Ripening behaviour and consumer acceptance of 'Conference' pears during shelf life after long term DCA-storage

With the increasing demand for ready to eat fruit, understanding how pear quality evolves during shelf life (SL) is of paramount importance for retailers. Accordingly, the relationships between physicochemical quality parameters, the emission of volatile compounds and consumer satisfaction were investigated in 'Conference' pears from different orchards and stored at 20 degrees C following 8 months of cold storage (-0.5 degrees C) under dynamic controlled atmosphere (DCA). Our results showed that DCA storage strongly inhibits firmness loss (< 5%) without negatively affecting other quality traits. Upon removal from cold storage and ripening at 20 degrees C, 'Conference' pears loss nearly 80% of its initial firmness in only 5 d. Firmness evolution from harvest to 5 d of SL was successfully fitted with a reverse Gompertz equation (R-2 > 0.96). Prolonged DCA storage of Conference did not completely impede ripening as indicated by the reducing trend of I-AD and the ethylene postclimacteric behavior of the fruit during SL. In parallel to the decrease of firmness during SL, there was a consistent increase in most ester-type volatiles and especially in hexyl acetate and butyl acetate. Generally, the highest consumer satisfaction after DCA cold storage of 'Conference' pears was reached after 3 d at 20 degrees C. In this sense, the most appreciated pears by consumer were those showing high flavour in combination with firmness values in the range of 10-30 N. The Partial Least Square (PLS) model showed that total soluble solids (TSS), the ratio TSS/TTA (total titratable acidity), consumer flavour perception and some particular volatile compounds (i.e. methyl, ethyl and hexyl acetates as well as ethyl trans,cis-2,4-decadienoate) were positively correlated to consumer's overall liking while firmness, TTA and index of absorbance difference (I-AD) had a negative correlation and higher prediction capability.