The Cold Storage Condition for a Fruit
If there were no cold chain for fresh fruits, the quality of most of our fresh produce would probably be compromised. Even just in a matter of a few days, it most likely wouldn’t be fresh anymore. It will begin its decay process from the moment it is harvested, and different kinds of bacteria will already start to develop.
Cold storage is almost a basic necessity in helping prolong the shelf life of its produce. Fruits, in particular, must be stored in refrigeration to ensure that the quality would last for at least more than a week. The reason being is due to the temperatures in the cold storage that help prevent the germination of pathogenic fungi. It functions as the means to minimize the spoilage of fruits. One example of temperature affecting the fruits is Apples; when kept at ambient or room temperatures, they soften and thus become less desirable in texture. The same applies to pears as well. Several fruits require different levels of temperature and humidity, thus the customization of cold storage is highly important.
For the tree fruits, the aforementioned apples, and pears share the longest life expectancy. If under ideal conditions, it can stay for at least up to four months, and if in Controlled Atmospheres (CA), it can last up until twelve months. The cold storage temperatures depend on the chilling sensitivity of its products, with at times ranging between 32 to 38ºF.
It isn’t really common to have one temperature that can cater to the needs of all fruits (or even vegetables) due to different reasons such as crop origins, the season of harvest, or crop maturity. They all function in an important role in determining the best temperature requirements. However, as a ‘rule of thumb’, the fruits and vegetables from the cooler seasons should be stored at 0-2°C while those from the warmer seasons are best kept in 7-10°C. However as stated earlier, some fruits and vegetables serve as an exception to these rules.
Life of a Perishable
An accessible overview has been devised by the Food & Biobased Research, showing details of current existing techniques and also the new preservation techniques with a major impact on the optimal storage life of products in numerous fresh chains. They also described the main quality and features of at least twenty fruits and vegetables. The overview serves as a suitable instrument in enabling fruit and vegetable retail companies in checking whether and to what extent a particular conditioning technique helps in prolonging the storage life or in reducing the risks of multimodal fruit and vegetable chains.
Techniques for Preservation
The Wageningen UR Food & Biobased Research, which was commissioned by the Fresh Corridor expertise network, to help research on the impact of several preservation techniques on product quality. According to their study, it shows that a closed cold chain and temperature control are both huge important methods in preserving the quality of fresh product chains. Other kinds of preservation techniques like controlling the humidity and/or other gases, will only be good if there is a noticeable development or enhancement in the cooling strategy.
Only the correct preservation techniques help fruits (and also vegetables) maintain their high initial quality for as long as it is possible. According to the study, the most important ways of preserving are control of temperature and a closed cold chain. The second most important way is humidity control. Controlled Atmosphere is rather useful when it comes to chains with a longer distribution. Controlled Atmosphere, when directly connected at the location of where it harvested, only reinforces the process.
A sufficient way of limiting the ethylene concentration is by refreshing the atmosphere with air from the outside, while Controlled Atmosphere operates on different kinds of air-purifying techniques. Meanwhile, on the other hand, UV, Ozone, and other kinds of air disinfectants show limited added benefits. Since this equipment is rather relatively new, it is still hard to make an objective judgment since there is still little research and minimal data about it.
One thing to add also is that picking the right packaging can prevent many quality problems. It’s very important to use the right materials, especially if it is an extra form of protection that is in the form of MA packaging. The cooling process is also determined by factors such as the design of the packaging and how the products are stacked.
Crucial Function of the Citrus Export Cold Chain
One of the most integral and critical roles in the world of citrus export cold chain is in ensuring that the qualities and conditions of fruit are being met or rather developed. Reducing the risk of economic losses means that all of the stages in the cold chain must be managed accurately and aptly.
The Importance of Harvest
One key factor in taking measures of appropriate and reliable quality for customers and consumers is that the temperatures being managed after they are harvested.
