The travelling life of capsicums and chillies
CQUniversity researchers have spent the past year tracking commercial capsicum and chilli deliveries across Australia to find out what happens to fruit after it leaves the farm.
The early results are giving growers a clearer picture of the conditions fruit experiences on its journey to market and show there can be significant variation in temperature and humidity conditions between monitored shipments.
The work is part of the five-year, $1.68 million Optimising Capsicum and Chilli Quality project (VG24002), funded by Hort Innovation through the Vegetable Levy Fund.
CQUniversity lead researcher Dr Karli Groves said the first year had focused on following fruit through the supply chain and gathering real-world data.
“We’re starting to see just how much variation there can be between consignments,” Dr Groves said.
“We’re looking at temperature and humidity from the time fruit leaves the farm, and that’s giving us a much better understanding of what conditions fruit is actually experiencing along the way.”
Researchers have used temperature and humidity trackers to monitor commercial consignments from major growing regions.
So far, 21 per cent of monitored batches did not reach the current 7–10°C temperature benchmark during monitoring, while almost half experienced moderate or high temperature variability.
For the loads that did reach the benchmark, it took an average of 10 hours to get there. On average, they spent 41 per cent of their monitored time within the benchmark range.
Rather than simply looking at whether fruit is too hot or too cold, the research has identified four different temperature patterns: in range and stable, in range but variable, out of range but stable, and out of range and variable.
Dr Groves said the next stage of the research would look at what those different conditions mean for the fruit itself.
“We now need to connect those temperature profiles with what happens to the fruit,” she said.
“Does it affect shelf life? Does it contribute to defects? And are there particular points in the supply chain where we can make a difference?”
The research is also looking at what happens before fruit leaves the farm.
Harvest times recorded across participating farms ranged from 7am to 1.30pm, while the time between harvest and cooling ranged from one to 24 hours.
Pre-dispatch storage temperatures also varied, ranging from 5°C to 10°C, with some fruit held at ambient temperature.
Researchers observed that fruit harvested during cooler parts of the day appeared to enter the supply chain at lower temperatures.
Dr Groves said it was too early to turn that observation into advice for growers.
“We’ve seen an interesting pattern, but we need to do more work before we can say what growers should or shouldn’t be doing,” she said.
“That’s really important to us. We want the recommendations that come out of this project to be based on good evidence and to be useful in a commercial growing environment.”
The project will now move into its second year, with researchers investigating how quickly fruit needs to be cooled after harvest, how harvest timing and pre-dispatch conditions affect quality, and what temperature fluctuations mean for shelf life.
The team will also continue tracking fruit further through the supply chain, including wholesale and distribution, before testing the findings under commercial conditions.
The project aims to develop practical recommendations to help maintain fruit quality, reduce post-harvest losses and increase the amount of saleable fruit.
Dr Groves said the research was ultimately about giving growers better information to make decisions on-farm and after harvest.
“We’re not looking for a one-size-fits-all answer,” she said.
“We want to understand what is happening to the fruit and then work with growers to develop practical ways to protect its quality.”
The Optimising Capsicum and Chilli Quality project is delivered by CQUniversity in partnership with Bundaberg Fruit and Vegetable Growers, Granite Belt Growers Association, Bowen Gumlu Growers Association and VegetablesWA.
This project has been funded by Hort Innovation, using the vegetable research and development levy and contributions from the Australian Government. Hort Innovation is the grower- owned, not-for-profit research and development corporation for Australian horticulture.
