Reducing flesh bruising and skin spotting in Hass avocado (AV10019)

What was it all about?

Flesh bruising is a major postharvest concern for the avocado industry. As much as 80 per cent of fruit on retail display can have some degree of internal quality issues, mainly flesh bruising.

This project set out to identify critical points in the supply chain where flesh bruising happens.

The project was comprised of several parts:

• Through a series of laboratory experiments, relationships between applied mechanical forces and bruising in Hass avocado were explored
• An MRI scan was evaluated as a way to assess bruising
• Fruit was gathered at six serial supply chain points: ripener arrival, ripener dispatch, distribution centre arrival, distribution centre dispatch, retail store arrival, and retail store display, and assessed for bruising at each point
• Wholesalers, retailers and shoppers were surveyed to assess attitudes to avocado appearance.

Findings included:

• The various ways that avocados can be bruised were documented, with bruising increasing with fruit softness, fruit harvested earlier in the season, and trays dropped on an angle rather than horizontal, as well as with stronger impacts
• MRI proved to be a useful tool for assessing bruising
• Bruising increased as the fruit passed through the supply chain, but was worst affected at the retail store display point
• Three commercially available means of determining impacts were tested in supply chain experiments as potential decision aid tools, to avoid squeezing by shoppers
• The impacts received by fruit during transit was successfully monitored using devices placed into trays
• Wholesalers and retailers were found to be less tolerant of avocado skin spotting than shoppers.

The research team’s recommendations were:

• Harvest fruit at and above the minimum recommended dry matter content
• Maintain stringent low temperature management including at retail outlets
• Ensure rapid progress through the supply chain to get produce to shops faster.