Avocado maturity testing using dry matter

Page last updated: Thursday, 17 May 2018 - 11:46am

Fruit must meet minimum quality levels to meet consumer expectations and encourage return purchases. Avocado fruit maturity will not improve after picking, so it is essential that the fruit reaches required marketing preferences before harvest. Research has shown a good relationship between dry matter content, fruit maturity and consumer preference. The following article provides a simple guide to testing dry matter.

Introduction

Avocados should not be harvested until they reach a degree of maturity at which they will ripen to acceptable eating quality and deliver a positive experience to consumers.

Harvest maturity will vary from year to year and with location on your property for each variety. Rootstocks may also have an influence.

Determining maturity

Avocado fruits have a number of characteristics that help indicate harvest maturity.

Judging maturity on these characteristics is not reliable, but with experience in comparing them with dry matter test results, they can help indicate when to start dry matter testing. These characteristics include:

  • fruit stalk is larger, swollen and distinctly yellow, rather than green
  • seed coat is dry, dark and somewhat shrivelled, rather than pale whitish
  • fruit is generally larger — but not always so
  • skin is dull and lustreless, with a powdery appearance rather than shiny. The usefulness of this depends on variety. For example, it is not much use on the early, thin-skinned types such as Bacon.

Percentage dry matter

Percentage dry matter is the easiest of the reasonably accurate maturity tests.

Research has shown a good correlation between dry matter and consumer acceptance. The level at which you harvest will depend on variety and intended market. For example, consumer research conducted for Avocados Australia Limited has demonstrated that the variety Hass has improved consumer acceptance if left to reach at least 23% dry matter.

Note that varieties also have an upper level of dry matter (maturity), after which palatability drops off. This is heavily location–dependent. Growers should discuss this with their marketing group.

Author

Alec Mccarthy