Post-harvest researchOver fifty air and sea freight table grape shipments were monitored from Victoria through to Asian countries using a range of real-time temperature loggers. Data collected were readily accessible via web-based dashboards, potentially allowing growers and exporters to make immediate informed logistical and marketing decisions if fruit temperatures increased above optimum, rather than having to wait for the consignment to arrive at the final destination. In the monitored shipments, generally very good temperature management was observed during sea freight, whilst on occasion temperature spikes of up to 5 °C were observed during unloading of containers and during transport to importer storage facilities.
The project tested different types of temperature loggers to determine their practicality and functionality (i.e. ease of use, cost, accuracy, reliability, single use or reusable and if it has SMS/email notifications) that may be of benefit to both growers and exporters.
On this page:
- Introduction
- Materials and methods
- Results
- Case Study
Introduction
Materials and Methods
As part of the temperature monitoring component of the SSC project, Agriculture Victoria recently monitored one sea freight container from Australia to China using a Sensitech TempTale® GEO Eagle temperature logger and one to Malaysia using a Frigga B9E logger with an external probe that also measured container temperatures. The advantage of these loggers is that they are relatively inexpensive (~ A$75+ each) and the shipment information (time, temperature and location data) can be accessed in ‘real-time’ on the cloud-based system as they contain a 3G-enabled SIM card that works off triangulation with mobile phone towers. Although no data is transferred when the logger is out of range (i.e. at sea), the logger temporarily stores the temperature data so that when it comes back into mobile phone coverage the data is uploaded. The Sensitech logger and Frigger logger were deployed in a carton of Crimson seedless and Luisco seedless table grapes repectively at a packhouse in Mildura (north-western Victoria) and the route and temperature monitored along the entire trip to Mainland China and Malaysia.
A Sensitech Temptale® GEO Eagle temperature logger (Figure 1) used to monitor a sea freight consignment of Crimson seedless table grapes and its route from Mildura to Hong Kong (Figure 2) followed by road transport to Mainland China (Figure 3).
A Frigga B9E logger (Figure 4) used to monitor a sea freight consignment of Luisco table grapes (Figure 5) and its route from Mildura to Malaysia (Figure 6).
Figure 1. Sensitech Temptale® GEO Eagle temperature logger
Figure 2. Table grapes – sea freight journey from Adelaide to Hong Kong
Figure 3. Table grapes - road transport from Hong Kong to Mainland China
Figure 4. Frigga B9E logger www.friggatech.com
Figure 5. Sea freight consignment of Luisco table grapes
Figure 6. Route from Mildura to Malaysia
Summary of results and discussion: tracking and inspection
Tracking
China:
The logger successfully tracked the shipping container and provided updates in Adelaide, Fremantle, Singapore, Hong Kong and China (Figure 1-3, see Methods and Materials). Transit times from Mildura to Hong Kong were approximately 24 days (Figure 7). The temperature profile shows a relatively ‘good’ cool-chain of between 1.0 to 1.5 °C with the occasional temperature spike to approximately 2 °C due to trans-shipping in Fremantle and Singapore.
The larger spike in temperature was attributed to unloading at the port in Hong Kong and the subsequent road transport to the importers warehouse in Guangzhou, China. Ideally, mature table grapes should be stored at a pulp temperature of -1.0 to 0.0 ̊C and 90 to 95% RH which will limit the rate of water loss from fruit stems and help extend shelf life. Therefore, the temperature of the monitored consignment was slightly higher than optimal. Air temperatures quickly recovered once power was restored (Figure 7).
Figure 7. Temperature profile of Crimson Seedless table grapes exported from Mildura to Hong Kong and Mainland China.
Malaysia:
The Frigga logger successfully monitored the temperature from the farm in Mildura all the way to Malaysia. Luisco table grapes were cooled to less than 3 °C within 12 hours of harvest and this temperature maintained for the entire trip of approximately ~35 days to Malaysia. Logger updates were observed at several locations in Adelaide, Fremantle, Indonesia, Singapore and Kuala Lumpur. (Figure 8).
Figure 8. Logger updates observed at Adelaide, Fremantle, Indonesia, Singapore and Kuala Lumpur
Inspection
China:
Scientists from Agriculture Victoria inspected another consignment of fruit that was stored at approximately 4 °C for up to 13 days at the importers warehouse. This fruit was part of a packaging trial and had recently been removed from the cool room prior to measuring the grape surface temperature with a handheld infrared digital sensor (Figure 9). Four to five grape bunches were then sub-sampled from multiple cartons and the fruit quality assessed within 24 hours. Soluble solids concentration of grapes as measured with an Atago pocket brix-acidity meter ranged between 22 and 26 °Brix with an acidity level of approximately 1%.
Overall quality of the grapes was generally ‘good’ with only slight browning on the main stem and laterals (Figures 10a & 10b). Minor scarring and some blemishes were observed on the berries which may deter consumers or result in a less than premium product. Eating quality was mostly ‘good to very good’ due to firm berries, high sugar levels and low acid concentration.
Data gained from these trials will be used to validate predicted changes in table grape quality from models developed in static experiments at Agribio, Bundoora. In these controlled experiments, fruit will be stored under different time and temperature regimes so that response functions can be developed to help predict changes in fruit quality and remaining shelf-life.
