zn reported increased resistance to force compression and was different to the treatment N-P-K-Mn-Zn (Tukey, p≤ .05). In the second experiment three cultivars were evaluated in two states of maturity, the fruits at physiological maturity were more resistant to attain the elastic limit (414 N) in relation to ripening (67 N), with statistical differences (Tukey, p≤ .05). The fruits of the hybrid PK 02 required more force to achieve the yield strength (298 N) with respect to the fruits of the variety Maradol roja (250 N) and the hybrid PK 03 (173 N), with differences (Tukey, p≤ .05). It is concluded that papaya fruits had different mechanical behavior depending on the nutritional management, the type of cultivar and maturity.