Hernández, I., Pontificia Universidad Católica de Valparaíso, Escuela de Agronomía, Quillota, Chile
Fuentealba, C., Pontificia Universidad Católica de Valparaíso, Escuela de Agronomía, Quillota, Chile
Olaeta, J.A., Pontificia Universidad Católica de Valparaíso, Escuela de Agronomía, Quillota, Chile
Poblete-Echeverría, C., Department of Viticulture and Oenology, Faculty of AgriSciences, Stellenbosch University, Matieland, Stellenbosch, South Africa
Defilippi, B.G., Instituto de Investigaciones Agropecuarias INIA, La Platina, Santiago, Chile
González-Agüero, M., Instituto de Investigaciones Agropecuarias INIA, La Platina, Santiago, Chile
Campos-Vargas, R., Centro de Biotecnología Vegetal, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile
Lurie, S., Department of Postharvest Science of Fresh Produce, Volcani Center, Israel
Pedreschi, R., Pontificia Universidad Católica de Valparaíso, Escuela de Agronomía, Quillota, Chile

Hass avocado ripening heterogeneity generates logistics problems to importers and ripeners due to higher labour costs, inconsistent quality delivery and postharvest losses. The main aims of this research were: (i) to evaluate two postharvest pre-treatments (nitrogen shock N2 and heat shock) prior controlled atmosphere (CA) on reduction of ripening heterogeneity of Hass avocado without being detrimental to fatty acid profile and (ii) to study the potential metabolic processes implicated in such ripening synchronization with focus on cell wall remodelling and ethylene biosynthetic pathways. Results showed that heat shock prior to CA storage significantly reduced ripening heterogeneity in early and middle season fruit while N2 + CA did not. Pectin methyl esterase (PME) and polygalacturonase (PG) activity did not display significant differences among treatments. Additionally, none of the treatments altered the fatty acid profile. ACS transcript for early and middle season fruit kept constant during storage for heat + CA, CA and N2 + CA. ACO instead displayed less abundance after 21 d storage for all treatments of early season fruit. These results point to ripening synchronization in Hass avocado subjected to heat to be related to induction of metabolic processes related to ethylene (biosynthesis), possibly at the action level (receptors) but the efficiency of the heat treatment was related to the maturity stage of the batch. © 2017 Elsevier B.V.