A Serviced Supply Chains project team has conducted work from Gayndah to Jakarta over the last couple of seasons with the citrus grower and exporter Greg Parr in monitoring the citrus lemon export consignments.
Before the forced air cooling and loading into the refrigerated sea containers, fruit cartons were installed with loggers.
Monitoring Invaluable Citrus Data
Using the wireless sensors and a range of conventional manual download (USB) loggers, monitoring of the temperature was being undertaken from the moment of harvest up until the outturn in the export market.
During the seasons of 2017 and 2018, monitoring during that time was used in documenting variations in ethylene and temperature conditions within lemon supply chains and also in identifying the critical control points that are expected to influence outturn quality, most especially skin damage likely related to chilling.
The Four Critical Points to Consider
During the process of chain monitoring, four critical control points were identified and also investigated by laboratory trials. The following critical control points are:
- The process of degreening before packing and grading, in which the risk of skin damage after cold disinfestation is increased if there are temperatures that are above 24°C and ethylene concentrations that are above 5ppm.
- The period of fruit consolidation, in which changes in time between packing and forced-air cooling during which fruit are put at 7°C might probably produce a conditioning effect.
- Forced air cooling prior to loading containers, in which the risk of skin damage has a probability of increasing if there are variations in conditions that bring all of the fruit down to the disinfestation protocol temperature.
- The in-transit disinfestation conditions from container loading to market destination, in which the risk of skin damage increases when the temperature reaches below 2°C.
The process has focused more on developing the temperature and managing the ethylene during the process of degreening moreover guaranteeing that the fruit will require multiple degreening events that were not included in export shipments. He has been closely working on collecting temperature data, within the chain, with the DAF. Furthermore, Greg has been working with analyzing the monitoring data, and in conducting thorough experiments to help in verifying where chain improvements can be made for the export customers that can be satisfied with consistently delivered lemons.
In conclusion, how do we improve the cold chain of these fruits?
After reading this article, it is clear that taking care of our fruits and vegetables is no measly task and rather if you are someone who often stores fruits and vegetables in your home, you’d want to be able to consume them before they turn mealy. That’s why it’s important to note the temperature regulations when storing certain kinds of fruits like citrus fruits.
It is very important to note that fruits and vegetables must always be stored separately because many fruits produce the ethylene hormone once they begin the process of ripening, which changes the color, texture, and even the flavor of the produce. Normally this wouldn’t be a concern, but the ethylene hormone affects its surrounding area, making the ripening process faster than normal. That’s why if fruits that contain this hormone are stored with vegetables, it will affect the quality and speed up the aging process of the product, thus creating food waste.
The same idea applies when stocking in the cold storage unit, meaning that you have to be careful in making sure it is not overstocked as it can risk speeding up the deterioration as well. Give your fruits and also your vegetables enough room so the internal fan can distribute the air freely.
Know the important information and factual history of the produce you consume such as the previous quality inspections, prior goods preparation, product maturity, and produce grading, to ensure that it can last a longer shelf life in your cold storage and to prevent any risk of spoilage. Remember again and don’t forget that there isn’t a temperature that fits all, so make sure that each variety of produce has its needs and requirements taken care of.
Reference Links:
- https://scholar.sun.ac.za/handle/10019.1/103667#:~:text=In%20the%20citrus%20export%20cold,the%20risk%20of%20economic%20losses.
- https://citrusaustralia.com.au/news/latest-news/managing-temperatures-after-harvest-is-a-key-factor-in-ensuring-appropriate-and-reliable-quality-for-customers-and-consumers
- https://www.wur.nl/en/show/Temperature-control-and-closed-cold-chain-most-important-preservation-methods-for-fruit-and-vegetable-produce.htm
- https://www.crscoldstorage.co.uk/news/cold-storage-fruit-and-veg.html
- https://extension.umaine.edu/fruit/harvest-and-storage-of-tree-fruits/cold-storage-conditions/#:~:text=Ideally%2C%20they%20should%20be%20able,38%20(2%20to%203%C2%BAC).