Figure 9. Measuring the surface temperature of Crimson Seedless table grapes with a handheld infrared digital sensor.
Figure 10a. Visual inspection and quality assessment of Crimson Seedless table grapes in Guangzhou, China.
Figure 10b. Visual inspection and quality assessment of Crimson Seedless table grapes in Guangzhou, China.
Malaysia:
Agriculture Victoria contracted a surveyor to inspect five bunch bags soon after arrival in Malaysia. A delay of several days at the freight forwarder in Mildura was due to combining a small sample of trial fruit with a commercial shipment. Overall quality was very good as assessed using a five-point rating scale (where 1=none, 3=slight and 5=severe). Main and lateral stem browning was minimal at less than 1.8 (Figures 11 and 12). Berry drop (or shatter) was rated at less than 1% and SSC high at 19 °Brix.
Figure 11. Minimal berry shatter, main and lateral stem browning was observed on Luisco table grapes
Figure 12. Visual inspection and quality assessment of Luisco table grapes in Kula Lumpur, Malaysia
Data gained from these trials will be used to validate predicted changes in table grape quality from models developed in static experiments at Agribio, Bundoora. In these controlled experiments, fruit is stored under different time and temperature regimes so that response functions can be developed to help predict changes in fruit quality and remaining shelf-life.
Case Study
Video: Interview with Allan Anderson, Managing director of AND Fresh Pty Ltd – advantages of temperature loggers and examples
ANDFesh is an exporter and logistics business, and fruit producer. They have invested in real-time data-loggers as part of their export business for fruit growers.
Transcript of Video interview - Allan Anderson (ANDFresh)
Temperature monitoring has been happening over the last 50 years, anyway. It started off with analogue temperature recorders in the form of paper and a battery with a, almost like a lie detector only, logging temperature. And, that was always put in sea containers. And, the first thing someone did the other end was dragged it out, rip it apart and look at the chat and that's progressed into, I would say digital loggers, and which had to be recovered, plugged in, downloaded to software- quite cumbersome in some respects. Then the industry progressed to USB loggers that were plug and play, and they're still about today, but they've still got to be recovered at the end point, whether it's by sea or by air or wherever. It's still got to be recovered, plugged into a PC and then downloaded. And somebody's got to find them, then they've got to send the information off. And they only, they can choose whether they find that, choose whether they plug it in, choose whether they send it to you. When there's insurance involved with sea containers, they must put two of those USB loggers in every container, to partially guaranteed that they will at least one back. That progression to real time has meant that well, one for insurance purposes, you only need one real time longer, because we're guaranteed to get the information. We're getting it all the time throughout the journey. The other thing with a real logger is that you, basically you can, I wont's say 'put out the fires before they start', but you can see what's happening, from the minute you're load into either a see freight or an air freight. And, if there's a problem before it leaves Australia, you can deal with that problem. If there's a problem during transit, you can at least know, before, upon arrival that you've got a problem. Then you can deal with it. And our motto is ‘manage the outcome’. In sea containers, if you're going into a protocol country, you can, you can either, if there's a problem, you can divert the container into a non protocol country, or you can alert the customer and say, we've got a temperature issue. We need to make a claim.
I think what it'll do is it'll make every link of the chain more responsible if they know it's happening. Look, shipping lines are becoming more and more responsible as well. And they tell me that they are putting, some of them are putting monitoring systems in, but traditionally, any system shipping lines have in, they do not impart their knowledge.
We're exporting stonefruit, citrus, mangoes, table grapes. We have some exports going out every week of the year. We do two things. We have our own exports, of which we religiously use loggers in. And then we service the fresh produce industry with loggers. So we sell to either growers-producers, grower-producer- exporters or exporters, and they will then put the logger in the product. We even sell to transport companies who, in the past, when there's been a problem, with outturn, the first thing in the producer turns to as the transport company and blames them. And, we've had multiple transport companies now approach us to be able to put them in their transport to at least prove that they're not at fault, it's happening somewhere else.
We've had a couple of instances in the grape industry this last season, in the 2020 season where, in one instance, I got a call from an exporter-grower who said 'Oh your logger's not working.' And, it had been sitting on, I think something like nine or 10 degrees for seven hours. And he said 'your logger's not working.' And so I had to look at it and, we've never had an instance of a logger not work. And it's always been, outside influences, and that in this case the generator on the train wasn't working. So it had travelled for seven hours at 10 degrees when it should have been travelling at zero to one. And, so they were able to then notify the people that run the train and, and put everybody on notice that they could have a potential claim.
Another instance where a container went by road from Mildura to Adelaide. And by the time it got to Adelaide, they had to notify the shipping line that the container wasn't working properly. And that got to the point where the shipping line, at their expense, actually unloaded that container, the produce had of that container and put it into another one because of a malfunction.
Acknowledgements:
The Serviced Supply Chains project is funded by the Hort Frontiers Asian Markets Fund, part of the Hort Frontiers strategic partnership initiative developed by Hort Innovation with co-investment from the Department of Agriculture and Fisheries, Queensland; Department of Jobs, Precincts and Regions (Victoria); Manbullo (mangoes); Montague Fresh (summerfruit); Glen Grove (citrus); and the Australian Government plus in-kind support from The University of Queensland and the Chinese Academy of Sciences.