Maturity Indexing and Postharvest Performance of Newly Developed ‘Lamb Hass’ Avocado Fruit

Abstract

ABSTRACT This study was conducted to identify reliable science-based maturity indices for ‘Lamb Hass’ avocado fruit and evaluate the effect of harvest maturity on the fruit postharvest performance. Fruits were harvested from outside and inside canopy positions at early and mid-season for quality assessment. The results showed that the canopy position had a highly significant effect (p < .001) on all maturity parameters: dry matter (DM) content, moisture content (MC) and oil content (OC). The outside canopy fruit were more mature (30% DM, 70% MC, 14.9% OC) than those harvested from the inside canopy (28.9% DM, 71.1% MC, 11.75% OC) at minimum maturity. However, fruit DM and MC did not differ significantly (p > .05) between the early and mid-season fruit, whilst significant differences in OC were found between the two harvesting stages. In both harvesting stages, the canopy positions did not affect the rate of fruit mass loss. Nonetheless, the overall analysis showed that early season fruit had a significantly (p < .001) higher fruit mass loss rate than the mid-season fruit. Notably, fruit maturity did not have a significant effect (p > .05) on the fruit softening rate as insignificant differences between the two harvesting stages were observed. In both the harvesting stages, inside canopy fruit were characterized by a higher concentration of mannoheptulose and perseitol than the outside canopy fruit. The early and mid-season fruit also differed significantly (p < .05) in phenolic content; with the mid-season fruit having a high phenolic content (2.7 µm/g) than the early season fruit (1.8 µm/g), suggesting the possibility of increased mesocarp discolouration with the advancement in maturity. These findings will be a valuable tool to assist growers in assessing fruit readiness for harvest and understanding the influence of maturity on the fruit postharvest behavior.