Question
We handle multiple commodities for multiple customers and clients, and have three separate storing rooms for storing non-compatible commodities.
My question concerns the average life-cycle of perishables, specifically Avocados. By life-cycle, I mean the longest we could store a commodity (at its optimal cold-storage temperature) and not see product quality loss. We are in a situation here where we have Avocado pallets that were packed more than 90 days ago. This product has obviously lost quality, whether it be softness, discoloration, or a combination of both. I know that on the UC Davis Postharvest website the data given is for 7-10 storage days. We are almost ten times that.
I was wondering if there is any data or research on extended storage and the expected product loss. Our customer was not able to move the Avocados (a large amount) and wanted to point the finger at us, assuming it was a problem with Ethylene levels. It is my belief that Ethylene control can only be applied to non-ripened pallets of Avocados, not product that is entering the ripened stage of its life-cycle.
I am constantly browsing the UC Davis website for more information. I am new to this field, and the website’s assistance has been very valuable to me. (C.G.)
Answer
You ask a very difficult question to answer about avocados. I assume from what you have written that you are dealing with imported avocados that have been in the handling chain, and I also assume that you started holding the avocados when they were still firm and they have now softened. There would be many, many additional questions that would need to be asked to sort this out completely, but I will give you some general information about postharvest handling of avocados:
1) It is a good rule of thumb to try to minimize any exposure to ethylene except when you want to ripen them.
2) Low levels of ethylene during cold storage (5 C) can stimulate softening even in storage
3) The fruit will normally store (in air, not CA) for about 3 to 4 weeks. After this time you will generally see an increase in internal discoloration and decay incidence. The relative decline of the fruit is dependent on many factors including fruit harvest maturity, speed of cooling after harvest, etc.
4) Controlled atmosphere shipment will delay what I described above. Once CA is broken and the fruit are placed in ambient conditions it will continue to age in storage.
5) The cold chain should never be compromised.
6) As for the maximum storage potential, a good rule of thumb is 3 to 4 weeks at 5C but I have seen lots of fruit deteriorate before this time and seen other fruit hold up for 6 to 8 weeks even in air storage. 90 days (12 weeks) is beyond a reasonable storage period for the fruit. I would expect to see many problems with this fruit.
I hope this information is helpful and if you want to provide me with additional details, I might be able to give you more specific information.
-Mary Lu Arpaia