A research and development (R&D) project being conducted by Agriculture Victoria looking at integrated quality management of stone fruit along the supply chain has given better knowledge of export performance, according to the researchers.
Horticulturist and supply chain researcher Dr John Lopresti explained the 4-5-year project at Hort Connections, explaining the state government department’s innovation protocol to maximise storage and shelf-life of not just stone fruit but mangoes. He says quite often supply chain models do not consider pre-harvest or what happens in the orchard.
“That is one of the most important factors in determining quality loss, and quality in general in export,” he said. “In pre-harvest, we are looking at the effect of individual cultivars, harvest maturity, agronomic practices and climate or environment. Then we have post-harvest treatments such as cooling, disinfestation, storage life extension and packaging. So, we have all these technologies or the ability to control or modify the way we handle our crops, and we all know that storage temperature is a key factor during export and storage duration. All these factors determine the quality loss during export.”
Photo: Stone fruit data logging (Source: Horticulture Industry Networks website)
He added that post-harvest research has been conducted for 40-50 years but has noticed a renewed interest in this area of supply chain research and this has led to more accurate and integrated results from R&D. Dr Lopresti says updated approaches are required because of new cultivars, new post-harvest treatments and changes in export market protocols and expectations.
The department did some simulations on air and sea freight in terms of cultivar performance and potential storage disorders for stone fruit, and real-time temperature monitoring, which allowed them to put together a shelf-life prediction calculator and model.
“For this project, we worked with Victorian growers and exporters in stone fruit, cherries and table grapes using various real-time logger technologies,” Dr Lopresti said. “We monitored more than 100 consignments over four years in both sea and air freight and did some retail quality assessments in the markets. We also used the data we collected to design our sea and air freight simulation trials. We all understand how important (temperature monitoring) is in the supply chain and it really should be standard practice for exporters – especially with the technology being cheap and easy to use. It potentially enables action during export, so shipments can be re-routed or action can be taken if temperatures spike, in real-time.”
Dr Lopresti says the real-time temperature data can also be used to estimate or predict the remaining shelf life of a particular crop in the export market, based on the temperature up to that point in the supply chain.
Photo: Delegates at Hort Connections listening to Dr Lopresti’s presentation via videolink (Courtesy: AUSVEG)
The project also looked at stepwise cooling after harvest. He says that there are a number of crops that are sensitive to chilling injury after harvest, including white nectarines. After more than five weeks in storage, they tend to develop flesh browning and do not ripen properly, which ultimately leads to a poor eating experience for the consumer.
“We looked at a technique where instead of directly cooling from the field down to 0-2 degrees within 24 hours, we cooled the fruit to a medium temperature of 12-18 degrees over 48 hours then cooled to final storage temperature,” Dr Lopresti said. “We had a significant reduction in chilling injury and flesh browning in long term storage. We found that those storage durations of 35-42 days are occurring in export markets, and sea freight is taking sometimes four weeks from Australia to the imported destinations. Those long storage durations are not unusual for stone fruit, and that is a real issue. We also developed commercial protocols for growers and exporters to implement pre-conditioning, and we will have some major exporters trialling this next season to try and improve their fruit.”
Simulation experiments were also conducted across 6-7 cultivars, with the early harvested fruit and commercially harvested fruit, to take into account harvest maturity. Along with real-time temperature data, the Department has formed a prediction tool or calculator, and Dr Lopresti says he has been able to get an accuracy of 2-3 days, which is fairly good due to the variability in stone fruit crops, even if picked at the same maturity.
“It is a simple calculator based on comprehensive research that can provide retailers, importers and exporters some idea of potential issues, or remaining shelf life for a particular cultivar,” he said. “This is a good way forward in terms of shelf-life prediction. In general, the work also highlighted that there needs to be more post-harvest testing in breeding programs, and that applies to other fruit and vegetable crops, not just stone fruit. There is a better understanding of the impact of temperature on quality and shelf-life, and the impact of poor temperature management with stone fruit might not be apparent until late in the supply chain.”
For information on not just this research but other fruit and vegetable R&D projects, visit Agriculture Victoria’s Horticulture Industry Networks.